// -*- C++ -*-
#include "Rivet/Analysis.hh"
#include "Rivet/Projections/UnstableParticles.hh"
#include "Rivet/Projections/DecayedParticles.hh"
namespace Rivet {
/// @brief D0 -> KS0 pi+ pi0 pi0
class BESIII_2022_I2088337 : public Analysis {
public:
/// Constructor
RIVET_DEFAULT_ANALYSIS_CTOR(BESIII_2022_I2088337);
/// @name Analysis methods
/// @{
/// Book histograms and initialise projections before the run
void init() {
// Initialise and register projections
UnstableParticles ufs = UnstableParticles(Cuts::abspid==411);
declare(ufs, "UFS");
DecayedParticles DD(ufs);
DD.addStable(PID::PI0);
DD.addStable(PID::K0S);
declare(DD, "DD");
// histograms
for(unsigned int ix=0;ix<7;++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 = { {310,1}, { 211,1}, { 111,2} };
static const map<PdgId,unsigned int> & modeCC = { {310,1}, {-211,1}, { 111,2} };
DecayedParticles DD = apply<DecayedParticles>(event, "DD");
// loop over particles
for(unsigned int ix=0;ix<DD.decaying().size();++ix) {
int sign = DD.decaying()[ix].pid()/DD.decaying()[ix].abspid();
if ( !DD.modeMatches(ix,4,mode) && !DD.modeMatches(ix,4,modeCC)) continue;
const Particles & KS0 = DD.decayProducts()[ix].at( 310);
const Particles & pip = DD.decayProducts()[ix].at( sign*211);
const Particles & pi0 = DD.decayProducts()[ix].at( 111);
_h[0]->fill((pi0[0].momentum()+pi0[1].momentum()).mass());
_h[3]->fill((KS0[0].momentum()+pip[0].momentum()).mass());
_h[5]->fill((KS0[0].momentum()+pi0[0].momentum()+pi0[1].momentum()).mass());
_h[6]->fill((pip[0].momentum()+pi0[0].momentum()+pi0[1].momentum()).mass());
for(unsigned int ix=0;ix<2;++ix) {
_h[1]->fill((KS0[0].momentum()+pi0[ix].momentum()).mass());
_h[2]->fill((pip[0].momentum()+pi0[ix].momentum()).mass());
_h[4]->fill((KS0[0].momentum()+pip[0].momentum()+pi0[ix].momentum()).mass());
}
}
}
/// Normalise histograms etc., after the run
void finalize() {
for(unsigned int ix=0;ix<7;++ix) {
normalize(_h[ix]);
}
}
/// @}
/// @name Histograms
/// @{
Histo1DPtr _h[7];
/// @}
};
RIVET_DECLARE_PLUGIN(BESIII_2022_I2088337);
}