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Rivet analyses reference

CMD2_2003_I601222

Cross section for $e^+e^-\to K^0_SK^0_L$ 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 $e^+e^-\to K^0_SK^0_L$ at energies between 1.05 and 1.38 GeV.. Beam energy must be specified as analysis option "ENERGY" when rivet-merging samples.

Source code: CMD2_2003_I601222.cc
 1// -*- C++ -*-
 2#include "Rivet/Analysis.hh"
 3#include "Rivet/Projections/FinalState.hh"
 4
 5namespace Rivet {
 6
 7
 8  /// @brief e+e- > KS0 KL0
 9  class CMD2_2003_I601222 : public Analysis {
10  public:
11
12    /// Constructor
13    RIVET_DEFAULT_ANALYSIS_CTOR(CMD2_2003_I601222);
14
15
16    /// @name Analysis methods
17    /// @{
18
19    /// Book histograms and initialise projections before the run
20    void init() {
21
22      declare(FinalState(), "FS");
23      book(_nK0K0, 1, 1, 1);
24      
25      for (const string& en : _nK0K0.binning().edges<0>()) {
26        double end = std::stod(en)*GeV;
27        if(isCompatibleWithSqrtS(end)) {
28          _ecms = en;
29          break;
30        }
31      }
32      if(_ecms.empty()) MSG_ERROR("Beam energy incompatible with analysis.");
33    }
34
35
36    /// Perform the per-event analysis
37    void analyze(const Event& event) {
38
39      const FinalState& fs = apply<FinalState>(event, "FS");
40
41      map<long,int> nCount;
42      int ntotal(0);
43      for (const Particle& p : fs.particles()) {
44	nCount[p.pid()] += 1;
45	++ntotal;
46      }
47      if(ntotal==2 &&
48	 nCount[130]==1 && nCount[310]==1)
49	_nK0K0->fill(_ecms);
50
51    }
52
53
54    /// Normalise histograms etc., after the run
55    void finalize() {
56      scale(_nK0K0, crossSection()/ sumOfWeights() /nanobarn);
57    }
58
59    /// @}
60
61
62    /// @name Histograms
63    /// @{
64    BinnedHistoPtr<string> _nK0K0;
65    string _ecms;
66    /// @}
67
68
69  };
70
71
72  RIVET_DECLARE_PLUGIN(CMD2_2003_I601222);
73
74
75}