// -*- C++ -*-
#include "Rivet/Analysis.hh"
#include "Rivet/Projections/UnstableParticles.hh"
#include "Rivet/Projections/DecayedParticles.hh"
namespace Rivet {
/// @brief D0 -> K- pi+ pi0 (or CC)
class BABAR_2006_I722905 : public Analysis {
public:
/// Constructor
RIVET_DEFAULT_ANALYSIS_CTOR(BABAR_2006_I722905);
/// @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
for(unsigned int ix=0;ix<2;++ix)
book(_h[ix],1+ix,1,1);
}
/// Perform the per-event analysis
void analyze(const Event& event) {
static const map<PdgId,unsigned int> & mode = { {-321,1},{ 211,1}, {111,1}};
static const map<PdgId,unsigned int> & modeCC = { { 321,1},{-211,1}, {111,1}};
DecayedParticles D0 = apply<DecayedParticles>(event, "D0");
// loop over particles
for(unsigned int ix=0;ix<D0.decaying().size();++ix) {
int sign = 1;
if (D0.modeMatches(ix,3,mode)) {
sign = 1;
}
else if (D0.modeMatches(ix,3,modeCC)) {
sign =-1;
}
else
continue;
const Particle & pi0= D0.decayProducts()[ix].at(111)[0];
const Particle & Km = D0.decayProducts()[ix].at(-sign*321)[0];
double m2 = (pi0.momentum()+Km.momentum()).mass2();
if( (D0.decaying()[ix].pid()>0 && sign== 1) ||
(D0.decaying()[ix].pid()<0 && sign== -1) )
_h[0]->fill(m2);
else
_h[1]->fill(m2);
}
}
/// Normalise histograms etc., after the run
void finalize() {
for(unsigned int ix=0;ix<2;++ix)
normalize(_h[ix]);
}
/// @}
/// @name Histograms
/// @{
Histo1DPtr _h[2];
/// @}
};
RIVET_DECLARE_PLUGIN(BABAR_2006_I722905);
}