// -*- C++ -*-
#include "Rivet/Analysis.hh"
#include "Rivet/Projections/UnstableParticles.hh"
#include "Rivet/Projections/DecayedParticles.hh"
namespace Rivet {
/// @brief D+ -> K_0S pi+ pi0
class BESIII_2014_I1277070 : public Analysis {
public:
/// Constructor
RIVET_DEFAULT_ANALYSIS_CTOR(BESIII_2014_I1277070);
/// @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 DP(ufs);
DP.addStable(PID::PI0);
DP.addStable(PID::K0S);
declare(DP,"DP");
// histos
book(_h_pipi ,1,1,1);
book(_h_KS0pi0,1,1,2);
book(_h_KS0pip,1,1,3);
book(_dalitz, "dalitz",50,0.3,3.1,50,0.,2.0);
}
/// Perform the per-event analysis
void analyze(const Event& event) {
static const map<PdgId,unsigned int> & mode = { { 211,1},{ 111,1}, {310,1}};
static const map<PdgId,unsigned int> & modeCC = { {-211,1},{ 111,1}, {310,1}};
DecayedParticles DP = apply<DecayedParticles>(event, "DP");
// loop over particles
for(unsigned int ix=0;ix<DP.decaying().size();++ix) {
int sign = 1;
if (DP.decaying()[ix].pid()>0 && DP.modeMatches(ix,3,mode)) {
sign=1;
}
else if (DP.decaying()[ix].pid()<0 && DP.modeMatches(ix,3,modeCC)) {
sign=-1;
}
else
continue;
const Particle & K0 = DP.decayProducts()[ix].at( 310)[0];
const Particle & pi0 = DP.decayProducts()[ix].at( 111)[0];
const Particle & pip = DP.decayProducts()[ix].at( sign*211)[0];
double mpipi = (pi0.momentum()+pip.momentum()).mass2();
double mKS0pip = (K0 .momentum()+pip.momentum()).mass2();
double mKS0pi0 = (K0 .momentum()+pi0.momentum()).mass2();
_h_pipi ->fill(mpipi);
_h_KS0pip->fill(mKS0pip);
_h_KS0pi0->fill(mKS0pi0);
_dalitz->fill(mKS0pi0,mpipi);
}
}
/// Normalise histograms etc., after the run
void finalize() {
normalize(_h_pipi);
normalize(_h_KS0pi0);
normalize(_h_KS0pip);
normalize(_dalitz);
}
/// @}
/// @name Histograms
/// @{
Histo1DPtr _h_pipi,_h_KS0pi0, _h_KS0pip;
Histo2DPtr _dalitz;
/// @}
};
RIVET_DECLARE_PLUGIN(BESIII_2014_I1277070);
}