// -*- C++ -*-
#include "Rivet/Analysis.hh"
#include "Rivet/Projections/UnstableParticles.hh"
#include "Rivet/Projections/DecayedParticles.hh"
namespace Rivet {
/// @brief D+/Ds+ -> K+ pi+ pi-
class FOCUS_2004_I654030 : public Analysis {
public:
/// Constructor
RIVET_DEFAULT_ANALYSIS_CTOR(FOCUS_2004_I654030);
/// @name Analysis methods
/// @{
/// Book histograms and initialise projections before the run
void init() {
// Initialise and register projections
UnstableParticles ufs = UnstableParticles(Cuts::abspid==411 or
Cuts::abspid==431);
declare(ufs, "UFS");
DecayedParticles DD(ufs);
DD.addStable(PID::PI0);
DD.addStable(PID::K0S);
declare(DD, "DD");
// histograms
for(unsigned int ix=0;ix<2;++ix) {
book(_h_Kpim[ix],1+ix,1,1);
book(_h_pipi[ix],1+ix,1,2);
book(_dalitz[ix],"dalitz_"+to_str(ix+1),50,0.3,3.5,50,0.,2.3);
}
}
/// Perform the per-event analysis
void analyze(const Event& event) {
static const map<PdgId,unsigned int> & mode = { { 211,1}, { 321,1}, {-211,1}};
static const map<PdgId,unsigned int> & modeCC = { {-211,1}, {-321,1}, { 211,1}};
DecayedParticles DD = apply<DecayedParticles>(event, "DD");
// loop over particles
for(unsigned int ix=0;ix<DD.decaying().size();++ix) {
int sign = 1;
if (DD.decaying()[ix].pid()>0 && DD.modeMatches(ix,3,mode)) {
sign=1;
}
else if (DD.decaying()[ix].pid()<0 && DD.modeMatches(ix,3,modeCC)) {
sign=-1;
}
else
continue;
const Particle & Kp = DD.decayProducts()[ix].at( sign*321)[0];
const Particle & pip = DD.decayProducts()[ix].at( sign*211)[0];
const Particle & pim = DD.decayProducts()[ix].at(-sign*211)[0];
double mm = (Kp .momentum()+pim.momentum()).mass2();
double mpipi = (pip.momentum()+pim.momentum()).mass2();
unsigned int iloc = DD.decaying()[ix].abspid()==411 ? 0 : 1;
_dalitz[iloc]->fill(mm,mpipi);
_h_pipi[iloc]->fill(mpipi);
_h_Kpim[iloc]->fill(mm);
}
}
/// Normalise histograms etc., after the run
void finalize() {
for(unsigned int ix=0;ix<2;++ix) {
normalize(_h_Kpim[ix]);
normalize(_h_pipi[ix]);
normalize(_dalitz[ix]);
}
}
/// @}
/// @name Histograms
/// @{
Histo1DPtr _h_Kpim[2],_h_pipi[2];
Histo2DPtr _dalitz[2];
/// @}
};
RIVET_DECLARE_PLUGIN(FOCUS_2004_I654030);
}