// -*- C++ -*-
#include "Rivet/Analysis.hh"
#include "Rivet/Projections/UnstableParticles.hh"
#include "Rivet/Projections/DecayedParticles.hh"
namespace Rivet {
/// @brief B0 -> pi+ pi- K*0
class BABAR_2012_I1081760 : public Analysis {
public:
/// Constructor
RIVET_DEFAULT_ANALYSIS_CTOR(BABAR_2012_I1081760);
/// @name Analysis methods
/// @{
/// Book histograms and initialise projections before the run
void init() {
// projections
UnstableParticles ufs = UnstableParticles(Cuts::abspid==511);
declare(ufs, "UFS");
DecayedParticles B0(ufs);
B0.addStable( 313);
B0.addStable(-313);
declare(B0, "B0");
// histogram
book(_h,1,1,1);
}
/// Perform the per-event analysis
void analyze(const Event& event) {
static const map<PdgId,unsigned int> & mode = { { 211,1}, {-211,1}, { 313,1}};
static const map<PdgId,unsigned int> & modeCC = { { 211,1}, {-211,1}, {-313,1}};
DecayedParticles B0 = apply<DecayedParticles>(event, "B0");
for(unsigned int ix=0;ix<B0.decaying().size();++ix) {
int sign = 1;
if (B0.decaying()[ix].pid()>0 && B0.modeMatches(ix,3,mode)) sign= 1;
else if (B0.decaying()[ix].pid()<0 && B0.modeMatches(ix,3,modeCC)) sign=-1;
else continue;
const Particle & pip = B0.decayProducts()[ix].at( sign*211)[0];
const Particle & pim = B0.decayProducts()[ix].at(-sign*211)[0];
_h->fill((pip.momentum()+pim.momentum()).mass());
}
}
/// Normalise histograms etc., after the run
void finalize() {
normalize(_h,1.,false);
}
/// @}
/// @name Histograms
/// @{
Histo1DPtr _h;
/// @}
};
RIVET_DECLARE_PLUGIN(BABAR_2012_I1081760);
}