// -*- C++ -*-
#include "Rivet/Analysis.hh"
#include "Rivet/Projections/FinalState.hh"
#include "Rivet/Projections/Beam.hh"
#include "Rivet/Projections/ChargedFinalState.hh"
#include "Rivet/Projections/UnstableParticles.hh"
namespace Rivet {
/// @brief L3 inclusive eta production in hadronic Z0 decays
/// @author Simone Amoroso
class L3_1992_I336180 : public Analysis {
public:
/// Constructor
RIVET_DEFAULT_ANALYSIS_CTOR(L3_1992_I336180);
/// @name Analysis methods
//@{
/// Book histograms and initialise projections before the run
void init() {
// Initialise and register projections
declare(Beam(), "Beams");
declare(ChargedFinalState(), "FS");
declare(UnstableParticles(), "UFS");
// Book histograms
book(_histXpEta , 1, 1, 1);
book(_histLnXpEta , 2, 1, 1);
}
/// Perform the per-event analysis
void analyze(const Event& event) {
// Even if we only generate hadronic events, we still need a cut on numCharged >= 2.
const FinalState& fs = apply<FinalState>(event, "FS");
if (fs.particles().size() < 2) {
MSG_DEBUG("Failed ncharged cut");
vetoEvent;
}
MSG_DEBUG("Passed ncharged cut");
// Get beams and average beam momentum
const ParticlePair& beams = apply<Beam>(event, "Beams").beams();
const double meanBeamMom = ( beams.first.p3().mod() + beams.second.p3().mod() ) / 2.0;
MSG_DEBUG("Avg beam momentum = " << meanBeamMom);
// Final state of unstable particles to get particle spectra
const Particles& etas = apply<UnstableParticles>(event, "UFS").particles(Cuts::abspid==PID::ETA);
for (const Particle& p : etas) {
double xp = p.p3().mod()/meanBeamMom;
MSG_DEBUG("Eta xp = " << xp);
_histXpEta->fill(xp);
_histLnXpEta->fill(log(1./xp));
}
}
/// Normalise histograms etc., after the run
void finalize() {
scale(_histXpEta, 1./sumOfWeights());
scale(_histLnXpEta, 1./sumOfWeights());
}
//@}
private:
Histo1DPtr _histXpEta;
Histo1DPtr _histLnXpEta;
};
// The hook for the plugin system
RIVET_DECLARE_PLUGIN(L3_1992_I336180);
}