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| // -*- C++ -*-
#include "Rivet/Analysis.hh"
#include "Rivet/Projections/Beam.hh"
#include "Rivet/Projections/UnstableParticles.hh"
namespace Rivet {
/// @brief Sigma*_c spectra
class CLEOII_1997_I424575 : public Analysis {
public:
/// Constructor
RIVET_DEFAULT_ANALYSIS_CTOR(CLEOII_1997_I424575);
/// @name Analysis methods
///@{
/// Book histograms and initialise projections before the run
void init() {
// projections
declare(Beam(), "Beams");
declare(UnstableParticles(), "UFS");
// book histos
book(_h_cTheta,2,1,1);
book(_h_x ,3,1,1);
}
/// 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 Emax = ( beams.first.p3().mod() + beams.second.p3().mod() ) / 2.0;
const double Pmax = sqrt(sqr(Emax)-sqr(2.518));
const UnstableParticles& ufs = apply<UnstableParticles>(event, "UFS");
for (const Particle& p : ufs.particles(Cuts::abspid==4114 or Cuts::abspid==4224)) {
// momentum fraction
double xp = p.momentum().p3().mod()/Pmax;
_h_x->fill(xp);
if(p.children().size()!=2) continue;
// decay angle
Particle pi;
int sign = p.pid()/p.abspid();
if(p.abspid()==4224) {
if(p.children()[0].pid() == sign*4122 &&
p.children()[1].pid() == sign*211 ) {
pi=p.children()[1];
}
else if(p.children()[1].pid() == sign*4122 &&
p.children()[0].pid() == sign*211 ) {
pi=p.children()[0];
}
else
continue;
}
else {
if(p.children()[0].pid() == sign*4122 &&
p.children()[1].pid() == -sign*211 ) {
pi=p.children()[1];
}
else if(p.children()[1].pid() == sign*4122 &&
p.children()[0].pid() == -sign*211 ) {
pi=p.children()[0];
}
else
continue;
}
LorentzTransform boost = LorentzTransform::mkFrameTransformFromBeta(p.momentum().betaVec());
Vector3 axis = boost.transform(pi.momentum()).p3().unit();
double cosL = axis.dot(p.momentum().p3().unit());
_h_cTheta->fill(cosL);
}
}
/// Normalise histograms etc., after the run
void finalize() {
normalize(_h_x ,1.,false);
normalize(_h_cTheta,1.,false);
}
///@}
/// @name Histograms
///@{
Histo1DPtr _h_x,_h_cTheta;
///@}
};
RIVET_DECLARE_PLUGIN(CLEOII_1997_I424575);
}
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