Rivet analyses

Cross section for KS0 production for energies between 3.645 and 3.7 GeV

Experiment: BESIII (BEPC)

Inspire ID: 1868813

Status: VALIDATED

Authors: - Peter Richardson

References: - Phys.Lett.B 820 (2021) 136576

Beams: e- e+

Beam energies: (1.8, 1.8); (1.8, 1.8); (1.8, 1.8); (1.8, 1.8); (1.8, 1.8); (1.8, 1.8); (1.8, 1.8); (1.8, 1.8); (1.8, 1.8); (1.8, 1.8); (1.8, 1.8); (1.8, 1.8); (1.8, 1.8); (1.8, 1.8); (1.8, 1.8); (1.8, 1.8); (1.8, 1.8); (1.8, 1.8); (1.8, 1.8); (1.8, 1.8); (1.8, 1.8); (1.9, 1.9)GeV

Run details: - e+ e- to hadrons

Cross section for the production of KS0 for energies between 3.645 and 3.7, i.e near the ψ(2S) resonace measured by BESIII.

Source code:BESIII_2021_I1868813.cc

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

namespace Rivet {


  /// @brief  kaon production at low energies
  class BESIII_2021_I1868813 : public Analysis {
  public:

    /// Constructor
    RIVET_DEFAULT_ANALYSIS_CTOR(BESIII_2021_I1868813);


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

    /// Book histograms and initialise projections before the run
    void init() {

      // Initialise and register projections
      declare(UnstableParticles(), "UFS");
      book(_c_kaons, "TMP/nK", refData<YODA::BinnedEstimate<string>>(1, 1, 1));

      for (const string& en : _c_kaons.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 UnstableParticles& ufs = apply<UnstableParticles>(event, "UFS");
      unsigned int count = ufs.particles(Cuts::pid==310).size();
      _c_kaons->fill(_sqs,count);
    }


    /// Normalise histograms etc., after the run
    void finalize() {
      BinnedEstimatePtr<string> mult;
      book(mult,1, 1, 1);
      barchart(_c_kaons,mult);
      scale(mult,crossSection()/nanobarn);
    }

    ///@}


    /// @name Histograms
    ///@{
    BinnedProfilePtr<string> _c_kaons;
    string _sqs = "";
    ///@}


  };


  RIVET_DECLARE_PLUGIN(BESIII_2021_I1868813);

}