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| // -*- C++ -*-
#include "Rivet/Analysis.hh"
#include "Rivet/Projections/FinalState.hh"
#include "Rivet/Projections/UnstableParticles.hh"
#include "Rivet/Projections/Beam.hh"
namespace Rivet {
/// @brief pi0 and gamma spectra at 14, 22 and 34
class CELLO_1983_I191415 : public Analysis {
public:
/// Constructor
RIVET_DEFAULT_ANALYSIS_CTOR(CELLO_1983_I191415);
/// @name Analysis methods
//@{
/// Book histograms and initialise projections before the run
void init() {
// Initialise and register projections
declare(Beam(), "Beams");
declare(FinalState(), "FS");
declare(UnstableParticles(), "UFS");
unsigned int iloc(0);
if(isCompatibleWithSqrtS(14.)) {
iloc=1;
}
else if (isCompatibleWithSqrtS(22.)) {
iloc=2;
}
else if (isCompatibleWithSqrtS(34.)) {
iloc=3;
}
else
MSG_ERROR("Beam energy not supported!");
// Book histograms
book(_h_gamma, iloc , 1, 1);
book(_h_pi0 , iloc+3, 1, 1);
}
/// Perform the per-event analysis
void analyze(const Event& event) {
// at least 5 charged FS particles
const FinalState& fs = apply<FinalState>(event, "FS");
const size_t numParticles = fs.particles().size();
if (numParticles < 5) {
MSG_DEBUG("Failed leptonic event cut");
vetoEvent;
}
MSG_DEBUG("Passed leptonic event cut");
// Get beams and average beam momentum
const ParticlePair& beams = apply<Beam>(event, "Beams").beams();
const double meanBeamMom = ( beams.first.p3().mod() +
beams.second.p3().mod() ) / 2.0;
MSG_DEBUG("Avg beam momentum = " << meanBeamMom);
// Final state to get particle spectra
for (const Particle& p : apply<UnstableParticles>(event, "UFS").particles(Cuts::pid==111)) {
double xE = p.E()/meanBeamMom;
_h_pi0->fill(xE);
}
for (const Particle& p : apply<FinalState>(event, "FS").particles(Cuts::pid==22)) {
double xE = p.E()/meanBeamMom;
_h_gamma->fill(xE);
}
}
/// Normalise histograms etc., after the run
void finalize() {
double fact = sqr(sqrtS())/GeV2*crossSection()/microbarn/sumOfWeights();
scale(_h_gamma, fact);
scale(_h_pi0 , fact);
}
//@}
/// @name Histograms
//@{
Histo1DPtr _h_gamma,_h_pi0;
//@}
};
// The hook for the plugin system
RIVET_DECLARE_PLUGIN(CELLO_1983_I191415);
}
|