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| // -*- C++ -*-
#include "Rivet/Analysis.hh"
#include "Rivet/Projections/UnstableParticles.hh"
namespace Rivet {
/// @brief Charged particle multiplicity in eta_c decays
class BESIII_2019_I1724880 : public Analysis {
public:
/// Constructor
RIVET_DEFAULT_ANALYSIS_CTOR(BESIII_2019_I1724880);
/// @name Analysis methods
//@{
/// Book histograms and initialise projections before the run
void init() {
// Initialise and register projections
declare(UnstableParticles(), "UFS");
// Book histograms
book(_h_n, 1, 1, 1);
}
void findChildren(const Particle & p,int & nCharged) {
for( const Particle &child : p.children()) {
if(child.children().empty()) {
if(PID::isCharged(child.pid())) ++nCharged;
}
else
findChildren(child,nCharged);
}
}
/// Perform the per-event analysis
void analyze(const Event& event) {
for (const Particle& p : apply<FinalState>(event, "UFS").particles(Cuts::pid==441)) {
int nCharged(0);
findChildren(p,nCharged);
_h_n->fill(min(nCharged,8));
}
}
/// Normalise histograms etc., after the run
void finalize() {
normalize(_h_n,2.);
}
//@}
/// @name Histograms
//@{
Histo1DPtr _h_n;
//@}
};
// The hook for the plugin system
RIVET_DECLARE_PLUGIN(BESIII_2019_I1724880);
}
|