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Rivet analyses reference
BABAR_2013_I1238276
Production of charged pions, kaons, and protons in $e^+e^-$ annihilations into hadrons at $\sqrt{s}=10.54$GeV
Experiment: BaBar (PEP-II)
Inspire ID: 1238276
Status: VALIDATED
Authors:
References:
Beams: e+ e-
Beam energies: (3.5, 8.0) GeV
Run details:
- $e^+ e^-$ analysis in the continuum near the $\Upsilon(4S)$ resonance, with CoM boosts of 8.0 GeV ($e^-$) and 3.5 GeV ($e^+$)
Measurement of charged pion, kaon and proton production in $e^+e^-$ collisions with the BABAR detector at the SLAC PEP-II electron-positron storage ring operating at a center-of-mass energy of 10.54 GeV. This is a measurement in the continuum.
Source code:
BABAR_2013_I1238276.cc
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117 | // -*- C++ -*-
#include "Rivet/Analysis.hh"
#include "Rivet/Projections/Beam.hh"
#include "Rivet/Projections/ChargedFinalState.hh"
namespace Rivet {
/// @brief BaBar pion, kaon and proton production in the continuum
/// @author Peter Richardson
class BABAR_2013_I1238276 : public Analysis {
public:
BABAR_2013_I1238276()
: Analysis("BABAR_2013_I1238276")
{ }
void init() {
declare(Beam(), "Beams");
declare(ChargedFinalState(), "FS");
_histPion_no_dec = bookHisto1D(1,1,1);
_histKaon_no_dec = bookHisto1D(1,1,2);
_histProton_no_dec = bookHisto1D(1,1,3);
_histPion_dec = bookHisto1D(2,1,1);
_histKaon_dec = bookHisto1D(2,1,2);
_histProton_dec = bookHisto1D(2,1,3);
}
void analyze(const Event& e) {
const double weight = e.weight();
// Loop through charged FS particles and look for charmed mesons/baryons
const ChargedFinalState& fs = apply<ChargedFinalState>(e, "FS");
const Beam beamproj = apply<Beam>(e, "Beams");
const ParticlePair& beams = beamproj.beams();
const FourMomentum mom_tot = beams.first.momentum() + beams.second.momentum();
const LorentzTransform cms_boost = LorentzTransform::mkFrameTransformFromBeta(mom_tot.betaVec());
MSG_DEBUG("CMS Energy sqrt s = " << beamproj.sqrtS());
foreach (const Particle& p, fs.particles()) {
// check if prompt or not
const GenParticle* pmother = p.genParticle();
const GenVertex* ivertex = pmother->production_vertex();
bool prompt = true;
while (ivertex) {
int n_inparts = ivertex->particles_in_size();
if (n_inparts < 1) break;
pmother = particles(ivertex, HepMC::parents)[0]; // first mother particle
int mother_pid = abs(pmother->pdg_id());
if (mother_pid==PID::K0S || mother_pid==PID::LAMBDA) {
prompt = false;
break;
}
else if (mother_pid<6) {
break;
}
ivertex = pmother->production_vertex();
}
// momentum in CMS frame
const double mom = cms_boost.transform(p.momentum()).vector3().mod();
const int PdgId = p.abspid();
MSG_DEBUG("pdgID = " << PdgId << " Momentum = " << mom);
switch (PdgId) {
case PID::PIPLUS:
if(prompt) _histPion_no_dec->fill(mom,weight);
_histPion_dec ->fill(mom,weight);
break;
case PID::KPLUS:
if(prompt) _histKaon_no_dec->fill(mom,weight);
_histKaon_dec ->fill(mom,weight);
break;
case PID::PROTON:
if(prompt) _histProton_no_dec->fill(mom,weight);
_histProton_dec ->fill(mom,weight);
default :
break;
}
}
}
void finalize() {
scale(_histPion_no_dec ,1./sumOfWeights());
scale(_histKaon_no_dec ,1./sumOfWeights());
scale(_histProton_no_dec,1./sumOfWeights());
scale(_histPion_dec ,1./sumOfWeights());
scale(_histKaon_dec ,1./sumOfWeights());
scale(_histProton_dec ,1./sumOfWeights());
}
private:
//@{
// Histograms for continuum data (sqrt(s) = 10.52 GeV)
// no K_S and Lambda decays
Histo1DPtr _histPion_no_dec;
Histo1DPtr _histKaon_no_dec;
Histo1DPtr _histProton_no_dec;
// including decays
Histo1DPtr _histPion_dec;
Histo1DPtr _histKaon_dec;
Histo1DPtr _histProton_dec;
//@}
};
// The hook for the plugin system
DECLARE_RIVET_PLUGIN(BABAR_2013_I1238276);
}
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