1// -*- C++ -*-
 2#include "Rivet/Analysis.hh"
 3#include "Rivet/Projections/FinalState.hh"
 4
 5namespace Rivet {
 6
 7
 8  /// @brief Measurement of R
 9  class PDG_R : public Analysis {
10  public:
11
12    /// Constructor
13    RIVET_DEFAULT_ANALYSIS_CTOR(PDG_R);
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 and nCount[13]==1 &&
42	 ntotal==2+nCount[22])
43	_c_muons->fill();
44      // everything else
45      else
46	_c_hadrons->fill();
47    }
48
49
50    /// Normalise histograms etc., after the run
51    void finalize() {
52      Estimate0D R = *_c_hadrons/ *_c_muons;
53      double fact = crossSection()/ sumOfWeights() /picobarn;
54      double sig_h = _c_hadrons->val()*fact;
55      double err_h = _c_hadrons->err()*fact;
56      double sig_m = _c_muons  ->val()*fact;
57      double err_m = _c_muons  ->err()*fact;
58      Estimate1DPtr hadrons;
59      book(hadrons, "sigma_hadrons");
60      Estimate1DPtr muons;
61      book(muons, "sigma_muons"  );
62      Estimate1DPtr mult;
63      book(mult, 1, 1, 1);
64      for (auto& b : mult->bins()) {
65      	if (inRange(sqrtS()/GeV, b.xMin(), b.xMax())) {
66      	  b.set(R.val(), R.errPos());
67      	  hadrons->bin(b.index()).set(sig_h, err_h);
68      	  muons  ->bin(b.index()).set(sig_m, err_m);
69      	}
70      }
71    }
72
73    /// @}
74
75
76    /// @name Histograms
77    /// @{
78    CounterPtr _c_hadrons, _c_muons;
79    /// @}
80
81
82  };
83
84
85  RIVET_DECLARE_PLUGIN(PDG_R);
86
87}