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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 gamma, pi0 and eta spectra at 35 and 44 GeV
class JADE_1990_I282847 : public Analysis {
public:
/// Constructor
RIVET_DEFAULT_ANALYSIS_CTOR(JADE_1990_I282847);
/// @name Analysis methods
//@{
/// Book histograms and initialise projections before the run
void init() {
declare(Beam(), "Beams");
declare(FinalState(), "FS");
declare(UnstableParticles(), "UFS");
int ioff=-1;
if(isCompatibleWithSqrtS(35)) {
ioff=0;
}
else if(isCompatibleWithSqrtS(44.)) {
ioff=1;
}
else
MSG_ERROR("Beam energy " << sqrtS() << " not supported!");
// Book histograms
book(_h_gamma, 1+ioff, 1, 1);
book(_h_pi0 , 3+ioff, 1, 1);
if(ioff==0) book(_h_eta, 5+ioff, 1, 1);
}
/// Perform the per-event analysis
void analyze(const Event& event) {
// 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;
// gamma
const FinalState& fs = apply<FinalState>(event, "FS");
for (const Particle& p : fs.particles(Cuts::pid==22)) {
double xE = p.E()/meanBeamMom;
_h_gamma->fill(xE);
}
// pi0, eta
const UnstableParticles& ufs = apply<UnstableParticles>(event, "UFS");
for (const Particle& p : ufs.particles(Cuts::pid==111 or Cuts::pid==221)) {
double modp = p.p3().mod();
double xE = p.E()/meanBeamMom;
double beta = modp/p.E();
if(p.pid()==111)
_h_pi0->fill(xE,1./beta);
else if(_h_eta)
_h_eta->fill(xE,1./beta);
}
}
/// Normalise histograms etc., after the run
void finalize() {
scale(_h_gamma, crossSection()*sqr(sqrtS())/microbarn/sumOfWeights());
scale(_h_pi0 , crossSection()*sqr(sqrtS())/microbarn/sumOfWeights());
if(_h_eta) scale(_h_eta , crossSection()*sqr(sqrtS())/microbarn/sumOfWeights());
}
//@}
/// @name Histograms
//@{
Histo1DPtr _h_gamma, _h_pi0, _h_eta;
//@}
};
// The hook for the plugin system
RIVET_DECLARE_PLUGIN(JADE_1990_I282847);
}
|