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Rivet analyses reference

CMD2_1999_I498859

Cross section for $e^+e^-\to \pi^+\pi^-$ at near the $\rho$ mass.
Experiment: CMD2 (VEPP-2M)
Inspire ID: 498859
Status: VALIDATED
Authors:
  • Peter Richardson
References:
  • Phys.Lett. B527 (2002) 161-172, 2002
Beams: e+ e-
Beam energies: (0.3, 0.3); (0.3, 0.3); (0.3, 0.3); (0.3, 0.3); (0.3, 0.3); (0.3, 0.3); (0.3, 0.3); (0.3, 0.3); (0.3, 0.3); (0.4, 0.4); (0.4, 0.4); (0.4, 0.4); (0.4, 0.4); (0.4, 0.4); (0.4, 0.4); (0.4, 0.4); (0.4, 0.4); (0.4, 0.4); (0.4, 0.4); (0.4, 0.4); (0.4, 0.4); (0.4, 0.4); (0.4, 0.4); (0.4, 0.4); (0.4, 0.4); (0.4, 0.4); (0.4, 0.4); (0.4, 0.4); (0.4, 0.4); (0.4, 0.4); (0.4, 0.4); (0.4, 0.4); (0.4, 0.4); (0.4, 0.4); (0.4, 0.4); (0.4, 0.4); (0.4, 0.4); (0.5, 0.5); (0.5, 0.5); (0.5, 0.5); (0.5, 0.5); (0.5, 0.5); (0.5, 0.5); (0.5, 0.5) GeV
Run details:
  • e+e- to hadrons

Source code: CMD2_1999_I498859.cc
 1// -*- C++ -*-
 2#include "Rivet/Analysis.hh"
 3#include "Rivet/Projections/FinalState.hh"
 4
 5
 6namespace Rivet {
 7
 8
 9  /// @brief e+e- > pi+pi-
10  class CMD2_1999_I498859 : public Analysis {
11  public:
12
13    /// Constructor
14    RIVET_DEFAULT_ANALYSIS_CTOR(CMD2_1999_I498859);
15
16
17    /// @name Analysis methods
18    /// @{
19
20    /// Book histograms and initialise projections before the run
21    void init() {
22      // Initialise and register projections
23      declare(FinalState(), "FS");
24
25      // Book histograms
26      book(_npion, 1, 1, 1);
27      for (const string& en : _npion.binning().edges<0>()) {
28        double end = std::stod(en)*MeV;
29        if(isCompatibleWithSqrtS(end)) {
30          _ecms = en;
31          break;
32        }
33      }
34      if(_ecms.empty()) MSG_ERROR("Beam energy incompatible with analysis.");
35    }
36
37
38    /// Perform the per-event analysis
39    void analyze(const Event& event) {
40      const FinalState& fs = apply<FinalState>(event, "FS");
41      if(fs.particles().size()!=2) vetoEvent;
42      for (const Particle& p : fs.particles()) {
43        if(abs(p.pid())!=PID::PIPLUS) vetoEvent;
44      }
45      _npion->fill(_ecms);
46    }
47
48
49    /// Normalise histograms etc., after the run
50    void finalize() {
51      scale(_npion,crossSection()/ sumOfWeights() /nanobarn);
52    }
53
54    /// @}
55
56
57    /// @name Histograms
58    /// @{
59    BinnedHistoPtr<string> _npion;
60    string _ecms;
61    /// @}
62
63
64  };
65
66
67  RIVET_DECLARE_PLUGIN(CMD2_1999_I498859);
68
69
70}