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| // -*- C++ -*-
#include "Rivet/Analysis.hh"
#include "Rivet/Projections/GammaGammaFinalState.hh"
#include "Rivet/Projections/FastJets.hh"
namespace Rivet {
/// @brief Dijet production in photon-photon collisions at 198 GeV
class OPAL_2003_I611415 : public Analysis {
public:
/// Constructor
RIVET_DEFAULT_ANALYSIS_CTOR(OPAL_2003_I611415);
/// @name Analysis methods
//@{
/// Book histograms and initialise projections before the run
void init() {
// get the hadronic final state
const GammaGammaKinematics& diskin = declare(GammaGammaKinematics(), "Kinematics");
const FinalState & fs = declare(GammaGammaFinalState(diskin), "FS");
declare(FastJets(fs, FastJets::KT,1.),"Jets");
book(_h_theta[0] , 1,1,1);
book(_h_theta[1] , 2,1,1);
book(_h_ET[0] , 3,1,1);
book(_h_ET[1] , 4,1,1);
book(_h_ET[2] , 5,1,1);
book(_h_xg[0][0] , 6,1,1);
book(_h_xg[0][1] , 7,1,1);
book(_h_xg[1][0] , 9,1,1);
book(_h_xg[1][1] , 10,1,1);
book(_h_xg[2][0] , 11,1,1);
book(_h_xg[2][1] , 12,1,1);
book(_h_xg_high , 8,1,1);
book(_h_xlog[0] , 13,1,1);
book(_h_xlog[1] , 14,1,1);
book(_h_xlog[2] , 15,1,1);
book(_h_eta_diff[0], 16,1,1);
book(_h_eta_diff[1], 17,1,1);
book(_h_eta_min[0] , 18,1,1);
book(_h_eta_min[1] , 19,1,1);
book(_h_eta_max[0] , 20,1,1);
book(_h_eta_max[1] , 21,1,1);
}
/// Perform the per-event analysis
void analyze(const Event& event) {
// need at least two jets with |eta|<2 and pT>3
Jets jets = apply<FastJets>(event, "Jets").jetsByPt(Cuts::Et > 3.*GeV and Cuts::abseta < 2.);
if(jets.size()<2) vetoEvent;
if(jets[0].Et()<jets[1].Et()) swap(jets[0],jets[1]);
// Ets of jets
double Et1 = jets[0].Et(), Et2 = jets[1].Et();
// average Et
double Etbar = 0.5*(Et1+Et2);
double etaBar = 0.5*(jets[0].eta()+jets[1].eta());
if(Etbar<5.) vetoEvent;
// assymetry cut
if((Et1-Et2)/(Et1+Et2)>.25) vetoEvent;
// calculate x_gamma
FourMomentum psum;
for(const Particle & part : apply<FinalState>(event,"FS").particles()) {
psum += part.momentum();
}
FourMomentum pj = jets[0].momentum()+jets[1].momentum();
double xp = (pj.E()+pj.pz())/(psum.E()+psum.pz());
double xm = (pj.E()-pj.pz())/(psum.E()-psum.pz());
double cost = tanh(0.5*(jets[0].eta()-jets[1].eta()));
// cost distributions
if(pj.mass()>15.*GeV && etaBar<=1.) {
if(xp>0.75 && xm>0.75)
_h_theta[0]->fill(abs(cost));
else if(xp<0.75 && xm<0.75)
_h_theta[1]->fill(abs(cost));
}
// ET distributions
_h_ET[0]->fill(Etbar);
if((xp<0.75 && xm>0.75)|| (xm<0.75&&xp>0.75))
_h_ET[1]->fill(Etbar);
else if(xp<0.75 && xm <0.75)
_h_ET[2]->fill(Etbar);
if(Etbar>=5.&&Etbar<7.) {
_h_xg[0][0]->fill(xp);
_h_xg[0][0]->fill(xm);
_h_xlog[0]->fill(log(xp));
_h_xlog[0]->fill(log(xm));
if((xp<0.75 && xm>0.75)|| (xm<0.75&&xp>0.75)) {
_h_xg[1][0]->fill(xp);
_h_xg[1][0]->fill(xm);
_h_xlog[1]->fill(log(xp));
_h_xlog[1]->fill(log(xm));
}
else if(xp<0.75 && xm <0.75) {
_h_xg[2][0]->fill(xp);
_h_xg[2][0]->fill(xm);
_h_xlog[2]->fill(log(xp));
_h_xlog[2]->fill(log(xm));
}
}
else if(Etbar>=7.&& Etbar<11.) {
_h_xg[0][1]->fill(xp);
_h_xg[0][1]->fill(xm);
if((xp<0.75 && xm>0.75)|| (xm<0.75&&xp>0.75)) {
_h_xg[1][1]->fill(xp);
_h_xg[1][1]->fill(xm);
}
else if(xp<0.75 && xm <0.75) {
_h_xg[2][1]->fill(xp);
_h_xg[2][1]->fill(xm);
}
}
else if(Etbar>=11.&& Etbar<25.) {
_h_xg_high->fill(xp);
_h_xg_high->fill(xm);
}
// vs eta
double etaMin = min(abs(jets[0].eta()),abs(jets[1].eta()));
double etaMax = max(abs(jets[0].eta()),abs(jets[1].eta()));
if((xp<0.75 && xm>0.75)|| (xm<0.75&&xp>0.75)) {
_h_eta_diff[0]->fill(abs(jets[0].eta()-jets[1].eta()));
_h_eta_min[0]->fill(etaMin);
_h_eta_max[0]->fill(etaMax);
}
else if(xp<0.75 && xm <0.75) {
_h_eta_diff[1]->fill(abs(jets[0].eta()-jets[1].eta()));
_h_eta_min[1]->fill(etaMin);
_h_eta_max[1]->fill(etaMax);
}
}
/// Normalise histograms etc., after the run
void finalize() {
double fact = crossSection()/picobarn/sumOfWeights();
for(unsigned int ix=0;ix<2;++ix) {
scale(_h_theta[ix], fact);
scale(_h_eta_diff[ix], fact);
scale(_h_eta_min[ix], fact);
scale(_h_eta_max[ix], fact);
for(unsigned int iy=0;iy<3;++iy) {
scale(_h_xg[iy][ix],fact);
}
}
for(unsigned int ix=0;ix<3;++ix) {
scale(_h_ET[ix],fact);
scale(_h_xlog[ix],fact);
}
scale(_h_xg_high,fact);
}
//@}
/// @name Histograms
//@{
Histo1DPtr _h_theta[2],_h_ET[3],_h_xg[3][2],_h_xg_high;
Histo1DPtr _h_xlog[3],_h_eta_diff[2],_h_eta_min[2],_h_eta_max[2];
//@}
};
// The hook for the plugin system
RIVET_DECLARE_PLUGIN(OPAL_2003_I611415);
}
|