// -*- C++ -*-
#include "Rivet/Analysis.hh"
#include "Rivet/Projections/UnstableParticles.hh"
#include "Rivet/Projections/DecayedParticles.hh"
namespace Rivet {
/// @brief D0 -> K0 pi0pi0
class CLEOC_2011_I913909 : public Analysis {
public:
/// Constructor
RIVET_DEFAULT_ANALYSIS_CTOR(CLEOC_2011_I913909);
/// @name Analysis methods
/// @{
/// Book histograms and initialise projections before the run
void init() {
// Initialise and register projections
UnstableParticles ufs = UnstableParticles(Cuts::abspid==421);
declare(ufs, "UFS");
DecayedParticles D0(ufs);
D0.addStable(PID::PI0);
D0.addStable(PID::K0S);
D0.addStable(PID::ETA);
D0.addStable(PID::ETAPRIME);
declare(D0, "D0");
// histograms
book(_h_Kpi ,1,1,1);
book(_h_pipi,1,1,2);
book(_dalitz, "dalitz",50,0.,1.9,50,0.3,3.1);
}
/// Perform the per-event analysis
void analyze(const Event& event) {
static const map<PdgId,unsigned int> & mode = { {111,2}, { 310,1}};
DecayedParticles D0 = apply<DecayedParticles>(event, "D0");
// loop over particles
for(unsigned int ix=0;ix<D0.decaying().size();++ix) {
if( ! D0.modeMatches(ix,3,mode ) ) continue;
const Particles & K0 = D0.decayProducts()[ix].at(310);
const Particles & pi0= D0.decayProducts()[ix].at(111);
double mpipi = (pi0[0].momentum()+pi0[1].momentum()).mass2();
_h_pipi->fill(mpipi);
for(unsigned int ix=0;ix<2;++ix) {
double mKpi = (K0[0].momentum()+pi0[ix].momentum()).mass2();
_h_Kpi->fill(mKpi);
_dalitz->fill(mpipi,mKpi);
}
}
}
/// Normalise histograms etc., after the run
void finalize() {
normalize(_h_pipi);
normalize(_h_Kpi);
normalize(_dalitz);
}
/// @}
/// @name Histograms
/// @{
Histo1DPtr _h_Kpi, _h_pipi;
Histo2DPtr _dalitz;
/// @}
};
RIVET_DECLARE_PLUGIN(CLEOC_2011_I913909);
}