diff --git a/include/HEJ/Event.hh b/include/HEJ/Event.hh
index 7d828d8..ebafcad 100644
--- a/include/HEJ/Event.hh
+++ b/include/HEJ/Event.hh
@@ -1,351 +1,369 @@
/** \file
* \brief Declares the Event class and helpers
*
* \authors The HEJ collaboration (see AUTHORS for details)
* \date 2019
* \copyright GPLv2 or later
*/
#pragma once
#include <array>
#include <memory>
#include <string>
#include <unordered_map>
#include <vector>
#include "boost/iterator/filter_iterator.hpp"
#include "fastjet/ClusterSequence.hh"
#include "HEJ/event_types.hh"
#include "HEJ/Parameters.hh"
#include "HEJ/Particle.hh"
#include "HEJ/RNG.hh"
namespace LHEF {
class HEPEUP;
class HEPRUP;
}
namespace fastjet {
class JetDefinition;
}
namespace HEJ {
struct UnclusteredEvent;
/** @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<Particle>::const_iterator
>;
//! Reverse Iterator over partons
using ConstReversePartonIterator = std::reverse_iterator<
ConstPartonIterator>;
//! No default Constructor
Event() = delete;
//! Event Constructor adding jet clustering to an unclustered event
//! @deprecated UnclusteredEvent will be replaced by EventData in HEJ 2.2.0
[[deprecated("UnclusteredEvent will be replaced by EventData")]]
Event(
UnclusteredEvent const & ev,
fastjet::JetDefinition const & jet_def, double min_jet_pt
);
//! @name Particle Access
//! @{
//! Incoming particles
std::array<Particle, 2> const & incoming() const{
return incoming_;
}
//! Outgoing particles
std::vector<Particle> 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<size_t, std::vector<Particle>> const & decays() const{
return decays_;
}
//! The jets formed by the outgoing partons, sorted in rapidity
std::vector<fastjet::PseudoJet> const & jets() const{
return jets_;
}
//! @}
//! @name Weight variations
//! @{
//! All chosen parameter, i.e. scale choices (const version)
Parameters<EventParameters> const & parameters() const{
return parameters_;
}
//! All chosen parameter, i.e. scale choices
Parameters<EventParameters> & 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<EventParameters> const & variations() const{
return parameters_.variations;
}
//! Parameter (scale) variations
std::vector<EventParameters> & variations(){
return parameters_.variations;
}
//! Parameter (scale) variation (const version)
/**
* @param i Index of the requested variation
*/
EventParameters const & variations(size_t i) const{
return parameters_.variations.at(i);
}
//! Parameter (scale) variation
/**
* @param i Index of the requested variation
*/
EventParameters & variations(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<int> particle_jet_indices(
std::vector<fastjet::PseudoJet> const & jets
) const {
return cs_.particle_jet_indices(jets);
}
//! particle_jet_indices() of the Event jets()
std::vector<int> 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(HEJ::RNG &);
//! 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
* `max_ext_soft_pt_fraction` of the total jet \f$ p_\perp \f$
*
* @note This is true for any resummed stated produced by the
* EventReweighter or any \ref is_resummable() "resummable" Leading
* Order state.
*
* @param max_ext_soft_pt_fraction Maximum transverse momentum fraction from
* soft radiation in extremal jets
* @param min_extparton_pt Absolute minimal \f$ p_\perp \f$,
* \b deprecated use max_ext_soft_pt_fraction
* instead
* @return True if this state could have been produced by HEJ
*/
bool valid_hej_state(
double max_ext_soft_pt_fraction, double min_extparton_pt = 0.) 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<Particle, 2> && incoming,
std::vector<Particle> && outgoing,
std::unordered_map<size_t, std::vector<Particle>> && decays,
Parameters<EventParameters> && parameters,
fastjet::JetDefinition const & jet_def,
double const min_jet_pt
);
+ //! Iterator over partons (non-const)
+ using PartonIterator = boost::filter_iterator<
+ bool (*)(Particle const &),
+ std::vector<Particle>::iterator
+ >;
+ //! Reverse Iterator over partons (non-const)
+ using ReversePartonIterator = std::reverse_iterator<PartonIterator>;
+
+ //! 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<Particle, 2> incoming_;
std::vector<Particle> outgoing_;
std::unordered_map<size_t, std::vector<Particle>> decays_;
std::vector<fastjet::PseudoJet> jets_;
Parameters<EventParameters> parameters_;
fastjet::ClusterSequence cs_;
double min_jet_pt_;
event_type::EventType type_;
}; // end class Event
//! 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<Particle, 2> incoming,
std::vector<Particle> outgoing,
std::unordered_map<size_t, std::vector<Particle>> decays,
Parameters<EventParameters> 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 const 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();
//! Incoming particles
std::array<Particle, 2> incoming;
//! Outcoing particles
std::vector<Particle> outgoing;
//! Particle decays in the format {outgoing index, decay products}
std::unordered_map<size_t, std::vector<Particle>> decays;
//! Parameters, e.g. scale or inital weight
Parameters<EventParameters> parameters;
}; // end class EventData
//! Print Event
std::ostream& operator<<(std::ostream & os, Event const & ev);
//! Square of the partonic centre-of-mass energy \f$\hat{s}\f$
double shat(Event const & ev);
//! Convert an event to a LHEF::HEPEUP
LHEF::HEPEUP to_HEPEUP(Event const & event, LHEF::HEPRUP *);
// put deprecated warning at the end, so don't get the warning inside Event.hh,
// additionally doxygen can not identify [[deprecated]] correctly
struct [[deprecated("UnclusteredEvent will be replaced by EventData")]]
UnclusteredEvent;
//! An event before jet clustering
//! @deprecated UnclusteredEvent will be replaced by EventData in HEJ 2.2.0
struct UnclusteredEvent{
//! Default Constructor
UnclusteredEvent() = default;
//! Constructor from LesHouches event information
UnclusteredEvent(LHEF::HEPEUP const & hepeup);
std::array<Particle, 2> incoming; /**< Incoming Particles */
std::vector<Particle> outgoing; /**< Outgoing Particles */
//! Particle decays in the format {outgoing index, decay products}
std::unordered_map<size_t, std::vector<Particle>> decays;
//! Central parameter (e.g. scale) choice
EventParameters central;
std::vector<EventParameters> variations; /**< For parameter variation */
};
} // namespace HEJ
diff --git a/src/Event.cc b/src/Event.cc
index 400b2e7..9bed9d5 100644
--- a/src/Event.cc
+++ b/src/Event.cc
@@ -1,1099 +1,1137 @@
/**
* \authors The HEJ collaboration (see AUTHORS for details)
* \date 2019
* \copyright GPLv2 or later
*/
#include "HEJ/Event.hh"
#include <algorithm>
#include <assert.h>
#include <iterator>
#include <numeric>
#include <unordered_set>
#include <utility>
#include "LHEF/LHEF.h"
#include "fastjet/JetDefinition.hh"
#include "HEJ/Constants.hh"
#include "HEJ/exceptions.hh"
#include "HEJ/PDG_codes.hh"
namespace HEJ{
namespace {
constexpr int status_in = -1;
constexpr int status_decayed = 2;
constexpr int status_out = 1;
//! true if leptonic W decay
bool valid_W_decay( int const w_type, // sign of W
std::vector<Particle> const & decays
){
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_type ) // correct charge
return false;
// leptonic decay (only check first, second follows from pidsum)
if( w_type == 1 ) // W+
return is_antilepton(decays[0]) || is_neutrino(decays[0]);
// W-
return is_lepton(decays[0]) || is_antineutrino(decays[0]);
}
/// @name helper functions to determine event type
//@{
/**
* \brief check if final state valid for HEJ
*
* check if there is at most one photon, W, H, Z in the final state
* and all the rest are quarks or gluons
*/
bool final_state_ok(Event const & ev){
std::vector<Particle> const & outgoing = ev.outgoing();
if(ev.decays().size() > 1) // at most one decay
return false;
bool has_AWZH_boson = false;
for( size_t i=0; i<outgoing.size(); ++i ){
auto const & out{ outgoing[i] };
if(is_AWZH_boson(out.type)){
// at most one boson
if(has_AWZH_boson) return false;
has_AWZH_boson = true;
// valid decay for W
if(std::abs(out.type) == ParticleID::Wp){
// exactly 1 decay of W
if( ev.decays().size() != 1 || ev.decays().cbegin()->first != i )
return false;
if( !valid_W_decay(out.type>0?+1:-1, ev.decays().cbegin()->second) )
return false;
}
}
else if(! is_parton(out.type)) return false;
}
return true;
}
/**
* returns all EventTypes implemented in HEJ
*/
size_t implemented_types(std::vector<Particle> const & bosons){
using namespace event_type;
if(bosons.empty()) return FKL | unob | unof | qqxexb | qqxexf | qqxmid;
if(bosons.size()>1) return non_resummable; // multi boson
switch (bosons[0].type) {
case ParticleID::Wp:
case ParticleID::Wm:
return FKL | unob | unof | qqxexb | qqxexf | qqxmid;
case ParticleID::h:
return FKL | unob | unof;
default:
return non_resummable;
}
}
/**
* \brief function which determines if type change is consistent with Wp emission.
* @param in incoming Particle id
* @param out outgoing Particle id
* @param qqx Current both incoming/both outgoing?
*
* \see is_Wm_Change
*/
bool is_Wp_Change(ParticleID in, ParticleID out, bool qqx){
if(!qqx && (in==-1 || in== 2 || in==-3 || in== 4)) return out== (in-1);
if( qqx && (in== 1 || in==-2 || in== 3 || in==-4)) 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 qqx Current both incoming/both outgoing?
*
* Ensures that change type of quark line is possible by a flavour changing
* Wm emission. Allows checking of qqx currents also.
*/
bool is_Wm_Change(ParticleID in, ParticleID out, bool qqx){
if(!qqx && (in== 1 || in==-2 || in== 3 || in==-4)) return out== (in+1);
if( qqx && (in==-1 || in== 2 || in==-3 || in== 4)) 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 qqx Current both incoming/outgoing?
*/
bool no_flavour_change(ParticleID in, ParticleID out, bool qqx){
const int qqxCurrent = qqx?-1:1;
if(abs(in)<=6 || in==pid::gluon) return (in==out*qqxCurrent);
else return false;
}
bool has_2_jets(Event const & event){
return event.jets().size() >= 2;
}
/**
* \brief check if we have a valid Impact factor
* @param in incoming Particle
* @param out outgoing Particle
* @param qqx 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 qqx, int & W_change
){
if( no_flavour_change(in, out, qqx) ){
return true;
}
if( is_Wp_Change(in, out, qqx) ) {
W_change+=1;
return true;
}
if( is_Wm_Change(in, out, qqx) ) {
W_change-=1;
return true;
}
return false;
}
//! 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<class OutIterator>
size_t possible_impact_factors(
ParticleID incoming_id, // incoming
OutIterator & begin_out, OutIterator const & end_out, // outgoing
int & W_change, std::vector<Particle> const & boson,
bool const backward // backward?
){
using namespace event_type;
assert(boson.size() < 2);
// keep track of all states that we don't test
size_t not_tested = qqxmid;
if(backward)
not_tested |= unof | qqxexf;
else
not_tested |= unob | qqxexb;
// Is this LL current?
if( is_valid_impact_factor(incoming_id, begin_out->type, false, W_change) ){
++begin_out;
return not_tested | FKL;
}
// or NLL current?
// -> needs two partons in two different jets
if( std::distance(begin_out, end_out)>=2
){
// Is this unordered emisson?
if( incoming_id!=pid::gluon && begin_out->type==pid::gluon ){
if( is_valid_impact_factor(
incoming_id, (begin_out+1)->type, false, W_change )
){
// veto Higgs inside uno
assert((begin_out+1)<end_out);
if( !boson.empty() && boson.front().type == ParticleID::h
){
if( (backward && boson.front().rapidity() < (begin_out+1)->rapidity())
||(!backward && boson.front().rapidity() > (begin_out+1)->rapidity()))
return non_resummable;
}
begin_out+=2;
return not_tested | (backward?unob:unof);
}
}
// Is this QQbar?
else if( incoming_id==pid::gluon ){
if( is_valid_impact_factor(
begin_out->type, (begin_out+1)->type, true, W_change )
){
// veto Higgs inside qqx
assert((begin_out+1)<end_out);
if( !boson.empty() && boson.front().type == ParticleID::h
){
if( (backward && boson.front().rapidity() < (begin_out+1)->rapidity())
||(!backward && boson.front().rapidity() > (begin_out+1)->rapidity()))
return non_resummable;
}
begin_out+=2;
return not_tested | (backward?qqxexb:qqxexf);
}
}
}
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<class OutIterator>
size_t possible_central(
OutIterator & begin_out, OutIterator const & end_out,
int & W_change, std::vector<Particle> const & boson
){
using namespace event_type;
assert(boson.size() < 2);
// 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 = unob | unof
| qqxexb | qqxexf;
// Find the first non-gluon/non-FKL
while( (begin_out->type==pid::gluon) && (begin_out<end_out) ){
++begin_out;
}
// end of chain -> FKL
if( begin_out==end_out ){
return possible | FKL;
}
// is this a qqbar-pair?
// needs two partons in two separate jets
if( is_valid_impact_factor(
begin_out->type, (begin_out+1)->type, true, W_change )
){
// veto Higgs inside qqx
if( !boson.empty() && boson.front().type == ParticleID::h
&& boson.front().rapidity() > begin_out->rapidity()
&& boson.front().rapidity() < (begin_out+1)->rapidity()
){
return non_resummable;
}
begin_out+=2;
// remaining chain should be pure gluon/FKL
for(; begin_out<end_out; ++begin_out){
if(begin_out->type != pid::gluon) return non_resummable;
}
return possible | qqxmid;
}
return non_resummable;
}
/**
* \brief Checks for all event types
* @param ev Event
* @returns Event Type
*
*/
event_type::EventType classify(Event const & ev){
using namespace event_type;
if(! has_2_jets(ev))
return no_2_jets;
// currently we can't handle multiple boson states in the ME. So they are
// considered "bad_final_state" even though the "classify" could work with
// them.
if(! final_state_ok(ev))
return bad_final_state;
// initialise variables
auto const & in = ev.incoming();
auto const & out = filter_partons(ev.outgoing());
assert(std::distance(begin(in), end(in)) == 2);
assert(out.size() >= 2);
assert(std::distance(begin(out), end(out)) >= 2);
assert(std::is_sorted(begin(out), end(out), rapidity_less{}));
auto const boson{ filter_AWZH_bosons(ev.outgoing()) };
// we only allow one boson through final_state_ok
assert(boson.size()<=1);
// keep track of potential W couplings, at the end the sum should be 0
int remaining_Wp = 0;
int remaining_Wm = 0;
if(!boson.empty() && abs(boson.front().type) == ParticleID::Wp ){
if(boson.front().type>0) ++remaining_Wp;
else ++remaining_Wm;
}
int W_change = 0;
// range for current checks
auto begin_out{out.cbegin()};
auto end_out{out.crbegin()};
size_t final_type = ~(no_2_jets | bad_final_state);
// check forward impact factor
final_type &= possible_impact_factors(
in.front().type,
begin_out, end_out.base(),
W_change, boson, 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;
W_change = 0;
// check backward impact factor
final_type &= possible_impact_factors(
in.back().type,
end_out, std::make_reverse_iterator(begin_out),
W_change, boson, 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;
W_change = 0;
// check central emissions
final_type &= possible_central(
begin_out, end_out.base(), W_change, boson );
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(boson)) != 0 )
return non_resummable;
return static_cast<EventType>(final_type);
}
//@}
Particle extract_particle(LHEF::HEPEUP const & hepeup, size_t i){
const ParticleID id = static_cast<ParticleID>(hepeup.IDUP[i]);
const fastjet::PseudoJet momentum{
hepeup.PUP[i][0], hepeup.PUP[i][1],
hepeup.PUP[i][2], hepeup.PUP[i][3]
};
if(is_parton(id))
return Particle{ id, std::move(momentum), hepeup.ICOLUP[i] };
return Particle{ id, std::move(momentum), {} };
}
bool is_decay_product(std::pair<int, int> const & mothers){
if(mothers.first == 0) return false;
return mothers.second == 0 || mothers.first == mothers.second;
}
} // namespace anonymous
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] == 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));
}
}
Event::Event(
UnclusteredEvent const & ev,
fastjet::JetDefinition const & jet_def, double const min_jet_pt
):
Event( Event::EventData{
ev.incoming, ev.outgoing, ev.decays,
Parameters<EventParameters>{ev.central, ev.variations}
}.cluster(jet_def, min_jet_pt) )
{}
//! @TODO remove in HEJ 2.2.0
UnclusteredEvent::UnclusteredEvent(LHEF::HEPEUP const & hepeup){
Event::EventData const evData{hepeup};
incoming = evData.incoming;
outgoing = evData.outgoing;
decays = evData.decays;
central = evData.parameters.central;
variations = evData.parameters.variations;
}
void Event::EventData::sort(){
// sort particles
std::sort(
begin(incoming), end(incoming),
[](Particle o1, Particle o2){return o1.p.pz()<o2.p.pz();}
);
auto old_outgoing = std::move(outgoing);
std::vector<size_t> 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; i<idx.size(); ++i) {
auto decay = old_decays.find(idx[i]);
if(decay != old_decays.end())
decays.emplace(i, std::move(decay->second));
}
assert(old_decays.size() == decays.size());
}
}
namespace {
Particle reconstruct_boson(std::vector<Particle> const & leptons) {
Particle decayed_boson;
decayed_boson.p = leptons[0].p + leptons[1].p;
const int pidsum = leptons[0].type + leptons[1].type;
if(pidsum == +1) {
assert(is_antilepton(leptons[0]));
if(is_antineutrino(leptons[0])) {
throw not_implemented{"lepton-flavour violating final state"};
}
assert(is_neutrino(leptons[1]));
// charged antilepton + neutrino means we had a W+
decayed_boson.type = pid::Wp;
}
else if(pidsum == -1) {
assert(is_antilepton(leptons[0]));
if(is_neutrino(leptons[1])) {
throw not_implemented{"lepton-flavour violating final state"};
}
assert(is_antineutrino(leptons[0]));
// charged lepton + antineutrino means we had a W-
decayed_boson.type = pid::Wm;
}
else {
throw not_implemented{
"final state with leptons "
+ name(leptons[0].type)
+ " and "
+ name(leptons[1].type)
};
}
return decayed_boson;
}
}
void Event::EventData::reconstruct_intermediate() {
const auto begin_leptons = std::partition(
begin(outgoing), end(outgoing),
[](Particle const & p) {return !is_anylepton(p);}
);
if(begin_leptons == end(outgoing)) return;
assert(is_anylepton(*begin_leptons));
std::vector<Particle> leptons(begin_leptons, end(outgoing));
outgoing.erase(begin_leptons, end(outgoing));
if(leptons.size() != 2) {
throw not_implemented{"Final states with one or more than two leptons"};
}
std::sort(
begin(leptons), end(leptons),
[](Particle const & p0, Particle const & p1) {
return p0.type < p1.type;
}
);
outgoing.emplace_back(reconstruct_boson(leptons));
decays.emplace(outgoing.size()-1, std::move(leptons));
}
Event Event::EventData::cluster(
fastjet::JetDefinition const & jet_def, double const min_jet_pt
){
sort();
Event ev{ std::move(incoming), std::move(outgoing), std::move(decays),
std::move(parameters),
jet_def, min_jet_pt
};
assert(std::is_sorted(begin(ev.outgoing_), end(ev.outgoing_),
rapidity_less{}));
ev.type_ = classify(ev);
return ev;
}
Event::Event(
std::array<Particle, 2> && incoming,
std::vector<Particle> && outgoing,
std::unordered_map<size_t, std::vector<Particle>> && decays,
Parameters<EventParameters> && 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_));
}
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 a colour line & update the line
//! returns false if connection not possible
bool can_connect(Particle const & part, Colour & line_colour){
if( line_colour.first == part.colour->second ){
line_colour.first = part.colour->first;
return true;
}
if( line_colour.second == part.colour->first ){
line_colour.second = part.colour->second;
return true;
}
return false;
}
}
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);
- for(auto it_part = outgoing().cbegin(); it_part<outgoing().cend(); ++it_part){
- // reasonable colour
- if(!correct_colour(*it_part))
- return false;
- if(!is_parton(*it_part)) // skip colour neutral particles
- continue;
+ // 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){
// if possible connect to line (t-channel)
if( !can_connect(*it_part, line_colour) ){
// else try u-channel
switch (type()) {
case event_type::FKL:
return false;
case event_type::unob:
case event_type::qqxexb: {
// u-channel only allowed at impact factor
- if(std::distance(outgoing().cbegin(), it_part)==0
- && can_connect(*(it_part+1), line_colour)
- && can_connect(*it_part, line_colour)
- ){
- ++it_part;
- break;
+ if(std::distance(cbegin_partons(), it_part)==0){
+ auto it_next = it_part;
+ ++it_next;
+ if( can_connect(*it_next, line_colour)
+ && can_connect(*it_part, line_colour)
+ ){
+ it_part=it_next;
+ break;
+ }
}
return false;
}
case event_type::unof:
case event_type::qqxexf: {
// u-channel only allowed at impact factor
- if(std::distance(it_part, outgoing().cend())==2
- && can_connect(*(it_part+1), line_colour)
- && can_connect(*it_part, line_colour)
- ){
- ++it_part;
- break;
+ if(std::distance(it_part, cend_partons())==2){
+ auto it_next = it_part;
+ ++it_next;
+ if( can_connect(*it_next, line_colour)
+ && can_connect(*it_part, line_colour)
+ ){
+ it_part=it_next;
+ break;
+ }
}
return false;
}
case event_type::qqxmid:{
// u-channel only allowed at qqx/qxq pair
- if( std::distance(outgoing_.begin(), it_part)>0
- && std::distance(it_part, outgoing_.end())>2
- && ( ( (is_quark(*it_part) && is_antiquark(*(it_part+1)) )
- || (is_antiquark(*it_part) && is_quark(*(it_part+1))) )
- )
- && can_connect(*(it_part+1), line_colour)
- && can_connect(*it_part, line_colour)
+ if( std::distance(cbegin_partons(), it_part)>0
+ && std::distance(it_part, cend_partons())>2
){
- ++it_part;
- break;
+ auto it_next = it_part;
+ ++it_next;
+ if( ( (is_quark(*it_part) && is_antiquark(*it_next))
+ || (is_antiquark(*it_part) && is_quark(*it_next)) )
+ && can_connect(*it_next, line_colour)
+ && can_connect(*it_part, line_colour)
+ ){
+ it_part=it_next;
+ break;
+ }
}
return false;
}
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;
return;
}
//! connect outgoing Particle to colour flow
void connect_outgoing(
Particle & part, int & colour, int & anti_colour, RNG & ran
){
assert(colour>0 || anti_colour>0);
if(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){
part.colour = std::make_pair(colour+2,colour);
colour+=2;
} else {
part.colour = std::make_pair(anti_colour, anti_colour+2);
anti_colour+=2;
}
} else if(colour > 0){
// on q line => connect to available colour
part.colour = std::make_pair(colour+2, colour);
colour+=2;
} else {
assert(colour<0 && anti_colour>0);
// on qx line => connect to available anti-colour
part.colour = std::make_pair(anti_colour, anti_colour+2);
anti_colour+=2;
}
} else if(is_quark(part)) {
// quark
assert(anti_colour>0);
if(colour>0){
// on g line => connect and remove anti-colour
part.colour = std::make_pair(anti_colour, 0);
anti_colour+=2;
anti_colour*=-1;
} else {
// on qx line => new colour
colour*=-1;
part.colour = std::make_pair(colour, 0);
}
} else if(is_antiquark(part)) {
// anti-quark
assert(colour>0);
if(anti_colour>0){
// on g line => connect and remove colour
part.colour = std::make_pair(0, colour);
colour+=2;
colour*=-1;
} else {
// on q line => new anti-colour
anti_colour*=-1;
part.colour = std::make_pair(0, anti_colour);
}
} else { // not a parton
assert(!is_parton(part));
part.colour = {};
}
}
//! connect to t- or u-channel colour flow
template<class OutIterator>
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_outgoing(*it_first, colour, anti_colour, ran);
connect_outgoing(*it_part, colour, anti_colour, ran);
- connect_outgoing(*(it_part+1), colour, anti_colour, ran);
}
else { // u-channel
- connect_outgoing(*(it_part+1), colour, anti_colour, ran);
connect_outgoing(*it_part, colour, anti_colour, ran);
+ connect_outgoing(*it_first, colour, anti_colour, ran);
}
- ++it_part;
}
}
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);
- for(auto it_part = outgoing_.begin(); it_part<outgoing_.end(); ++it_part){
+ // 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::qqxexb: {
- if( std::distance(outgoing_.begin(), it_part)==0)
+ if( std::distance(begin_partons(), it_part)==0)
connect_utchannel(it_part, colour, anti_colour, ran);
else
connect_outgoing(*it_part, colour, anti_colour, ran);
break;
}
case event_type::unof:
case event_type::qqxexf: {
- if( std::distance(it_part, outgoing_.end())==2)
+ if( std::distance(it_part, end_partons())==2)
connect_utchannel(it_part, colour, anti_colour, ran);
else
connect_outgoing(*it_part, colour, anti_colour, ran);
break;
}
case event_type::qqxmid:{
- if( std::distance(outgoing_.begin(), it_part)>0
- && std::distance(it_part, outgoing_.end())>2
- && ( (is_quark(*it_part) && is_antiquark(*(it_part+1)))
- || (is_antiquark(*it_part) && is_quark(*(it_part+1))) )
+ auto it_next = it_part;
+ ++it_next;
+ 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_outgoing(*it_part, colour, anti_colour, ran);
break;
}
default: // rest has to be t-channel
connect_outgoing(*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<fastjet::PseudoJet> const & jets,
Particle const & parton, int const idx,
double const max_ext_soft_pt_fraction, double const min_extparton_pt
){
// TODO code overlap with PhaseSpacePoint::pass_extremal_cuts
if(min_extparton_pt > parton.pt()) return false;
if(idx<0) return false;
assert(static_cast<int>(jets.size())>=idx);
auto const & jet{ jets[idx] };
if( (parton.p - jet).pt()/jet.pt() > max_ext_soft_pt_fraction)
return false;
return true;
}
}
// this should work with multiple types
bool Event::valid_hej_state(double const max_frac,
double const min_pt
) const {
using namespace event_type;
if(!is_resummable(type()))
return false;
auto const & jet_idx{ particle_jet_indices() };
auto idx_begin{ jet_idx.cbegin() };
auto idx_end{ jet_idx.crbegin() };
auto part_begin{ cbegin_partons() };
auto part_end{ crbegin_partons() };
// always seperate extremal jets
if( !valid_parton(jets(), *part_begin, *idx_begin, max_frac, min_pt) )
return false;
++part_begin;
++idx_begin;
if( !valid_parton(jets(), *part_end, *idx_end, max_frac, min_pt) )
return false;
++part_end;
++idx_end;
// unob -> second parton in own jet
if( type() & (unob | qqxexb) ){
if( !valid_parton(jets(), *part_begin, *idx_begin, max_frac, min_pt) )
return false;
++part_begin;
++idx_begin;
}
if( type() & (unof | qqxexf) ){
if( !valid_parton(jets(), *part_end, *idx_end, max_frac, min_pt) )
return false;
++part_end;
++idx_end;
}
if( type() & qqxmid ){
// find qqx pair
auto begin_qqx{ std::find_if( part_begin, part_end.base(),
[](Particle const & part) -> bool {
return part.type != ParticleID::gluon;
}
)};
assert(begin_qqx != part_end.base());
long int qqx_pos{ std::distance(part_begin, begin_qqx) };
assert(qqx_pos >= 0);
idx_begin+=qqx_pos;
if( !( valid_parton(jets(),*begin_qqx, *idx_begin, max_frac,min_pt)
&& valid_parton(jets(),*(++begin_qqx),*(++idx_begin),max_frac,min_pt)
))
return false;
}
return true;
}
Event::ConstPartonIterator Event::begin_partons() const {
return cbegin_partons();
}
Event::ConstPartonIterator Event::cbegin_partons() const {
return boost::make_filter_iterator(
static_cast<bool (*)(Particle const &)>(is_parton),
cbegin(outgoing()),
cend(outgoing())
);
}
Event::ConstPartonIterator Event::end_partons() const {
return cend_partons();
}
Event::ConstPartonIterator Event::cend_partons() const {
return boost::make_filter_iterator(
static_cast<bool (*)(Particle const &)>(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<ConstPartonIterator>( cend_partons() );
}
Event::ConstReversePartonIterator Event::rend_partons() const {
return crend_partons();
}
Event::ConstReversePartonIterator Event::crend_partons() const {
return std::reverse_iterator<ConstPartonIterator>( cbegin_partons() );
}
+ Event::PartonIterator Event::begin_partons() {
+ return boost::make_filter_iterator(
+ static_cast<bool (*)(Particle const &)>(is_parton),
+ begin(outgoing_),
+ end(outgoing_)
+ );
+ }
+
+ Event::PartonIterator Event::end_partons() {
+ return boost::make_filter_iterator(
+ static_cast<bool (*)(Particle const &)>(is_parton),
+ end(outgoing_),
+ end(outgoing_)
+ );
+ }
+
+ Event::ReversePartonIterator Event::rbegin_partons() {
+ return std::reverse_iterator<PartonIterator>( end_partons() );
+ }
+
+ Event::ReversePartonIterator Event::rend_partons() {
+ return std::reverse_iterator<PartonIterator>( begin_partons() );
+ }
+
namespace {
void print_momentum(std::ostream & os, fastjet::PseudoJet const & part){
const std::streamsize orig_prec = os.precision();
os <<std::scientific<<std::setprecision(6) << "["
<<std::setw(13)<<std::right<< part.px() << ", "
<<std::setw(13)<<std::right<< part.py() << ", "
<<std::setw(13)<<std::right<< part.pz() << ", "
<<std::setw(13)<<std::right<< part.E() << "]"<< std::fixed;
os.precision(orig_prec);
}
void print_colour(std::ostream & os, optional<Colour> const & col){
if(!col)
os << "(no color)"; // American spelling for better alignment
else
os << "(" <<std::setw(3)<<std::right<< col->first
<< ", " <<std::setw(3)<<std::right<< col->second << ")";
}
}
std::ostream& operator<<(std::ostream & os, Event const & ev){
const std::streamsize orig_prec = os.precision();
os <<std::setprecision(4)<<std::fixed;
os << "########## " << event_type::name(ev.type()) << " ##########" << std::endl;
os << "Incoming particles:\n";
for(auto const & in: ev.incoming()){
os <<std::setw(3)<< in.type << ": ";
print_colour(os, in.colour);
os << " ";
print_momentum(os, in.p);
os << std::endl;
}
os << "\nOutgoing particles: " << ev.outgoing().size() << "\n";
for(auto const & out: ev.outgoing()){
os <<std::setw(3)<< out.type << ": ";
print_colour(os, out.colour);
os << " ";
print_momentum(os, out.p);
os << " => rapidity="
<<std::setw(7)<<std::right<< out.rapidity() << std::endl;
}
os << "\nForming Jets: " << ev.jets().size() << "\n";
for(auto const & jet: ev.jets()){
print_momentum(os, jet);
os << " => rapidity="
<<std::setw(7)<<std::right<< jet.rapidity() << std::endl;
}
if(ev.decays().size() > 0 ){
os << "\nDecays: " << ev.decays().size() << "\n";
for(auto const & decay: ev.decays()){
os <<std::setw(3)<< ev.outgoing()[decay.first].type
<< " (" << decay.first << ") to:\n";
for(auto const & out: decay.second){
os <<" "<<std::setw(3)<< out.type << ": ";
print_momentum(os, out.p);
os << " => rapidity="
<<std::setw(7)<<std::right<< out.rapidity() << std::endl;
}
}
}
os << std::defaultfloat;
os.precision(orig_prec);
return os;
}
double shat(Event const & ev){
return (ev.incoming()[0].p + ev.incoming()[1].p).m2();
}
LHEF::HEPEUP to_HEPEUP(Event const & event, LHEF::HEPRUP * heprup){
LHEF::HEPEUP result;
result.heprup = heprup;
result.weights = {{event.central().weight, nullptr}};
for(auto const & var: event.variations()){
result.weights.emplace_back(var.weight, nullptr);
}
size_t num_particles = event.incoming().size() + event.outgoing().size();
for(auto const & decay: event.decays()) num_particles += decay.second.size();
result.NUP = num_particles;
// the following entries are pretty much meaningless
result.IDPRUP = event.type(); // event type
result.AQEDUP = 1./128.; // alpha_EW
//result.AQCDUP = 0.118 // alpha_QCD
// end meaningless part
result.XWGTUP = event.central().weight;
result.SCALUP = event.central().muf;
result.scales.muf = event.central().muf;
result.scales.mur = event.central().mur;
result.scales.SCALUP = event.central().muf;
result.pdfinfo.p1 = event.incoming().front().type;
result.pdfinfo.p2 = event.incoming().back().type;
result.pdfinfo.scale = event.central().muf;
result.IDUP.reserve(num_particles); // PID
result.ISTUP.reserve(num_particles); // status (in, out, decay)
result.PUP.reserve(num_particles); // momentum
result.MOTHUP.reserve(num_particles); // index mother particle
result.ICOLUP.reserve(num_particles); // colour
// incoming
std::array<Particle, 2> 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(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)?status_decayed: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(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<double>(num_particles, unknown_spin);
result.SPINUP = result.VTIMUP;
return result;
}
}
diff --git a/t/test_colours2.cc b/t/test_colours2.cc
index a06301e..e590a4f 100644
--- a/t/test_colours2.cc
+++ b/t/test_colours2.cc
@@ -1,200 +1,236 @@
/**
* \authors The HEJ collaboration (see AUTHORS for details)
* \date 2020
* \copyright GPLv2 or later
*/
#include <array>
#include <stdlib.h>
#include <string>
#include <vector>
#include "HEJ/Event.hh"
#include "HEJ/Constants.hh"
#include "hej_test.hh"
namespace {
const fastjet::JetDefinition jet_def{fastjet::JetAlgorithm::antikt_algorithm, 0.4};
const double min_jet_pt{30.};
struct colour_flow {
std::array<std::string,2> incoming;
std::vector<std::string> outgoing;
std::string colour;
HEJ::Event to_event(){
using namespace HEJ;
- ASSERT(colour.front()=='a' && colour.back()=='a'); // only closed loops
-
auto event = parse_configuration(incoming, outgoing);
+ if(colour.size()==0)
+ return event.cluster(jet_def,min_jet_pt);
+
+ ASSERT(colour.front()=='a' && colour.back()=='a'); // only closed loops
event.sort();
// fill colours with dummy value
for(auto & p: event.incoming)
p.colour = Colour{-1, -1};
for(auto & p: event.outgoing)
p.colour = Colour{-1, -1};
int current_colour = COLOUR_OFFSET;
int backup_colour = current_colour;
Particle* last_part = &event.incoming.front();
// loop connections
for(auto const & entry: colour){
if(entry == '_'){ // '_' -> skip connection
backup_colour = current_colour;
current_colour = 0;
continue;
}
auto & part = get_particle(event, entry);
part.colour->first = last_part->colour->second = current_colour;
current_colour = ++backup_colour;
last_part = ∂
}
for(auto & in: event.incoming)
std::swap(in.colour->first, in.colour->second);
// reset untouched colours
for(auto & out: event.outgoing)
if(out.colour->first == -1 && out.colour->second ==-1)
out.colour = {};
shuffle_particles(event);
return event.cluster(jet_def,min_jet_pt);
}
private:
HEJ::Particle & get_particle(
HEJ::Event::EventData & event, char const name
){
if(name == 'a')
return event.incoming[0];
if(name == 'b')
return event.incoming[1];
size_t idx = name-'0';
ASSERT(idx<event.outgoing.size());
return event.outgoing[idx];
}
};
const colour_flow FKL_ggg{{"g","g"},{"g","g","g"},{}};
const colour_flow FKL_qgq{{"1","2"},{"1","g","2"},{}};
const colour_flow FKL_qxgqx{{"-1","-2"},{"-1","g","-2"},{}};
const colour_flow FKL_qhgq{{"1","2"},{"1","h","g","2"},{}};
+
const colour_flow uno_gqgq{{"1","2"},{"g","1","g","2"},{}};
const colour_flow uno_qgqg{{"1","2"},{"1","g","2","g"},{}};
+ const colour_flow uno_Wgqq{{"2","2"},{"W+","g","1","2"},{}};
+ const colour_flow uno_gWqq{{"2","2"},{"g","W+","1","2"},{}};
+ const colour_flow uno_gqWq{{"2","2"},{"g","1","W+","2"},{}};
+ const colour_flow uno_qWqg{{"2","2"},{"1","W+","2","g"},{}};
+ const colour_flow uno_qqWg{{"2","2"},{"1","2","W+","g"},{}};
+ const colour_flow uno_qqgW{{"2","2"},{"1","2","g","W+"},{}};
+
const colour_flow qqx_qxqgq{{"g","2"},{"-1","1","g","2"},{}};
const colour_flow qqx_qgqqx{{"1","g"},{"1","g","2","-2"},{}};
const colour_flow qqx_qgqxq{{"1","g"},{"1","g","-2","2"},{}};
+ const colour_flow qqx_Wqxqq{{"g","2"},{"W+","-2","1","2"},{}};
+ const colour_flow qqx_qxWqq{{"g","2"},{"-2","W+","1","2"},{}};
+ const colour_flow qqx_qxqWq{{"g","2"},{"-2","1","W+","2"},{}};
+ const colour_flow qqx_qWqqx{{"2","g"},{"1","W+","2","-2"},{}};
+ const colour_flow qqx_qqWqx{{"2","g"},{"1","2","W+","-2"},{}};
+ const colour_flow qqx_qqqxW{{"2","g"},{"1","2","-2","W+"},{}};
+
const colour_flow qqx_gqqxq{{"g","2"},{"g","3","-3","2"},{}};
const colour_flow qqx_qqxqg{{"1","g"},{"1","-3","3","g"},{}};
const colour_flow qqx_qqxqqx{{"1","-1"},{"1","-1","1","-1"},{}};
+ const colour_flow qqx_qWqxqqx{{"2","-1"},{"1","W+","-1","1","-1"},{}};
+ const colour_flow qqx_qqxWqqx{{"2","-1"},{"1","-1","W+","1","-1"},{}};
+ const colour_flow qqx_qqxqWqx{{"2","-1"},{"1","-1","1","W+","-1"},{}};
void verify_colour(colour_flow configuration, std::string line,
bool const expectation = true
){
configuration.colour = std::move(line);
auto const event = configuration.to_event();
if(event.is_leading_colour() != expectation){
std::cerr << "Expected "<< (expectation?"":"non-") <<"leading colour\n"
<< event
<< "\nwith connection: " << configuration.colour << "\n";
throw std::logic_error("Colour verification failed");
}
}
void all_colours_possible(
colour_flow momenta, std::vector<std::string> allowed
){
- std::vector<HEJ::Event> possible_connections;
+ std::vector<HEJ::Event> possible;
for(auto & line: allowed){
momenta.colour = std::move(line);
- possible_connections.push_back(momenta.to_event());
- if(!possible_connections.back().is_leading_colour()){
+ possible.push_back(momenta.to_event());
+ if(!possible.back().is_leading_colour()){
std::cerr << "Expected leading colour\n"
- << possible_connections.back()
+ << possible.back()
<< "\nwith connection: " << momenta.colour << "\n";
throw std::logic_error("Colour verification failed");
}
}
}
}
int main() {
// FKL
all_colours_possible(FKL_ggg, {"a012ba","a01b2a","a02b1a","a0b21a",
"a12b0a","a1b20a","a2b10a","ab210a"});
all_colours_possible(FKL_qgq, {"a12_b0_a", "a2_b10_a"});
all_colours_possible(FKL_qxgqx, {"a_01b_2a", "a_0b_21a"});
all_colours_possible(FKL_qhgq, {"a23_b0_a", "a3_b20_a"});
// uno
all_colours_possible(uno_gqgq, {"a023_b1_a","a03_b21_a",
"a23_b01_a","a3_b201_a"}); // u-channel
all_colours_possible(uno_qgqg, {"a12_b30_a","a2_b310_a",
"a132_b0_a","a32_b10_a"}); // u-channel
+ all_colours_possible(uno_Wgqq, {"a13_b2_a","a3_b12_a"});
+ all_colours_possible(uno_gWqq, {"a03_b2_a","a3_b02_a"});
+ all_colours_possible(uno_gqWq, {"a03_b1_a","a3_b01_a"});
+ all_colours_possible(uno_qWqg, {"a2_b30_a","a32_b0_a"});
+ all_colours_possible(uno_qqWg, {"a1_b30_a","a31_b0_a"});
+ all_colours_possible(uno_qqgW, {"a1_b20_a","a21_b0_a"});
+
// extremal qqx
all_colours_possible(qqx_qgqqx, {"a12_3b0_a","a2_3b10_a",
"a1b2_30_a","ab2_310_a"}); // u-channel
all_colours_possible(qqx_qgqxq, {"a1b3_20_a", "ab3_210_a",
"a13_2b0_a","a3_2b10_a"}); // u-channel
all_colours_possible(qqx_qxqgq, {"a23_b1_0a","a3_b21_0a",
"a1_023_ba","a1_03_b2a"}); // u-channel
+ all_colours_possible(qqx_Wqxqq, {"a3_b2_1a","a2_13_ba"});
+ all_colours_possible(qqx_qxWqq, {"a3_b2_0a","a2_03_ba"});
+ all_colours_possible(qqx_qxqWq, {"a3_b1_0a","a1_03_ba"});
+ all_colours_possible(qqx_qWqqx, {"a2_3b0_a","ab2_30_a"});
+ all_colours_possible(qqx_qqWqx, {"a1_3b0_a","ab1_30_a"});
+ all_colours_possible(qqx_qqqxW, {"a1_2b0_a","ab1_20_a"});
+
// central qqx
all_colours_possible(qqx_gqqxq, {"a01_23_ba","a1_23_b0a",
"a03_b1_2a","a3_b1_20a"}); // u-channel
all_colours_possible(qqx_qqxqg, {"a3b2_10_a","ab32_10_a",
"a2_13b0_a","a2_1b30_a"}); // u-channel
- all_colours_possible(qqx_qqxqqx, {"ab_32_10_a",
- "a2_1b_30_a"}); // u-channel
+ all_colours_possible(qqx_qqxqqx, {"ab_32_10_a","a2_1b_30_a"});
+ all_colours_possible(qqx_qWqxqqx, {"ab_43_20_a","a3_2b_40_a"});
+ all_colours_possible(qqx_qqxWqqx, {"ab_43_10_a","a3_1b_40_a"});
+ all_colours_possible(qqx_qqxqWqx, {"ab_42_10_a","a2_1b_40_a"});
// forbidden
// crossed FKL
verify_colour(FKL_ggg, "a021ba",false);
verify_colour(FKL_ggg, "a0b12a",false);
verify_colour(FKL_ggg, "a10b2a",false);
verify_colour(FKL_ggg, "a1b02a",false);
verify_colour(FKL_ggg, "a20b1a",false);
verify_colour(FKL_ggg, "a21b0a",false);
verify_colour(FKL_ggg, "a2b01a",false);
verify_colour(FKL_ggg, "ab120a",false);
// quark with anti-colour
verify_colour(FKL_qgq, "a_01b_2a",false);
verify_colour(FKL_qgq, "a_0b_21a",false);
verify_colour(FKL_qxgqx, "a12_b0_a",false);
verify_colour(FKL_qxgqx, "a2_b10_a",false);
// higgs with colour
verify_colour(FKL_qhgq, "a123_b0_a",false);
verify_colour(FKL_qhgq, "a3_1_b20_a",false);
verify_colour(FKL_qhgq, "a3_11_b20_a",false);
// not-connected
verify_colour(FKL_ggg, "a012a",false);
verify_colour(FKL_ggg, "a012aa",false);
verify_colour(FKL_ggg, "a01ba",false);
verify_colour(FKL_ggg, "a0b2a",false);
verify_colour(FKL_ggg, "a_01b2a",false);
verify_colour(FKL_ggg, "a01_b2a",false);
verify_colour(FKL_ggg, "a0b_12a",false);
verify_colour(FKL_ggg, "a012b_a",false);
verify_colour(uno_gqgq, "a_1023_ba",false);
// uno
verify_colour(uno_gqgq, "a203_b1_a",false);
verify_colour(uno_qgqg, "a312_b0_a",false);
// extremal qqx
verify_colour(qqx_qgqqx, "a10_3b2_a",false);
verify_colour(qqx_qgqqx, "a2_31b0_a",false);
verify_colour(qqx_qgqqx, "a2_31b0_a",false);
verify_colour(qqx_qgqxq, "ab13_20_a",false);
verify_colour(qqx_qxqgq, "a3_b1_02a",false);
verify_colour(qqx_qxqgq, "a21_b3_0a",false);
// central qqx
verify_colour(qqx_gqqxq, "a1_203_ba",false);
verify_colour(qqx_gqqxq, "a3_21_b0a",false);
verify_colour(qqx_qqxqg, "ab2_130_a",false);
verify_colour(qqx_qqxqg, "a3b0_12_a",false);
verify_colour(qqx_qqxqqx, "a0_1b_32_a",false);
verify_colour(qqx_qqxqqx, "a0_3b_12_a",false);
verify_colour(qqx_qqxqqx, "a2_3b_10_a",false);
verify_colour(qqx_qqxqqx, "ab_12_30_a",false);
return EXIT_SUCCESS;
}