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 SND_2018_I1694988 : public Analysis {
10  public:
11
12    /// Constructor
13    RIVET_DEFAULT_ANALYSIS_CTOR(SND_2018_I1694988);
14
15
16    /// @name Analysis methods
17    //@{
18
19    /// Book histograms and initialise projections before the run
20    void init() {
21      declare(FinalState(), "FS");
22      book(_numPi0Gamma, "TMP/Pi0Gamma");
23    }
24
25
26    /// Perform the per-event analysis
27    void analyze(const Event& event) {
28
29      const FinalState& fs = apply<FinalState>(event, "FS");
30
31      map<long,int> nCount;
32      int ntotal(0);
33      for (const Particle& p : fs.particles()) {
34	nCount[p.pid()] += 1;
35	++ntotal;
36      }
37      if(ntotal==2 && nCount[22]==1 && nCount[111]==1)
38	_numPi0Gamma->fill();
39    }
40
41
42    /// Normalise histograms etc., after the run
43    void finalize() {
44      double sigma = _numPi0Gamma->val();
45      double error = _numPi0Gamma->err();
46      sigma *= crossSection()/ sumOfWeights() /picobarn;
47      error *= crossSection()/ sumOfWeights() /picobarn;
48      Scatter2D temphisto(refData(1, 1, 1));
49      Scatter2DPtr mult;
50      book(mult, 1, 1, 1);
51      for (size_t b = 0; b < temphisto.numPoints(); b++) {
52	const double x  = temphisto.point(b).x();
53	pair<double,double> ex = temphisto.point(b).xErrs();
54	pair<double,double> ex2 = ex;
55	if(ex2.first ==0.) ex2. first=0.0001;
56	if(ex2.second==0.) ex2.second=0.0001;
57	if (inRange(sqrtS()/MeV, x-ex2.first, x+ex2.second)) {
58	  mult->addPoint(x, sigma, ex, make_pair(error,error));
59	}
60	else {
61	  mult->addPoint(x, 0., ex, make_pair(0.,.0));
62	}
63      }
64    }
65
66    //@}
67
68
69    /// @name Histograms
70    //@{
71    CounterPtr _numPi0Gamma;
72    //@}
73
74
75  };
76
77
78  // The hook for the plugin system
79  RIVET_DECLARE_PLUGIN(SND_2018_I1694988);
80
81
82}