rivet is hosted by Hepforge, IPPP Durham

Rivet analyses reference

CMD2_2004_I648023

Cross section for $e^+e^-\to\pi^+\pi^+\pi^-\pi^+$ between 0.98 and 1.38 GeV
Experiment: CMD2 (VEPP-2M)
Inspire ID: 648023
Status: VALIDATED
Authors:
  • Peter Richardson
References:
  • Phys.Lett. B595 (2004) 101-108, 2004
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); (0.5, 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); (0.6, 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); (0.7, 0.7); (0.7, 0.7); (0.7, 0.7); (0.7, 0.7); (0.7, 0.7); (0.7, 0.7); (0.7, 0.7) GeV
Run details:
  • e+e- to hadrons

Measurement of the cross section for $e^+e^-\to\pi^+\pi^+\pi^-\pi^+$ between 0.98 and 1.38 GeV. Beam energy must be specified as analysis option "ENERGY" when rivet-merging samples.

Source code: CMD2_2004_I648023.cc
 1// -*- C++ -*-
 2#include "Rivet/Analysis.hh"
 3#include "Rivet/Projections/FinalState.hh"
 4
 5namespace Rivet {
 6
 7
 8  /// @brief Add a short analysis description here
 9  class CMD2_2004_I648023 : public Analysis {
10  public:
11
12    /// Constructor
13    RIVET_DEFAULT_ANALYSIS_CTOR(CMD2_2004_I648023);
14
15
16    /// @name Analysis methods
17    /// @{
18
19    /// Book histograms and initialise projections before the run
20    void init() {
21
22      // Initialise and register projections
23      declare(FinalState(), "FS");
24
25      // Book histograms
26      book(_npion, 1, 1, 1);
27
28    }
29
30
31    /// Perform the per-event analysis
32    void analyze(const Event& event) {
33      const FinalState& fs = apply<FinalState>(event, "FS");
34      if(fs.particles().size()!=4) vetoEvent;
35      for (const Particle& p : fs.particles()) {
36	if(abs(p.pid())!=PID::PIPLUS) vetoEvent;
37      }
38      _npion->fill(round(sqrtS()/MeV));
39    }
40
41
42    /// Normalise histograms etc., after the run
43    void finalize() {
44      scale(_npion, crossSection()/ sumOfWeights() /nanobarn);
45    }
46
47    /// @}
48
49
50    /// @name Histograms
51    /// @{
52    BinnedHistoPtr<int> _npion;
53    /// @}
54
55
56  };
57
58
59  RIVET_DECLARE_PLUGIN(CMD2_2004_I648023);
60
61
62}