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Rivet analyses reference

MUPI_1972_I84978

Measurement of $R$ and the hadronic cross section for energies between 1.2 and 2.1 GeV
Experiment: MUPI (ADONE)
Inspire ID: 84978
Status: VALIDATED
Authors:
  • Peter Richardson
References:
  • Phys.Lett. B218 (1989) 499-507, 1989
Beams: e- e+
Beam energies: (0.6, 0.6); (0.8, 0.8); (0.9, 0.9); (1.1, 1.1) GeV
Run details:
  • e+ e- to hadrons and e+ e- to mu+ mu- (for normalization)

Measurement of $R$ and the hadronic cross seection in $e^+e^-$ collisions by the Mu-Pi group for energies between 1.2 and 2.1 GeV. Beam energy must be specified as analysis option "ENERGY" when rivet-merging samples.

Source code: MUPI_1972_I84978.cc
 1// -*- C++ -*-
 2#include "Rivet/Analysis.hh"
 3#include "Rivet/Projections/FinalState.hh"
 4
 5namespace Rivet {
 6
 7
 8  /// @brief e+e- R measurement
 9  class MUPI_1972_I84978 : public Analysis {
10  public:
11
12    /// Constructor
13    RIVET_DEFAULT_ANALYSIS_CTOR(MUPI_1972_I84978);
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, 1, 1, 1);
26      book(_c_muons  , "/TMP/sigma_muons"  , refData<YODA::BinnedEstimate<string>>(2,1,1));
27      for (const string& en : _c_hadrons.binning().edges<0>()) {
28        const double end = std::stod(en)*GeV;
29        if (isCompatibleWithSqrtS(end)) {
30          _ecms = en;
31          break;
32        }
33      }
34      if (_ecms.empty())
35        MSG_ERROR("Beam energy incompatible with analysis.");
36    }
37
38
39    /// Perform the per-event analysis
40    void analyze(const Event& event) {
41      const FinalState& fs = apply<FinalState>(event, "FS");
42
43      map<long,int> nCount;
44      int ntotal(0);
45      for (const Particle& p : fs.particles()) {
46	nCount[p.pid()] += 1;
47	++ntotal;
48      }
49      // mu+mu- + photons
50      if(nCount[-13]==1 and nCount[13]==1 &&
51	 ntotal==2+nCount[22])
52	_c_muons->fill(_ecms);
53      // everything else
54      else
55	_c_hadrons->fill(_ecms);
56    }
57
58
59    /// Normalise histograms etc., after the run
60    void finalize() {
61      BinnedEstimatePtr<string> mult;
62      book(mult, 2, 1, 1);
63      divide(_c_hadrons,_c_muons,mult);
64      scale(_c_hadrons, crossSection()/sumOfWeights()/nanobarn);
65    }
66
67    /// @}
68
69
70    /// @name Histograms
71    /// @{
72    BinnedHistoPtr<string> _c_hadrons, _c_muons;
73    string _ecms;
74    /// @}
75
76
77  };
78
79
80  RIVET_DECLARE_PLUGIN(MUPI_1972_I84978);
81
82
83}