Rivet analyses
Cross section for e+e−→ proton and antiproton between 2.2324 and 3.671 GeV
Experiment: BESIII (BEPC II)
Inspire ID: 1358937
Status: VALIDATED
Authors: - Peter Richardson
References: - Phys.Rev. D91 (2015) 112004, 2015
Beams: e+ e-
Beam energies: (1.1, 1.1); (1.2, 1.2); (1.4, 1.4); (1.5, 1.5); (1.5, 1.5); (1.5, 1.5); (1.7, 1.7); (1.8, 1.8); (1.8, 1.8); (1.8, 1.8); (1.8, 1.8); (1.8, 1.8)GeV
Run details: - e+ e- to hadrons
Measurement of the cross section for e+e− → pp̄ for energies between 2.2324 and 3.671 GeV.
Source
code:BESIII_2015_I1358937.cc
// -*- C++ -*-
#include "Rivet/Analysis.hh"
#include "Rivet/Projections/FinalState.hh"
namespace Rivet {
/// @brief Cross section for $e^+e^-\to$ proton and antiproton between 2.2324 and 3.671 GeV
class BESIII_2015_I1358937 : public Analysis {
public:
/// Constructor
RIVET_DEFAULT_ANALYSIS_CTOR(BESIII_2015_I1358937);
/// @name Analysis methods
/// @{
/// Book histograms and initialise projections before the run
void init() {
// Initialise and register projections
declare(FinalState(), "FS");
// Book histograms
book(_nproton, 1, 1, 5);
for (const string& en : _nproton.binning().edges<0>()) {
const double eval = stod(en)*GeV;
if (isCompatibleWithSqrtS(eval)) {
_sqs = en; break;
}
}
raiseBeamErrorIf(_sqs.empty());
}
/// Perform the per-event analysis
void analyze(const Event& event) {
const FinalState& fs = apply<FinalState>(event, "FS");
if (fs.particles().size()!=2) vetoEvent;
for (const Particle& p : fs.particles()) {
if (p.abspid()!=PID::PROTON) vetoEvent;
}
_nproton->fill(_sqs);
}
/// Normalise histograms etc., after the run
void finalize() {
scale(_nproton, crossSection()/ sumOfWeights() /picobarn);
}
/// @}
/// @name Histograms
/// @{
BinnedHistoPtr<string> _nproton;
string _sqs = "";
/// @}
};
RIVET_DECLARE_PLUGIN(BESIII_2015_I1358937);
}