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CLEO_1998_I445351

Measurement of $R$ at 10.52 GeV
Experiment: CLEO (CESR)
Inspire ID: 445351
Status: VALIDATED
Authors:
  • Peter Richardson
References:
  • Phys.Rev. D57 (1998) 1350-1358, 1998
Beams: e- e+
Beam energies: (5.3, 5.3) GeV
Run details:
  • e+ e- to hadrons and e+ e- to mu+ mu- (for normalization)

Measurement of $R$ in $e^+e^-$ collisions by CLEO for 10.52 GeV. The individual hadronic and muonic cross sections are also outputted to the yoda file so that ratio $R$ can be recalcuated if runs are combined.

Source code: CLEO_1998_I445351.cc
 1// -*- C++ -*-
 2#include "Rivet/Analysis.hh"
 3#include "Rivet/Projections/FinalState.hh"
 4
 5namespace Rivet {
 6
 7
 8  /// @brief R measurement
 9  class CLEO_1998_I445351 : public Analysis {
10  public:
11
12    /// Constructor
13    RIVET_DEFAULT_ANALYSIS_CTOR(CLEO_1998_I445351);
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, "sigma_hadrons", refData<YODA::BinnedEstimate<string>>(1,1,1));
26      book(_c_muons, "sigma_muons", refData<YODA::BinnedEstimate<string>>(1,1,1));
27    }
28
29
30    /// Perform the per-event analysis
31    void analyze(const Event& event) {
32      const FinalState& fs = apply<FinalState>(event, "FS");
33
34      map<long,int> nCount;
35      int ntotal(0);
36      for (const Particle& p : fs.particles()) {
37        nCount[p.pid()] += 1;
38        ++ntotal;
39      }
40      // mu+mu- + photons
41      if(nCount[-13]==1 and nCount[13]==1 &&  ntotal==2+nCount[22]) {
42        _c_muons->fill(Ecm);
43      }
44      else  _c_hadrons->fill(Ecm); // everything else
45    }
46
47
48    /// Normalise histograms etc., after the run
49    void finalize() {
50      const double fact = crossSection()/ sumOfWeights() /picobarn;
51      scale({_c_hadrons, _c_muons}, fact);
52      BinnedEstimatePtr<string> mult;
53      book(mult, 1,1,1);
54      divide(_c_hadrons, _c_muons, mult);
55    }
56
57    /// @}
58
59
60    /// @name Histograms
61    /// @{
62    BinnedHistoPtr<string> _c_hadrons, _c_muons;
63    const string Ecm = "10.52";
64    /// @}
65
66
67  };
68
69
70  RIVET_DECLARE_PLUGIN(CLEO_1998_I445351);
71
72
73}