diff --git a/Changes-API.md b/Changes-API.md index eaeae98..1b81134 100644 --- a/Changes-API.md +++ b/Changes-API.md @@ -1,139 +1,139 @@ # Changelog for HEJ API This log lists only changes on the HEJ API. These are primarily code changes relevant for calling HEJ as an API. This file should only be read as an addition to [`Changes.md`](Changes.md), where the main features are documented. ## Version 2.2 ### 2.2.0 #### New and updated functions * New functions to decide whether particles are massive, charged, charged leptons, antiparticles. * Added `to_string` function for `Event`. * Updated function `Event::EventData.reconstruct_intermediate()` - Now requires an `EWConstants` argument - Added support for WpWp and WmWm events. - In the case of WW same-flavour the reconstruction will minimise the total off-shell momentum. * Replaced `no_2_jets` and `bad_final_state` enumerators in `EventType` with `invalid` and `unknown`. * Added helper functions `is_backward_g_to_h`, `is_forward_g_to_h` to detect incoming gluon to outgoing Higgs transitions. * Updated function `implemented_types()` to now be in HEJ namespace. * `EventWriter` has a new `set_xs_scale` member function to set the ratio between the sum of event weights and the cross section. -#### Removed interfaces -* The `UnclusteredEvent` class was removed following its deprecation in 2.1.0. -* Removed the deprecated `Weights.hh` header file. - +#### Removed previously deprecated interfaces +* Removed the `UnclusteredEvent` class. +* Removed the `Weights.hh` header file. +* Removed the `min_extparton_pt` and `max_ext_soft_pt_fraction` settings. ## Version 2.1 ### 2.1.0 #### Changes to Event class * Restructured `Event` class - `Event` can now only be build from a (new) `Event::EventData` class - Removed default constructor for `Event` - `Event::EventData` replaces the old `UnclusteredEvent` struct. - `UnclusteredEvent` is now **deprecated**, and will be removed in version 2.2.0 - Removed `Event.unclustered()` function - Added new member function `Events.parameters()`, to directly access (underlying) `Parameters` - New member functions `begin_partons`, `end_partons` (`rbegin_partons`, `rend_partons`) with aliases `cbegin_partons`, `cend_partons` (`crbegin_partons`, `crend_partons`) for constant (reversed) iterators over outgoing partons. * New function `Event::EventData.reconstruct_intermediate()` to reconstruct bosons from decays, e.g. `positron + nu_e => Wp` * Added optional Colour charges to particles (`Particle.colour`) - Colour connection in the HEJ limit can be generated via `Event.generate_colours` (automatically done in the resummation) - Colour configuration of input events can be checked with `Event.is_leading_colour` * Added function `Event.valid_hej_state` to check if event _could have_ been produced by `HEJ` according to the `soft pt regulator` cut on the jets #### New and updated functions * Renamed `EventType::nonHEJ` to `EventType::non_resummable` and `is_HEJ()` to `is_resummable()` such that run card is consistent with internal workings * Made `MatrixElement.tree_kin(...)` and `MatrixElement.tree_param(...)` public * New `EventReweighter` member function `treatment` to query the treatment with respect to resummation for the various event types. * Added auxiliary functions to obtain a `std::string` from `EventDescription` (`to_string` for human readable, and `to_simple_string` for easy parsable string) * New `get_analyses` function to read in multiple `HEJ::Analysis` at once, similar to `get_analysis` * New `get_ew_parameters` function to extract electroweak parameters from YAML configuration. #### New classes * New class `Unweighter` to do unweighting * New class `CrossSectionAccumulator` to keep track of Cross Section of the different subprocess * New template struct `Parameters` similar to old `Weights` - `Weights` are now an alias for `Parameters`. Calling `Weights` did not change - `Weights.hh` was replaced by `Parameters.hh`. The old `Weights.hh` header will be removed in version 2.2.0 * Function to multiplication and division of `EventParameters.weight` by double - This can be combined with `Parameters`, e.g. `Parameters*Weights`, see also `Events.parameters()` - Moved `EventParameters` to `Parameters.hh` header * new class `EWConstants` replaces previously hard coded `vev` - `EWConstants` have to be set in the general `Config` and the `MatrixElementConfig` #### Input/Output * New abstract `EventReader` class, as base for reading events from files - Moved LHE file reader to `HEJ::LesHouchesReader` * New (optional) function `finish()` in abstract class `EventWriter`. `finish()` is called _after_ all events are written. * Support reading (`HDF5Reader`) and writing (`HDF5Writer`) `hdf5` files * New `BufferedEventReader` class that allows to put events back into the reader. * New `SherpaLHEReader` to read Sherpa LHE files with correct weights * `get_analysis` now requires `YAML::Node` and `LHEF::HEPRUP` as arguments * Replaced `HepMCInterface` and `HepMCWriter` by `HepMCInterfaceX` and `HepMCWriterX` respectively, with `X` being the major version of HepMC (2 or 3) - Renamed `HepMCInterfaceX::init_kinematics` to `HepMCInterfaceX::init_event` and protected it, use `HepMCInterfaceX::operator()` instead - Removed redundant `HepMCInterfaceX::add_variation` function #### Linking * Export cmake target `HEJ::HEJ` to link directly against `libHEJ` * Preprocessor flags (`HEJ_BUILD_WITH_XYZ`) for enabled/disabled dependencies are now written to `ConfigFlags.hh` * Provide links to version specific object files, e.g. `libHEJ.so -> libHEJ.so.2.1 (soname) -> libHEJ.so.2.1.0` * Removed `LHAPDF` from public interface #### Miscellaneous * Capitalisation of `Config.hh` now matches class `Config` (was `config.hh`) * Renamed `Config::max_ext_soft_pt_fraction` to `Config::soft_pt_regulator`. The new `Config::soft_pt_regulator` parameter is optional and the old `Config::max_ext_soft_pt_fraction` is **deprecated**. * Replaced redundant member `EventReweighterConfig::jet_param` with getter function `EventReweighter.jet_param()` (`JetParameters` are already in `PhaseSpacePointConfig`) * Avoid storing reference to the Random Number Generator inside classes - Constructors of `EventReweighter` now expect `std::shared_ptr` (was reference) - Moved reference to `HEJ::RNG` from constructor of `JetSplitter` to `JetSplitter.split` ## Version 2.0 ### 2.0.4 * Fixed wrong path of `HEJ_INCLUDE_DIR` in `hej-config.cmake` ### 2.0.0 * First release diff --git a/Changes.md b/Changes.md index 71c8186..13b97c2 100644 --- a/Changes.md +++ b/Changes.md @@ -1,206 +1,207 @@ # Changelog This is the log for changes to the HEJ program. Further changes to the HEJ API are documented in [`Changes-API.md`](Changes-API.md). If you are using HEJ as a library, please also read the changes there. ## Version 2.2 This release adds support for the new processes: * Wp+Wp with jets. * Wm+Wm with jets. In addition, there are new options when running HEJ: * Enable NLO truncation for use in HEJ@NLO predictions. * Require a lowpt jet, used for running lowpt separately. This release includes minor changes which affect users of HEJ as a library (see [`Changes-API.md`](Changes-API.md)). Compilation now requires a compiler supporting C++17. ### 2.2.0 #### New Processes * Resummation for WpWp/WmWm with jets, including interference between configurations. * Significantly improved description of Higgs boson plus jet production: - Processes with extremal Higgs boson emission are now treated as leading-log. - Resummation is now enabled for Higgs boson production with a single jet. * `HEJFOG` can generate multiple jets together with a charged lepton-antilepton pair via a virtual Z boson or photon. #### Updates to configuration file * With the new option `off-shell tolerance` HEJ repairs the momenta of massless particles that are slightly off-shell and incoming particles with small but non-vanishing transverse momenta. * Introduced new event types `unknown` and `invalid` under the `event treatment` option. `unknown` indicates processes that are not recognised by HEJ. `invalid` is reserved for unphysical processes. * Introduced new event treatment `abort` for aborting the program when an undesired event type is encountered. +* Removed the deprecated settings `min extparton pt` and `max ext soft pt fraction`. #### Changes to input/output * Event reader supports event input from named pipes (fifo) ## Version 2.1 This release adds support for two new processes: * W boson with jets. * Jets with a charged lepton-antilepton pair via a virtual Z boson or photon. In addition, the complete set of first subleading processes (unordered gluon, central and extremal quark-antiquark pair) is implemented for pure jets and W + jets, see [arXiv:2012.10310](https://arxiv.org/abs/2012.10310). Unordered gluon emission is also supported for Higgs boson + jets and Z boson/photon + jets. This release include many changes to the code, which affect users of HEJ as a library (see [`Changes-API.md`](Changes-API.md)). ### 2.1.3 * Updated documentation. ### 2.1.2 * Updated `cxxopts.hpp` dependency. ### 2.1.1 * Fixed invalid iterator accesses. * Reorganised automated tests. * Updated documentation. ### 2.1.0 #### New Processes * Resummation for W bosons with jets - New subleading processes `extremal qqbar` & `central qqbar` for a quark and anti-quark in the final state, e.g. `g g => u d_bar Wm g` (the other subleading processes also work with W's) - `HEJFOG` can generate multiple jets together with a (off-shell) W bosons decaying into lepton & neutrino * Resummation for jets with a charged lepton-antilepton pair via a virtual Z boson or photon. Includes the `unordered` subleading process. * Resummation can now be performed on all subleading processes within pure jets also. This includes `unordered`, `extremal qqbar` and `central qqbar` processes. #### More Physics implementation * Partons now have a Colour charge - Colours are read from and written to LHE files - For reweighted events the colours are created according to leading colour in the FKL limit * Use relative fraction for soft transverse momentum in tagging jets (`soft pt regulator`) as new (optional) parameter. - This supersedes `min extparton pt`, which is marked **deprecated** and will be removed in version 2.2.0 - This is a direct replacement for the old `max ext soft pt fraction`, which is also **deprecated**. * Changed the redistribution of the momenta of soft emissions. Now also bosons can take part of the recoil (previously only jets). #### Updates to Runcard * Allow multiplication and division of multiple scale functions e.g. `H_T/2*m_j1j2` * Grouped `event treatment` for subleading channels together in runcard - Rename `non-HEJ` processes to `non-resummable` * Read electro-weak constants from input - new mandatory setting `vev` to change vacuum expectation value - new mandatory settings `particle properties` to specify mass & width of bosons - `HEJFOG`: decays are now specified in `decays` setting (previously under `particle properties`) * Allow loading multiple analyses with `analyses`. The old `analysis` (with "i") is marked **deprecated**. * Optional setting to specify maximal number of Fixed Order events (`max events`, default is all) * Allow changing the regulator lambda in input (`regulator parameter`, only for advanced users) #### Changes to Input/Output * Added support to read & write `hdf5` event files suggested in [arXiv:1905.05120](https://arxiv.org/abs/1905.05120) (needs [HighFive](https://github.com/BlueBrain/HighFive)) * Support input with average weight equal to the cross section (`IDWTUP=1 or 4`) * Support unmodified Les Houches Event Files written by Sherpa with `cross section = sum(weights)/sum(trials)` * Analyses now get general run information (`LHEF::HEPRUP`) in the constructor. **This might break previously written, external analyses!** - external analyses should now be created with `make_analysis(YAML::Node const & config, LHEF::HEPRUP const & heprup)` * Support `rivet` version 3 with both `HepMC` version 2 and 3 - Multiple weights with `rivet 3` will only create one `.yoda` file (instead of one per weight/scale) * Added option to unweight only resummation events (`unweight: {type: resummation}`) * Added option for partially unweighting resummation events, similar to the fixed-order generator. * Improved unweighting algorithm. * Follow HepMC convention for particle Status codes: incoming = 11, decaying = 2, outgoing = 1 (unchanged) #### Miscellaneous * Print cross sections at end of run * Added example analysis & scale to `examples/`. Everything in `examples/` will be build when the flag `-DBUILD_EXAMPLES=TRUE` is set in `cmake`. * Dropped support for HepMC 3.0.0, either HepMC version 2 or >3.1 is required - It is now possible to write out both HepMC 2 and HepMC 3 events at the same time * Require LHADPF version 6. Dropped support for all other versions. * Use `git-lfs` for raw data in test (`make test` now requires `git-lfs`) * Currents are now generated with [`FORM`](https://github.com/vermaseren/form) - `FORM` is included as a `git submodule`, use `git submodule update --init` to download `FORM` * Create [Sphinx](http://sphinx-doc.org/) and [Doxygen](http://doxygen.org/) documentation by `make sphinx` or `make doxygen` in your `build/` folder ## Version 2.0 First release of HEJ 2. Complete code rewrite compared to HEJ 1. Improved matching to Fixed Order ([arXiv:1805.04446](https://arxiv.org/abs/1805.04446)). Implemented processes: Higgs boson with jets (FKL and unordered gluon emission, with finite quark mass loop, [arXiv:1812.08072](https://arxiv.org/abs/1812.08072)), and pure jets (only FKL). See [arXiv:1902.08430](https://arxiv.org/abs/1902.08430) ## 2.0.7 * Added missing `#include` directives. ### 2.0.6 * Fixed compiling rivet when YODA headers are _outside_ of rivet directory. ### 2.0.5 * Fixed event classification for input not ordered in rapidity. ### 2.0.4 * Fixed wrong path of `HEJ_INCLUDE_DIR` in `hej-config.cmake`. ### 2.0.3 * Fixed parsing of (numerical factor) * (base scale) in configuration. * Don't change scale names, but sanitise Rivet output file names instead. ### 2.0.2 * Changed scale names to `"_over_"` and `"_times_"` for proper file names (was `"/"` and `"*"` before). ### 2.0.1 * Fixed name of fixed-order generator in error message. ### 2.0.0 * First release. diff --git a/config.yml b/config.yml index 4859c3f..9828ea9 100644 --- a/config.yml +++ b/config.yml @@ -1,140 +1,133 @@ ## Number of attempted resummation phase space points for each input event trials: 10 resummation jets: # resummation jet properties min pt: 30 # minimum jet transverse momentum algorithm: antikt # jet clustering algorithm R: 0.4 # jet R parameter fixed order jets: # properties of input jets min pt: 20 # by default, algorithm and R are like for resummation jets ## Treatment of he various event classes ## the supported settings are: reweight, keep, discard, abort ## non-resummable, unknown, and invalid events cannot be reweighted event treatment: FKL: reweight unordered: keep extremal qqbar: keep central qqbar: keep non-resummable: keep ## Central scale choice or choices # ## multiple scales are allowed, e.g. # scales: [125, max jet pperp, H_T/2, 2*jet invariant mass, m_j1j2] scales: 91.188 ## Factors by which the central scales should be multiplied ## renormalisation and factorisation scales are varied independently # # scale factors: [0.5, 0.7071, 1, 1.41421, 2] ## Maximum ratio between renormalisation and factorisation scale # # max scale ratio: 2.0001 ## Import scale setting functions # # import scales: # lib_my_scales.so: [scale0,scale1] ## Unweighting setting ## remove to obtain weighted events # unweight: # # type of unweighting (one of 'weighted', 'resummation', 'partial') # type: partial # trials: 10000 # max deviation: 0 ## Event output files # # the supported formats are # - Les Houches (suffix .lhe) # - HepMC2 (suffix .hepmc2) # - HepMC3 (suffix .hepmc3 or .hepmc) # - HDF5 (suffix .hdf5) # ## An output file's format is deduced either automatically from the suffix ## or from an explicit specification, e.g. ## - Les Houches: outfile # event output: - HEJ.lhe # - HEJ_events.hepmc ## Analyses # # analyses: ## Rivet analysis # - rivet: MC_XS # rivet analysis name # output: HEJ # name of the yoda files, ".yoda" and scale suffix will be added ## Custom analysis # - plugin: /path/to/libmyanalysis.so # my analysis parameter: some value ## Selection of random number generator and seed ## The choices are ## - mixmax (seed is an integer) ## - ranlux64 (seed is a filename containing parameters) random generator: name: mixmax # seed: 1 ## Whether or not to include higher order logs log correction: false ## Truncate higher-order corrections at NLO NLO truncation: enabled: false # nlo order: 2 ## Only keep low pt contributions # require low pt jet: false ## Vacuum expectation value vev: 246.2196508 ## Properties of the weak gauge bosons particle properties: Higgs: mass: 125 width: 0.004165 W: mass: 80.385 width: 2.085 Z: mass: 91.187 width: 2.495 ## Parameters for Higgs-gluon couplings ## This requires compilation with QCDloop # # Higgs coupling: # use impact factors: false # mt: 174 # include bottom: true # mb: 4.7 # # Tolerance towards numerical inaccuracies in input momenta # off-shell tolerance: 0.01 ## ---------------------------------------------------------------------- ## ## The following settings are only intended for advanced users. ## ## Please DO NOT SET them unless you know exactly what you are doing! ## ## ---------------------------------------------------------------------- ## # ## Maximum soft transverse momentum fraction in any tagging jets, e.g. ## extremal or qqbar jet # soft pt regulator: 0.1 # -## Minimum transverse momentum of extremal partons -## deprecated: use "soft pt regulator" instead -# min extparton pt: 30 -# -## deprecated: this cot directly replaced by "soft pt regulator" -# max ext soft pt fraction: 0.1 -# # max events: -1 # Maximal number of fixed order Events to process # regulator parameter: 0.2 # The regulator lambda for the subtraction terms diff --git a/doc/sphinx/HEJ.rst b/doc/sphinx/HEJ.rst index 302e8fa..f203f20 100644 --- a/doc/sphinx/HEJ.rst +++ b/doc/sphinx/HEJ.rst @@ -1,519 +1,504 @@ .. _`Running HEJ 2`: Running HEJ 2 ============= Quick start ----------- In order to run HEJ 2, you need a configuration file and a file containing fixed-order events. A sample configuration is given by the :file:`config.yml` file distributed together with HEJ 2. Events in the Les Houches Event File format can be generated with standard Monte Carlo generators like `MadGraph5_aMC@NLO `_ or `Sherpa `_. If HEJ 2 was compiled with `HDF5 `_ support, it can also read and write event files in the format suggested in `arXiv:1905.05120 `_. HEJ 2 assumes that the cross section is given by the sum of the event weights. Depending on the fixed-order generator it may be necessary to adjust the weights in the Les Houches Event File accordingly. The processes supported by HEJ 2 are - Pure multijet production - Production of a Higgs boson with jets - Production of a W boson with jets - Production of jets with a charged lepton-antilepton pair, via a virtual Z boson and/or photon - Production of two same-sign W bosons with jets where at least two jets are required in each case. For the time being, only leading-order input events are supported. After generating an event file :file:`events.lhe` adjust the parameters under the `fixed order jets`_ setting in :file:`config.yml` to the settings in the fixed-order generation. Resummation can then be added by running:: HEJ config.yml events.lhe Alternatively it can be more efficient to run HEJ with input events piped from a fixed order generator. To do this with e.g. Sherpa (where the event output file is specified in the Sherpa runcard as :file:`events.lhe`), run:: mkfifo events.lhe Sherpa -f Run.dat & HEJ config.yml events.lhe Using the default settings, this will produce an output event file :file:`HEJ.lhe` with events including high-energy resummation. When using the `Docker image `_, HEJ can be run with .. code-block:: bash docker run -v $PWD:$PWD -w $PWD hejdock/hej HEJ config.yml events.lhe .. _`HEJ 2 settings`: Settings -------- HEJ 2 configuration files follow the `YAML `_ format. The following configuration parameters are supported: .. _`trials`: **trials** High-energy resummation is performed by generating a number of resummation phase space configurations corresponding to an input fixed-order event. This parameter specifies how many such configurations HEJ 2 should try to generate for each input event. Typical values vary between 10 and 100. .. _`fixed order jets`: **fixed order jets** This tag collects a number of settings specifying the jet definition in the event input. The settings should correspond to the ones used in the fixed-order Monte Carlo that generated the input events. .. _`fixed order jets: min pt`: **min pt** Minimum transverse momentum in GeV of fixed-order jets. .. _`fixed order jets: algorithm`: **algorithm** The algorithm used to define jets. Allowed settings are :code:`kt`, :code:`cambridge`, :code:`antikt`, :code:`cambridge for passive`. See the `FastJet `_ documentation for a description of these algorithms. .. _`fixed order jets: R`: **R** The R parameter used in the jet algorithm, roughly corresponding to the jet radius in the plane spanned by the rapidity and the azimuthal angle. .. _`resummation jets`: **resummation jets** This tag collects a number of settings specifying the jet definition in the observed, i.e. resummed events. These settings are optional, by default the same values as for the `fixed order jets`_ are assumed. .. _`resummation jets: min pt`: **min pt** Minimum transverse momentum in GeV of resummation jets. This should be between 25% and 50% larger than the minimum transverse momentum of fixed order jets set by `fixed order jets: min pt`_. The contribution from the lower min pt fixed order jets can also be calculated separately using the `require low pt jet`_ option. .. _`resummation jets: algorithm`: **algorithm** The algorithm used to define jets. The HEJ 2 approach to resummation relies on properties of :code:`antikt` jets, so this value is strongly recommended. For a list of possible other values, see the `fixed order jets: algorithm`_ setting. .. _`resummation jets: R`: **R** The R parameter used in the jet algorithm. .. _`event treatment`: **event treatment** Specify how to treat different event types. The different event types contribute to different orders in the high-energy limit. The types are: .. _`FKL`: **FKL** Specifies how to treat events respecting FKL rapidity ordering, where all but the two partons extremal in rapidity have to be gluons, e.g. :code:`u d => u g d`. These configurations are dominant in the high-energy limit. .. _`unordered`: **unordered** Specifies how to treat events with one gluon emission that does not respect FKL ordering, e.g. :code:`u d => g u d`. In the high-energy limit, such configurations are logarithmically suppressed compared to FKL configurations. .. _`extremal qqbar`: **extremal qqbar** Specifies how to treat events with a quark-antiquark pair as extremal partons in rapidity, e.g. :code:`g d => u u_bar d`. In the high-energy limit, such configurations are logarithmically suppressed compared to FKL configurations. .. _`central qqbar`: **central qqbar** Specifies how to treat events with a quark-antiquark pair central in rapidity, e.g. :code:`g g => g u u_bar g`. In the high-energy limit, such configurations are logarithmically suppressed compared to FKL configurations. .. _`non-resummable`: **non-resummable** Specifies how to treat events where resummation is currently not supported for the given rapidity ordering and/or assignment of parton flavours. .. _`unknown`: **unknown** Specifies how to treat events for processes that are not implemented, e.g. di-photon production. .. _`invalid`: **invalid** Specifies how to treat events that are considered unphysical. Events in this category violate one or more of the following requirements: - Charge conservation. - Four-momentum conservation. - Momenta of massless particles must be lightlike. - Incoming particles must not have transverse momentum. The possible treatments are - :code:`reweight` to enable resummation - :code:`keep` to keep the events as they are up to a possible change of renormalisation and factorisation scale - :code:`discard` to discard these events - :code:`abort` to abort the program if one of these events is encountered The settings :code:`keep`, :code:`discard`, and :code:`abort` are supported for all event types. The :code:`reweight` treatment is implemented for different event types depending on the considered process: .. csv-table:: :header: , "FKL", "unordered", "extremal qqbar", "central qqbar" :widths: auto :align: center :stub-columns: 1 "pure jets", "Yes", "Yes", "Yes", "Yes" "Higgs + jets", "Yes", "Yes", "No", "No" "W + jets", "Yes", "Yes", "Yes", "Yes" "Z/γ + jets", "Yes", "Yes", "No", "No" "same-sign W + jets", "Yes", "No", "No", "No" .. _`scales`: **scales** Specifies the renormalisation and factorisation scales for the output events. This can either be a single entry or a list :code:`[scale1, scale2, ...]`. For the case of a list the first entry defines the central scale. Possible values are fixed numbers to set the scale in GeV or the following: - :code:`H_T`: The sum of the scalar transverse momenta of all final-state particles - :code:`max jet pperp`: The maximum transverse momentum of all jets - :code:`jet invariant mass`: Sum of the invariant masses of all jets - :code:`m_j1j2`: Invariant mass between the two hardest jets. Scales can be multiplied or divided by overall factors, e.g. :code:`H_T/2`. It is also possible to import scales from an external library, see :ref:`Custom scales` .. _`scale factors`: **scale factors** A list of numeric factors by which each of the `scales`_ should be multiplied. Renormalisation and factorisation scales are varied independently. For example, a list with entries :code:`[0.5, 2]` would give the four scale choices (0.5μ\ :sub:`r`, 0.5μ\ :sub:`f`); (0.5μ\ :sub:`r`, 2μ\ :sub:`f`); (2μ\ :sub:`r`, 0.5μ\ :sub:`f`); (2μ\ :sub:`r`, 2μ\ :sub:`f`) in this order. The ordering corresponds to the order of the final event weights. .. _`max scale ratio`: **max scale ratio** Specifies the maximum factor by which renormalisation and factorisation scales may difer. For a value of :code:`2` and the example given for the `scale factors`_ the scale choices (0.5μ\ :sub:`r`, 2μ\ :sub:`f`) and (2μ\ :sub:`r`, 0.5μ\ :sub:`f`) will be discarded. .. _`log correction`: **log correction** Whether to include corrections due to the evolution of the strong coupling constant in the virtual corrections. Allowed values are :code:`true` and :code:`false`. .. _`NLO truncation`: **NLO truncation** Options to truncate the HEJ resummation at next-to-leading order. Used for bin-by-bin NLO reweighting. .. _`NLO truncation: enabled`: **enabled** Enable truncation. Allowed values are :code:`true` and :code:`false` (default). .. _`NLO truncation: nlo order`: **nlo order** Set the (base) number of jets in the NLO sample. Allowed values are integers (default: 2). .. _`unweight`: **unweight** Settings for unweighting events. Unweighting can greatly reduce the number of resummation events, speeding up analyses and shrinking event file sizes. .. _`type`: **type** How to unweight events. The supported settings are - :code:`weighted`: Generate weighted events. Default, if nothing else specified. - :code:`resummation`: Unweight only resummation events. Each set of resummation events coming from *a single fixed order event* are unweighted separately according to the largest weight in the current chunk of events. - :code:`partial`: Unweight only resummation events with weights below a certain threshold. The weight threshold is determined automatically in a calibration run prior to the usual event generation. .. _`unweight: trials`: **trials** Maximum number of trial resummation events generated in the calibration run for partial unweighting. This option should only be set for partial unweighting. If possible, each trial is generated from a different input fixed-order event. If there are not sufficiently many input events, more than one trial event may be generated for each of them and the actual number of trial events may be smaller than requested. Increasing the number of trials generally leads to better unweighting calibration but increases the run time. Between 1000 and 10000 trials are usually sufficient. .. _`unweight: max deviation`: **max deviation** Controls the range of events to which unweighting is applied. This option should only be set for partial unweighting. A larger value means that a larger fraction of events are unweighted. Typical values are between -1 and 1. .. _`event output`: **event output** Specifies the name of a single event output file or a list of such files. The file format is either specified explicitly or derived from the suffix. For example, :code:`events.lhe` or, equivalently :code:`Les Houches: events.lhe` generates an output event file :code:`events.lhe` in the Les Houches format. The supported formats are - :code:`file.lhe` or :code:`Les Houches: file`: The Les Houches event file format. - :code:`file.hepmc2` or :code:`HepMC2: file`: HepMC format version 2. - :code:`file.hepmc3` or :code:`HepMC3: file`: HepMC format version 3. - :code:`file.hepmc` or :code:`HepMC: file`: The latest supported version of the HepMC format, currently version 3. - :code:`file.hdf5` or :code:`HDF5: file`: The HDF5-based format of `arXiv:1905.05120 `_. .. _`random generator`: **random generator** Sets parameters for random number generation. .. _`random generator: name`: **name** Which random number generator to use. Currently, :code:`mixmax` and :code:`ranlux64` are supported. Mixmax is recommended. See the `CLHEP documentation `_ for details on the generators. .. _`random generator: seed`: **seed** The seed for random generation. This should be a single number for :code:`mixmax` and the name of a state file for :code:`ranlux64`. .. _`analyses`: **analyses** Names and settings for one or more custom and Rivet event analyses. Entries containing the :code:`rivet` key are interpreted as Rivet analyses; the values corresponding to this key should be the analyses names. In addition, there is a mandatory :code:`output` key which determines the prefix for the yoda output file. For a custom analysis the :code:`plugin` sub-entry should be set to the analysis file path. All further entries are passed on to the analysis. See :ref:`Writing custom analyses` for details. .. _`vev`: **vev** Higgs vacuum expectation value in GeV. All electro-weak constants are derived from this together with the `particle properties`_. .. _`particle properties`: **particle properties** Specifies various properties of the different particles (Higgs, W or Z). All electro-weak constants are derived from these together with the :ref:`vacuum expectation value`. .. _`particle properties: particle`: **Higgs, W or Z** The particle (Higgs, |W+| or |W-|, Z) for which the following properties are defined. .. |W+| replace:: W\ :sup:`+` .. |W-| replace:: W\ :sup:`-` .. _`particle properties: particle: mass`: **mass** The mass of the particle in GeV. .. _`particle properties: particle: width`: **width** The total decay width of the particle in GeV. .. _`Higgs coupling`: **Higgs coupling** This collects a number of settings concerning the effective coupling of the Higgs boson to gluons. This is only relevant for the production process of a Higgs boson with jets and only supported if HEJ 2 was compiled with `QCDLoop `_ support. .. _`Higgs coupling: use impact factors`: **use impact factors** Whether to use impact factors for the coupling to the most forward and most backward partons. Impact factors imply the infinite top-quark mass limit. .. _`Higgs coupling: mt`: **mt** The value of the top-quark mass in GeV. If this is not specified, the limit of an infinite mass is taken. .. _`Higgs coupling: include bottom`: **include bottom** Whether to include the Higgs coupling to bottom quarks. .. _`Higgs coupling: mb`: **mb** The value of the bottom-quark mass in GeV. Only used for the Higgs coupling, external bottom-quarks are always assumed to be massless. .. _`require low pt jet`: **require low pt jet** Restrict output to only include events which have fixed order jets with pT less than the `resummation jets: min pt`_. Used to calculate the contribution from a lower min pt in the fixed order jets. This option allows this calculation to be done separately from the calculation where the fixed order min pt is equal to the resummation jets min pt. This is usually a small correction. .. _`off-shell tolerance`: **off-shell tolerance** Tolerance for numerical inaccuracies in input momenta. Momenta of massless particles with an invariant mass below the given value are rescaled to be on-shell. Transverse momentum components of incoming particles that are smaller than the given tolerance are set to zero. The default value is 0, leaving input momenta unchanged. Advanced Settings ~~~~~~~~~~~~~~~~~ All of the following settings are optional. Please **do not set** any of the following options, unless you know exactly what you are doing. The default behaviour gives the most reliable results for a wide range of observables. .. _`soft pt regulator`: **soft pt regulator** Specifies the maximum fraction that soft radiation can contribute to the transverse momentum of each the tagging jets, i.e. any jet that affects the event classification, like the most forward and most backward jet or the jets of the central qqbar pair. This setting is needed to regulate an otherwise cancelled divergence. Default is 0.1. -.. _`max ext soft pt fraction`: - -**max ext soft pt fraction** - This is the same as `soft pt regulator`_ and will be removed in future - versions. - -.. _`min extparton pt`: - -**min extparton pt** - Specifies the minimum transverse momentum in GeV of the most forward and the - most backward parton. Its value should be slightly below the minimum - transverse momentum of jets specified by `resummation jets: min pt`_. This - setting got superseded by `soft pt regulator`_ and will be removed in future - versions. - .. _`max events`: **max events** Maximal number of (input) Fixed Order events. HEJ will stop after processing `max events` many events. Default considers all events. .. _`regulator parameter`: **regulator parameter** Slicing parameter to regularise the subtraction term, called :math:`\lambda` in `arxiv:1706.01002 `_. Default is 0.2. diff --git a/include/HEJ/Config.hh b/include/HEJ/Config.hh index e1f0b26..8a8b2ea 100644 --- a/include/HEJ/Config.hh +++ b/include/HEJ/Config.hh @@ -1,292 +1,274 @@ /** \file * \brief HEJ 2 configuration parameters * * \authors The HEJ collaboration (see AUTHORS for details) * \date 2019-2022 * \copyright GPLv2 or later */ #pragma once #include #include #include #include #include #include "fastjet/JetDefinition.hh" #include "yaml-cpp/yaml.h" #include "HEJ/Constants.hh" #include "HEJ/EWConstants.hh" #include "HEJ/Fraction.hh" #include "HEJ/HiggsCouplingSettings.hh" #include "HEJ/ScaleFunction.hh" #include "HEJ/event_types.hh" #include "HEJ/output_formats.hh" namespace HEJ { //! Jet parameters struct JetParameters{ fastjet::JetDefinition def; /**< Jet Definition */ double min_pt{}; /**< Minimum Jet Transverse Momentum */ }; //! Settings for scale variation struct ScaleConfig{ //! Base scale choices std::vector base; //! Factors for multiplicative scale variation std::vector factors; //! Maximum ratio between renormalisation and factorisation scale double max_ratio{}; }; //! Settings for random number generator struct RNGConfig { //! Random number generator name std::string name; //! Optional initial seed std::optional seed; }; //! Settings for partial unweighting struct PartialUnweightConfig { //! Number of trials for training size_t trials; //! Maximum distance in standard deviations from mean logarithmic weight double max_dev; }; //! Settings for HEJ@NLO struct NLOConfig { //! Settings for HEJ@NLO Truncation bool enabled = false; //! NLO Born number of jets size_t nj = 2; }; /**! Possible treatments for fixed-order input events. * * The program will decide on how to treat an event based on * the value of this enumeration. */ enum class EventTreatment{ reweight, /**< Perform resummation */ keep, /**< Keep the event */ discard, /**< Discard the event */ abort, /**< Throw an exception */ }; //! Container to store the treatments for various event types using EventTreatMap = std::map; //! Possible setting for the event weight enum class WeightType{ weighted, //!< weighted events unweighted_resum, //!< unweighted only resummation part partially_unweighted //!< mixed weighted and unweighted }; /**! Input parameters. * * This struct handles stores all configuration parameters * needed in a HEJ 2 run. * * \internal To add a new option: * 1. Add a member to the Config struct. * 2. Inside "src/YAMLreader.cc": * - Add the option name to the "supported" Node in * get_supported_options. * - Initialise the new Config member in to_Config. * The functions set_from_yaml (for mandatory options) and * set_from_yaml_if_defined (non-mandatory) may be helpful. * 3. Add a new entry (with short description) to config.yaml * 4. Update the user documentation in "doc/Sphinx/" */ struct Config { //! %Parameters for scale variation ScaleConfig scales; //! Resummation jet properties JetParameters resummation_jets; //! Fixed-order jet properties JetParameters fixed_order_jets; - //! Minimum transverse momentum for extremal partons - //! \deprecated This will be removed in future versions. - //! Use \ref soft_pt_regulator instead. - double min_extparton_pt = 0.; - //! \deprecated This is equivalent to\ref soft_pt_regulator - //! and will be removed in future versions. - std::optional> max_ext_soft_pt_fraction{}; //! @brief Maximum transverse momentum fraction from soft radiation in any //! tagging jet (e.g. extremal or qqbar jet) Fraction soft_pt_regulator{ DEFAULT_SOFT_PT_REGULATOR }; //! The regulator lambda for the subtraction terms double regulator_lambda = CLAMBDA; //! Number of resummation configurations to generate per fixed-order event size_t trials{}; //! Maximal number of events std::optional max_events; //! Whether to include the logarithmic correction from \f$\alpha_s\f$ running bool log_correction{}; //! Event output files names and formats std::vector output; //! Parameters for random number generation RNGConfig rng; //! Map to decide what to do for different event types EventTreatMap treat; //! %Parameters for custom analysis //! @deprecated use analyses_parameters instead YAML::Node analysis_parameters; //! %Parameters for custom analyses std::vector analyses_parameters; //! Settings for effective Higgs-gluon coupling HiggsCouplingSettings Higgs_coupling; //! elector weak parameters EWConstants ew_parameters; //! Type of event weight e.g. (un)weighted WeightType weight_type; //! Settings for partial unweighting std::optional unweight_config; //! HEJ@NLO settings NLOConfig nlo; //! LowPT settings bool lowpt = false; //! Tolerance towards numerical inaccuracies in input momenta double off_shell_tolerance = 0.; }; //! Configuration options for the PhaseSpacePoint class struct PhaseSpacePointConfig { PhaseSpacePointConfig() = default; PhaseSpacePointConfig( JetParameters jet_param, NLOConfig nlo, - double min_extparton_pt = 0., Fraction soft_pt_regulator = Fraction{DEFAULT_SOFT_PT_REGULATOR} ): jet_param{std::move(jet_param)}, nlo{std::move(nlo)}, - min_extparton_pt{min_extparton_pt}, soft_pt_regulator{std::move(soft_pt_regulator)} {} //! Properties of resummation jets JetParameters jet_param; //! HEJ@NLO settings NLOConfig nlo; - //! Minimum transverse momentum for extremal partons - //! \deprecated This will be removed in future versions. - //! Use \ref soft_pt_regulator instead. - double min_extparton_pt = 0.; - //! \deprecated This is equivalent to\ref soft_pt_regulator - //! and will be removed in future versions. - std::optional> max_ext_soft_pt_fraction{}; //! @brief Maximum transverse momentum fraction from soft radiation in any //! tagging jet (e.g. extremal or qqbar jet) Fraction soft_pt_regulator{ DEFAULT_SOFT_PT_REGULATOR }; }; //! Configuration options for the MatrixElement class struct MatrixElementConfig { MatrixElementConfig() = default; MatrixElementConfig( bool log_correction, HiggsCouplingSettings Higgs_coupling, EWConstants ew_parameters, NLOConfig nlo, Fraction soft_pt_regulator = Fraction{DEFAULT_SOFT_PT_REGULATOR}, double regulator_lambda = CLAMBDA ): log_correction{log_correction}, Higgs_coupling{std::move(Higgs_coupling)}, ew_parameters{std::move(ew_parameters)}, nlo{std::move(nlo)}, soft_pt_regulator{soft_pt_regulator}, regulator_lambda{regulator_lambda} {} //! Whether to include the logarithmic correction from \f$\alpha_s\f$ running bool log_correction{}; //! Settings for effective Higgs-gluon coupling HiggsCouplingSettings Higgs_coupling; //! elector weak parameters EWConstants ew_parameters; //! HEJ@NLO settings NLOConfig nlo; //! @brief Maximum transverse momentum fraction from soft radiation in any //! tagging jet (e.g. extremal or qqbar jet) Fraction soft_pt_regulator{ DEFAULT_SOFT_PT_REGULATOR }; //! The regulator lambda for the subtraction terms double regulator_lambda = CLAMBDA; }; //! Configuration options for the EventReweighter class struct EventReweighterConfig { //! Settings for phase space point generation PhaseSpacePointConfig psp_config; //! Settings for matrix element calculation MatrixElementConfig ME_config; //! Access properties of resummation jets JetParameters & jet_param() { return psp_config.jet_param;} //! Access properties of resummation jets (const version) JetParameters const & jet_param() const { return psp_config.jet_param;} //! Treatment of the various event types EventTreatMap treat; //! Option to only keep lowpt contribution bool lowpt = false; }; /**! Extract PhaseSpacePointConfig from Config * * \internal We do not provide a PhaseSpacePointConfig constructor from Config * so that PhaseSpacePointConfig remains an aggregate. * This faciliates writing client code (e.g. the HEJ fixed-order generator) * that creates a PhaseSpacePointConfig *without* a Config object. * * @see to_MatrixElementConfig, to_EventReweighterConfig */ inline PhaseSpacePointConfig to_PhaseSpacePointConfig(Config const & conf) { return { conf.resummation_jets, conf.nlo, - conf.min_extparton_pt, - conf.max_ext_soft_pt_fraction?*conf.max_ext_soft_pt_fraction - :conf.soft_pt_regulator + conf.soft_pt_regulator }; } /**! Extract MatrixElementConfig from Config * * @see to_PhaseSpacePointConfig, to_EventReweighterConfig */ inline MatrixElementConfig to_MatrixElementConfig(Config const & conf) { return { conf.log_correction, conf.Higgs_coupling, conf.ew_parameters, conf.nlo, conf.soft_pt_regulator, conf.regulator_lambda }; } /**! Extract EventReweighterConfig from Config * * @see to_PhaseSpacePointConfig, to_MatrixElementConfig */ inline EventReweighterConfig to_EventReweighterConfig(Config const & conf) { return { to_PhaseSpacePointConfig(conf), to_MatrixElementConfig(conf), conf.treat, conf.lowpt }; } } // namespace HEJ diff --git a/include/HEJ/Event.hh b/include/HEJ/Event.hh index 1c0e848..469ee22 100644 --- a/include/HEJ/Event.hh +++ b/include/HEJ/Event.hh @@ -1,390 +1,385 @@ /** \file * \brief Declares the Event class and helpers * * \authors The HEJ collaboration (see AUTHORS for details) * \date 2019-2020 * \copyright GPLv2 or later */ #pragma once #include #include #include #include #include #include #include #include #include "boost/iterator/filter_iterator.hpp" #include "fastjet/ClusterSequence.hh" #include "fastjet/PseudoJet.hh" #include "HEJ/Constants.hh" #include "HEJ/Parameters.hh" #include "HEJ/Particle.hh" #include "HEJ/event_types.hh" namespace LHEF { class HEPEUP; class HEPRUP; } namespace fastjet { class JetDefinition; } namespace HEJ { class EWConstants; struct RNG; //! Method for accessing implemented types size_t implemented_types(std::vector const & bosons); /** @brief An event with clustered jets * * This is the main HEJ 2 event class. * It contains kinematic information including jet clustering, * parameter (e.g. scale) settings and the event weight. */ class Event { public: class EventData; //! Iterator over partons using ConstPartonIterator = boost::filter_iterator< bool (*)(Particle const &), std::vector::const_iterator >; //! Reverse Iterator over partons using ConstReversePartonIterator = std::reverse_iterator< ConstPartonIterator>; //! No default Constructor Event() = delete; //! @name Particle Access //! @{ //! Incoming particles std::array const & incoming() const{ return incoming_; } //! Outgoing particles std::vector const & outgoing() const{ return outgoing_; } //! Iterator to the first outgoing parton ConstPartonIterator begin_partons() const; //! Iterator to the first outgoing parton ConstPartonIterator cbegin_partons() const; //! Iterator to the end of the outgoing partons ConstPartonIterator end_partons() const; //! Iterator to the end of the outgoing partons ConstPartonIterator cend_partons() const; //! Reverse Iterator to the first outgoing parton ConstReversePartonIterator rbegin_partons() const; //! Reverse Iterator to the first outgoing parton ConstReversePartonIterator crbegin_partons() const; //! Reverse Iterator to the first outgoing parton ConstReversePartonIterator rend_partons() const; //! Reverse Iterator to the first outgoing parton ConstReversePartonIterator crend_partons() const; //! Particle decays /** * The key in the returned map corresponds to the index in the * vector returned by outgoing() */ std::unordered_map> const & decays() const { return decays_; } //! The jets formed by the outgoing partons, sorted in rapidity std::vector const & jets() const{ return jets_; } //! @} //! @name Weight variations //! @{ //! All chosen parameter, i.e. scale choices (const version) Parameters const & parameters() const{ return parameters_; } //! All chosen parameter, i.e. scale choices Parameters & parameters(){ return parameters_; } //! Central parameter choice (const version) EventParameters const & central() const{ return parameters_.central; } //! Central parameter choice EventParameters & central(){ return parameters_.central; } //! Parameter (scale) variations (const version) std::vector const & variations() const{ return parameters_.variations; } //! Parameter (scale) variations std::vector & variations(){ return parameters_.variations; } //! Parameter (scale) variation (const version) /** * @param i Index of the requested variation */ EventParameters const & variations(std::size_t i) const{ return parameters_.variations.at(i); } //! Parameter (scale) variation /** * @param i Index of the requested variation */ EventParameters & variations(std::size_t i){ return parameters_.variations.at(i); } //! @} //! Indices of the jets the outgoing partons belong to /** * @param jets Jets to be tested * @returns A vector containing, for each outgoing parton, * the index in the vector of jets the considered parton * belongs to. If the parton is not inside any of the * passed jets, the corresponding index is set to -1. */ std::vector particle_jet_indices( std::vector const & jets ) const { return cs_.particle_jet_indices(jets); } //! particle_jet_indices() of the Event jets() std::vector particle_jet_indices() const { return particle_jet_indices(jets()); } //! Jet definition used for clustering fastjet::JetDefinition const & jet_def() const{ return cs_.jet_def(); } //! Minimum jet transverse momentum double min_jet_pt() const{ return min_jet_pt_; } //! Event type event_type::EventType type() const{ return type_; } //! Give colours to each particle /** * @returns true if new colours are generated, i.e. same as is_resummable() * @details Colour ordering is done according to leading colour in the MRK * limit, see \cite Andersen:2011zd. This only affects \ref * is_resummable() "HEJ" configurations, all other \ref event_type * "EventTypes" will be ignored. * @note This overwrites all previously set colours. */ bool generate_colours(RNG & /*ran*/); //! Check that current colours are leading in the high energy limit /** * @details Checks that the colour configuration can be split up in * multiple, rapidity ordered, non-overlapping ladders. Such * configurations are leading in the MRK limit, see * \cite Andersen:2011zd * * @note This is _not_ to be confused with \ref is_resummable(), however * for all resummable states it is possible to create a leading colour * configuration, see generate_colours() */ bool is_leading_colour() const; /** * @brief Check if given event could have been produced by HEJ * @details A HEJ state has to fulfil: * 1. type() has to be \ref is_resummable() "resummable" * 2. Soft radiation in the tagging jets contributes at most to * `soft_pt_regulator` of the total jet \f$ p_\perp \f$ * 3. Partons related to subleading configurations (uno gluon, qqbar) * must be in separate jets. * * @note This is true for any resummed stated produced by the * EventReweighter or any \ref is_resummable() "resummable" Leading * Order state. * * @param soft_pt_regulator Maximum transverse momentum fraction from soft * radiation in tagging jets - * @param min_pt Absolute minimal \f$ p_\perp \f$, - * \b deprecated use soft_pt_regulator instead * @return True if this state could have been produced by HEJ */ - bool valid_hej_state( - double soft_pt_regulator = DEFAULT_SOFT_PT_REGULATOR, - double min_pt = 0. - ) const; + bool valid_hej_state(double soft_pt_regulator = DEFAULT_SOFT_PT_REGULATOR) const; //! Check that the incoming momenta are valid /** * @details Checks that the incoming parton momenta are on-shell and have * vanishing transverse components. * */ bool valid_incoming() const; private: //! \internal //! @brief Construct Event explicitly from input. /** This is only intended to be called from EventData. * * \warning The input is taken _as is_, sorting and classification has to be * done externally, i.e. by EventData */ Event( std::array && incoming, std::vector && outgoing, std::unordered_map> && decays, Parameters && parameters, fastjet::JetDefinition const & jet_def, double min_jet_pt ); //! Iterator over partons (non-const) using PartonIterator = boost::filter_iterator< bool (*)(Particle const &), std::vector::iterator >; //! Reverse Iterator over partons (non-const) using ReversePartonIterator = std::reverse_iterator; //! Iterator to the first outgoing parton (non-const) PartonIterator begin_partons(); //! Iterator to the end of the outgoing partons (non-const) PartonIterator end_partons(); //! Reverse Iterator to the first outgoing parton (non-const) ReversePartonIterator rbegin_partons(); //! Reverse Iterator to the first outgoing parton (non-const) ReversePartonIterator rend_partons(); std::array incoming_; std::vector outgoing_; std::unordered_map> decays_; std::vector jets_; Parameters parameters_; fastjet::ClusterSequence cs_; double min_jet_pt_; event_type::EventType type_; }; // end class Event //! Detect if a backward incoming gluon turns into a backward outgoing Higgs boson inline bool is_backward_g_to_h(Event const & ev) { return ev.outgoing().front().type == pid::higgs && ev.incoming().front().type == pid::gluon; } //! Detect if a forward incoming gluon turns into a forward outgoing Higgs boson inline bool is_forward_g_to_h(Event const & ev) { return ev.outgoing().back().type == pid::higgs && ev.incoming().back().type == pid::gluon; } //! Class to store general Event setup, i.e. Phase space and weights class Event::EventData { public: //! Default Constructor EventData() = default; //! Constructor from LesHouches event information EventData(LHEF::HEPEUP const & hepeup); //! Constructor with all values given EventData( std::array incoming, std::vector outgoing, std::unordered_map> decays, Parameters parameters ): incoming(std::move(incoming)), outgoing(std::move(outgoing)), decays(std::move(decays)), parameters(std::move(parameters)) {} //! Generate an Event from the stored EventData. /** * @details Do jet clustering and classification. * Use this to generate an Event. * * @note Calling this function destroys EventData * * @param jet_def Jet definition * @param min_jet_pt minimal \f$p_T\f$ for each jet * * @returns Full clustered and classified event. */ Event cluster( fastjet::JetDefinition const & jet_def, double min_jet_pt); //! Alias for cluster() Event operator()( fastjet::JetDefinition const & jet_def, double const min_jet_pt){ return cluster(jet_def, min_jet_pt); } //! Sort particles in rapidity void sort(); //! Reconstruct intermediate particles from final-state leptons /** * Final-state leptons are created from virtual photons, W, or Z bosons. * This function tries to reconstruct such intermediate bosons if they * are not part of the event record. */ void reconstruct_intermediate(EWConstants const & /*ew_parameters*/); //! Repair momenta of massless particles /** * This function changes the momenta of massless particles as follows: * - Close-to-zero incoming transverse momenta are set to zero. * - Nearly on-shell momenta are made lightlike by rescaling energy * and spatial components. This rescaling is applied to both incoming * and outgoing particles, including decay products. */ void repair_momenta(double tolerance); //! Incoming particles std::array incoming; //! Outcoing particles std::vector outgoing; //! Particle decays in the format {outgoing index, decay products} std::unordered_map> decays; //! Parameters, e.g. scale or inital weight Parameters parameters; }; // end class EventData //! Print Event std::ostream& operator<<(std::ostream & os, Event const & ev); std::string to_string(Event const & ev); //! Square of the partonic centre-of-mass energy \f$\hat{s}\f$ double shat(Event const & ev); //! Tolerance parameter for validity check on incoming momenta static constexpr double TOL = 1e-6; //! Convert an event to a LHEF::HEPEUP LHEF::HEPEUP to_HEPEUP(Event const & event, LHEF::HEPRUP * /*heprup*/); } // namespace HEJ diff --git a/src/Event.cc b/src/Event.cc index ad9d9f2..06bddc4 100644 --- a/src/Event.cc +++ b/src/Event.cc @@ -1,1489 +1,1486 @@ /** * \authors The HEJ collaboration (see AUTHORS for details) * \date 2019-2020 * \copyright GPLv2 or later */ #include "HEJ/Event.hh" #include #include #include #include #include #include #include #include #include #include #include #include #include #include "HEJ/event_types.hh" #include "fastjet/ClusterSequence.hh" #include "fastjet/JetDefinition.hh" #include "fastjet/PseudoJet.hh" #include "LHEF/LHEF.h" #include "HEJ/Constants.hh" #include "HEJ/EWConstants.hh" #include "HEJ/PDG_codes.hh" #include "HEJ/RNG.hh" #include "HEJ/exceptions.hh" #include "HEJ/LorentzVector.hh" #include "HEJ/utility.hh" namespace HEJ { /** * returns all EventTypes implemented in HEJ */ size_t implemented_types(std::vector const & bosons){ using namespace event_type; // no bosons if(bosons.empty()) return FKL | UNO | QQBAR; // 1 boson if(bosons.size()== 1) { switch (bosons[0].type) { case ParticleID::Wp: case ParticleID::Wm: return FKL | UNO | QQBAR; case ParticleID::Z_photon_mix: return FKL | UNO; case ParticleID::h: return FKL | UNO; default: return non_resummable; } } // 2 bosons if(bosons.size() == 2) { // Resum only samesign W events if(bosons[0].type == ParticleID::Wp && bosons[1].type == ParticleID::Wp) { return FKL; } else if(bosons[0].type == ParticleID::Wm && bosons[1].type == ParticleID::Wm) { return FKL; } } return non_resummable; } namespace { using std::size_t; //! LHE status codes namespace lhe_status { enum Status: int { in = -1, decay = 2, out = 1, }; } using LHE_Status = lhe_status::Status; //! true if leptonic W decay bool valid_W_decay( int const w_charge, std::vector const & decays ){ assert(std::abs(w_charge) == 1); if(decays.size() != 2) // no 1->2 decay return false; const int pidsum = decays[0].type + decays[1].type; if( std::abs(pidsum) != 1 || pidsum != w_charge ) // correct charge return false; // leptonic decay (only check first, second follows from pidsum) if( w_charge == 1 ) // W+ return is_charged_antilepton(decays[0]) || is_neutrino(decays[0]); // W- return is_charged_lepton(decays[0]) || is_antineutrino(decays[0]); } //! true for Z decay to charged leptons bool valid_Z_decay(std::vector const & decays){ if(decays.size() != 2) // no 1->2 decay return false; if(decays[0].type != anti(decays[1].type)) { return false; } // leptonic decay (only check first, second follows from above) return is_charged_anylepton(decays[0]); } //! true if supported decay bool valid_decay(std::vector const & decays){ return valid_W_decay(+1, decays) || // Wp valid_W_decay(-1, decays) || // Wm valid_Z_decay( decays) // Z/gamma ; } /// @name helper functions to determine event type //@{ /** * \brief function which determines if type change is consistent with Wp emission. * @param in incoming Particle id * @param out outgoing Particle id * @param is_qqbar Current both incoming/both outgoing? * * \see is_Wm_Change */ bool is_Wp_Change(ParticleID in, ParticleID out, bool is_qqbar){ using namespace pid; if(!is_qqbar && (in==d_bar || in==u || in==s_bar || in==c)) return out == (in-1); if( is_qqbar && (in==d || in==u_bar || in==s || in==c_bar)) return out == -(in+1); return false; } /** * \brief function which determines if type change is consistent with Wm emission. * @param in incoming Particle id * @param out outgoing Particle id * @param is_qqbar Current both incoming/both outgoing? * * Ensures that change type of quark line is possible by a flavour changing * Wm emission. Allows checking of is_qqbar currents also. */ bool is_Wm_Change(ParticleID in, ParticleID out, bool is_qqbar){ using namespace pid; if(!is_qqbar && (in==d || in==u_bar || in==s || in==c_bar)) return out == (in+1); if( is_qqbar && (in==d_bar || in==u || in==s_bar || in==c)) return out == -(in-1); return false; } /** * \brief checks if particle type remains same from incoming to outgoing * @param in incoming Particle * @param out outgoing Particle * @param is_qqbar Current both incoming/outgoing? */ bool no_flavour_change(ParticleID in, ParticleID out, bool is_qqbar){ const int qqbarCurrent = is_qqbar?-1:1; if(std::abs(in)<=pid::top || in==pid::gluon) return (in==out*qqbarCurrent); return false; } bool is_gluon_to_Higgs(const ParticleID in, const ParticleID out) { return in == pid::gluon && out == pid::Higgs; } /** * \brief check if we have a valid Impact factor * @param in incoming Particle * @param out outgoing Particle * @param is_qqbar Current both incoming/outgoing? * @param W_change returns +1 if Wp, -1 if Wm, else 0 */ bool is_valid_impact_factor( ParticleID in, ParticleID out, bool is_qqbar, int & W_change ){ if( no_flavour_change(in, out, is_qqbar) || is_gluon_to_Higgs(in, out)) { return true; } if( is_Wp_Change(in, out, is_qqbar) ) { W_change+=1; return true; } if( is_Wm_Change(in, out, is_qqbar) ) { W_change-=1; return true; } return false; } bool is_extremal_higgs_off_quark( const ParticleID in, const ParticleID extremal_out, const ParticleID out ) { return in == out && extremal_out == pid::higgs && is_anyquark(in); } //! Returns all possible classifications from the impact factors // the beginning points are changed s.t. after the the classification they // point to the beginning of the (potential) FKL chain // sets W_change: + if Wp change // 0 if no change // - if Wm change // This function can be used with forward & backwards iterators template size_t possible_impact_factors( ParticleID incoming_id, // incoming OutIterator & begin_out, OutIterator const & end_out, // outgoing int & W_change, std::vector const & boson, bool const backward // backward? ){ using namespace event_type; if(begin_out == end_out) return non_resummable; // keep track of all states that we don't test size_t not_tested = qqbar_mid; if(backward) not_tested |= unof | qqbar_exf; else not_tested |= unob | qqbar_exb; // Is this LL current? if( is_valid_impact_factor(incoming_id, begin_out->type, false, W_change) ){ ++begin_out; return not_tested | FKL; } // q -> H q and qbar -> H qbar are technically not LL, // but we treat them as such anyway const auto next = std::next(begin_out); if( // first ensure that the next particle is not part of the *other* impact factor next != end_out && is_extremal_higgs_off_quark(incoming_id, begin_out->type, next->type) ) { std::advance(begin_out, 2); return not_tested | FKL; } // or NLL current? // -> needs two partons in two different jets if( std::distance(begin_out, end_out)>=2 ){ auto next = std::next(begin_out); // Is this unordered emisson? if( incoming_id!=pid::gluon && begin_out->type==pid::gluon ){ if( is_valid_impact_factor( incoming_id, next->type, false, W_change ) ){ // veto Higgs inside uno assert(next!=end_out); if( !boson.empty() && boson.front().type == ParticleID::h ){ if( (backward && boson.front().rapidity() < next->rapidity()) ||(!backward && boson.front().rapidity() > next->rapidity())) return non_resummable; } begin_out = std::next(next); return not_tested | (backward?unob:unof); } } // Is this QQbar? else if( incoming_id==pid::gluon ){ if( is_valid_impact_factor( begin_out->type, next->type, true, W_change ) ){ // veto Higgs inside qqbar assert(next!=end_out); if( !boson.empty() && boson.front().type == ParticleID::h ){ if( (backward && boson.front().rapidity() < next->rapidity()) ||(!backward && boson.front().rapidity() > next->rapidity())) return non_resummable; } begin_out = std::next(next); return not_tested | (backward?qqbar_exb:qqbar_exf); } } } return non_resummable; } //! Returns all possible classifications from central emissions // the beginning points are changed s.t. after the the classification they // point to the end of the emission chain // sets W_change: + if Wp change // 0 if no change // - if Wm change template size_t possible_central( OutIterator & begin_out, OutIterator const & end_out, int & W_change, std::vector const & boson ){ using namespace event_type; // if we already passed the central chain, // then it is not a valid all-order state if(std::distance(begin_out, end_out) < 0) return non_resummable; // keep track of all states that we don't test size_t possible = UNO | EXTREMAL_QQBAR; // Find the first quark or antiquark emission begin_out = std::find_if( begin_out, end_out, [](Particle const & p) { return is_anyquark(p); } ); // end of chain -> FKL if( begin_out==end_out ){ return possible | FKL; } // is this a qqbar-pair? // needs two partons in two separate jets auto next = std::next(begin_out); if( next != end_out && is_valid_impact_factor(begin_out->type, next->type, true, W_change) ){ // veto Higgs inside qqbar if( !boson.empty() && boson.front().type == ParticleID::h && boson.front().rapidity() > begin_out->rapidity() && boson.front().rapidity() < next->rapidity() ){ return non_resummable; } begin_out = std::next(next); // remaining chain should be pure FKL (gluon or higgs) if(std::any_of( begin_out, end_out, [](Particle const & p) { return is_anyquark(p); } )) { return non_resummable; } return possible | qqbar_mid; } return non_resummable; } namespace { bool is_parton_or_higgs(Particle const & p) { return is_parton(p) || p.type == pid::higgs; } bool decay_conserves_charge( Particle const &parent, std::vector const &products ) { auto charge_diff = charge(parent); for (auto const &p : products) { charge_diff -= charge(p); } return charge_diff == 0; } bool charge_conserved(Event const &ev) { boost::rational charge_diff{0}; for (auto const &in : ev.incoming()) { charge_diff += charge(in); } for (auto const &out : ev.outgoing()) { charge_diff -= charge(out); } if (charge_diff != 0) return false; return std::all_of( ev.decays().begin(), ev.decays().end(), [&ev](auto const &decay) { auto const &[parent, products] = decay; return decay_conserves_charge(ev.outgoing()[parent], products); }); } bool decay_conserves_momentum( Particle const &parent, std::vector const &products, const double tolerance ) { fastjet::PseudoJet total_p; for (auto const &p : products) total_p += p.p; return nearby_ep(parent.p, total_p, tolerance); } bool event_momentum_conserved(Event const &ev, const double tolerance) { return momentum_conserved(ev, tolerance) && std::all_of( ev.decays().begin(), ev.decays().end(), [&ev, tolerance](auto const &decay) { auto const &[parent, products] = decay; return decay_conserves_momentum( ev.outgoing()[parent], products, tolerance); }); } template bool massless_particles_onshell( Container const &c, const double tolerance ) { return std::all_of( c.begin(), c.end(), [tolerance](Particle const & p) { return is_massive(p) || p.m() < tolerance * std::max(p.E(), 1.0); } ); } bool all_massless_particles_onshell( Event const &ev, const double tolerance ) { return massless_particles_onshell(ev.incoming(), tolerance) && massless_particles_onshell(ev.outgoing(), tolerance) && std::all_of( ev.decays().begin(), ev.decays().end(), [tolerance](auto const &decay) { return massless_particles_onshell(decay.second, tolerance); }); } bool no_incoming_pt(Event const &ev, const double tolerance) { return std::all_of( ev.incoming().cbegin(), ev.incoming().end(), [tolerance](Particle const &p) { return std::abs(p.px()) < tolerance && std::abs(p.py()) < tolerance; }); } bool is_invalid(Event const &ev, const double tolerance) { return !( charge_conserved(ev) && event_momentum_conserved(ev, tolerance) && no_incoming_pt(ev, tolerance) && all_massless_particles_onshell(ev, tolerance) ); } // TODO: choose reasonable value or make configurable constexpr double TOLERANCE = 1e-3; bool incoming_are_partons(Event const &ev) { return std::all_of( ev.incoming().begin(), ev.incoming().end(), [](Particle const &p) { return is_parton(p); } ); } bool known_outgoing(Event const &ev) { return std::all_of( ev.outgoing().begin(), ev.outgoing().end(), [](Particle const &p) { return is_parton(p) || p.type == pid::Higgs || std::abs(p.type) == pid::Wp || p.type == pid::Z_photon_mix; }); } bool is_same_sign_WW(std::vector const &particles) { return particles.size() == 2 && std::abs(particles.front().type) == pid::Wp && particles.front().type == particles.back().type; } bool all_W_Zphoton_decay(Event const &ev) { auto const &out = ev.outgoing(); for (std::size_t i = 0; i < out.size(); ++i) { if ( (std::abs(out[i].type) == pid::Wp || out[i].type == pid::Z_photon_mix) && ev.decays().count(i) == 0 ) { return false; } } return true; } bool decay_known( Particle const &parent, std::vector const &products ) { if (parent.type == pid::Higgs) return true; if (parent.type == pid::Z_photon_mix) return valid_Z_decay(products); if (std::abs(parent.type) == pid::Wp) { assert(charge(parent).denominator() == 1); return valid_W_decay(charge(parent).numerator(), products); } return false; } bool all_decays_known(Event const &ev) { return std::all_of( ev.decays().begin(), ev.decays().end(), [&ev](auto const &decay) { auto const &[parent, products] = decay; return decay_known(ev.outgoing()[parent], products); }); } bool is_known_process_type(Event const &ev) { if (!incoming_are_partons(ev)) return false; if (!known_outgoing(ev)) return false; if (!all_W_Zphoton_decay(ev)) return false; if (!all_decays_known(ev)) return false; auto const bosons = filter_AWZH_bosons(ev.outgoing()); if (bosons.size() > 2) return false; if (bosons.size() == 2 && !is_same_sign_WW(bosons)) { return false; } if (bosons.size() == 1 && bosons.front().type == pid::Higgs) { return !ev.jets().empty(); } return ev.jets().size() >= 2; } } /** * \brief Checks for all event types * @param ev Event * @returns Event Type * */ event_type::EventType classify(Event const & ev){ using namespace event_type; if(is_invalid(ev, TOLERANCE)) return invalid; if(! is_known_process_type(ev)) return unknown; // initialise variables auto const & in = ev.incoming(); // range for current checks auto begin_out = boost::make_filter_iterator( is_parton_or_higgs, cbegin(ev.outgoing()), cend(ev.outgoing()) ); auto rbegin_out = std::make_reverse_iterator( boost::make_filter_iterator( is_parton_or_higgs, cend(ev.outgoing()), cend(ev.outgoing()) ) ); assert(std::distance(begin(in), end(in)) == 2); assert(std::distance(begin_out, rbegin_out.base()) >= 2); assert(std::is_sorted(begin_out, rbegin_out.base(), rapidity_less{})); auto const bosons{ filter_AWZH_bosons(ev.outgoing()) }; // keep track of potential W couplings, at the end the sum should be 0 int remaining_Wp = 0; int remaining_Wm = 0; for(auto const & boson : bosons){ if(boson.type == ParticleID::Wp) ++remaining_Wp; else if(boson.type == ParticleID::Wm) ++remaining_Wm; } size_t final_type = VALID; // check forward impact factor int W_change = 0; final_type &= possible_impact_factors( in.front().type, begin_out, rbegin_out.base(), W_change, bosons, true ); if( final_type == non_resummable ) return non_resummable; if(W_change>0) remaining_Wp-=W_change; else if(W_change<0) remaining_Wm+=W_change; // check backward impact factor W_change = 0; final_type &= possible_impact_factors( in.back().type, rbegin_out, std::make_reverse_iterator(begin_out), W_change, bosons, false ); if( final_type == non_resummable ) return non_resummable; if(W_change>0) remaining_Wp-=W_change; else if(W_change<0) remaining_Wm+=W_change; // check central emissions W_change = 0; final_type &= possible_central( begin_out, rbegin_out.base(), W_change, bosons ); if( final_type == non_resummable ) return non_resummable; if(W_change>0) remaining_Wp-=W_change; else if(W_change<0) remaining_Wm+=W_change; // Check whether the right number of Ws are present if( remaining_Wp != 0 || remaining_Wm != 0 ) return non_resummable; // result has to be unique if( (final_type & (final_type-1)) != 0) return non_resummable; // check that each sub processes is implemented // (has to be done at the end) if( (final_type & ~implemented_types(bosons)) != 0 ) return non_resummable; return static_cast(final_type); } //@} Particle extract_particle(LHEF::HEPEUP const & hepeup, size_t i){ auto id = static_cast(hepeup.IDUP[i]); auto colour = is_parton(id)?hepeup.ICOLUP[i]:std::optional(); return { id, { hepeup.PUP[i][0], hepeup.PUP[i][1], hepeup.PUP[i][2], hepeup.PUP[i][3] }, colour }; } bool is_decay_product(std::pair const & mothers){ if(mothers.first == 0) return false; return mothers.second == 0 || mothers.first == mothers.second; } } // namespace Event::EventData::EventData(LHEF::HEPEUP const & hepeup){ parameters.central = EventParameters{ hepeup.scales.mur, hepeup.scales.muf, hepeup.XWGTUP }; size_t in_idx = 0; for (int i = 0; i < hepeup.NUP; ++i) { // skip decay products // we will add them later on, but we have to ensure that // the decayed particle is added before if(is_decay_product(hepeup.MOTHUP[i])) continue; auto particle = extract_particle(hepeup, i); // needed to identify mother particles for decay products particle.p.set_user_index(i+1); if(hepeup.ISTUP[i] == LHE_Status::in){ if(in_idx > incoming.size()) { throw std::invalid_argument{ "Event has too many incoming particles" }; } incoming[in_idx++] = std::move(particle); } else outgoing.emplace_back(std::move(particle)); } // add decay products for (int i = 0; i < hepeup.NUP; ++i) { if(!is_decay_product(hepeup.MOTHUP[i])) continue; const int mother_id = hepeup.MOTHUP[i].first; const auto mother = std::find_if( begin(outgoing), end(outgoing), [mother_id](Particle const & particle){ return particle.p.user_index() == mother_id; } ); if(mother == end(outgoing)){ throw std::invalid_argument{"invalid decay product parent"}; } const int mother_idx = std::distance(begin(outgoing), mother); assert(mother_idx >= 0); decays[mother_idx].emplace_back(extract_particle(hepeup, i)); } } void Event::EventData::sort(){ // sort particles std::sort( begin(incoming), end(incoming), [](Particle const & o1, Particle const & o2){return o1.p.pz() idx(old_outgoing.size()); std::iota(idx.begin(), idx.end(), 0); std::sort(idx.begin(), idx.end(), [&old_outgoing](size_t i, size_t j){ return old_outgoing[i].rapidity() < old_outgoing[j].rapidity(); }); outgoing.clear(); outgoing.reserve(old_outgoing.size()); for(size_t i: idx) { outgoing.emplace_back(std::move(old_outgoing[i])); } // find decays again if(!decays.empty()){ auto old_decays = std::move(decays); decays.clear(); for(size_t i=0; isecond)); } assert(old_decays.size() == decays.size()); } } namespace { // use valid_X_decay to determine boson type ParticleID reconstruct_type(std::vector const & progeny) { if(valid_W_decay(+1, progeny)) { return ParticleID::Wp; } if(valid_W_decay(-1, progeny)) { return ParticleID::Wm; } if(valid_Z_decay(progeny)) { return ParticleID::Z_photon_mix; } throw not_implemented{ "final state with decay X -> " + name(progeny[0].type) + " + " + name(progeny[1].type) }; } // reconstruct particle with explicit ParticleID Particle reconstruct_boson( std::vector const & progeny, ParticleID const & type ) { Particle progenitor; progenitor.p = progeny[0].p + progeny[1].p; progenitor.type = type; return progenitor; } // reconstruct via call to reconstruct_type Particle reconstruct_boson(std::vector const & progeny) { Particle progenitor {reconstruct_boson(progeny, reconstruct_type(progeny))}; assert(is_AWZH_boson(progenitor)); return progenitor; } using GroupedParticles = std::vector >; using Decay = std::pair >; using Decays = std::vector; // return groups of reconstructable progeny std::vector group_progeny(std::vector & leptons) { /** Warning: The partition in to charged/neutral leptons is valid ONLY for WW. **/ assert(leptons.size() == 4); auto const begin_neutrino = std::partition( begin(leptons), end(leptons), [](Particle const & p) {return !is_anyneutrino(p);} ); std::vector neutrinos (begin_neutrino, end(leptons)); leptons.erase(begin_neutrino, end(leptons)); if(leptons.size() != 2 || neutrinos.size() != 2) { return {}; } assert(leptons.size() == 2 && neutrinos.size() == 2); std::vector valid_groupings; GroupedParticles candidate_grouping{{leptons[0], neutrinos[0]}, {leptons[1], neutrinos[1]}}; if(valid_decay(candidate_grouping.front()) && valid_decay(candidate_grouping.back())) { valid_groupings.emplace_back(std::move(candidate_grouping)); } candidate_grouping = {{leptons[1], neutrinos[0]}, {leptons[0], neutrinos[1]}}; if(valid_decay(candidate_grouping.front()) && valid_decay(candidate_grouping.back())) { valid_groupings.emplace_back(std::move(candidate_grouping)); } return valid_groupings; } // 'best' decay ordering measure double decay_measure(const Particle& reconstructed, EWConstants const & params) { ParticleProperties ref = params.prop(reconstructed.type); return std::abs(reconstructed.p.m() - ref.mass); } // decay_measure accumulated over decays double decay_measure(Decays const & decays, EWConstants const & params) { return std::accumulate( cbegin(decays), cend(decays), 0., [¶ms] (double dm, Decay const & decay) -> double { return dm + decay_measure(decay.first, params); } ); } // select best combination of decays for the event Decays select_decays ( std::vector & leptons, EWConstants const & ew_parameters ) { std::vector groupings = group_progeny(leptons); std::vector valid_decays; valid_decays.reserve(groupings.size()); // Reconstruct all groupings for(GroupedParticles const & group : groupings) { Decays decays; for(auto const & progeny : group) { decays.emplace_back(make_pair(reconstruct_boson(progeny), progeny)); } valid_decays.emplace_back(decays); } if (valid_decays.empty()) { throw not_implemented{"No supported intermediate reconstruction available"}; } if (valid_decays.size() == 1) { return valid_decays[0]; } // select decay with smallest decay_measure auto selected = std::min_element(cbegin(valid_decays), cend(valid_decays), [&ew_parameters] (auto const & d1, auto const & d2) -> bool { return decay_measure(d1, ew_parameters) < decay_measure(d2, ew_parameters); } ); return *selected; } } // namespace void Event::EventData::reconstruct_intermediate(EWConstants const & ew_parameters) { auto const begin_leptons = std::partition( begin(outgoing), end(outgoing), [](Particle const & p) {return !is_anylepton(p);} ); std::vector leptons(begin_leptons, end(outgoing)); outgoing.erase(begin_leptons, end(outgoing)); if(leptons.empty()) { return; } // nothing to do if(leptons.size() == 2) { outgoing.emplace_back(reconstruct_boson(leptons)); std::sort(begin(leptons), end(leptons), type_less{}); decays.emplace(outgoing.size()-1, std::move(leptons)); } else if(leptons.size() == 4) { Decays valid_decays = select_decays(leptons, ew_parameters); for(auto &decay : valid_decays) { outgoing.emplace_back(decay.first); std::sort(begin(decay.second), end(decay.second), type_less{}); decays.emplace(outgoing.size()-1, std::move(decay.second)); } } else { throw not_implemented { std::to_string(leptons.size()) + " leptons in the final state" }; } } namespace { void repair_momentum(fastjet::PseudoJet & p, const double tolerance) { if(p.e() > 0. && p.m2() != 0. && (p.m2() < tolerance * tolerance)) { const double rescale = std::sqrt(p.modp() / p.e()); const double e = p.e() * rescale; const double px = p.px() / rescale; const double py = p.py() / rescale; const double pz = p.pz() / rescale; p.reset(px, py, pz, e); } } } void Event::EventData::repair_momenta(const double tolerance) { for(auto & in: incoming) { if(is_massless(in)) { const double px = (std::abs(in.px()) < tolerance)?0.:in.px(); const double py = (std::abs(in.py()) < tolerance)?0.:in.py(); in.p.reset(px, py, in.p.pz(), in.p.e()); repair_momentum(in.p, tolerance); } } for(auto & out: outgoing) { if(is_massless(out)) repair_momentum(out.p, tolerance); } for(auto & decay: decays) { for(auto & out: decay.second) { if(is_massless(out)) repair_momentum(out.p, tolerance); } } } Event Event::EventData::cluster( fastjet::JetDefinition const & jet_def, double const min_jet_pt ){ sort(); return Event{ std::move(incoming), std::move(outgoing), std::move(decays), std::move(parameters), jet_def, min_jet_pt }; } Event::Event( std::array && incoming, std::vector && outgoing, std::unordered_map> && decays, Parameters && parameters, fastjet::JetDefinition const & jet_def, double const min_jet_pt ): incoming_{std::move(incoming)}, outgoing_{std::move(outgoing)}, decays_{std::move(decays)}, parameters_{std::move(parameters)}, cs_{ to_PseudoJet( filter_partons(outgoing_) ), jet_def }, min_jet_pt_{min_jet_pt} { jets_ = sorted_by_rapidity(cs_.inclusive_jets(min_jet_pt_)); assert(std::is_sorted(begin(outgoing_), end(outgoing_), rapidity_less{})); type_ = classify(*this); } namespace { //! check that Particles have a reasonable colour bool correct_colour(Particle const & part){ ParticleID id{ part.type }; if(!is_parton(id)) return !part.colour; if(!part.colour) return false; Colour const & col{ *part.colour }; if(is_quark(id)) return col.first != 0 && col.second == 0; if(is_antiquark(id)) return col.first == 0 && col.second != 0; assert(id==ParticleID::gluon); return col.first != 0 && col.second != 0 && col.first != col.second; } //! Connect parton to t-channel colour line & update the line //! returns false if connection not possible template bool try_connect_t(OutIterator const & it_part, Colour & line_colour){ if( line_colour.first == it_part->colour->second ){ line_colour.first = it_part->colour->first; return true; } if( line_colour.second == it_part->colour->first ){ line_colour.second = it_part->colour->second; return true; } return false; } //! Connect parton to u-channel colour line & update the line //! returns false if connection not possible template bool try_connect_u(OutIterator & it_part, Colour & line_colour){ auto it_next = std::next(it_part); if( try_connect_t(it_next, line_colour) && try_connect_t(it_part, line_colour) ){ it_part=it_next; return true; } return false; } } // namespace bool Event::is_leading_colour() const { if( !correct_colour(incoming()[0]) || !correct_colour(incoming()[1]) ) return false; Colour line_colour = *incoming()[0].colour; std::swap(line_colour.first, line_colour.second); // reasonable colour if(!std::all_of(outgoing().cbegin(), outgoing().cend(), correct_colour)) return false; for(auto it_part = cbegin_partons(); it_part!=cend_partons(); ++it_part){ switch (type()) { case event_type::FKL: if( !try_connect_t(it_part, line_colour) ) return false; break; case event_type::unob: case event_type::qqbar_exb: { if( !try_connect_t(it_part, line_colour) // u-channel only allowed at impact factor && (std::distance(cbegin_partons(), it_part)!=0 || !try_connect_u(it_part, line_colour))) return false; break; } case event_type::unof: case event_type::qqbar_exf: { if( !try_connect_t(it_part, line_colour) // u-channel only allowed at impact factor && (std::distance(it_part, cend_partons())!=2 || !try_connect_u(it_part, line_colour))) return false; break; } case event_type::qqbar_mid:{ auto it_next = std::next(it_part); if( !try_connect_t(it_part, line_colour) // u-channel only allowed at q-qbar/qbar-q pair && ( ( !(is_quark(*it_part) && is_antiquark(*it_next)) && !(is_antiquark(*it_part) && is_quark(*it_next))) || !try_connect_u(it_part, line_colour)) ) return false; break; } default: throw std::logic_error{"unreachable"}; } // no colour singlet exchange/disconnected diagram if(line_colour.first == line_colour.second) return false; } return (incoming()[1].colour->first == line_colour.first) && (incoming()[1].colour->second == line_colour.second); } namespace { //! connect incoming Particle to colour flow void connect_incoming(Particle & in, int & colour, int & anti_colour){ in.colour = std::make_pair(anti_colour, colour); // gluon if(in.type == pid::gluon) return; if(in.type > 0){ // quark assert(is_quark(in)); in.colour->second = 0; colour*=-1; return; } // anti-quark assert(is_antiquark(in)); in.colour->first = 0; anti_colour*=-1; } //! connect outgoing Particle to t-channel colour flow template void connect_tchannel( OutIterator & it_part, int & colour, int & anti_colour, RNG & ran ){ assert(colour>0 || anti_colour>0); if(it_part->type == ParticleID::gluon){ // gluon if(colour>0 && anti_colour>0){ // on g line => connect to colour OR anti-colour (random) if(ran.flat() < 0.5){ it_part->colour = std::make_pair(colour+2,colour); colour+=2; } else { it_part->colour = std::make_pair(anti_colour, anti_colour+2); anti_colour+=2; } } else if(colour > 0){ // on q line => connect to available colour it_part->colour = std::make_pair(colour+2, colour); colour+=2; } else { assert(colour<0 && anti_colour>0); // on qbar line => connect to available anti-colour it_part->colour = std::make_pair(anti_colour, anti_colour+2); anti_colour+=2; } } else if(is_quark(*it_part)) { // quark assert(anti_colour>0); if(colour>0){ // on g line => connect and remove anti-colour it_part->colour = std::make_pair(anti_colour, 0); anti_colour+=2; anti_colour*=-1; } else { // on qbar line => new colour colour*=-1; it_part->colour = std::make_pair(colour, 0); } } else if(is_antiquark(*it_part)) { // anti-quark assert(colour>0); if(anti_colour>0){ // on g line => connect and remove colour it_part->colour = std::make_pair(0, colour); colour+=2; colour*=-1; } else { // on q line => new anti-colour anti_colour*=-1; it_part->colour = std::make_pair(0, anti_colour); } } else { // not a parton assert(!is_parton(*it_part)); it_part->colour = {}; } } //! connect to t- or u-channel colour flow template void connect_utchannel( OutIterator & it_part, int & colour, int & anti_colour, RNG & ran ){ OutIterator it_first = it_part++; if(ran.flat()<.5) {// t-channel connect_tchannel(it_first, colour, anti_colour, ran); connect_tchannel(it_part, colour, anti_colour, ran); } else { // u-channel connect_tchannel(it_part, colour, anti_colour, ran); connect_tchannel(it_first, colour, anti_colour, ran); } } } // namespace bool Event::generate_colours(RNG & ran){ // generate only for HEJ events if(!event_type::is_resummable(type())) return false; assert(std::is_sorted( begin(outgoing()), end(outgoing()), rapidity_less{})); assert(incoming()[0].pz() < incoming()[1].pz()); // positive (anti-)colour -> can connect // negative (anti-)colour -> not available/used up by (anti-)quark int colour = COLOUR_OFFSET; int anti_colour = colour+1; // initialise first connect_incoming(incoming_[0], colour, anti_colour); // reset outgoing colours std::for_each(outgoing_.begin(), outgoing_.end(), [](Particle & part){ part.colour = {};}); for(auto it_part = begin_partons(); it_part!=end_partons(); ++it_part){ switch (type()) { // subleading can connect to t- or u-channel case event_type::unob: case event_type::qqbar_exb: { if( std::distance(begin_partons(), it_part)==0) connect_utchannel(it_part, colour, anti_colour, ran); else connect_tchannel(it_part, colour, anti_colour, ran); break; } case event_type::unof: case event_type::qqbar_exf: { if( std::distance(it_part, end_partons())==2) connect_utchannel(it_part, colour, anti_colour, ran); else connect_tchannel(it_part, colour, anti_colour, ran); break; } case event_type::qqbar_mid:{ auto it_next = std::next(it_part); if( std::distance(begin_partons(), it_part)>0 && std::distance(it_part, end_partons())>2 && ( (is_quark(*it_part) && is_antiquark(*it_next)) || (is_antiquark(*it_part) && is_quark(*it_next)) ) ) connect_utchannel(it_part, colour, anti_colour, ran); else connect_tchannel(it_part, colour, anti_colour, ran); break; } default: // rest has to be t-channel connect_tchannel(it_part, colour, anti_colour, ran); } } // Connect last connect_incoming(incoming_[1], anti_colour, colour); assert(is_leading_colour()); return true; } // generate_colours namespace { bool valid_parton( std::vector const & jets, Particle const & parton, int const idx, - double const soft_pt_regulator, double const min_extparton_pt + double const soft_pt_regulator ){ // TODO code overlap with PhaseSpacePoint::pass_extremal_cuts - if(min_extparton_pt > parton.pt()) return false; if(idx<0) return false; assert(static_cast(jets.size())>=idx); auto const & jet{ jets[idx] }; return (parton.p - jet).pt()/jet.pt() <= soft_pt_regulator; } } // namespace - bool Event::valid_hej_state(double const soft_pt_regulator, - double const min_pt - ) const { + bool Event::valid_hej_state(double const soft_pt_regulator) const { using namespace event_type; const auto is_valid_parton = [&](Particle const & parton, int const jet_idx) { - return valid_parton(jets(), parton, jet_idx, soft_pt_regulator, min_pt); + return valid_parton(jets(), parton, jet_idx, soft_pt_regulator); }; if(!is_resummable(type())) return false; auto const & jet_indices{ particle_jet_indices() }; auto jet_idx_begin{ jet_indices.cbegin() }; auto jet_idx_end{ jet_indices.crbegin() }; auto part_begin{ cbegin_partons() }; auto part_end{ crbegin_partons() }; if(!is_backward_g_to_h(*this)) { const int first_jet_idx = *jet_idx_begin; if(! is_valid_parton(*part_begin, first_jet_idx)) { return false; } ++part_begin; ++jet_idx_begin; // unob -> second parton in own jet if( type() & (unob | qqbar_exb) ){ if( (*jet_idx_begin == first_jet_idx) || !is_valid_parton(*part_begin, *jet_idx_begin) ) { return false; } ++part_begin; ++jet_idx_begin; } } if(!is_forward_g_to_h(*this)) { const int last_jet_idx = *jet_idx_end; if(!is_valid_parton(*part_end, last_jet_idx)) { return false; } ++part_end; ++jet_idx_end; if( type() & (unof | qqbar_exf) ){ if( (*jet_idx_end == last_jet_idx) || !is_valid_parton(*part_end, *jet_idx_end) ) { return false; } ++part_end; // ++jet_idx_end; // last check, we don't need idx_end afterwards } } if( type() & qqbar_mid ){ // find qqbar pair auto begin_qqbar{ std::find_if( part_begin, part_end.base(), [](Particle const & part) -> bool { return part.type != ParticleID::gluon; } )}; assert(begin_qqbar != part_end.base()); long int qqbar_pos{ std::distance(part_begin, begin_qqbar) }; assert(qqbar_pos >= 0); jet_idx_begin += qqbar_pos; const int next_jet_idx = *std::next(jet_idx_begin); if( (*jet_idx_begin == next_jet_idx) || ! is_valid_parton(*begin_qqbar, *jet_idx_begin) || ! is_valid_parton(*std::next(begin_qqbar), next_jet_idx) ) { return false; } } return true; } bool Event::valid_incoming() const{ for(std::size_t i=0; i < incoming_.size(); ++i){ if(!(HEJ::nearby_ep(std::abs(incoming_[i].pz()), incoming_[i].E(), TOL*incoming_[i].E()) && (incoming_[i].pt()==0.))) return false; } return true; } Event::ConstPartonIterator Event::begin_partons() const { return cbegin_partons(); } Event::ConstPartonIterator Event::cbegin_partons() const { return {HEJ::is_parton, cbegin(outgoing()), cend(outgoing())}; } Event::ConstPartonIterator Event::end_partons() const { return cend_partons(); } Event::ConstPartonIterator Event::cend_partons() const { return {HEJ::is_parton, cend(outgoing()), cend(outgoing())}; } Event::ConstReversePartonIterator Event::rbegin_partons() const { return crbegin_partons(); } Event::ConstReversePartonIterator Event::crbegin_partons() const { return std::reverse_iterator( cend_partons() ); } Event::ConstReversePartonIterator Event::rend_partons() const { return crend_partons(); } Event::ConstReversePartonIterator Event::crend_partons() const { return std::reverse_iterator( cbegin_partons() ); } Event::PartonIterator Event::begin_partons() { return {HEJ::is_parton, begin(outgoing_), end(outgoing_)}; } Event::PartonIterator Event::end_partons() { return {HEJ::is_parton, end(outgoing_), end(outgoing_)}; } Event::ReversePartonIterator Event::rbegin_partons() { return std::reverse_iterator( end_partons() ); } Event::ReversePartonIterator Event::rend_partons() { return std::reverse_iterator( begin_partons() ); } namespace { void print_momentum(std::ostream & os, fastjet::PseudoJet const & part){ constexpr int prec = 6; const std::streamsize orig_prec = os.precision(); os < const & col){ constexpr int width = 3; if(!col) os << "(no color)"; // American spelling for better alignment else os << "(" <first << ", " <second << ")"; } } // namespace std::ostream& operator<<(std::ostream & os, Event const & ev){ constexpr int prec = 4; constexpr int wtype = 3; // width for types const std::streamsize orig_prec = os.precision(); os < rapidity=" < rapidity=" < rapidity=" < incoming{ event.incoming() }; // First incoming should be positive pz according to LHE standard // (or at least most (everyone?) do it this way, and Pythia assumes it) if(incoming[0].pz() < incoming[1].pz()) std::swap(incoming[0], incoming[1]); for(Particle const & in: incoming){ result.IDUP.emplace_back(in.type); result.ISTUP.emplace_back(LHE_Status::in); result.PUP.push_back({in.p[0], in.p[1], in.p[2], in.p[3], in.p.m()}); result.MOTHUP.emplace_back(0, 0); assert(in.colour); result.ICOLUP.emplace_back(*in.colour); } // outgoing for(size_t i = 0; i < event.outgoing().size(); ++i){ Particle const & out = event.outgoing()[i]; result.IDUP.emplace_back(out.type); const int status = event.decays().count(i) != 0u ?LHE_Status::decay :LHE_Status::out; result.ISTUP.emplace_back(status); result.PUP.push_back({out.p[0], out.p[1], out.p[2], out.p[3], out.p.m()}); result.MOTHUP.emplace_back(1, 2); if(out.colour) result.ICOLUP.emplace_back(*out.colour); else{ result.ICOLUP.emplace_back(std::make_pair(0,0)); } } // decays for(auto const & decay: event.decays()){ for(auto const & out: decay.second){ result.IDUP.emplace_back(out.type); result.ISTUP.emplace_back(LHE_Status::out); result.PUP.push_back({out.p[0], out.p[1], out.p[2], out.p[3], out.p.m()}); const size_t mother_idx = 1 + event.incoming().size() + decay.first; result.MOTHUP.emplace_back(mother_idx, mother_idx); result.ICOLUP.emplace_back(0,0); } } assert(result.ICOLUP.size() == num_particles); static constexpr double unknown_spin = 9.; //per Les Houches accord result.VTIMUP = std::vector(num_particles, unknown_spin); result.SPINUP = result.VTIMUP; return result; } } // namespace HEJ diff --git a/src/EventReweighter.cc b/src/EventReweighter.cc index 7ee97df..ba97ca9 100644 --- a/src/EventReweighter.cc +++ b/src/EventReweighter.cc @@ -1,301 +1,294 @@ /** * \authors The HEJ collaboration (see AUTHORS for details) * \date 2019-2020 * \copyright GPLv2 or later */ #include "HEJ/EventReweighter.hh" #include #include #include #include #include #include #include #include #include "fastjet/ClusterSequence.hh" #include "fastjet/PseudoJet.hh" #include "LHEF/LHEF.h" #include "HEJ/Event.hh" #include "HEJ/Fraction.hh" #include "HEJ/PDG_codes.hh" #include "HEJ/Particle.hh" #include "HEJ/PhaseSpacePoint.hh" #include "HEJ/exceptions.hh" namespace HEJ { EventReweighter::EventReweighter( LHEF::HEPRUP const & heprup, ScaleGenerator scale_gen, EventReweighterConfig conf, std::shared_ptr ran ): EventReweighter{ Beam{ heprup.EBMUP.first, {{ static_cast(heprup.IDBMUP.first), static_cast(heprup.IDBMUP.second) }} }, heprup.PDFSUP.first, std::move(scale_gen), std::move(conf), std::move(ran) } { if(heprup.EBMUP.second != E_beam_){ throw std::invalid_argument( "asymmetric beam: " + std::to_string(E_beam_) + " ---> <--- " + std::to_string(heprup.EBMUP.second) ); } if(heprup.PDFSUP.second != pdf_.id()){ throw std::invalid_argument( "conflicting PDF ids: " + std::to_string(pdf_.id()) + " vs. " + std::to_string(heprup.PDFSUP.second) ); } } EventReweighter::EventReweighter( Beam const & beam, int pdf_id, ScaleGenerator scale_gen, EventReweighterConfig conf, std::shared_ptr ran ): param_{std::move(conf)}, E_beam_{beam.E}, pdf_{pdf_id, beam.type.front(), beam.type.back()}, MEt2_{ [this](double mu){ return pdf_.Halphas(mu); }, param_.ME_config }, scale_gen_{std::move(scale_gen)}, ran_{std::move(ran)} { - // legacy code: override new variable with old - if(param_.psp_config.max_ext_soft_pt_fraction){ - param_.psp_config.soft_pt_regulator = *param_.psp_config.max_ext_soft_pt_fraction; - param_.psp_config.max_ext_soft_pt_fraction = {}; - } assert(ran_); } PDF const & EventReweighter::pdf() const{ return pdf_; } bool EventReweighter::pass_low_pt( HEJ::Event const & input_ev ){ // Keep only events where there is a fixed order event with at least 1 // jet below the resummation jet pt but all resummation jets are above // the resummation jet pt if(param_.treat.at(EventType::non_resummable) != EventTreatment::discard){ throw std::logic_error{ "Non-resummable events should be discarded for lowpt runs" }; } return std::any_of(begin(input_ev.jets()), end(input_ev.jets()), [&](fastjet::PseudoJet jet) {return jet.pt() < param_.jet_param().min_pt;}); } std::vector EventReweighter::reweight( Event const & input_ev, std::size_t num_events ){ if(param_.lowpt && !EventReweighter::pass_low_pt(input_ev)){ return {}; } auto res_events{ gen_res_events(input_ev, num_events) }; if(res_events.empty()) return {}; for(auto & event: res_events) event = scale_gen_(std::move(event)); return rescale(input_ev, std::move(res_events)); } EventTreatment EventReweighter::treatment(EventType type) const { return param_.treat.at(type); } std::vector EventReweighter::gen_res_events( Event const & ev, std::size_t phase_space_points ){ assert(ev.variations().empty()); status_.clear(); switch(treatment(ev.type())){ case EventTreatment::discard: { status_.emplace_back(StatusCode::discard); return {}; } case EventTreatment::keep: if(! jets_pass_resummation_cuts(ev)) { status_.emplace_back(StatusCode::failed_resummation_cuts); return {}; } else { status_.emplace_back(StatusCode::good); return {ev}; } case EventTreatment::abort: throw abort_event{ev}; default:; } const double Born_shat = shat(ev); std::vector resummation_events; status_.reserve(phase_space_points); for(std::size_t psp_number = 0; psp_number < phase_space_points; ++psp_number){ PhaseSpacePoint psp{ev, param_.psp_config, *ran_}; status_.emplace_back(psp.status()); assert(psp.status() != StatusCode::unspecified); if(psp.status() != StatusCode::good) continue; assert(psp.weight() != 0.); if(psp.incoming()[0].E() > E_beam_ || psp.incoming()[1].E() > E_beam_) { status_.back() = StatusCode::too_much_energy; continue; } resummation_events.emplace_back( to_EventData( std::move(psp) ).cluster( param_.jet_param().def, param_.jet_param().min_pt ) ); auto & new_event = resummation_events.back(); - assert( new_event.valid_hej_state( - param_.psp_config.soft_pt_regulator, - param_.psp_config.min_extparton_pt ) ); + assert( new_event.valid_hej_state(param_.psp_config.soft_pt_regulator) ); if( new_event.type() != ev.type() ) { throw std::logic_error{ "Resummation Event does not match Born event: " + name(new_event.type()) + " != " + name(ev.type()) }; } new_event.generate_colours(*ran_); assert(new_event.variations().empty()); new_event.central().mur = ev.central().mur; new_event.central().muf = ev.central().muf; const double resum_shat = shat(new_event); new_event.central().weight *= ev.central().weight*Born_shat*Born_shat/ (phase_space_points*resum_shat*resum_shat); } return resummation_events; } std::vector EventReweighter::rescale( Event const & Born_ev, std::vector events ) const{ const double Born_pdf = pdf_factors(Born_ev).central; const double Born_ME = tree_matrix_element(Born_ev); for(auto & cur_event: events){ const auto pdf = pdf_factors(cur_event); assert(pdf.variations.size() == cur_event.variations().size()); const auto ME = matrix_elements(cur_event); assert(ME.variations.size() == cur_event.variations().size()); cur_event.parameters() *= pdf*ME/(Born_pdf*Born_ME); } return events; } bool EventReweighter::jets_pass_resummation_cuts( Event const & ev ) const{ const auto out_as_PseudoJet = to_PseudoJet(filter_partons(ev.outgoing())); fastjet::ClusterSequence cs{out_as_PseudoJet, param_.jet_param().def}; return cs.inclusive_jets(param_.jet_param().min_pt).size() == ev.jets().size(); } Weights EventReweighter::pdf_factors(Event const & ev) const{ auto const & a = ev.incoming().front(); auto const & b = ev.incoming().back(); const double xa = a.p.e()/E_beam_; const double xb = b.p.e()/E_beam_; Weights result; std::unordered_map known_pdf; result.central = pdf_.pdfpt(0,xa,ev.central().muf,a.type)* pdf_.pdfpt(1,xb,ev.central().muf,b.type); known_pdf.emplace(ev.central().muf, result.central); result.variations.reserve(ev.variations().size()); for(auto const & ev_param: ev.variations()){ const double muf = ev_param.muf; auto cur_pdf = known_pdf.find(muf); if(cur_pdf == known_pdf.end()){ cur_pdf = known_pdf.emplace( muf, pdf_.pdfpt(0,xa,muf,a.type)*pdf_.pdfpt(1,xb,muf,b.type) ).first; } result.variations.emplace_back(cur_pdf->second); } assert(result.variations.size() == ev.variations().size()); return result; } Weights EventReweighter::matrix_elements(Event const & ev) const{ assert(param_.treat.count(ev.type()) > 0); if(param_.treat.find(ev.type())->second == EventTreatment::keep){ return fixed_order_scale_ME(ev); } return MEt2_(ev); } double EventReweighter::tree_matrix_element(Event const & ev) const{ assert(ev.variations().empty()); assert(param_.treat.count(ev.type()) > 0); if(param_.treat.find(ev.type())->second == EventTreatment::keep){ return fixed_order_scale_ME(ev).central; } return MEt2_.tree(ev).central; } Weights EventReweighter::fixed_order_scale_ME(Event const & ev) const{ int alpha_s_power = 0; for(auto const & part: ev.outgoing()){ if(is_parton(part)) ++alpha_s_power; else if(part.type == pid::Higgs) { alpha_s_power += 2; } // nothing to do for other uncoloured particles } Weights result; result.central = std::pow(pdf_.Halphas(ev.central().mur), alpha_s_power); for(auto const & var: ev.variations()){ result.variations.emplace_back( std::pow(pdf_.Halphas(var.mur), alpha_s_power) ); } return result; } abort_event::abort_event(Event const & ev): std::invalid_argument{ "Encountered `" + name(ev.type()) + "` event:\n" + to_string(ev) } {} } // namespace HEJ diff --git a/src/PhaseSpacePoint.cc b/src/PhaseSpacePoint.cc index 8e1b0a5..d314fd1 100644 --- a/src/PhaseSpacePoint.cc +++ b/src/PhaseSpacePoint.cc @@ -1,983 +1,976 @@ /** * \authors The HEJ collaboration (see AUTHORS for details) * \date 2019-2020 * \copyright GPLv2 or later */ #include "HEJ/PhaseSpacePoint.hh" #include #include #include #include #include #include #include #include #include #include #include "fastjet/ClusterSequence.hh" #include "fastjet/JetDefinition.hh" #include "HEJ/Constants.hh" #include "HEJ/Event.hh" #include "HEJ/JetSplitter.hh" #include "HEJ/PDG_codes.hh" #include "HEJ/RNG.hh" #include "HEJ/event_types.hh" #include "HEJ/kinematics.hh" #include "HEJ/resummation_jet.hh" #include "HEJ/utility.hh" namespace HEJ { namespace { constexpr int MAX_JET_USER_IDX = 1000; bool is_nonjet_parton(fastjet::PseudoJet const & parton){ assert(parton.user_index() != -1); return parton.user_index() > MAX_JET_USER_IDX; } bool is_jet_parton(fastjet::PseudoJet const & parton){ assert(parton.user_index() != -1); return parton.user_index() <= MAX_JET_USER_IDX; } namespace user_idx { //! user indices for partons with extremal rapidity enum ID: int { qqbar_mid1 = -9, qqbar_mid2 = -8, qqbarb = -7, qqbarf = -6, unob = -5, unof = -4, backward_fkl = -3, forward_fkl = -2, }; } // namespace user_idx using UID = user_idx::ID; double phase_space_normalisation( int num_Born_jets, int num_out_partons ){ return std::pow(16.*std::pow(M_PI,3), num_Born_jets - num_out_partons); } } // namespace Event::EventData to_EventData(PhaseSpacePoint psp){ Event::EventData result; result.incoming = std::move(psp).incoming_; // NOLINT(bugprone-use-after-move) result.outgoing = std::move(psp).outgoing_; // NOLINT(bugprone-use-after-move) // technically Event::EventData doesn't have to be sorted, // but PhaseSpacePoint should be anyway assert( std::is_sorted( begin(result.outgoing), end(result.outgoing), rapidity_less{} ) ); assert(result.outgoing.size() >= 2); static_assert( std::numeric_limits::has_quiet_NaN, "no quiet NaN for double" ); constexpr double nan = std::numeric_limits::quiet_NaN(); result.decays = std::move(psp).decays_; // NOLINT(bugprone-use-after-move) result.parameters.central = {nan, nan, psp.weight()}; // NOLINT(bugprone-use-after-move) return result; } std::vector PhaseSpacePoint::cluster_jets( std::vector const & partons ) const{ fastjet::ClusterSequence cs(partons, param_.jet_param.def); return sorted_by_rapidity(cs.inclusive_jets(param_.jet_param.min_pt)); } bool PhaseSpacePoint::pass_resummation_cuts( std::vector const & jets ) const{ return cluster_jets(jets).size() == jets.size(); } namespace { // find iterators to central qqbar emission auto get_central_qqbar(Event const & ev) { // find born quarks (ignore extremal partons) auto const firstquark = std::find_if( std::next(ev.begin_partons()), std::prev(ev.end_partons(), 2), [](Particle const & s){ return (is_anyquark(s)); } ); // assert that it is a q-q_bar pair. assert(std::distance(firstquark, ev.end_partons()) != 2); assert( ( is_quark(*firstquark) && is_antiquark(*std::next(firstquark)) ) || ( is_antiquark(*firstquark) && is_quark(*std::next(firstquark)) ) ); return std::make_pair(firstquark, std::next(firstquark)); } //! returns index of most backward q-qbar jet template int get_back_quark_jet(Event const & ev, Iterator firstquark){ // find jets at FO corresponding to the quarks // technically this isn't necessary for LO std::vector const born_indices{ ev.particle_jet_indices() }; const auto firstquark_idx = std::distance(ev.begin_partons(), firstquark); int const firstjet_idx = born_indices[firstquark_idx]; assert(firstjet_idx>0); assert( born_indices[firstquark_idx+1] == firstjet_idx+1 ); return firstjet_idx; } //! returns index of most backward q-qbar jet int getBackQuarkJet(Event const & ev){ const auto firstquark = get_central_qqbar(ev).first; return get_back_quark_jet(ev, firstquark); } } // namespace double PhaseSpacePoint::estimate_emission_rapidity_range( Event const & ev ) const { assert(std::is_sorted(begin(ev.jets()), end(ev.jets()), rapidity_less{})); const double ymin = is_backward_g_to_h(ev)? ev.outgoing().front().rapidity(): most_backward_FKL(ev.jets()).rapidity(); const double ymax = is_forward_g_to_h(ev)? ev.outgoing().back().rapidity(): most_forward_FKL(ev.jets()).rapidity(); double delta_y = ymax - ymin; // neglect tiny probability for emission between central qqbar pair if(ev.type() == event_type::central_qqbar) { const int qjet = getBackQuarkJet(ev); delta_y -= ev.jets()[qjet+1].rapidity() - ev.jets()[qjet].rapidity(); } assert(delta_y >= 0); return delta_y; } double PhaseSpacePoint::estimate_ng_mean(Event const & ev) const { // Formula derived from fit in arXiv:1805.04446 (see Fig. 2) constexpr double GLUONS_PER_RAPIDITY = 0.975052; return GLUONS_PER_RAPIDITY*estimate_emission_rapidity_range(ev); } int PhaseSpacePoint::sample_ng(Event const & event, RNG & ran){ if (param_.nlo.enabled == true){ std::uniform_int_distribution<> dist(0, 1); const int ng = dist(ran); weight_ *= 2; assert(ng < 2); assert(ng >= 0); return ng; } else{ const double ng_mean = estimate_ng_mean(event); std::poisson_distribution dist(ng_mean); const int ng = dist(ran); assert(ng >= 0); assert(ng < MAX_JET_USER_IDX); weight_ *= std::tgamma(ng + 1)*std::exp(ng_mean)*std::pow(ng_mean, -ng); return ng; } } void PhaseSpacePoint::boost_AWZH_bosons_from( std::vector const & boosted_bosons, Event const & event ){ auto const & from = event.outgoing(); auto find_AWZH = [](Particle const & p){ return is_AWZH_boson(p); }; size_t boosted_idx = 0; for( auto original_boson = std::find_if(begin(from), end(from), find_AWZH); original_boson != end(from); original_boson = std::find_if(++original_boson, end(from), find_AWZH), ++boosted_idx ){ auto insertion_point = std::lower_bound( begin(outgoing_), end(outgoing_), *original_boson, rapidity_less{} ); // copy AWZH particle const int new_idx = std::distance(begin(outgoing_), insertion_point); assert(new_idx >= 0); // insert invalidates distance outgoing_.insert(insertion_point, {original_boson->type, boosted_bosons[boosted_idx], original_boson->colour} ); assert(outgoing_[new_idx].type == original_boson->type); assert(std::is_sorted(begin(outgoing_), end(outgoing_), rapidity_less{})); // copy & boost decay products const int idx = std::distance(begin(from), original_boson); assert(idx >= 0); const auto decay_it = event.decays().find(idx); if(decay_it != end(event.decays())){ auto decayparticles = decay_it->second; // change the momenta of the decay products. fastjet::PseudoJet sum; for(auto & particle: decayparticles){ auto & p = particle.p; // boost _to_ rest frame of input boson p.unboost(original_boson->p); // then boost _from_ rest frame of shuffled boson p.boost(boosted_bosons[boosted_idx]); if(p.E() < std::abs(p.pz())){ throw std::underflow_error("Reshuffled decay with E<|pz|"); } sum += p; } if(!nearby(boosted_bosons[boosted_idx], sum, boosted_bosons[boosted_idx].E())){ throw std::underflow_error("Boson and decays momenta do not match after reshuffling"); } decays_.emplace(new_idx, decayparticles); } } } namespace { template void label_extremal_qqbar( ConstIterator born_begin, ConstIterator born_end, Iterator first_out ){ // find born quarks const auto firstquark = std::find_if( born_begin, born_end-1, [](Particle const & s){ return (is_anyquark(s)); } ); assert(firstquark != born_end-1); const auto secondquark = std::find_if( firstquark+1, born_end, [](Particle const & s){ return (is_anyquark(s)); } ); assert(secondquark != born_end); assert( ( is_quark(*firstquark) && is_antiquark(*secondquark) ) || ( is_antiquark(*firstquark) && is_quark(*secondquark) )); assert(first_out->type == ParticleID::gluon); assert((first_out+1)->type == ParticleID::gluon); // copy type from born first_out->type = firstquark->type; (first_out+1)->type = secondquark->type; } } // namespace void PhaseSpacePoint::label_qqbar(Event const & event){ assert(std::is_sorted(begin(outgoing_), end(outgoing_), rapidity_less{})); assert(filter_partons(outgoing_).size() == outgoing_.size()); if(qqbarb_){ label_extremal_qqbar(event.outgoing().cbegin(), event.outgoing().cend(), outgoing_.begin() ); return; } if(qqbarf_){ // same as qqbarb with reversed order label_extremal_qqbar( event.outgoing().crbegin(), event.outgoing().crend(), outgoing_.rbegin() ); return; } // central qqbar const auto firstquark = get_central_qqbar(event).first; // find jets at FO corresponding to the quarks // technically this isn't necessary for LO const auto firstjet_idx = get_back_quark_jet(event, firstquark); // find corresponding jets after resummation fastjet::ClusterSequence cs{to_PseudoJet(outgoing_), param_.jet_param.def}; auto const jets = fastjet::sorted_by_rapidity( cs.inclusive_jets( param_.jet_param.min_pt )); std::vector const resum_indices{ cs.particle_jet_indices({jets}) }; // assert that jets didn't move assert(nearby_ep( ( event.jets().cbegin()+firstjet_idx )->rapidity(), jets[ firstjet_idx ].rapidity(), 1e-2) ); assert(nearby_ep( ( event.jets().cbegin()+firstjet_idx+1 )->rapidity(), jets[ firstjet_idx+1 ].rapidity(), 1e-2) ); // find last partons in first (central) jet size_t idx_out = 0; for(size_t i=resum_indices.size()-2; i>0; --i) if(resum_indices[i] == firstjet_idx){ idx_out = i; break; } assert(idx_out != 0); // check that there is sufficient pt in jets from the quarks const double minpartonjetpt = 1. - param_.soft_pt_regulator; if (outgoing_[idx_out].p.pt()pt()){ weight_=0.; status_ = StatusCode::wrong_jets; return; } if (outgoing_[idx_out+1].p.pt()pt()){ weight_=0.; status_ = StatusCode::wrong_jets; return; } // check that no additional emission between jets // such configurations are possible if we have an gluon gets generated // inside the rapidities of the qqbar chain, but clusted to a // differnet/outside jet. Changing this is non trivial if(resum_indices[idx_out+1] != resum_indices[idx_out]+1){ weight_=0.; status_ = StatusCode::gluon_in_qqbar; return; } outgoing_[idx_out].type = firstquark->type; outgoing_[idx_out+1].type = std::next(firstquark)->type; } void PhaseSpacePoint::label_quarks(Event const & ev){ const auto WZEmit = std::find_if( begin(ev.outgoing()), end(ev.outgoing()), [](Particle const & s){ return (std::abs(s.type) == pid::Wp || s.type == pid::Z_photon_mix); } ); if (WZEmit != end(ev.outgoing())){ if(!qqbarb_) { const size_t backward_FKL_idx = unob_?1:0; const auto backward_FKL = std::next(ev.begin_partons(), backward_FKL_idx); outgoing_[backward_FKL_idx].type = backward_FKL->type; } if(!qqbarf_) { const size_t forward_FKL_idx = unof_?1:0; const auto forward_FKL = std::prev(ev.end_partons(), 1+forward_FKL_idx); outgoing_.rbegin()[unof_].type = forward_FKL->type; // NOLINT } } else { if(!is_backward_g_to_h(ev)) { most_backward_FKL(outgoing_).type = ev.incoming().front().type; } if(!is_forward_g_to_h(ev)) { most_forward_FKL(outgoing_).type = ev.incoming().back().type; } } if(qqbar_mid_||qqbarb_||qqbarf_){ label_qqbar(ev); } } PhaseSpacePoint::PhaseSpacePoint( Event const & ev, PhaseSpacePointConfig conf, RNG & ran ): unob_{ev.type() == event_type::unob}, unof_{ev.type() == event_type::unof}, qqbarb_{ev.type() == event_type::qqbar_exb}, qqbarf_{ev.type() == event_type::qqbar_exf}, qqbar_mid_{ev.type() == event_type::qqbar_mid}, param_{std::move(conf)}, status_{unspecified} { - // legacy code: override new variable with old - if(param_.max_ext_soft_pt_fraction){ - param_.soft_pt_regulator = *param_.max_ext_soft_pt_fraction; - param_.max_ext_soft_pt_fraction = {}; - } - weight_ = 1; auto const & Born_jets = ev.jets(); const int ng = sample_ng(ev, ran); weight_ /= std::tgamma(ng + 1); const int ng_jets = sample_ng_jets(ev, ng, ran); std::vector out_partons = gen_non_jet( ng - ng_jets, CMINPT, param_.jet_param.min_pt, ran ); const auto qperp = std::accumulate( begin(out_partons), end(out_partons), fastjet::PseudoJet{} ); std::vector jets; std::vector bosons; std::tie(jets, bosons) = reshuffle(ev, qperp); if(weight_ == 0.) { status_ = failed_reshuffle; return; } if(! pass_resummation_cuts(jets)){ status_ = failed_resummation_cuts; weight_ = 0.; return; } // split jets in multiple partons std::vector jet_partons = split( ev, jets, ng_jets, ran ); if(weight_ == 0.) { status_ = StatusCode::failed_split; return; } const double ymin = is_backward_g_to_h(ev)? ev.outgoing().front().rapidity(): most_backward_FKL(jet_partons).rapidity() ; const double ymax = is_forward_g_to_h(ev)? ev.outgoing().back().rapidity(): most_forward_FKL(jet_partons).rapidity() ; if(qqbar_mid_){ const int qqbar_backjet = getBackQuarkJet(ev); rescale_qqbar_rapidities( out_partons, jets, ymin, ymax, qqbar_backjet ); } else{ rescale_rapidities(out_partons, ymin, ymax); } if(! cluster_jets(out_partons).empty()){ weight_ = 0.; status_ = StatusCode::empty_jets; return; } std::sort(begin(out_partons), end(out_partons), rapidity_less{}); assert( std::is_sorted(begin(jet_partons), end(jet_partons), rapidity_less{}) ); const auto first_jet_parton = out_partons.insert( end(out_partons), begin(jet_partons), end(jet_partons) ); std::inplace_merge( begin(out_partons), first_jet_parton, end(out_partons), rapidity_less{} ); if(! jets_ok(ev, out_partons)){ weight_ = 0.; status_ = StatusCode::wrong_jets; return; } weight_ *= phase_space_normalisation(Born_jets.size(), out_partons.size()); outgoing_.reserve(out_partons.size() + 2); // two slots for possible A, W, Z, H for( auto it = std::make_move_iterator(out_partons.begin()); it != std::make_move_iterator(out_partons.end()); ++it ){ outgoing_.emplace_back( Particle{pid::gluon, *it, {}}); } assert(!outgoing_.empty()); label_quarks(ev); if(weight_ == 0.) { //! @TODO optimise s.t. this is not possible // status is handled internally return; } // reattach bosons & decays if(!bosons.empty()){ try { boost_AWZH_bosons_from(bosons, ev); } catch (std::underflow_error const & e){ weight_ = 0.; status_ = StatusCode::failed_reshuffle; return; } } reconstruct_incoming(ev.incoming()); status_ = StatusCode::good; } std::vector PhaseSpacePoint::gen_non_jet( int const ng_non_jet, double const ptmin, double const ptmax, RNG & ran ){ // heuristic parameters for pt sampling const double ptpar = 1.3 + ng_non_jet/5.; const double temp1 = std::atan((ptmax - ptmin)/ptpar); std::vector partons(ng_non_jet); for(int i = 0; i < ng_non_jet; ++i){ const double r1 = ran.flat(); const double pt = ptmin + ptpar*std::tan(r1*temp1); const double temp2 = std::cos(r1*temp1); const double phi = 2*M_PI*ran.flat(); weight_ *= 2.0*M_PI*pt*ptpar*temp1/(temp2*temp2); // we don't know the allowed rapidity span yet, // set a random value to be rescaled later on const double y = ran.flat(); partons[i].reset_PtYPhiM(pt, y, phi); // Set user index higher than any jet-parton index // in order to assert that these are not inside jets partons[i].set_user_index(i + 1 + MAX_JET_USER_IDX); assert(ptmin-1e-5 <= partons[i].pt() && partons[i].pt() <= ptmax+1e-5); } assert(std::all_of(partons.cbegin(), partons.cend(), is_nonjet_parton)); return sorted_by_rapidity(partons); } void PhaseSpacePoint::rescale_qqbar_rapidities( std::vector & out_partons, std::vector const & jets, const double ymin1, const double ymax2, const int qqbar_backjet ){ const double ymax1 = jets[qqbar_backjet].rapidity(); const double ymin2 = jets[qqbar_backjet+1].rapidity(); constexpr double ep = 1e-7; const double tot_y = ymax1 - ymin1 + ymax2 - ymin2; std::vector> refpart( out_partons.begin(), out_partons.end()); double ratio = (ymax1 - ymin1)/tot_y; const auto gap{ std::find_if(refpart.begin(), refpart.end(), [ratio](fastjet::PseudoJet const & p){ return (p.rapidity()>=ratio);} ) }; double ymin = ymin1; double ymax = ymax1; double dy = ymax - ymin - 2*ep; double offset = 0.; for(auto it_part=refpart.begin(); it_part & partons, double ymin, double ymax ){ constexpr double ep = 1e-7; for(auto & parton: partons){ assert(0 <= parton.rapidity() && parton.rapidity() <= 1); const double dy = ymax - ymin - 2*ep; const double y = ymin + ep + dy*parton.rapidity(); parton.reset_momentum_PtYPhiM(parton.pt(), y, parton.phi()); weight_ *= dy; assert(ymin <= parton.rapidity() && parton.rapidity() <= ymax); } } namespace { template auto min(T const & a, T const & b, Rest&&... r) { using std::min; return min(a, min(b, std::forward(r)...)); } } double PhaseSpacePoint::probability_in_jet(Event const & ev) const{ const double dy = estimate_emission_rapidity_range(ev); const double R = param_.jet_param.def.R(); // jets into which we predominantly emit const int njets = ev.jets().size() - unof_ - unob_ - qqbarb_ - qqbarf_; //NOLINT assert(njets >= 1); const size_t nextremal_jets = std::min(njets, 2); const double p_J_y_large = (njets - nextremal_jets/2.)*R*R/(2.*dy); const double p_J_y0 = njets*R/M_PI; return min(p_J_y_large, p_J_y0, 1.); } int PhaseSpacePoint::sample_ng_jets(Event const & event, int ng, RNG & ran){ const double p_J = probability_in_jet(event); std::binomial_distribution<> bin_dist(ng, p_J); const int ng_J = bin_dist(ran); weight_ *= std::pow(p_J, -ng_J)*std::pow(1 - p_J, ng_J - ng); return ng_J; } std::pair< std::vector, std::vector > PhaseSpacePoint::reshuffle( Event const & ev, fastjet::PseudoJet const & q ){ // Create a copy of the outgoing momenta not containing decay products std::vector born_momenta; born_momenta.reserve(ev.jets().size()); std::transform(ev.jets().cbegin(), ev.jets().cend(), back_inserter(born_momenta), [](fastjet::PseudoJet const & t) { return &t; }); auto bosons = filter_AWZH_bosons(ev.outgoing()); std::vector p_boson_momenta; std::transform(bosons.cbegin(), bosons.cend(), back_inserter(p_boson_momenta), [](Particle const & t) { return &(t.p); }); std::vector boson_momenta; std::transform(bosons.cbegin(), bosons.cend(), back_inserter(boson_momenta), [](Particle const & t) { return t.p; }); // reshuffle all momenta if(q == fastjet::PseudoJet{0, 0, 0, 0}) return {ev.jets(), boson_momenta}; // add bosons to reshuffling if(!bosons.empty()) { born_momenta.insert( born_momenta.end(), p_boson_momenta.begin(), p_boson_momenta.end() ); } auto shuffle_momenta = resummation_jet_momenta(born_momenta, q); if(shuffle_momenta.empty()){ weight_ = 0; return {}; } // additional Jacobian to ensure Born integration over delta gives 1 weight_ *= resummation_jet_weight(born_momenta, q); // take out bosons again if(!bosons.empty()) { std::vector shuffle_bosons; for(size_t i = 0; i < bosons.size(); ++i) { shuffle_bosons.push_back(shuffle_momenta.back()); shuffle_momenta.pop_back(); } std::reverse(shuffle_bosons.begin(), shuffle_bosons.end()); return {shuffle_momenta, shuffle_bosons}; } return {shuffle_momenta, {}}; } std::vector PhaseSpacePoint::distribute_jet_partons( int ng_jets, std::vector const & jets, RNG & ran ){ size_t first_valid_jet = 0; size_t num_valid_jets = jets.size(); const double R_eff = 5./3.*param_.jet_param.def.R(); // if there is an unordered jet too far away from the FKL jets // then extra gluon constituents of the unordered jet would // violate the FKL rapidity ordering if((unob_||qqbarb_) && jets[0].delta_R(jets[1]) > R_eff){ ++first_valid_jet; --num_valid_jets; } else if((unof_||qqbarf_) && jets[jets.size()-1].delta_R(jets[jets.size()-2]) > R_eff){ --num_valid_jets; } std::vector np(jets.size(), 1); for(int i = 0; i < ng_jets; ++i){ ++np[first_valid_jet + ran.flat() * num_valid_jets]; } weight_ *= std::pow(num_valid_jets, ng_jets); return np; } #ifndef NDEBUG namespace { bool tagged_FKL_backward( std::vector const & jet_partons ){ return std::find_if( begin(jet_partons), end(jet_partons), [](fastjet::PseudoJet const & p){ return p.user_index() == UID::backward_fkl; } ) != end(jet_partons); } bool tagged_FKL_forward( std::vector const & jet_partons ){ // the most forward FKL parton is most likely near the end of jet_partons; // start search from there return std::find_if( jet_partons.rbegin(), jet_partons.rend(), [](fastjet::PseudoJet const & p){ return p.user_index() == UID::forward_fkl; } ) != jet_partons.rend(); } } // namespace #endif std::vector PhaseSpacePoint::split( Event const & Born_event, std::vector const & jets, int ng_jets , RNG & ran ){ return split( Born_event, jets, distribute_jet_partons(ng_jets, jets, ran), ran ); } bool PhaseSpacePoint::pass_extremal_cuts( fastjet::PseudoJet const & ext_parton, fastjet::PseudoJet const & jet ) const{ - if(ext_parton.pt() < param_.min_extparton_pt) return false; return (ext_parton - jet).pt()/jet.pt() < param_.soft_pt_regulator; } std::vector PhaseSpacePoint::split( Event const & Born_event, std::vector const & jets, std::vector const & np, RNG & ran ){ assert(! jets.empty()); assert(jets.size() == np.size()); assert(pass_resummation_cuts(jets)); constexpr auto no_such_jet_idx = std::numeric_limits::max(); const size_t most_backward_FKL_idx = is_backward_g_to_h(Born_event)? no_such_jet_idx: // we have backward Higgs instead of FKL jet (0 + unob_ + qqbarb_); // NOLINT const size_t most_forward_FKL_idx = is_forward_g_to_h(Born_event)? no_such_jet_idx: // we have forward Higgs instead of FKL jet (jets.size() - 1 - unof_ - qqbarf_); // NOLINT const size_t qqbar_jet_idx = qqbar_mid_? getBackQuarkJet(Born_event): no_such_jet_idx; auto const & jet = param_.jet_param; const JetSplitter jet_splitter{jet.def, jet.min_pt}; std::vector jet_partons; // randomly distribute jet gluons among jets for(size_t i = 0; i < jets.size(); ++i){ auto split_res = jet_splitter.split(jets[i], np[i], ran); weight_ *= split_res.weight; if(weight_ == 0) return {}; assert( std::all_of( begin(split_res.constituents), end(split_res.constituents), is_jet_parton ) ); const auto first_new_parton = jet_partons.insert( end(jet_partons), begin(split_res.constituents), end(split_res.constituents) ); // mark uno and extremal FKL emissions here so we can check // their position once all emissions are generated // also mark qqbar_mid partons, and apply appropriate pt cut. auto extremal = end(jet_partons); if (i == most_backward_FKL_idx){ //FKL backward emission extremal = std::min_element( first_new_parton, end(jet_partons), rapidity_less{} ); extremal->set_user_index(UID::backward_fkl); } else if(((unob_ || qqbarb_) && i == 0)){ // unordered/qqbarb extremal = std::min_element( first_new_parton, end(jet_partons), rapidity_less{} ); extremal->set_user_index((unob_)?UID::unob:UID::qqbarb); } else if (i == most_forward_FKL_idx){ extremal = std::max_element( first_new_parton, end(jet_partons), rapidity_less{} ); extremal->set_user_index(UID::forward_fkl); } else if(((unof_ || qqbarf_) && i == jets.size() - 1)){ // unordered/qqbarf extremal = std::max_element( first_new_parton, end(jet_partons), rapidity_less{} ); extremal->set_user_index((unof_)?UID::unof:UID::qqbarf); } else if((qqbar_mid_ && i == qqbar_jet_idx)){ extremal = std::max_element( first_new_parton, end(jet_partons), rapidity_less{} ); extremal->set_user_index(UID::qqbar_mid1); } else if((qqbar_mid_ && i == qqbar_jet_idx+1)){ extremal = std::min_element( first_new_parton, end(jet_partons), rapidity_less{} ); extremal->set_user_index(UID::qqbar_mid2); } if( extremal != end(jet_partons) && !pass_extremal_cuts(*extremal, jets[i]) ){ weight_ = 0; return {}; } } assert(is_backward_g_to_h(Born_event) || tagged_FKL_backward(jet_partons)); assert(is_forward_g_to_h(Born_event) || tagged_FKL_forward(jet_partons)); std::sort(begin(jet_partons), end(jet_partons), rapidity_less{}); if( !extremal_ok(Born_event, jet_partons) || !split_preserved_jets(jets, jet_partons) ){ weight_ = 0.; return {}; } return jet_partons; } bool PhaseSpacePoint::extremal_ok( Event const & Born_event, std::vector const & partons ) const{ assert(std::is_sorted(begin(partons), end(partons), rapidity_less{})); if(unob_ && partons.front().user_index() != UID::unob) return false; if(unof_ && partons.back().user_index() != UID::unof) return false; if(qqbarb_ && partons.front().user_index() != UID::qqbarb) return false; if(qqbarf_ && partons.back().user_index() != UID::qqbarf) return false; if(is_backward_g_to_h(Born_event)) { if(partons.front().rapidity() < Born_event.outgoing().front().rapidity()){ return false; } } else if(most_backward_FKL(partons).user_index() != UID::backward_fkl) { return false; } if(is_forward_g_to_h(Born_event)) { return partons.back().rapidity() <= Born_event.outgoing().back().rapidity(); } return most_forward_FKL(partons).user_index() == UID::forward_fkl; } bool PhaseSpacePoint::split_preserved_jets( std::vector const & jets, std::vector const & jet_partons ) const{ assert(std::is_sorted(begin(jets), end(jets), rapidity_less{})); const auto split_jets = cluster_jets(jet_partons); // this can happen if two overlapping jets // are both split into more than one parton if(split_jets.size() != jets.size()) return false; for(size_t i = 0; i < split_jets.size(); ++i){ // this can happen if there are two overlapping jets // and a parton is assigned to the "wrong" jet if(!nearby_ep(jets[i].rapidity(), split_jets[i].rapidity(), 1e-2)){ return false; } } return true; } template Particle const & PhaseSpacePoint::most_backward_FKL( std::vector const & partons ) const{ return partons[0 + unob_ + qqbarb_]; } template Particle const & PhaseSpacePoint::most_forward_FKL( std::vector const & partons ) const{ const size_t idx = partons.size() - 1 - unof_ - qqbarf_; assert(idx < partons.size()); return partons[idx]; } template Particle & PhaseSpacePoint::most_backward_FKL( std::vector & partons ) const{ return partons[0 + unob_ + qqbarb_]; } template Particle & PhaseSpacePoint::most_forward_FKL( std::vector & partons ) const{ const size_t idx = partons.size() - 1 - unof_ - qqbarf_; assert(idx < partons.size()); return partons[idx]; } bool PhaseSpacePoint::contains_idx( fastjet::PseudoJet const & jet, fastjet::PseudoJet const & parton ) const { auto const & constituents = jet.constituents(); const int idx = parton.user_index(); const bool injet = std::find_if( begin(constituents), end(constituents), [idx](fastjet::PseudoJet const & con){return con.user_index() == idx;} ) != end(constituents); const double minpartonjetpt = 1. - param_.soft_pt_regulator; return ((parton.pt()>minpartonjetpt*jet.pt())&&injet); } bool PhaseSpacePoint::jets_ok( Event const & Born_event, std::vector const & partons ) const{ fastjet::ClusterSequence cs(partons, param_.jet_param.def); const auto jets = sorted_by_rapidity(cs.inclusive_jets(param_.jet_param.min_pt)); if(jets.size() != Born_event.jets().size()) return false; int in_jet = 0; for(auto const & jet : jets){ assert(jet.has_constituents()); for(auto && parton: jet.constituents()){ if(is_nonjet_parton(parton)) return false; } in_jet += jet.constituents().size(); } const int expect_in_jet = std::count_if( partons.cbegin(), partons.cend(), is_jet_parton ); if(in_jet != expect_in_jet) return false; // note that PseudoJet::contains does not work here if( !is_backward_g_to_h(Born_event) && !contains_idx(most_backward_FKL(jets), most_backward_FKL(partons)) ) return false; if( !is_forward_g_to_h(Born_event) && !contains_idx(most_forward_FKL(jets), most_forward_FKL(partons)) ) return false; if(unob_ && !contains_idx(jets.front(), partons.front())) return false; if(qqbarb_ && !contains_idx(jets.front(), partons.front())) return false; if(unof_ && !contains_idx(jets.back(), partons.back())) return false; if(qqbarf_ && !contains_idx(jets.back(), partons.back())) return false; #ifndef NDEBUG for(size_t i = 0; i < jets.size(); ++i){ assert(nearby_ep(jets[i].rapidity(), Born_event.jets()[i].rapidity(), 1e-2)); } #endif return true; } void PhaseSpacePoint::reconstruct_incoming( std::array const & Born_incoming ){ std::tie(incoming_[0].p, incoming_[1].p) = incoming_momenta(outgoing_); for(size_t i = 0; i < incoming_.size(); ++i){ incoming_[i].type = Born_incoming[i].type; } assert(momentum_conserved()); } bool PhaseSpacePoint::momentum_conserved() const{ return HEJ::momentum_conserved(*this); } } //namespace HEJ diff --git a/src/YAMLreader.cc b/src/YAMLreader.cc index 2c4c899..6b17ad5 100644 --- a/src/YAMLreader.cc +++ b/src/YAMLreader.cc @@ -1,608 +1,593 @@ /** * \authors The HEJ collaboration (see AUTHORS for details) * \date 2019-2020 * \copyright GPLv2 or later */ #include "HEJ/YAMLreader.hh" #include #include #include #include #include #include #include #include #include "HEJ/ConfigFlags.hh" #include "HEJ/Constants.hh" #include "HEJ/ScaleFunction.hh" #include "HEJ/event_types.hh" #include "HEJ/output_formats.hh" namespace HEJ { class Event; namespace { //! Get YAML tree of supported options /** * The configuration file is checked against this tree of options * in assert_all_options_known. */ YAML::Node const & get_supported_options(){ const static YAML::Node supported = [](){ YAML::Node supported; static const auto opts = { - "trials", "min extparton pt", "max ext soft pt fraction", + "trials", "soft pt regulator", "scales", "scale factors", "max scale ratio", "import scales", "log correction", "event output", "analysis", "analyses", "vev", "regulator parameter", "max events", "off-shell tolerance", "require low pt jet" }; // add subnodes to "supported" - the assigned value is irrelevant for(auto && opt: opts) supported[opt] = ""; for(auto && jet_opt: {"min pt", "algorithm", "R"}){ supported["resummation jets"][jet_opt] = ""; supported["fixed order jets"][jet_opt] = ""; } for(auto && opt: {"mt", "use impact factors", "include bottom", "mb"}){ supported["Higgs coupling"][opt] = ""; } for(auto && opt: {"name", "seed"}){ supported["random generator"][opt] = ""; } for(auto && opt: {"enabled", "nlo order"}){ supported["NLO truncation"][opt] = ""; } for( auto && opt: { "FKL", "unordered", "extremal qqbar", "central qqbar", "non-resummable", "unknown", "invalid" }){ supported["event treatment"][opt] = ""; } for(auto && particle_type: {"Higgs", "W", "Z"}){ for(auto && particle_opt: {"mass", "width"}){ supported["particle properties"][particle_type][particle_opt] = ""; } } for(auto && opt: {"type", "trials", "max deviation"}){ supported["unweight"][opt] = ""; } return supported; }(); return supported; } fastjet::JetAlgorithm to_JetAlgorithm(std::string const & algo){ using namespace fastjet; static const std::map known = { {"kt", kt_algorithm}, {"cambridge", cambridge_algorithm}, {"antikt", antikt_algorithm}, {"cambridge for passive", cambridge_for_passive_algorithm}, {"plugin", plugin_algorithm} }; const auto res = known.find(algo); if(res == known.end()){ throw std::invalid_argument("Unknown jet algorithm \"" + algo + "\""); } return res->second; } EventTreatment to_EventTreatment(std::string const & name){ static const std::map known = { {"reweight", EventTreatment::reweight}, {"keep", EventTreatment::keep}, {"discard", EventTreatment::discard}, {"abort", EventTreatment::abort} }; const auto res = known.find(name); if(res == known.end()){ throw std::invalid_argument("Unknown event treatment \"" + name + "\""); } return res->second; } WeightType to_weight_type(std::string const & setting){ if(setting == "weighted") return WeightType::weighted; if(setting =="resummation") return WeightType::unweighted_resum; if(setting =="partial") return WeightType::partially_unweighted; throw std::invalid_argument{"Unknown weight type \"" + setting + "\""}; } } // namespace namespace detail{ void set_from_yaml(fastjet::JetAlgorithm & setting, YAML::Node const & yaml){ setting = to_JetAlgorithm(yaml.as()); } void set_from_yaml(EventTreatment & setting, YAML::Node const & yaml){ setting = to_EventTreatment(yaml.as()); } void set_from_yaml(ParticleID & setting, YAML::Node const & yaml){ setting = to_ParticleID(yaml.as()); } void set_from_yaml(WeightType & setting, YAML::Node const & yaml){ setting = to_weight_type(yaml.as()); } } // namespace detail JetParameters get_jet_parameters( YAML::Node const & node, std::string const & entry ){ assert(node); JetParameters result; fastjet::JetAlgorithm jet_algo = fastjet::antikt_algorithm; double R = NAN; set_from_yaml_if_defined(jet_algo, node, entry, "algorithm"); set_from_yaml(R, node, entry, "R"); result.def = fastjet::JetDefinition{jet_algo, R}; set_from_yaml(result.min_pt, node, entry, "min pt"); return result; } RNGConfig to_RNGConfig( YAML::Node const & node, std::string const & entry ){ assert(node); RNGConfig result; set_from_yaml(result.name, node, entry, "name"); set_from_yaml_if_defined(result.seed, node, entry, "seed"); return result; } NLOConfig to_NLOConfig( YAML::Node const & node, std::string const & entry ){ assert(node); NLOConfig result; set_from_yaml_if_defined(result.enabled, node, entry, "enabled"); set_from_yaml_if_defined(result.nj, node, entry, "nlo order"); return result; } ParticleProperties get_particle_properties( YAML::Node const & node, std::string const & entry, std::string const & boson ){ ParticleProperties result{}; set_from_yaml(result.mass, node, entry, boson, "mass"); set_from_yaml(result.width, node, entry, boson, "width"); return result; } EWConstants get_ew_parameters(YAML::Node const & node){ EWConstants result; double vev = NAN; set_from_yaml(vev, node, "vev"); result.set_vevWZH(vev, get_particle_properties(node, "particle properties", "W"), get_particle_properties(node, "particle properties", "Z"), get_particle_properties(node, "particle properties", "Higgs") ); return result; } HiggsCouplingSettings get_Higgs_coupling( YAML::Node const & node, std::string const & entry ){ assert(node); static constexpr double mt_max = 2e4; #ifndef HEJ_BUILD_WITH_QCDLOOP if(node[entry].IsDefined()){ throw std::invalid_argument{ "Higgs coupling settings require building HEJ 2 " "with QCDloop support" }; } #endif HiggsCouplingSettings settings; set_from_yaml_if_defined(settings.mt, node, entry, "mt"); set_from_yaml_if_defined(settings.mb, node, entry, "mb"); set_from_yaml_if_defined(settings.include_bottom, node, entry, "include bottom"); set_from_yaml_if_defined(settings.use_impact_factors, node, entry, "use impact factors"); if(settings.use_impact_factors){ if(settings.mt != std::numeric_limits::infinity()){ throw std::invalid_argument{ "Conflicting settings: " "impact factors may only be used in the infinite top mass limit" }; } } else{ // huge values of the top mass are numerically unstable settings.mt = std::min(settings.mt, mt_max); } return settings; } FileFormat to_FileFormat(std::string const & name){ static const std::map known = { {"Les Houches", FileFormat::Les_Houches}, {"HepMC", FileFormat::HepMC}, {"HepMC2", FileFormat::HepMC2}, {"HepMC3", FileFormat::HepMC3}, {"HDF5", FileFormat::HDF5} }; const auto res = known.find(name); if(res == known.end()){ throw std::invalid_argument("Unknown file format \"" + name + "\""); } return res->second; } std::string extract_suffix(std::string const & filename){ size_t separator = filename.rfind('.'); if(separator == std::string::npos) return {}; return filename.substr(separator + 1); } FileFormat format_from_suffix(std::string const & filename){ const std::string suffix = extract_suffix(filename); if(suffix == "lhe") return FileFormat::Les_Houches; if(suffix == "hepmc") return FileFormat::HepMC; if(suffix == "hepmc3") return FileFormat::HepMC3; if(suffix == "hepmc2") return FileFormat::HepMC2; if(suffix == "hdf5") return FileFormat::HDF5; throw std::invalid_argument{ "Can't determine format for output file \"" + filename + "\"" }; } void assert_all_options_known( YAML::Node const & conf, YAML::Node const & supported ){ if(!conf.IsMap()) return; if(!supported.IsMap()) throw invalid_type{"must not have sub-entries"}; for(auto const & entry: conf){ const auto name = entry.first.as(); if(! supported[name]) throw unknown_option{name}; /* check sub-options, e.g. 'resummation jets: min pt' * we don't check analyses sub-options * those depend on the analysis being used and should be checked there * similar for "import scales" */ if(name != "analyses" && name != "analysis" && name != "import scales"){ try{ assert_all_options_known(conf[name], supported[name]); } catch(unknown_option const & ex){ throw unknown_option{name + ": " + ex.what()}; } catch(invalid_type const & ex){ throw invalid_type{name + ": " + ex.what()}; } } } } } // namespace HEJ namespace YAML { Node convert::encode(HEJ::OutputFile const & outfile) { Node node; node[to_string(outfile.format)] = outfile.name; return node; } bool convert::decode(Node const & node, HEJ::OutputFile & out) { switch(node.Type()){ case NodeType::Map: { YAML::const_iterator it = node.begin(); out.format = HEJ::to_FileFormat(it->first.as()); out.name = it->second.as(); return true; } case NodeType::Scalar: out.name = node.as(); out.format = HEJ::format_from_suffix(out.name); return true; default: return false; } } } // namespace YAML namespace HEJ { namespace detail{ void set_from_yaml(OutputFile & setting, YAML::Node const & yaml){ setting = yaml.as(); } } namespace { void update_fixed_order_jet_parameters( JetParameters & fixed_order_jets, YAML::Node const & yaml ){ if(!yaml["fixed order jets"]) return; set_from_yaml_if_defined( fixed_order_jets.min_pt, yaml, "fixed order jets", "min pt" ); fastjet::JetAlgorithm algo = fixed_order_jets.def.jet_algorithm(); set_from_yaml_if_defined(algo, yaml, "fixed order jets", "algorithm"); double R = fixed_order_jets.def.R(); set_from_yaml_if_defined(R, yaml, "fixed order jets", "R"); fixed_order_jets.def = fastjet::JetDefinition{algo, R}; } // like std::stod, but throw if not the whole string can be converted double to_double(std::string const & str){ std::size_t pos = 0; const double result = std::stod(str, &pos); if(pos < str.size()){ throw std::invalid_argument(str + " is not a valid double value"); } return result; } using EventScale = double (*)(Event const &); void import_scale_functions( std::string const & file, std::vector const & scale_names, std::unordered_map & known ) { void * handle = dlopen(file.c_str(), RTLD_NOW); char * error = dlerror(); if(error != nullptr) throw std::runtime_error{error}; for(auto const & scale: scale_names) { void * sym = dlsym(handle, scale.c_str()); error = dlerror(); if(error != nullptr) throw std::runtime_error{error}; known.emplace(scale, reinterpret_cast(sym)); // NOLINT } } auto get_scale_map( YAML::Node const & yaml ) { std::unordered_map scale_map; scale_map.emplace("H_T", H_T); scale_map.emplace("max jet pperp", max_jet_pt); scale_map.emplace("jet invariant mass", jet_invariant_mass); scale_map.emplace("m_j1j2", m_j1j2); if(yaml["import scales"].IsDefined()) { if(! yaml["import scales"].IsMap()) { throw invalid_type{"Entry 'import scales' is not a map"}; } for(auto const & import: yaml["import scales"]) { const auto file = import.first.as(); const auto scale_names = import.second.IsSequence() ?import.second.as>() :std::vector{import.second.as()}; import_scale_functions(file, scale_names, scale_map); } } return scale_map; } // simple (as in non-composite) scale functions /** * An example for a simple scale function would be H_T, * H_T/2 is then composite (take H_T and then divide by 2) */ ScaleFunction parse_simple_ScaleFunction( std::string const & scale_fun, std::unordered_map const & known ) { assert( scale_fun.empty() || (!std::isspace(scale_fun.front()) && !std::isspace(scale_fun.back())) ); const auto it = known.find(scale_fun); if(it != end(known)) return {it->first, it->second}; try{ const double scale = to_double(scale_fun); return {scale_fun, FixedScale{scale}}; } catch(std::invalid_argument const &){} throw std::invalid_argument{"Unknown scale choice: \"" + scale_fun + "\""}; } std::string trim_front(std::string const & str){ const auto new_begin = std::find_if( begin(str), end(str), [](char c){ return std::isspace(c) == 0; } ); return std::string(new_begin, end(str)); } std::string trim_back(std::string str){ size_t pos = str.size() - 1; // use guaranteed wrap-around behaviour to check whether we have // traversed the whole string for(; pos < str.size() && std::isspace(str[pos]); --pos) {} str.resize(pos + 1); // note that pos + 1 can be 0 return str; } ScaleFunction parse_ScaleFunction( std::string const & scale_fun, std::unordered_map const & known ){ assert( scale_fun.empty() || (!std::isspace(scale_fun.front()) && !std::isspace(scale_fun.back())) ); // parse from right to left => a/b/c gives (a/b)/c const size_t delim = scale_fun.find_last_of("*/"); if(delim == std::string::npos){ return parse_simple_ScaleFunction(scale_fun, known); } const std::string first = trim_back(std::string{scale_fun, 0, delim}); const std::string second = trim_front(std::string{scale_fun, delim+1}); if(scale_fun[delim] == '/'){ return parse_ScaleFunction(first, known) / parse_ScaleFunction(second, known); } assert(scale_fun[delim] == '*'); return parse_ScaleFunction(first, known) * parse_ScaleFunction(second, known); } EventTreatMap get_event_treatment( YAML::Node const & node, std::string const & entry ){ using namespace event_type; EventTreatMap treat { {FKL, EventTreatment::discard}, {unob, EventTreatment::discard}, {unof, EventTreatment::discard}, {qqbar_exb, EventTreatment::discard}, {qqbar_exf, EventTreatment::discard}, {qqbar_mid, EventTreatment::discard}, {non_resummable, EventTreatment::discard}, {unknown, EventTreatment::abort}, {invalid, EventTreatment::abort} }; set_from_yaml(treat.at(FKL), node, entry, "FKL"); set_from_yaml(treat.at(unob), node, entry, "unordered"); treat.at(unof) = treat.at(unob); set_from_yaml(treat.at(qqbar_exb), node, entry, "extremal qqbar"); treat.at(qqbar_exf) = treat.at(qqbar_exb); set_from_yaml(treat.at(qqbar_mid), node, entry, "central qqbar"); set_from_yaml(treat.at(non_resummable), node, entry, "non-resummable"); set_from_yaml_if_defined(treat.at(unknown), node, entry, "unknown"); set_from_yaml_if_defined(treat.at(invalid), node, entry, "invalid"); for(auto type: {non_resummable, unknown, invalid}) { if(treat[type] == EventTreatment::reweight){ throw std::invalid_argument{"Cannot reweight " + name(type) + " events"}; } } return treat; } Config to_Config(YAML::Node const & yaml){ try{ assert_all_options_known(yaml, get_supported_options()); } catch(unknown_option const & ex){ throw unknown_option{std::string{"Unknown option '"} + ex.what() + "'"}; } Config config; config.resummation_jets = get_jet_parameters(yaml, "resummation jets"); config.fixed_order_jets = config.resummation_jets; update_fixed_order_jet_parameters(config.fixed_order_jets, yaml); - set_from_yaml_if_defined(config.min_extparton_pt, yaml, "min extparton pt"); - if(config.min_extparton_pt!=0) - std::cerr << "WARNING: \"min extparton pt\" is deprecated." - << " Please remove this entry or set \"soft pt regulator\" instead.\n"; - set_from_yaml_if_defined( - config.max_ext_soft_pt_fraction, yaml, "max ext soft pt fraction" - ); - if(config.max_ext_soft_pt_fraction){ - std::cerr << "WARNING: \"max ext soft pt fraction\" is deprecated." - << " Please remove this entry or set \"soft pt regulator\" instead.\n"; - config.soft_pt_regulator = *config.max_ext_soft_pt_fraction; - } else { - set_from_yaml_if_defined( - config.soft_pt_regulator, yaml, "soft pt regulator" - ); - } + set_from_yaml_if_defined(config.soft_pt_regulator, yaml, "soft pt regulator"); // Sets the standard value, then changes this if defined config.regulator_lambda=CLAMBDA; set_from_yaml_if_defined(config.regulator_lambda, yaml, "regulator parameter"); set_from_yaml_if_defined(config.max_events, yaml, "max events"); set_from_yaml(config.trials, yaml, "trials"); config.weight_type = WeightType::weighted; set_from_yaml_if_defined(config.weight_type, yaml, "unweight", "type"); if(config.weight_type == WeightType::partially_unweighted) { config.unweight_config = PartialUnweightConfig{}; set_from_yaml( config.unweight_config->trials, yaml, "unweight", "trials" ); set_from_yaml( config.unweight_config->max_dev, yaml, "unweight", "max deviation" ); } else if(yaml["unweight"].IsDefined()) { for(auto && opt: {"trials", "max deviation"}) { if(yaml["unweight"][opt].IsDefined()) { throw std::invalid_argument{ "'unweight: " + std::string{opt} + "' " "is only supported if 'unweight: type' is set to 'partial'" }; } } } set_from_yaml(config.log_correction, yaml, "log correction"); config.treat = get_event_treatment(yaml, "event treatment"); set_from_yaml_if_defined(config.output, yaml, "event output"); config.rng = to_RNGConfig(yaml, "random generator"); set_from_yaml_if_defined(config.lowpt, yaml, "require low pt jet"); set_from_yaml_if_defined(config.analyses_parameters, yaml, "analyses"); if(yaml["analysis"].IsDefined()){ std::cerr << "WARNING: Configuration entry 'analysis' is deprecated. " " Use 'analyses' instead.\n"; set_from_yaml(config.analysis_parameters, yaml, "analysis"); if(!config.analysis_parameters.IsNull()){ config.analyses_parameters.push_back(config.analysis_parameters); } } config.scales = to_ScaleConfig(yaml); config.ew_parameters = get_ew_parameters(yaml); config.Higgs_coupling = get_Higgs_coupling(yaml, "Higgs coupling"); //HEJ@NLO Truncation config.nlo = to_NLOConfig(yaml, "NLO truncation"); set_from_yaml_if_defined( config.off_shell_tolerance, yaml, "off-shell tolerance" ); return config; } } // namespace ScaleConfig to_ScaleConfig(YAML::Node const & yaml){ ScaleConfig config; auto scale_funs = get_scale_map(yaml); std::vector scales; set_from_yaml(scales, yaml, "scales"); config.base.reserve(scales.size()); std::transform( begin(scales), end(scales), std::back_inserter(config.base), [scale_funs](auto const & entry){ return parse_ScaleFunction(entry, scale_funs); } ); set_from_yaml_if_defined(config.factors, yaml, "scale factors"); config.max_ratio = std::numeric_limits::infinity(); set_from_yaml_if_defined(config.max_ratio, yaml, "max scale ratio"); return config; } Config load_config(std::string const & config_file){ try{ return to_Config(YAML::LoadFile(config_file)); } catch(...){ std::cerr << "Error reading " << config_file << ":\n "; throw; } } } // namespace HEJ