1// -*- C++ -*-
 2#include "Rivet/Analysis.hh"
 3#include "Rivet/Projections/FinalState.hh"
 4
 5namespace Rivet {
 6
 7
 8  /// @brief e+e- > K0S K0L
 9  class BABAR_2020_I1769654 : public Analysis {
10  public:
11
12    /// Constructor
13    RIVET_DEFAULT_ANALYSIS_CTOR(BABAR_2020_I1769654);
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 histograms
26      book(_nKSKL    , "TMP/nKSKL");
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
41      if(ntotal==2 && nCount[130]==1 && nCount[310]==1)
42	_nKSKL->fill();
43    }
44
45
46    /// Normalise histograms etc., after the run
47    void finalize() {
48      double sigma =  _nKSKL->val()*crossSection()/ sumOfWeights() /picobarn;
49      double error =  _nKSKL->err()*crossSection()/ sumOfWeights() /picobarn;
50      Estimate1DPtr  mult;
51      book(mult, 1, 1, 1);
52      for (auto& b : mult->bins()) {
53        if (inRange(sqrtS()/GeV, b.xMin(), b.xMax())) {
54          b.set(sigma, error);
55        }
56      }
57    }
58
59    /// @}
60
61
62    /// @name Histograms
63    /// @{
64    CounterPtr _nKSKL;
65    /// @}
66
67
68  };
69
70
71  RIVET_DECLARE_PLUGIN(BABAR_2020_I1769654);
72
73}