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CLEO_2007_I753556

Measurement of $R$ for energies between 6.964 and 10.538 GeV
Experiment: CLEO (CESR)
Inspire ID: 753556
Status: VALIDATED
Authors:
  • Peter Richardson
References:
  • Phys.Rev. D76 (2007) 072008, 2007
Beams: e- e+
Beam energies: ANY
Run details:
  • e+ e- to hadrons and e+ e- to mu+ mu- (for normalization)

Measurement of $R$ in $e^+e^-$ collisions by CLEO for energies between 6.964 and 10.538 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_2007_I753556.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 CLEO_2007_I753556 : public Analysis {
10  public:
11
12    /// Constructor
13    RIVET_DEFAULT_ANALYSIS_CTOR(CLEO_2007_I753556);
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(_c_hadrons, "/TMP/sigma_hadrons");
27      book(_c_muons, "/TMP/sigma_muons");
28
29    }
30
31
32    /// Perform the per-event analysis
33    void analyze(const Event& event) {
34      const FinalState& fs = apply<FinalState>(event, "FS");
35
36      map<long,int> nCount;
37      int ntotal(0);
38      for (const Particle& p : fs.particles()) {
39	nCount[p.pid()] += 1;
40	++ntotal;
41      }
42      // mu+mu- + photons
43      if(nCount[-13]==1 and nCount[13]==1 &&
44	 ntotal==2+nCount[22])
45	_c_muons->fill();
46      // everything else
47      else
48	_c_hadrons->fill();
49    }
50
51
52    /// Normalise histograms etc., after the run
53    void finalize() {
54      Estimate0D R = *_c_hadrons/ *_c_muons;
55      double fact = crossSection()/ sumOfWeights() /picobarn;
56      double sig_h = _c_hadrons->val()*fact;
57      double err_h = _c_hadrons->err()*fact;
58      double sig_m = _c_muons  ->val()*fact;
59      double err_m = _c_muons  ->err()*fact;
60      Estimate1DPtr hadrons;
61      book(hadrons, "sigma_hadrons");
62      Estimate1DPtr muons;
63      book(muons, "sigma_muons"  );
64      Estimate1DPtr mult;
65      book(mult, 1, 1, 1);
66      for (auto& b : mult->bins()) {
67        if (inRange(sqrtS()/GeV, b.xMin(), b.xMax())) {
68          b.set(R.val(), R.errPos());
69          hadrons->bin(b.index()).set(sig_h, err_h);
70          muons  ->bin(b.index()).set(sig_m, err_m);
71        }
72      }
73    }
74
75    /// @}
76
77
78    /// @name Histograms
79    /// @{
80    CounterPtr _c_hadrons, _c_muons;
81    /// @}
82
83
84  };
85
86
87  RIVET_DECLARE_PLUGIN(CLEO_2007_I753556);
88
89
90}