1// -*- C++ -*-
 2#include "Rivet/Analysis.hh"
 3#include "Rivet/Projections/FinalState.hh"
 4
 5namespace Rivet {
 6
 7
 8  /// @brief Measurement of $R$ for energies between 2.6 and 3.65 GeV
 9  class BESII_2009_I814778 : public Analysis {
10  public:
11
12    /// Constructor
13    RIVET_DEFAULT_ANALYSIS_CTOR(BESII_2009_I814778);
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      // Book histograms
24      book(_c_hadrons, "/TMP/sigma_hadrons", refData<YODA::BinnedEstimate<string>>(1,1,1));
25      book(_c_muons,   "/TMP/sigma_muons"  , refData<YODA::BinnedEstimate<string>>(1,1,1));
26      for (const string& en : _c_hadrons.binning().edges<0>()) {
27        double end = std::stod(en)*GeV;
28        if(isCompatibleWithSqrtS(end)) {
29          _ecms = en;
30          break;
31        }
32      }
33      if(_ecms.empty()) MSG_ERROR("Beam energy incompatible with analysis.");
34    }
35
36
37    /// Perform the per-event analysis
38    void analyze(const Event& event) {
39      const FinalState& fs = apply<FinalState>(event, "FS");
40
41      map<long,int> nCount;
42      int ntotal(0);
43      for (const Particle& p : fs.particles()) {
44        nCount[p.pid()] += 1;
45        ++ntotal;
46      }
47      // mu+mu- + photons
48      if(nCount[-13]==1 and nCount[13]==1 &&
49         ntotal==2+nCount[22])
50        _c_muons->fill(_ecms);
51      // everything else
52      else
53        _c_hadrons->fill(_ecms);
54    }
55
56
57    /// Normalise histograms etc., after the run
58    void finalize() {
59      BinnedEstimatePtr<string> mult;
60      book(mult, 1, 1, 1);
61      divide(_c_hadrons,_c_muons,mult);
62    }
63
64    /// @}
65
66
67    /// @name Histograms
68    /// @{
69    BinnedHistoPtr<string> _c_hadrons, _c_muons;
70    string _ecms;
71    /// @}
72
73
74  };
75
76
77  RIVET_DECLARE_PLUGIN(BESII_2009_I814778);
78
79
80}