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SND_1999_I508003

Cross section for $e^+e^-\to \pi^+\pi^-\pi^0$ between 1.04 and 1.38 GeV.
Experiment: SND (VEPP-2M)
Inspire ID: 508003
Status: VALIDATED
Authors:
  • Peter Richardson
References:
  • Phys.Lett. B462 (1999) 365-370, 1999
Beams: e+ e-
Beam energies: ANY
Run details:
  • e+ e- to hadrons

Measurement of the cross section for $e^+e^-\to \pi^+\pi^-\pi^0$ by SND for energies between 1.04 and 1.38 GeV.

Source code: SND_1999_I508003.cc
 1// -*- C++ -*-
 2#include "Rivet/Analysis.hh"
 3#include "Rivet/Projections/FinalState.hh"
 4
 5
 6namespace Rivet {
 7
 8
 9  /// @brief Add a short analysis description here
10  class SND_1999_I508003 : public Analysis {
11  public:
12
13    /// Constructor
14    RIVET_DEFAULT_ANALYSIS_CTOR(SND_1999_I508003);
15
16
17    /// @name Analysis methods
18    /// @{
19
20    /// Book histograms and initialise projections before the run
21    void init() {
22
23      // Initialise and register projections
24      declare(FinalState(), "FS");
25
26      book(_num3pi, "TMP/num3");
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
35      map<long,int> nCount;
36      int ntotal(0);
37      for (const Particle& p : fs.particles()) {
38	nCount[p.pid()] += 1;
39	++ntotal;
40      }
41      if(ntotal!=3) vetoEvent;
42      if(nCount[-211]==1&&nCount[211]==1&&nCount[111]==1)
43	_num3pi->fill();
44
45    }
46
47
48    /// Normalise histograms etc., after the run
49    void finalize() {
50
51      double sigma = _num3pi->val();
52      double error = _num3pi->err();
53      sigma *= crossSection()/ sumOfWeights() /nanobarn;
54      error *= crossSection()/ sumOfWeights() /nanobarn;
55      Estimate1DPtr mult;
56      book(mult, 1, 1, 1);
57      for (auto& b : mult->bins()) {
58        if (inRange(sqrtS()/MeV, b.xMin(), b.xMax())) {
59          b.set(sigma, error);
60        }
61      }
62    }
63
64    /// @}
65
66
67    /// @name Histograms
68    /// @{
69    CounterPtr _num3pi;
70    /// @}
71
72
73  };
74
75
76  RIVET_DECLARE_PLUGIN(SND_1999_I508003);
77
78
79}