// -*- C++ -*-
#include "Rivet/Analysis.hh"
#include "Rivet/Projections/UnstableParticles.hh"
#include "Rivet/Projections/DecayedParticles.hh"
namespace Rivet {
/// @brief chi_c0 -> pi+ pi- K+ K-
class BESII_2005_I690784 : public Analysis {
public:
/// Constructor
RIVET_DEFAULT_ANALYSIS_CTOR(BESII_2005_I690784);
/// @name Analysis methods
/// @{
/// Book histograms and initialise projections before the run
void init() {
UnstableParticles ufs = UnstableParticles(Cuts::pid==10441);
declare(ufs, "UFS");
DecayedParticles chi(ufs);
chi.addStable( PID::PI0);
chi.addStable( PID::K0S);
chi.addStable( PID::ETA);
declare(chi, "chi");
for(unsigned int ix=0;ix<4;++ix)
book(_h[ix],1,1,ix+1);
}
/// Perform the per-event analysis
void analyze(const Event& event) {
static const map<PdgId,unsigned int> & mode1 = { { 211,1}, {-211,1}, {321,1}, {-321,1} };
DecayedParticles chi = apply<DecayedParticles>(event, "chi");
// loop over particles
for(unsigned int ix=0;ix<chi.decaying().size();++ix) {
if(!chi.modeMatches(ix,4,mode1)) continue;
const Particle & pim = chi.decayProducts()[ix].at(-211)[0];
const Particle & pip = chi.decayProducts()[ix].at( 211)[0];
const Particle & Km = chi.decayProducts()[ix].at(-321)[0];
const Particle & Kp = chi.decayProducts()[ix].at( 321)[0];
_h[0]->fill((Km .momentum() +Kp.momentum()).mass());
_h[1]->fill((pim.momentum()+pip.momentum()).mass());
_h[2]->fill((Km .momentum()+pip.momentum()).mass());
_h[2]->fill((Kp .momentum()+pim.momentum()).mass());
_h[3]->fill((Km .momentum()+pip.momentum()+pim.momentum()).mass());
_h[3]->fill((Kp .momentum()+pim.momentum()+pip.momentum()).mass());
}
}
/// Normalise histograms etc., after the run
void finalize() {
for(unsigned int ix=0;ix<4;++ix)
normalize(_h[ix]);
}
/// @}
/// @name Histograms
/// @{
Histo1DPtr _h[4];
/// @}
};
RIVET_DECLARE_PLUGIN(BESII_2005_I690784);
}