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| // -*- C++ -*-
#include "Rivet/Analysis.hh"
#include "Rivet/Projections/UnstableParticles.hh"
namespace Rivet {
/// @brief Xi_c0 Xi_c+ spectrum in upsilon(4s) decays
class CLEOII_1997_I442910 : public Analysis {
public:
/// Constructor
RIVET_DEFAULT_ANALYSIS_CTOR(CLEOII_1997_I442910);
/// @name Analysis methods
//@{
/// Book histograms and initialise projections before the run
void init() {
// projections
declare(UnstableParticles(), "UFS");
// book histos
book(_h_Xi_c0 ,1,1,1);
book(_h_Xi_cPlus,2,1,1);
}
void findDecayProducts(Particle parent, Particles & Xic) {
for(const Particle & p : parent.children()) {
int id = abs(p.pid());
if(id==4132 || id==4232) {
Xic.push_back(p);
}
else if(!p.children().empty()) {
findDecayProducts(p,Xic);
}
}
}
/// Perform the per-event analysis
void analyze(const Event& event) {
// Find the upsilons
for (const Particle& p : apply<UnstableParticles>(event, "UFS").particles(Cuts::pid==300553)) {
// Find the decay products we want
Particles Xic;
findDecayProducts(p, Xic);
if(Xic.empty()) continue;
LorentzTransform boost;
if (p.p3().mod() > 1*MeV)
boost = LorentzTransform::mkFrameTransformFromBeta(p.momentum().betaVec());
for(const Particle & xi : Xic) {
double Emax = sqrt(0.25*sqr(p.mass())-sqr(xi.mass()));
double xp = boost.transform(xi.momentum()).vector3().mod()/Emax;
if(xi.abspid()==4132)
_h_Xi_c0->fill(xp);
else
_h_Xi_cPlus->fill(xp);
}
}
}
/// Normalise histograms etc., after the run
void finalize() {
// normalize to the data as norm in hepdata is weird
normalize(_h_Xi_c0 ,0.144);
normalize(_h_Xi_cPlus,0.453);
}
//@}
/// @name Histograms
//@{
Histo1DPtr _h_Xi_c0, _h_Xi_cPlus;
//@}
};
RIVET_DECLARE_PLUGIN(CLEOII_1997_I442910);
}
|