rivet is hosted by Hepforge, IPPP Durham

Rivet analyses reference

CMD2_1999_I502164

Cross section for $e^+e^-\to K^0_SK^0_L$ at energies near the $\phi$ mass
Experiment: CMD2 (VEPP-2M)
Inspire ID: 502164
Status: VALIDATED
Authors:
  • Peter Richardson
References:
  • Phys.Lett. B466 (1999) 385, 1999
Beams: e+ e-
Beam energies: ANY
Run details:
  • e+e- to hadrons

Source code: CMD2_1999_I502164.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 CMD2_1999_I502164 : public Analysis {
11  public:
12
13    /// Constructor
14    RIVET_DEFAULT_ANALYSIS_CTOR(CMD2_1999_I502164);
15
16
17    /// @name Analysis methods
18    //@{
19
20    /// Book histograms and initialise projections before the run
21    void init() {
22      declare(FinalState(), "FS");
23      book(_nK0K0, "TMP/K0K0");
24
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      for(unsigned int ix=1;ix<5;++ix) {
54	Scatter2D temphisto(refData(ix, 1, 1));
55	Scatter2DPtr mult;
56	book(mult, ix, 1, 1);
57	for (size_t b = 0; b < temphisto.numPoints(); b++) {
58	  const double x  = temphisto.point(b).x();
59	  pair<double,double> ex = temphisto.point(b).xErrs();
60	  pair<double,double> ex2 = ex;
61	  if(ex2.first ==0.) ex2. first=0.0001;
62	  if(ex2.second==0.) ex2.second=0.0001;
63	  if (inRange(sqrtS()/MeV, x-ex2.first, x+ex2.second)) {
64	    mult->addPoint(x, sigma, ex, make_pair(error,error));
65	  }
66	  else {
67	    mult->addPoint(x, 0., ex, make_pair(0.,.0));
68	  }
69	}
70      }
71    }
72
73    //@}
74
75
76    /// @name Histograms
77    //@{
78    CounterPtr _nK0K0;
79    //@}
80
81
82  };
83
84
85  // The hook for the plugin system
86  RIVET_DECLARE_PLUGIN(CMD2_1999_I502164);
87
88
89}