// -*- C++ -*-
#include "Rivet/Analysis.hh"
#include "Rivet/Projections/FinalState.hh"
#include "Rivet/Projections/FastJets.hh"
#include "Rivet/Projections/DressedLeptons.hh"
#include "Rivet/Projections/MissingMomentum.hh"
#include "Rivet/Projections/DirectFinalState.hh"
#include "Rivet/Projections/UnstableParticles.hh"
namespace Rivet {
/// @brief direct photon spectrum in upslion decay
class CRYSTAL_BALL_1991_I315873 : public Analysis {
public:
/// Constructor
RIVET_DEFAULT_ANALYSIS_CTOR(CRYSTAL_BALL_1991_I315873);
/// @name Analysis methods
/// @{
/// Book histograms and initialise projections before the run
void init() {
// projections
declare(UnstableParticles(), "UFS");
book(_h_gamma[0],2,1,1);
book(_h_gamma[1],2,1,2);
}
/// Perform the per-event analysis
void analyze(const Event& event) {
// Find the Upsilons among the unstables
for (const Particle& ups : apply<UnstableParticles>(event, "UFS").particles(Cuts::pid==553)) {
unsigned int nhadron(0);
Particles photons;
for(const Particle & child : ups.children()) {
if(PID::isHadron(child.pid()))
++nhadron;
else if(child.pid()==PID::PHOTON)
photons.push_back(child);
}
if(nhadron!=0 && !photons.empty()) {
LorentzTransform boost;
if (ups.p3().mod() > 1*MeV)
boost = LorentzTransform::mkFrameTransformFromBeta(ups.momentum().betaVec());
for(const Particle & gamma:photons) {
double z = 2.*boost.transform(gamma.momentum()).E()/ups.mass();
_h_gamma[0]->fill(z);
_h_gamma[1]->fill(z);
}
}
}
}
/// Normalise histograms etc., after the run
void finalize() {
normalize(_h_gamma[0],1.,false);
normalize(_h_gamma[1],1.,false);
}
/// @}
/// @name Histograms
/// @{
Histo1DPtr _h_gamma[2];
/// @}
};
RIVET_DECLARE_PLUGIN(CRYSTAL_BALL_1991_I315873);
}