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| // -*- C++ -*-
#include "Rivet/Analysis.hh"
#include "Rivet/Particle.hh"
namespace Rivet {
class LHCB_2010_I867355 : public Analysis {
public:
LHCB_2010_I867355() : Analysis("LHCB_2010_I867355")
{ }
void init() {
//@ Results are presented for two different fragmentation functions, LEP and Tevatron. Therefore, we have two sets of histograms.
book(_h_sigma_vs_eta_lep ,1, 1, 1);
book(_h_sigma_vs_eta_tvt ,1, 1, 2);
book(_h_sigma_total_lep ,2, 1, 1);
book(_h_sigma_total_tvt ,2, 1, 2);
}
/// Perform the per-event analysis
void analyze(const Event& event) {
Particles bhadrons;
for(ConstGenParticlePtr p: HepMCUtils::particles(event.genEvent())) {
if (!( PID::isHadron( p->pdg_id() ) && PID::hasBottom( p->pdg_id() )) ) continue;
ConstGenVertexPtr dv = p->end_vertex();
bool hasBdaughter = false;
if ( PID::isHadron( p->pdg_id() ) && PID::hasBottom( p->pdg_id() )) { // selecting b-hadrons
if (dv) {
for (ConstGenParticlePtr pp: HepMCUtils::particles(dv, Relatives::CHILDREN)){
if (PID::isHadron(pp->pdg_id() ) && PID::hasBottom(pp->pdg_id() )) {
hasBdaughter = true;
}
}
}
}
if (hasBdaughter) continue; // continue if the daughter is another b-hadron
bhadrons += Particle(*p);
}
for (const Particle& particle : bhadrons) {
// take fabs() to use full statistics and then multiply weight by 0.5 because LHCb is single-sided
double eta = fabs(particle.eta());
_h_sigma_vs_eta_lep->fill( eta, 0.5 );
_h_sigma_vs_eta_tvt->fill( eta, 0.5 );
_h_sigma_total_lep->fill( eta, 0.5 ); // histogram for full kinematic range
_h_sigma_total_tvt->fill( eta, 0.5 ); // histogram for full kinematic range
}
}
void finalize() {
double norm = crossSection()/microbarn/sumOfWeights();
double binwidth = 4.; // integrated over full rapidity space from 2 to 6.
// to get the avergae of b and bbar, we scale with 0.5
scale(_h_sigma_vs_eta_lep, 0.5*norm);
scale(_h_sigma_vs_eta_tvt, 0.5*norm);
scale(_h_sigma_total_lep, 0.5*norm*binwidth);
scale(_h_sigma_total_tvt, 0.5*norm*binwidth);
}
private:
Histo1DPtr _h_sigma_total_lep;
Histo1DPtr _h_sigma_total_tvt;
Histo1DPtr _h_sigma_vs_eta_lep;
Histo1DPtr _h_sigma_vs_eta_tvt;
};
// Hook for the plugin system
RIVET_DECLARE_PLUGIN(LHCB_2010_I867355);
}
|