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Rivet analyses reference

SND_2006_I720035

Measurement of the cross section for $e^+e^-\to K_S^0K_L^0$ at energies between 1.04 and 1.38 GeV
Experiment: SND (VEPP-2M)
Inspire ID: 720035
Status: VALIDATED
Authors:
  • Peter Richardson
References:
  • J. Exp. Theor. Phys. 103, 720 (2006)
Beams: e+ e-
Beam energies: ANY
Run details:
  • e+e- to hadrons

Source code: SND_2006_I720035.cc
 1// -*- C++ -*-
 2#include "Rivet/Analysis.hh"
 3#include "Rivet/Projections/FinalState.hh"
 4
 5
 6namespace Rivet {
 7
 8
 9  /// @brief Add a short analysis description here
10  class SND_2006_I720035 : public Analysis {
11  public:
12
13    /// Constructor
14    RIVET_DEFAULT_ANALYSIS_CTOR(SND_2006_I720035);
15
16
17    /// @name Analysis methods
18    //@{
19
20    /// Book histograms and initialise projections before the run
21    void init() {
22      
23      declare(FinalState(), "FS");
24      book(_nK0K0, "TMP/K0K0");
25    }
26
27
28    /// Perform the per-event analysis
29    void analyze(const Event& event) {
30
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==2 &&
40	 nCount[130]==1 && nCount[310]==1)
41	_nK0K0->fill();
42
43    }
44
45
46    /// Normalise histograms etc., after the run
47    void finalize() {
48
49      double sigma = _nK0K0->val();
50      double error = _nK0K0->err();
51      sigma *= crossSection()/ sumOfWeights() /nanobarn;
52      error *= crossSection()/ sumOfWeights() /nanobarn; 
53      Scatter2D temphisto(refData(1, 1, 1));
54      Scatter2DPtr mult;
55      book(mult, 1, 1, 1);
56      for (size_t b = 0; b < temphisto.numPoints(); b++) {
57	const double x  = temphisto.point(b).x();
58	pair<double,double> ex = temphisto.point(b).xErrs();
59	pair<double,double> ex2 = ex;
60	if(ex2.first ==0.) ex2. first=0.0001;
61	if(ex2.second==0.) ex2.second=0.0001;
62	if (inRange(sqrtS()/GeV, x-ex2.first, x+ex2.second)) {
63	  mult->addPoint(x, sigma, ex, make_pair(error,error));
64	}
65	else {
66	  mult->addPoint(x, 0., ex, make_pair(0.,.0));
67	}
68      }
69    }
70
71    //@}
72
73
74    /// @name Histograms
75    //@{
76    CounterPtr _nK0K0;
77    //@}
78
79
80  };
81
82
83  // The hook for the plugin system
84  RIVET_DECLARE_PLUGIN(SND_2006_I720035);
85
86
87}