1// -*- C++ -*-
 2#include "Rivet/Analysis.hh"
 3#include "Rivet/Projections/FinalState.hh"
 4
 5namespace Rivet {
 6
 7
 8  /// @brief e+e- -> pi+pi-pi0
 9  class BABAR_2021_I1937349 : public Analysis {
10  public:
11
12    /// Constructor
13    RIVET_DEFAULT_ANALYSIS_CTOR(BABAR_2021_I1937349);
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(_num3pi, "TMP/num3");
26    }
27
28
29    /// Perform the per-event analysis
30    void analyze(const Event& event) {
31      const FinalState& fs = apply<FinalState>(event, "FS");
32
33      map<long,int> nCount;
34      int ntotal(0);
35      for (const Particle& p : fs.particles()) {
36	nCount[p.pid()] += 1;
37	++ntotal;
38      }
39      if(ntotal!=3) vetoEvent;
40      if(nCount[-211]==1&&nCount[211]==1&&nCount[111]==1)
41	_num3pi->fill();
42    }
43
44
45    /// Normalise histograms etc., after the run
46    void finalize() {
47      double sigma = _num3pi->val();
48      double error = _num3pi->err();
49      sigma *= crossSection()/ sumOfWeights() /nanobarn;
50      error *= crossSection()/ sumOfWeights() /nanobarn;
51      Scatter2D temphisto(refData(1, 1, 1));
52      Scatter2DPtr  mult;
53      book(mult, 1, 1, 1);
54      for (size_t b = 0; b < temphisto.numPoints(); b++) {
55	const double x  = temphisto.point(b).x();
56	pair<double,double> ex = temphisto.point(b).xErrs();
57	pair<double,double> ex2 = ex;
58	if(ex2.first ==0.) ex2. first=0.0001;
59	if(ex2.second==0.) ex2.second=0.0001;
60	if (inRange(sqrtS()/GeV, x-ex2.first, x+ex2.second)) {
61	  mult->addPoint(x, sigma, ex, make_pair(error,error));
62	}
63	else {
64	  mult->addPoint(x, 0., ex, make_pair(0.,.0));
65	}
66      }
67    }
68
69    ///@}
70
71
72    /// @name Histograms
73    ///@{
74    CounterPtr _num3pi;
75    ///@}
76
77
78  };
79
80
81  RIVET_DECLARE_PLUGIN(BABAR_2021_I1937349);
82
83}