// -*- C++ -*-
#include "Rivet/Analysis.hh"
#include "Rivet/Projections/UnstableParticles.hh"
#include "Rivet/Projections/DecayedParticles.hh"
namespace Rivet {
/// @brief B0 -> KS0 K-+ pi+-
class BELLE_2019_I1729723 : public Analysis {
public:
/// Constructor
RIVET_DEFAULT_ANALYSIS_CTOR(BELLE_2019_I1729723);
/// @name Analysis methods
/// @{
/// Book histograms and initialise projections before the run
void init() {
UnstableParticles ufs = UnstableParticles(Cuts::abspid==511);
declare(ufs, "UFS");
DecayedParticles B0(ufs);
B0.addStable(PID::PI0);
B0.addStable(PID::K0S);
B0.addStable(PID::ETA);
B0.addStable(PID::ETAPRIME);
declare(B0, "B0");
for(unsigned int ix=0;ix<3;++ix) {
for(unsigned int iy=0;iy<2;++iy) {
book(_h[ix][iy],1+ix,1,1+iy);
}
}
book(_n,"TMP/nB0");
}
/// Perform the per-event analysis
void analyze(const Event& event) {
static const map<PdgId,unsigned int> & mode = { { 310,1}, {-321,1}, { 211,1} };
static const map<PdgId,unsigned int> & modeCC = { { 310,1}, { 321,1}, {-211,1} };
DecayedParticles B0 = apply<DecayedParticles>(event, "B0");
// loop over particles
for(unsigned int ix=0;ix<B0.decaying().size();++ix) {
_n->fill();
unsigned int iloc(0);
int sign=1;
if(B0.modeMatches(ix,3,mode)) {
sign=1;
iloc = B0.decaying()[ix].pid()>0 ? 1 : 0;
}
else if(B0.modeMatches(ix,3,modeCC)) {
sign=-1;
iloc = B0.decaying()[ix].pid()>0 ? 0 : 1;
}
else
continue;
const Particle & pip = B0.decayProducts()[ix].at( sign*211)[0];
const Particle & Km = B0.decayProducts()[ix].at(-sign*321)[0];
const Particle & K0 = B0.decayProducts()[ix].at( 310)[0];
_h[0][iloc]->fill((Km.momentum()+pip.momentum()).mass());
_h[1][iloc]->fill((K0.momentum()+pip.momentum()).mass());
_h[2][iloc]->fill((Km.momentum()+K0 .momentum()).mass());
}
}
/// Normalise histograms etc., after the run
void finalize() {
for(unsigned int ix=0;ix<3;++ix) {
for(unsigned int iy=0;iy<2;++iy) {
scale(_h[ix][iy], 1e7/ *_n);
}
}
}
/// @}
/// @name Histograms
/// @{
Histo1DPtr _h[3][2];
CounterPtr _n;
/// @}
};
RIVET_DECLARE_PLUGIN(BELLE_2019_I1729723);
}