Rivet analyses

Cross section for e+e− → pp̄ between 1.9 and 2.44 GeV

Experiment: FENICE (ADONE)

Inspire ID: 377833

Status: VALIDATED

Authors: - Peter Richardson

References: - Phys.Lett. B334 (1994) 431-434, 1994

Beams: e+ e-

Beam energies: (1.0, 1.0); (1.0, 1.0); (1.1, 1.1); (1.2, 1.2)GeV

Run details: - e+e- to hadrons

Measurement of the cross section for e+e− → pp̄ between 1.9 and 2.44 GeV.

Source code:FENICE_1994_I377833.cc

// -*- C++ -*-
#include "Rivet/Analysis.hh"
#include "Rivet/Projections/FinalState.hh"
#include "Rivet/Projections/UnstableParticles.hh"

namespace Rivet {


  /// @brief e+e- -> p pbar
  class FENICE_1994_I377833 : public Analysis {
  public:

    /// Constructor
    RIVET_DEFAULT_ANALYSIS_CTOR(FENICE_1994_I377833);


    /// @name Analysis methods
    /// @{

    /// Book histograms and initialise projections before the run
    void init() {
      // Initialise and register projections
      declare(FinalState(), "FS");
      declare(UnstableParticles(), "UFS");
      book(_nProton, 1, 1, 1);
      for (const string& en : _nProton.binning().edges<0>()) {
        const double eval = sqrt(stod(en));
        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");
      // total hadronic and muonic cross sections
      map<long,int> nCount;
      int ntotal(0);
      for (const Particle& p : fs.particles()) {
        ++nCount[p.pid()];
        ++ntotal;
      }
      if (ntotal==2 && nCount[2212]==1 && nCount[-2212]==1) _nProton->fill(_sqs);
    }


    /// Normalise histograms etc., after the run
    void finalize() {
      scale(_nProton, crossSection()/ sumOfWeights() /nanobarn);
    }

    /// @}


    /// @name Histograms
    /// @{
    BinnedHistoPtr<string> _nProton;
    string _sqs = "";
    /// @}


  };


  RIVET_DECLARE_PLUGIN(FENICE_1994_I377833);
}