rivet is hosted by Hepforge, IPPP Durham

Rivet analyses reference

BESII_2005_I685906

Cross section for $e^+e^-\to$ proton and antiproton between 2 and 3.07 GeV
Experiment: BESII (BEPC)
Inspire ID: 685906
Status: VALIDATED
Authors:
  • Peter Richardson
References:
  • Phys.Rev. D91 (2015) 112004, 2015
Beams: e+ e-
Beam energies: ANY
Run details:
  • e+ e- to hadrons

Measurement of the cross section for $e^+e^-\to p\bar{p}$ for energies between 2 and 3.07 GeV

Source code: BESII_2005_I685906.cc
 1// -*- C++ -*-
 2#include "Rivet/Analysis.hh"
 3#include "Rivet/Projections/FinalState.hh"
 4
 5namespace Rivet {
 6
 7
 8  /// @brief Cross section for e+e- to proton and antiproton between 2 and 3.07 GeV
 9  class BESII_2005_I685906 : public Analysis {
10  public:
11
12    /// Constructor
13    RIVET_DEFAULT_ANALYSIS_CTOR(BESII_2005_I685906);
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(_nproton, "TMP/proton");
27    }
28
29
30    /// Perform the per-event analysis
31    void analyze(const Event& event) {
32      const FinalState& fs = apply<FinalState>(event, "FS");
33      if (fs.particles().size()!=2) vetoEvent;
34      for (const Particle& p : fs.particles()) {
35        if (abs(p.pid())!=PID::PROTON) vetoEvent;
36      }
37      _nproton->fill();
38
39    }
40
41
42    /// Normalise histograms etc., after the run
43    void finalize() {
44      double sigma = _nproton->val();
45      double error = _nproton->err();
46      sigma *= crossSection()/ sumOfWeights() /picobarn;
47      error *= crossSection()/ sumOfWeights() /picobarn;
48      Estimate1DPtr  mult;
49      book(mult, 1, 1, 1);
50      for (auto& b : mult->bins()) {
51        if (inRange(sqrtS()/GeV, b.xMin(), b.xMax())) {
52          b.set(sigma, error);
53        }
54      }
55    }
56
57    /// @}
58
59
60    /// @name Histograms
61    /// @{
62    CounterPtr _nproton;
63    /// @}
64
65
66  };
67
68
69  RIVET_DECLARE_PLUGIN(BESII_2005_I685906);
70
71}