// -*- C++ -*-
#include "Rivet/Analysis.hh"
#include "Rivet/Projections/UnstableParticles.hh"
#include "Rivet/Projections/DecayedParticles.hh"
namespace Rivet {
/// @brief B+ -> phi phi K+
class BELLE_2021_I1841899 : public Analysis {
public:
/// Constructor
RIVET_DEFAULT_ANALYSIS_CTOR(BELLE_2021_I1841899);
/// @name Analysis methods
/// @{
/// Book histograms and initialise projections before the run
void init() {
// Initialise and register projections
UnstableParticles ufs = UnstableParticles(Cuts::abspid==521);
declare(ufs, "UFS");
DecayedParticles BP(ufs);
BP.addStable(PID::PI0);
BP.addStable(PID::K0S);
BP.addStable(PID::ETA);
BP.addStable(PID::ETAPRIME);
BP.addStable(PID::PHI);
declare(BP, "BP");
// histograms
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) {
// define the decay mode
static const map<PdgId,unsigned int> & mode = { { 321,1},{ 333,2}};
static const map<PdgId,unsigned int> & modeCC = { {-321,1},{ 333,2}};
DecayedParticles BP = apply<DecayedParticles>(event, "BP");
// loop over particles
for(unsigned int ix=0;ix<BP.decaying().size();++ix) {
int sign = 1;
if (BP.decaying()[ix].pid()>0 && BP.modeMatches(ix,3,mode)) {
sign=1;
}
else if (BP.decaying()[ix].pid()<0 && BP.modeMatches(ix,3,modeCC)) {
sign=-1;
}
else
continue;
const Particles & Kp = BP.decayProducts()[ix].at( sign*321);
const Particles & phi = BP.decayProducts()[ix].at( 333);
_h[0]->fill((phi[0].momentum()+phi[1].momentum()).mass());
_h[1]->fill((Kp [0].momentum()+phi[0].momentum()).mass());
_h[1]->fill((Kp [0].momentum()+phi[1].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(BELLE_2021_I1841899);
}