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 5 GeV
 9  class BESII_2000_I505323 : public Analysis {
10  public:
11
12    /// Constructor
13    RIVET_DEFAULT_ANALYSIS_CTOR(BESII_2000_I505323);
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");
26      book(_c_muons,   "/TMP/sigma_muons");
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 && nCount[13]==1 && ntotal==2+nCount[22])
42        _c_muons->fill();
43      // everything else
44      else
45        _c_hadrons->fill();
46    }
47
48
49    /// Normalise histograms etc., after the run
50    void finalize() {
51      Estimate0D R = *_c_hadrons/ *_c_muons;
52      double fact = crossSection()/ sumOfWeights() /nanobarn;
53      double sig_h = _c_hadrons->val()*fact;
54      double err_h = _c_hadrons->err()*fact;
55      double sig_m = _c_muons  ->val()*fact;
56      double err_m = _c_muons  ->err()*fact;
57      Estimate1DPtr hadrons;
58      book(hadrons, "sigma_hadrons");
59      Estimate1DPtr muons;
60      book(muons, "sigma_muons"  );
61      Estimate1DPtr     mult;
62      book(mult, 1, 1, 1);
63      for (auto& b : mult->bins()) {
64        if (inRange(sqrtS()/GeV, b.xMin(), b.xMax())) {
65          b.set(R.val(), R.errPos());
66          hadrons->bin(b.index()).set(sig_h, err_h);
67          muons->bin(b.index()).set(sig_m,  err_m);
68        }
69      }
70    }
71
72    /// @}
73
74
75    /// @name Histograms
76    /// @{
77    CounterPtr _c_hadrons, _c_muons;
78    /// @}
79
80
81  };
82
83
84  RIVET_DECLARE_PLUGIN(BESII_2000_I505323);
85
86}