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| // -*- C++ -*-
#include "Rivet/Analysis.hh"
#include "Rivet/Projections/UnstableParticles.hh"
namespace Rivet {
/// @brief Add a short analysis description here
class BELLE_2007_I753243 : public Analysis {
public:
/// Constructor
RIVET_DEFAULT_ANALYSIS_CTOR(BELLE_2007_I753243);
/// @name Analysis methods
//@{
/// Book histograms and initialise projections before the run
void init() {
declare(UnstableParticles(), "UFS");
book(_hist_Kpi, 1, 1, 1);
}
void findDecayProducts(const Particle & mother, unsigned int & nstable,
unsigned int & npip, unsigned int & npim,
unsigned int & nK, FourMomentum & ptot) {
for(const Particle & p : mother.children()) {
int id = p.pid();
if (id == PID::K0S ) {
++nK;
++nstable;
ptot += p.momentum();
}
else if (id == PID::PIPLUS) {
++npip;
++nstable;
ptot += p.momentum();
}
else if (id == PID::PIMINUS) {
++npim;
++nstable;
ptot += p.momentum();
}
else if (id == PID::PI0 || id == PID::KPLUS ||
id == PID::KMINUS) {
++nstable;
}
else if ( !p.children().empty() ) {
findDecayProducts(p, nstable, npip, npim, nK,ptot);
}
else
++nstable;
}
}
/// Perform the per-event analysis
void analyze(const Event& event) {
// Loop over taus
for(const Particle& tau : apply<UnstableParticles>(event, "UFS").particles(Cuts::abspid==PID::TAU)) {
unsigned int nstable(0),npip(0),npim(0),nK(0);
FourMomentum p_tot(0,0,0,0);
findDecayProducts(tau, nstable, npip, npim, nK, p_tot);
if (tau.pid() < 0) swap(npip, npim);
if(nstable==3 && npim==1 && nK==1)
_hist_Kpi->fill(p_tot.mass());
}
}
/// Normalise histograms etc., after the run
void finalize() {
normalize(_hist_Kpi);
}
//@}
/// @name Histograms
//@{
Histo1DPtr _hist_Kpi;
//@}
};
// The hook for the plugin system
RIVET_DECLARE_PLUGIN(BELLE_2007_I753243);
}
|