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Rivet analyses reference

DM1_1982_I168552

Cross section for $e^+e^-\to\pi^+\pi^+\pi^-\pi^+$ between 1.4 and 2.18 GeV
Experiment: DM1 (DCI)
Inspire ID: 168552
Status: VALIDATED
Authors:
  • Peter Richardson
References:
  • Phys.Lett. B109 (1982) 129-132, 1982
Beams: e+ e-
Beam energies: (0.7, 0.7); (0.7, 0.7); (0.7, 0.7); (0.7, 0.7); (0.7, 0.7); (0.8, 0.8); (0.8, 0.8); (0.8, 0.8); (0.8, 0.8); (0.8, 0.8); (0.8, 0.8); (0.8, 0.8); (0.8, 0.8); (0.8, 0.8); (0.8, 0.8); (0.9, 0.9); (0.9, 0.9); (0.9, 0.9); (0.9, 0.9); (0.9, 0.9); (0.9, 0.9); (0.9, 0.9); (0.9, 0.9); (0.9, 0.9); (0.9, 0.9); (1.0, 1.0); (1.0, 1.0); (1.0, 1.0); (1.0, 1.0); (1.0, 1.0); (1.0, 1.0); (1.0, 1.0); (1.0, 1.0); (1.1, 1.1); (1.1, 1.1); (1.1, 1.1); (1.1, 1.1) GeV
Run details:
  • e+e- to hadrons

Measurement of the cross section for $e^+e^-\to\pi^+\pi^+\pi^-\pi^+$ between 1.4 and 2.18 GeV. Beam energy must be specified as analysis option "ENERGY" when rivet-merging samples.

Source code: DM1_1982_I168552.cc
 1// -*- C++ -*-
 2#include "Rivet/Analysis.hh"
 3#include "Rivet/Projections/FinalState.hh"
 4
 5namespace Rivet {
 6
 7
 8  /// @brief e+ e- -> 2pi+ 2pi-
 9  class DM1_1982_I168552 : public Analysis {
10  public:
11
12    /// Constructor
13    RIVET_DEFAULT_ANALYSIS_CTOR(DM1_1982_I168552);
14
15
16    /// @name Analysis methods
17    /// @{
18
19    /// Book histograms and initialise projections before the run
20    void init() {
21      // Initialise and register projections
22      declare(FinalState(), "FS");
23      // Book histograms
24      book(_npion, 1, 1, 1);
25      for (const string& en : _npion.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      const FinalState& fs = apply<FinalState>(event, "FS");
39      if(fs.particles().size()!=4) vetoEvent;
40      for (const Particle& p : fs.particles()) {
41	if(abs(p.pid())!=PID::PIPLUS) vetoEvent;
42      }
43      _npion->fill(_ecms);
44    }
45
46
47    /// Normalise histograms etc., after the run
48    void finalize() {
49      scale(_npion, crossSection()/ sumOfWeights() /nanobarn);
50    }
51
52    /// @}
53
54
55    /// @name Histograms
56    /// @{
57    BinnedHistoPtr<string> _npion;
58    string _ecms;
59    /// @}
60
61
62  };
63
64
65  RIVET_DECLARE_PLUGIN(DM1_1982_I168552);
66
67
68}