// -*- C++ -*-
#include "Rivet/Analysis.hh"
#include "Rivet/Projections/UnstableParticles.hh"
#include "Rivet/Projections/DecayedParticles.hh"
namespace Rivet {
/// @brief B_c -> J/psi p pbar pi+
class LHCB_2014_I1309880 : public Analysis {
public:
/// Constructor
RIVET_DEFAULT_ANALYSIS_CTOR(LHCB_2014_I1309880);
/// @name Analysis methods
/// @{
/// Book histograms and initialise projections before the run
void init() {
UnstableParticles ufs = UnstableParticles(Cuts::abspid==541);
declare(ufs, "UFS");
DecayedParticles BC(ufs);
BC.addStable( PID::PI0);
BC.addStable( PID::K0S);
BC.addStable( PID::JPSI);
declare(BC, "BC");
for(unsigned int ix=0;ix<2;++ix)
book(_h[ix],1,1,1+ix);
}
/// Perform the per-event analysis
void analyze(const Event& event) {
static const map<PdgId,unsigned int> & mode = { { 443,1}, { 2212,1}, { 2212,1}, { 211,1} };
static const map<PdgId,unsigned int> & modeCC = { { 443,1}, { 2212,1}, { 2212,1}, {-211,1} };
DecayedParticles BC = apply<DecayedParticles>(event, "BC");
// loop over particles
for(unsigned int ix=0;ix<BC.decaying().size();++ix) {
int sign = BC.decaying()[ix].pid()/BC.decaying()[ix].abspid();
if ((sign== 1 && BC.modeMatches(ix,4,mode )) ||
(sign==-1 && BC.modeMatches(ix,4,modeCC))) {
const Particle & prot = BC.decayProducts()[ix].at( sign*2212)[0];
const Particle & pbar = BC.decayProducts()[ix].at(-sign*2212)[0];
const Particle & pip = BC.decayProducts()[ix].at( sign*211 )[0];
_h[0]->fill((prot.momentum()+pbar.momentum()).mass());
_h[1]->fill((prot.momentum()+pip .momentum()).mass());
}
}
}
/// Normalise histograms etc., after the run
void finalize() {
for(unsigned int ix=0;ix<2;++ix)
normalize(_h[ix],1.,false);
}
/// @}
/// @name Histograms
/// @{
Histo1DPtr _h[2];
/// @}
};
RIVET_DECLARE_PLUGIN(LHCB_2014_I1309880);
}