// -*- C++ -*-
#include "Rivet/Analysis.hh"
#include "Rivet/Projections/Beam.hh"
#include "Rivet/Projections/FinalState.hh"
#include "Rivet/Projections/ChargedFinalState.hh"
#include "Rivet/Projections/UnstableParticles.hh"
namespace Rivet {
/// @brief OPAL Delta++ fragmentation function paper
/// @author Peter Richardson
class OPAL_1995_S3198391 : public Analysis {
public:
/// Constructor
OPAL_1995_S3198391()
: Analysis("OPAL_1995_S3198391")
{}
/// @name Analysis methods
//@{
void init() {
declare(Beam(), "Beams");
declare(ChargedFinalState(), "FS");
declare(UnstableParticles(), "UFS");
book(_histXpDelta, 1, 1, 1);
}
void analyze(const Event& e) {
// First, veto on leptonic events by requiring at least 4 charged FS particles
const FinalState& fs = apply<FinalState>(e, "FS");
const size_t numParticles = fs.particles().size();
// Even if we only generate hadronic events, we still need a cut on numCharged >= 2.
if (numParticles < 2) {
MSG_DEBUG("Failed leptonic event cut");
vetoEvent;
}
MSG_DEBUG("Passed leptonic event cut");
// Get beams and average beam momentum
const ParticlePair& beams = apply<Beam>(e, "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 UnstableParticles& ufs = apply<UnstableFinalState>(e, "UFS");
for (const Particle& p : ufs.particles()) {
if(p.abspid()==2224) {
double xp = p.p3().mod()/meanBeamMom;
_histXpDelta->fill(xp);
}
}
}
/// Finalize
void finalize() {
scale(_histXpDelta, 1./sumOfWeights());
}
//@}
private:
Histo1DPtr _histXpDelta;
//@}
};
// The hook for the plugin system
DECLARE_RIVET_PLUGIN(OPAL_1995_S3198391);
}