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113 | // -*- C++ -*-
#include "Rivet/Analysis.hh"
#include "Rivet/Projections/UnstableParticles.hh"
#include "Rivet/Projections/DecayedParticles.hh"
namespace Rivet {
/// @brief psi(2S) -> pbar K+ Sigma^$ and chi_cJ -> pbar K+Lambda
class BESIII_2013_I1203840 : public Analysis {
public:
/// Constructor
RIVET_DEFAULT_ANALYSIS_CTOR(BESIII_2013_I1203840);
/// @name Analysis methods
/// @{
/// Book histograms and initialise projections before the run
void init() {
UnstableParticles ufs = UnstableParticles(Cuts::pid==20443 or
Cuts::pid==445 or
Cuts::pid==10441 or
Cuts::pid==100443);
declare(ufs, "UFS");
DecayedParticles chi(ufs);
chi.addStable( PID::PI0);
chi.addStable( PID::K0S);
chi.addStable( PID::SIGMA0);
chi.addStable( PID::SIGMA0);
chi.addStable( PID::LAMBDA);
chi.addStable(-PID::LAMBDA);
declare(chi, "chi");
// histograms
for(unsigned int ix=0;ix<2;++ix) {
book(_h_psi[ix],1,1,ix+1);
for(unsigned int iy=0;iy<3;++iy)
book(_h_chi[iy][ix],2,iy+1,ix+1);
}
book(_h_pLam,3,1,1);
}
/// Perform the per-event analysis
void analyze(const Event& event) {
static const map<PdgId,unsigned int> & mode1 = { {-2212,1}, { 3212,1}, { 321,1} };
static const map<PdgId,unsigned int> & mode1CC = { { 2212,1}, {-3212,1}, {-321,1} };
static const map<PdgId,unsigned int> & mode2 = { {-2212,1}, { 3122,1}, { 321,1} };
static const map<PdgId,unsigned int> & mode2CC = { { 2212,1}, {-3122,1}, {-321,1} };
DecayedParticles chi = apply<DecayedParticles>(event, "chi");
// loop over particles
for(unsigned int ix=0;ix<chi.decaying().size();++ix) {
int sign=1;
if(chi.decaying()[ix].pid()==100443) {
if(chi.modeMatches(ix,3,mode1)) {
sign = 1;
}
else if(chi.modeMatches(ix,3,mode1CC)) {
sign = -1;
}
else continue;
const Particle & pbar = chi.decayProducts()[ix].at(-sign*2212)[0];
const Particle & Kp = chi.decayProducts()[ix].at( sign*321 )[0];
const Particle & sigma = chi.decayProducts()[ix].at( sign*3212)[0];
_h_psi[0]->fill((pbar.momentum()+sigma.momentum()).mass());
_h_psi[1]->fill((Kp .momentum()+sigma.momentum()).mass());
}
else {
if(chi.modeMatches(ix,3,mode2)) {
sign = 1;
}
else if(chi.modeMatches(ix,3,mode2CC)) {
sign = -1;
}
else continue;
unsigned int iloc = chi.decaying()[ix].pid()==10441 ? 0 : chi.decaying()[ix].pid()==445 ? 2 : 1;
const Particle & pbar = chi.decayProducts()[ix].at(-sign*2212)[0];
const Particle & Kp = chi.decayProducts()[ix].at( sign*321 )[0];
const Particle & lam = chi.decayProducts()[ix].at( sign*3122)[0];
_h_chi[iloc][0]->fill((pbar.momentum()+Kp .momentum()).mass());
_h_chi[iloc][1]->fill((Kp .momentum()+lam.momentum()).mass());
if(iloc==0) _h_pLam->fill((pbar.momentum()+lam.momentum()).mass());
}
}
}
/// Normalise histograms etc., after the run
void finalize() {
for(unsigned int ix=0;ix<2;++ix) {
normalize(_h_psi[ix],1.,false);
for(unsigned int iy=0;iy<3;++iy)
normalize(_h_chi[iy][ix],1.,false);
}
normalize(_h_pLam,1.,false);
}
/// @}
/// @name Histograms
/// @{
Histo1DPtr _h_psi[2],_h_chi[3][2],_h_pLam;
/// @}
};
RIVET_DECLARE_PLUGIN(BESIII_2013_I1203840);
}
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