Rivet analyses

Cross section for e+e− → pp̄ between 1.925 and 2.18 GeV

Experiment: DM1 (DCI)

Inspire ID: 141565

Status: VALIDATED

Authors: - Peter Richardson

References: - Phys.Lett. B86 (1979) 395-398, 1979

Beams: e+ e-

Beam energies: ANY

Run details: - e+e- to hadrons

Measurement of the cross section for e+e− → pp̄ between 1.925 and 2.18 GeV.

Source code:DM1_1979_I141565.cc

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

namespace Rivet {


  /// @brief e+e- > p pbar
  class DM1_1979_I141565 : public Analysis {
  public:

    /// Constructor
    RIVET_DEFAULT_ANALYSIS_CTOR(DM1_1979_I141565);


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

    /// Book histograms and initialise projections before the run
    void init() {
      // Initialise and register projections
      declare(FinalState(), "FS");
      book(_nProton, "/TMP/nProton", refData(1, 1, 1));
    }


    /// 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()] += 1;
        ++ntotal;
      }
      if (ntotal == 2 && nCount[2212] == 1 && nCount[-2212] == 1) _nProton->fill(sqrtS() / GeV);
    }


    /// Normalise histograms etc., after the run
    void finalize() {
      scale(_nProton, crossSection() / sumOfWeights() / nanobarn);
      Estimate1DPtr mult;
      book(mult, 1, 1, 1);
      barchart(_nProton, mult);
    }

    /// @}


    /// @name Histograms
    /// @{
    Histo1DPtr _nProton;
    /// @}
  };


  RIVET_DECLARE_PLUGIN(DM1_1979_I141565);


}