Rivet analyses

Cross section for e+e− → KS0KL0 at energies between 1.05 and 1.38 GeV

Experiment: CMD2 (VEPP-2M)

Inspire ID: 601222

Status: VALIDATED

Authors: - Peter Richardson

References: - Phys.Lett. B551 (2003) 27-34, 2003

Beams: e+ e-

Beam energies: (0.5, 0.5); (0.5, 0.5); (0.5, 0.5); (0.5, 0.5); (0.5, 0.5); (0.6, 0.6); (0.6, 0.6); (0.6, 0.6); (0.6, 0.6); (0.6, 0.6); (0.6, 0.6); (0.6, 0.6); (0.6, 0.6); (0.6, 0.6); (0.6, 0.6); (0.6, 0.6); (0.6, 0.6); (0.6, 0.6); (0.6, 0.6); (0.6, 0.6); (0.7, 0.7); (0.7, 0.7)GeV

Run details: - e+e- to hadrons

Measurement of the cross section for e+e− → KS0KL0 at energies between 1.05 and 1.38 GeV.

Source code:CMD2_2003_I601222.cc

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

namespace Rivet {


  /// @brief e+e- > KS0 KL0
  class CMD2_2003_I601222 : public Analysis {
  public:

    /// Constructor
    RIVET_DEFAULT_ANALYSIS_CTOR(CMD2_2003_I601222);


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

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

      declare(FinalState(), "FS");
      book(_nK0K0, 1, 1, 1);

      for (const string& en : _nK0K0.binning().edges<0>()) {
        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");

      map<long,int> nCount;
      int ntotal(0);
      for (const Particle& p : fs.particles()) {
        nCount[p.pid()] += 1;
        ++ntotal;
      }
      if (ntotal==2 && nCount[130]==1 && nCount[310]==1) _nK0K0->fill(_sqs);
    }


    /// Normalise histograms etc., after the run
    void finalize() {
      scale(_nK0K0, crossSection()/sumOfWeights()/nanobarn);
    }

    /// @}


    /// @name Histograms
    /// @{
    BinnedHistoPtr<string> _nK0K0;
    string _sqs = "";
    /// @}


  };


  RIVET_DECLARE_PLUGIN(CMD2_2003_I601222);
}