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| // -*- C++ -*-
#include "Rivet/Analysis.hh"
#include "Rivet/Projections/FinalState.hh"
#include "Rivet/Projections/FastJets.hh"
#include "Rivet/Projections/DISKinematics.hh"
#include "fastjet/SISConePlugin.hh"
#include<cmath>
namespace Rivet {
/// @brief Forward jet production in deep inelastic scattering at HERA (ZEUS)
class ZEUS_1999_I470499 : public Analysis {
public:
/// Constructor
RIVET_DEFAULT_ANALYSIS_CTOR(ZEUS_1999_I470499);
/// @name Analysis methods
///@{
/// Book histograms and initialise projections before the run
void init() {
// Initialise and register projections
// The basic final-state projection:
// all final-state particles within
// the given eta acceptance
const FinalState fs; /// SHOULD I KEEP THIS AT ALL?
declare(fs, "FS");
// declare jets
double jet_radius = 1.0;///FIGURE THIS OUT
declare(FastJets(fs, FastJets::PXCONE, jet_radius), "Jets");//FIGURE THE JET OUT
// declare DIS Kinematics
declare(DISLepton(), "Lepton");
declare(DISKinematics(), "Kinematics");
// take binning from reference data using HEPData ID (digits in "d01-x01-y01" etc.)
book(_h["xbj"], 1, 1, 1);
}
/// Perform the per-event analysis
void analyze(const Event& event) {
// Retrieve dressed leptons, sorted by pT
const FinalState& fs = apply<FinalState>(event, "FS");
const size_t numParticles = fs.particles().size();
if (numParticles < 2) {
MSG_DEBUG("Failed leptonic event cut");
vetoEvent;
}
const DISKinematics& dk = applyProjection<DISKinematics>(event, "Kinematics");
const DISLepton& dl = applyProjection<DISLepton>(event,"Lepton");
// Get the DIS kinematics
double xbj = dk.x();
double ybj = dk.y();
double Q2 = dk.Q2()/GeV;
//cut on y
if (ybj<0.1) vetoEvent;
if (4.5*pow(10,-4)>xbj && xbj>4.5*pow(10,-2)) vetoEvent;
//Frame transfer
const LorentzTransform breitboost = dk.boostBreit();
//on scattered lepton
FourMomentum leptonMom = dl.out().momentum();
double enel = leptonMom.E();
bool cut = enel>10*GeV;
if (!cut) vetoEvent;
//scattered jets
const Jets jets = apply<FastJets>(event, "Jets").jets(Cuts::Et > 5*GeV && Cuts::eta<2.6, cmpMomByEt);
//Cuts::pz/(820*GeV)>0.036
//&& Cuts::0.5<pow(Et,2)/Q2<2 && Cuts::breMom.pz>0
bool loopjet=false;
for (const Jet&j:jets){
//cout << " j.pz " << j.pz()/(820*GeV) << endl;
if (j.pz()/(820*GeV)<0.036) continue;
// cout << pow(j.Et(),2) << endl;
if (0.5>pow(j.Et(),2)/Q2||pow(j.Et(),2)/Q2>2) continue;
FourMomentum breMom = breitboost.transform(j.momentum());
//cout<< " pz " << breMom.pz() << endl;
if (breMom.pz()<0) continue;
loopjet=true;
}
// cout<< " loojet " << loopjet << endl;
if(loopjet) _h["xbj"]->fill(xbj);
// Fill histogram with leading b-jet pT
}
/// Normalise histograms etc., after the run
void finalize() {
scale(_h["xbj"], crossSection()/nanobarn/sumW());
//normalize(_h["xbj"]);
}
///@}
/// @name Histograms
///@{
map<string, Histo1DPtr> _h;
map<string, Profile1DPtr> _p;
map<string, CounterPtr> _c;
///@}
};
RIVET_DECLARE_PLUGIN(ZEUS_1999_I470499);
}
|