1// -*- C++ -*-
 2#include "Rivet/Analysis.hh"
 3#include "Rivet/Projections/FinalState.hh"
 4
 5namespace Rivet {
 6
 7
 8  /// @brief gamma gamma -> K0S K0S
 9  class BELLE_2013_I1245023 : public Analysis {
10  public:
11
12    /// Constructor
13    RIVET_DEFAULT_ANALYSIS_CTOR(BELLE_2013_I1245023);
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      // histos
24      if (inRange(sqrtS()/GeV,1.05,4.0)) {
25        if (sqrtS()>1.1) book(_sigmaKK[0],"TMP/nKK_1",refData( 1, 1, 1));
26        book(_sigmaKK[1],"TMP/nKK_2",refData( 1, 1, 2));
27        double sMin=1.1, step=0.01;
28        unsigned int ihist=2,iy=1;
29        while (sMin<3.3) {
30          if (inRange(sqrtS()/GeV, sMin, sMin+step)) {
31            break;
32          }
33          sMin+=step;
34          iy+=1;
35          if (iy==4) {
36            ihist+=1;
37            iy=1;
38          }
39          if (fuzzyEquals(1.9, sMin)) step=0.02;
40          else if (fuzzyEquals(2.4, sMin)) step=0.04;
41          else if (fuzzyEquals(2.6, sMin)) step=0.1;
42        }
43        if (ihist<=40) book(_h_cTheta,ihist,1,iy);
44      }
45      else {
46       	throw Error("Invalid CMS energy for BELLE_2013_I1245023");
47      }
48    }
49
50
51    /// Perform the per-event analysis
52    void analyze(const Event& event) {
53      Particles part = apply<FinalState>(event,"FS").particles();
54      if (part.size()!=2) vetoEvent;
55      for (const Particle & p : part) {
56        if (p.pid()!=PID::K0S) vetoEvent;
57      }
58      const double cTheta = abs(part[0].momentum().z()/part[0].momentum().p3().mod());
59      if (cTheta<=0.6)               _sigmaKK[1]->fill(sqrtS());
60      if (cTheta<=0.8 &&_sigmaKK[0]) _sigmaKK[0]->fill(sqrtS());
61      if (_h_cTheta )                _h_cTheta ->fill(cTheta);
62    }
63
64
65    /// Normalise histograms etc., after the run
66    void finalize() {
67      const double fact = crossSection()/nanobarn/sumOfWeights();
68      if (_h_cTheta ) scale(_h_cTheta ,fact);
69      for(unsigned int ix=0; ix<2; ++ix) {
70        if (!_sigmaKK[ix]) continue;
71        scale(_sigmaKK[ix],fact);
72        Estimate1DPtr tmp;
73        book(tmp,1,1,1+ix);
74        barchart(_sigmaKK[ix],tmp);
75      }
76    }
77
78    /// @}
79
80
81    /// @name Histograms
82    /// @{
83    Histo1DPtr _sigmaKK[2],_h_cTheta;
84    /// @}
85
86
87  };
88
89
90  RIVET_DECLARE_PLUGIN(BELLE_2013_I1245023);
91
92}