// -*- C++ -*-
#include "Rivet/Analysis.hh"
#include "Rivet/Projections/UnstableParticles.hh"
#include "Rivet/Projections/DecayedParticles.hh"
namespace Rivet {
/// @brief Lambda_c+ -> p K- e+ nu_e
class BESIII_2022_I2122399 : public Analysis {
public:
/// Constructor
RIVET_DEFAULT_ANALYSIS_CTOR(BESIII_2022_I2122399);
/// @name Analysis methods
/// @{
/// Book histograms and initialise projections before the run
void init() {
// Initialise and register projections
UnstableParticles ufs = UnstableParticles(Cuts::pid==4122);
declare(ufs, "UFS");
DecayedParticles LambdaC(ufs);
LambdaC.addStable(PID::PI0);
LambdaC.addStable(PID::K0S);
LambdaC.addStable(PID::ETA);
LambdaC.addStable(PID::ETAPRIME);
declare(LambdaC, "LambdaC");
// Book histogram
book(_h,1,1,1);
}
/// Perform the per-event analysis
void analyze(const Event& event) {
static const map<PdgId,unsigned int> & mode = { { -321,1}, { 2212,1}, {-11,1}, { 12,1}};
DecayedParticles LambdaC = apply<DecayedParticles>(event, "LambdaC");
// loop over particles
for(unsigned int ix=0;ix<LambdaC.decaying().size();++ix) {
if ( !LambdaC.modeMatches(ix,4,mode) ) continue;
const Particle & Km = LambdaC.decayProducts()[ix].at(-321 )[0];
const Particle & pp = LambdaC.decayProducts()[ix].at( 2212)[0];
_h->fill((Km.momentum()+pp.momentum()).mass());
}
}
/// Normalise histograms etc., after the run
void finalize() {
normalize(_h);
}
/// @}
/// @name Histograms
/// @{
Histo1DPtr _h;
/// @}
};
RIVET_DECLARE_PLUGIN(BESIII_2022_I2122399);
}