// -*- C++ -*-
#include "Rivet/Analysis.hh"
#include "Rivet/Projections/UnstableParticles.hh"
#include "Rivet/Projections/DecayedParticles.hh"
namespace Rivet {
/// @brief D_s+ -> KS0 K+ pi0
class BESIII_2022_I2070086 : public Analysis {
public:
/// Constructor
RIVET_DEFAULT_ANALYSIS_CTOR(BESIII_2022_I2070086);
/// @name Analysis methods
/// @{
/// Book histograms and initialise projections before the run
void init() {
// Initialise and register projections
// Initialise and register projections
UnstableParticles ufs = UnstableParticles(Cuts::abspid==431);
declare(ufs, "UFS");
DecayedParticles DS(ufs);
DS.addStable(PID::PI0);
DS.addStable(PID::K0S);
declare(DS, "DS");
// histograms
book(_h_KK ,1,1,1);
book(_h_K0pi,1,1,2);
book(_h_Kppi,1,1,3);
book(_dalitz,"dalitz",50,0.3,2.3,50,0.3,2.3);
}
/// Perform the per-event analysis
void analyze(const Event& event) {
static const map<PdgId,unsigned int> & mode = { { 321,1},{ 111,1}, {310,1}};
static const map<PdgId,unsigned int> & modeCC = { {-321,1},{ 111,1}, {310,1}};
DecayedParticles DS = apply<DecayedParticles>(event, "DS");
// loop over particles
for(unsigned int ix=0;ix<DS.decaying().size();++ix) {
int sign = 1;
if (DS.decaying()[ix].pid()>0 && DS.modeMatches(ix,3,mode)) {
sign=1;
}
else if (DS.decaying()[ix].pid()<0 && DS.modeMatches(ix,3,modeCC)) {
sign=-1;
}
else
continue;
const Particle & K0 = DS.decayProducts()[ix].at( 310)[0];
const Particle & pi0 = DS.decayProducts()[ix].at( 111)[0];
const Particle & Kp = DS.decayProducts()[ix].at( sign*321)[0];
double m0 = (K0.momentum()+pi0.momentum()).mass2();
double mp = (Kp.momentum()+pi0.momentum()).mass2();
double mKK = (K0.momentum()+Kp.momentum()).mass2();
_dalitz->fill(mp,m0);
_h_KK->fill(sqrt(mKK));
_h_Kppi->fill(sqrt(mp));
_h_K0pi->fill(sqrt(m0));
}
}
/// Normalise histograms etc., after the run
void finalize() {
normalize(_h_K0pi);
normalize(_h_Kppi);
normalize(_h_KK );
normalize(_dalitz);
}
/// @}
/// @name Histograms
/// @{
Histo1DPtr _h_K0pi,_h_Kppi,_h_KK;
Histo2DPtr _dalitz;
/// @}
};
RIVET_DECLARE_PLUGIN(BESIII_2022_I2070086);
}