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| // -*- C++ -*-
#include "Rivet/Analysis.hh"
#include "Rivet/Projections/Beam.hh"
#include "Rivet/Projections/ChargedFinalState.hh"
namespace Rivet {
/// @brief BELLE pion and kaon continuum production
/// @author Peter Richardson
class BELLE_2013_I1216515 : public Analysis {
public:
BELLE_2013_I1216515()
: Analysis("BELLE_2013_I1216515")
{ }
void analyze(const Event& e) {
// Loop through charged FS particles and look for charmed mesons/baryons
const ChargedFinalState& fs = apply<ChargedFinalState>(e, "FS");
const Beam beamproj = apply<Beam>(e, "Beams");
const ParticlePair& beams = beamproj.beams();
const FourMomentum mom_tot = beams.first.momentum() + beams.second.momentum();
const LorentzTransform cms_boost = LorentzTransform::mkFrameTransformFromBeta(mom_tot.betaVec());
MSG_DEBUG("CMS energy sqrt s = " << beamproj.sqrtS());
for (const Particle& p : fs.particles()) {
// energy in CMS frame
const double en = cms_boost.transform(p.momentum()).t();
const double z = 2.*en/beamproj.sqrtS();
const int PdgId = p.abspid();
MSG_DEBUG("pdgID = " << PdgId << " Energy = " << en);
switch (PdgId) {
case PID::PIPLUS:
_histPion->fill(z);
break;
case PID::KPLUS:
_histKaon->fill(z);
break;
default :
break;
}
}
} // analyze
void finalize() {
scale(_histPion,crossSection()/femtobarn/sumOfWeights());
scale(_histKaon,crossSection()/femtobarn/sumOfWeights());
} // finalize
void init() {
declare(Beam(), "Beams");
declare(ChargedFinalState(), "FS");
book(_histPion ,1,1,1);
book(_histKaon ,1,1,2);
} // init
private:
//@{
// Histograms for continuum data (sqrt(s) = 10.52 GeV)
Histo1DPtr _histPion;
Histo1DPtr _histKaon;
//@}
};
// The hook for the plugin system
RIVET_DECLARE_PLUGIN(BELLE_2013_I1216515);
}
|