/*
* Delphes: a framework for fast simulation of a generic collider experiment
* Copyright (C) 2012-2014 Universite catholique de Louvain (UCL), Belgium
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see .
*/
/** \class TrackCountingBTagging
*
* b-tagging algorithm based on counting tracks with large impact parameter
*
* \author M. Selvaggi - UCL, Louvain-la-Neuve
*
*/
#include "modules/TrackCountingBTagging.h"
#include "classes/DelphesClasses.h"
#include "classes/DelphesFactory.h"
#include "classes/DelphesFormula.h"
#include "TMath.h"
#include "TString.h"
#include "TFormula.h"
#include "TRandom3.h"
#include "TObjArray.h"
#include "TLorentzVector.h"
#include
#include
#include
#include
using namespace std;
//------------------------------------------------------------------------------
TrackCountingBTagging::TrackCountingBTagging() :
fItTrackInputArray(0), fItJetInputArray(0)
{
}
//------------------------------------------------------------------------------
TrackCountingBTagging::~TrackCountingBTagging()
{
}
//------------------------------------------------------------------------------
void TrackCountingBTagging::Init()
{
fBitNumber = GetInt("BitNumber", 0);
fPtMin = GetDouble("TrackPtMin", 1.0);
fDeltaR = GetDouble("DeltaR", 0.3);
fIPmax = GetDouble("TrackIPMax", 2.0);
fSigMin = GetDouble("SigMin", 6.5);
fNtracks = GetInt("Ntracks", 3);
fUse3D = GetBool("Use3D", false);
// import input array(s)
fTrackInputArray = ImportArray(GetString("TrackInputArray", "Calorimeter/eflowTracks"));
fItTrackInputArray = fTrackInputArray->MakeIterator();
fJetInputArray = ImportArray(GetString("JetInputArray", "FastJetFinder/jets"));
fItJetInputArray = fJetInputArray->MakeIterator();
}
//------------------------------------------------------------------------------
void TrackCountingBTagging::Finish()
{
if(fItTrackInputArray) delete fItTrackInputArray;
if(fItJetInputArray) delete fItJetInputArray;
}
//------------------------------------------------------------------------------
void TrackCountingBTagging::Process()
{
Candidate *jet, *track;
Double_t jpx, jpy, jpz;
Double_t dr, tpt;
Double_t xd, yd, zd, d0, dd0, dz, ddz, sip;
Int_t sign;
Int_t count;
// loop over all input jets
fItJetInputArray->Reset();
while((jet = static_cast(fItJetInputArray->Next())))
{
const TLorentzVector &jetMomentum = jet->Momentum;
jpx = jetMomentum.Px();
jpy = jetMomentum.Py();
jpz = jetMomentum.Pz();
// loop over all input tracks
fItTrackInputArray->Reset();
count = 0;
// stop once we have enough tracks
while((track = static_cast(fItTrackInputArray->Next())) and count < fNtracks)
{
const TLorentzVector &trkMomentum = track->Momentum;
tpt = trkMomentum.Pt();
if(tpt < fPtMin) continue;
d0 = TMath::Abs(track->D0);
if(d0 > fIPmax) continue;
dr = jetMomentum.DeltaR(trkMomentum);
if(dr > fDeltaR) continue;
xd = track->Xd;
yd = track->Yd;
zd = track->Zd;
dd0 = TMath::Abs(track->ErrorD0);
dz = TMath::Abs(track->DZ);
ddz = TMath::Abs(track->ErrorDZ);
if(fUse3D){
sign = (jpx*xd + jpy*yd + jpz*zd > 0.0) ? 1 : -1;
//add transverse and longitudinal significances in quadrature
sip = sign * TMath::Sqrt( TMath::Power(d0 / dd0, 2) + TMath::Power(dz / ddz, 2) );
}
else {
sign = (jpx*xd + jpy*yd > 0.0) ? 1 : -1;
sip = sign * d0 / TMath::Abs(dd0);
}
if(sip > fSigMin) count++;
}
// set BTag flag to true if count >= Ntracks
jet->BTag |= (count >= fNtracks) << fBitNumber;
}
}
//------------------------------------------------------------------------------