// -*- C++ -*-
#include "Rivet/Analysis.hh"
#include "Rivet/Projections/UnstableParticles.hh"
#include "Rivet/Projections/DecayedParticles.hh"
namespace Rivet {
/// @brief D_s+ -> omega pi+ pi0
class CLEO_2009_I822856 : public Analysis {
public:
/// Constructor
RIVET_DEFAULT_ANALYSIS_CTOR(CLEO_2009_I822856);
/// @name Analysis methods
/// @{
/// Book histograms and initialise projections before the run
void init() {
// projections
UnstableParticles ufs = UnstableParticles(Cuts::abspid==431);
declare(ufs, "UFS");
DecayedParticles DS(ufs);
DS.addStable(PID::PI0);
DS.addStable(PID::K0S);
DS.addStable(PID::ETA);
DS.addStable(PID::OMEGA);
DS.addStable(PID::ETAPRIME);
declare(DS, "DS");
// histograms
book(_h_pipi,1,1,1);
}
/// Perform the per-event analysis
void analyze(const Event& event) {
static const map<PdgId,unsigned int> & mode = { { 211,1},{ 111,1}, { 223,1}};
static const map<PdgId,unsigned int> & modeCC = { {-211,1},{ 111,1}, { 223,1}};
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 Particles & pi0 = DS.decayProducts()[ix].at( 111);
const Particles & pip = DS.decayProducts()[ix].at( sign*211);
_h_pipi->fill((pi0[0].momentum()+pip[0].momentum()).mass());
}
}
/// Normalise histograms etc., after the run
void finalize() {
normalize(_h_pipi,1.,false);
}
/// @}
/// @name Histograms
/// @{
Histo1DPtr _h_pipi;
/// @}
};
RIVET_DECLARE_PLUGIN(CLEO_2009_I822856);
}