Page MenuHomeHEPForge
Files F8308635

README
No OneTemporary
Actions

README
View Options

--------------------------------------------------------------------------------
Boosted-object wavelet tagger Package
--------------------------------------------------------------------------------
This package was developed by Joey Huston, Matthew Mondragon, Forrest Phillips,
Ivan Pogrebnyak, Vikram Rentala, William Shepherd and Tim M. P. Tait.
The boosted-object wavelet tagger package is based on the technique described in:
Tagging Boosted Ws with Wavelets
Vikram Rentala, William Shepherd and Tim M. P. Tait
to appear in JHEP, arXiv:hep-ph/1404.1929
The wavelet-tagging technique has been generalized in this package to work
on any boosted resonance decaying to dijets. Two parameters need to be specified
when using the tagger:
a) m - the mass of the resonance in GeV.
b) w_cut - the wavelet cut parameter (dimensionless).
The m parameter is used to proportionally rescale the grid resolution of the LEGO plot,
so that the prongs of the boosted resonance decay are approximately 8 pixels apart
for all P_T values of the jet. The default value is set to 80.4 GeV.
The w_cut parameter is the wavelet cut parameter as defined in hep-ph/1404.1929.
This parameter is set to a default value of 0.16 .
--------------------------------------------------------------------------------
Core Classes
--------------------------------------------------------------------------------
There is only one class for the wavelet tagger which is WaveletTagger.
WaveletTagger [WaveletTagger.hh]
--------------------------------------------------------------------------------
Basic Usage: Wavelet_tagger [WaveletTagger.hh]
--------------------------------------------------------------------------------
The basic use of WaveletTagger is shown below:
1. Define an object of type WaveletTagger
WaveletTagger wave_tagger(w_cut, m);
// w_cut - the wavelet cut parameter (dimensionless).
// m - the mass of the resonance in GeV.
2. Check if a given pseudo-jet pass the wavelet cut (parameterized by w_cut)
bool pass = wave_tagger.execute(PseudoJet, verbose, kinematic);
// PseudoJet is the pseduojet of interest
// verbose is an int, if it equals 1 then the LEGO plot, average coefficients,
// and maximum second derivative will be shown as text, if it equals 0 then these won't be shown.
// The default is verbose = 0.
// kinematic is the kinematic the wavelet tagger fills the LEGO plot with
// The options are "pt", "Et", and "E". The default is "pt".
3. (Optional) If users want to use the average coefficients themselves they can run,
vector<double> avgCoeff = wave_tagger.getAvgCoeff();
after they have run execute. This returns a vector of the average coefficients.
--------------------------------------------------------------------------------
Example files
--------------------------------------------------------------------------------
Two basic examples are included.
example.cc:
This is an example file to demonstrate the use of the WaveletTagger class for fastjet.
This example is designed to work with the default text input file format in ../data/single-event.dat
Compile using "make", followed by "make examples".
Usage: "cat ../data/single-event.dat | ./example"
Output is printed to screen.
The example follows the procedure outlined in hep-ph/1404.1929 for W-tagging.
This example clusters the jets using a CA algorithm, applies a jet mass cut (70 GeV < m < 100 GeV),
followed by a mass drop cut, and finally the wavelet cut.
The output shows the pseudo-calorimeter entries (with X marking the jet center), the wavelet coefficients,
and the maximum second derivative used to compare against w_cut.
Note: In order to let some of the jets in the single-event.dat file pass the cuts, the mass cut has been commented out.
example2.cc:
This EXAMPLE requires ROOT to be installed.
This is an example file to demonstrate the use of the WaveletTagger class for fastjet.
This example is designed to work on an input root file with entries created from STDHEP, such as PYTHIA output.
An input file for this example is NOT provided. The user must generate their own root file to use as input.
Compile using "make", followed by "make examples".
Usage: ./example2 <inputrootfile.root>
The example follows the procedure outlined in hep-ph/1404.1929 for W-tagging.
This example clusters the jets using a CA algorithm, applies a jet mass cut (70 GeV < m < 100 GeV),
followed by a mass drop cut, and finally the wavelet cut.
Output is written to example2_output.root
The output root file has histograms of E, px, py, pz and pt of the jets before (h1) and after (h2) application of
the wavelet tagger. Additionaly, the values of E, px, py, pz for the two leading jets after the wavelet tagger has been applied are stored.

File Metadata

Mime Type
text/plain
Expires
Sat, Dec 21, 12:41 PM (1 d, 21 h)
Storage Engine
blob
Storage Format
Raw Data
Storage Handle
4022804
Default Alt Text
README (4 KB)

Event Timeline