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Rivet analyses reference

AMY_1990_I294525

Measurement of $R$ for energies between 50 and 61.4 GeV.
Experiment: AMY (Tristan)
Inspire ID: 294525
Status: VALIDATED
Authors:
  • Peter Richardson
References:
  • Phys.Rev. D42 (1990) 1339-1349, 1990
Beams: e- e+
Beam energies: (25.0, 25.0); (26.0, 26.0); (27.0, 27.0); (27.5, 27.5); (28.0, 28.0); (28.2, 28.2); (28.5, 28.5); (29.2, 29.2); (29.5, 29.5); (29.5, 29.5); (30.0, 30.0); (30.4, 30.4); (30.7, 30.7) GeV
Run details:
  • e+ e- to hadrons and e+ e- to mu+ mu- (for normalization)

Measurement of $R$ in $e^+e^-$ collisions by AMY for energies between 50 and 61.4 GeV. The individual hadronic and muonic cross sections are also outputted to the yoda file so that ratio $R$ can be recalculated if runs are combined.

Source code: AMY_1990_I294525.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 AMY_1990_I294525 : public Analysis {
10  public:
11
12    /// Constructor
13    RIVET_DEFAULT_ANALYSIS_CTOR(AMY_1990_I294525);
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
24      // Book histograms
25      book(_c_hadrons, "/TMP/sigma_hadrons", refData<YODA::BinnedEstimate<string>>(1,1,1));
26      book(_c_muons,   "/TMP/sigma_muons"  , refData<YODA::BinnedEstimate<string>>(1,1,1));
27      for (const string& en : _c_hadrons.binning().edges<0>()) {
28        double end = std::stod(en)*GeV;
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
42      map<long,int> nCount;
43      int ntotal(0);
44      for (const Particle& p : fs.particles()) {
45	nCount[p.pid()] += 1;
46	++ntotal;
47      }
48      // mu+mu- + photons
49      if(nCount[-13]==1 and nCount[13]==1 &&
50	 ntotal==2+nCount[22])
51	_c_muons->fill(_ecms);
52      // everything else
53      else
54	_c_hadrons->fill(_ecms);
55    }
56
57
58    /// Normalise histograms etc., after the run
59    void finalize() {
60      BinnedEstimatePtr<string> mult;
61      book(mult, 1, 1, 1);
62      divide(_c_hadrons,_c_muons,mult);
63    }
64
65    /// @}
66
67
68    /// @name Histograms
69    /// @{
70    BinnedHistoPtr<string> _c_hadrons, _c_muons;
71    string _ecms;
72    /// @}
73
74  };
75
76
77  RIVET_DECLARE_PLUGIN(AMY_1990_I294525);
78
79
80}