rivet is hosted by Hepforge, IPPP Durham

Rivet analyses reference

BABAR_2013_I1238807

Cross section for $e^+e^-\to K^+K^-$ between threshold and 5 GeV
Experiment: BABAR (PEP-II)
Inspire ID: 1238807
Status: VALIDATED
Authors:
  • Peter Richardson
References:
  • Phys.Rev. D88 (2013) no.3, 032013
Beams: e+ e-
Beam energies: ANY
Run details:
  • e+ e- to hadrons

Measurement of the cross section for $e^+e^-\to K^+K^-$ at energies between threshold and 5 GeV using radiative return

Source code: BABAR_2013_I1238807.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 BABAR_2013_I1238807 : public Analysis {
11  public:
12
13    /// Constructor
14    RIVET_DEFAULT_ANALYSIS_CTOR(BABAR_2013_I1238807);
15
16
17    /// @name Analysis methods
18    //@{
19
20    /// Book histograms and initialise projections before the run
21    void init() {
22
23      // Initialise and register projections
24      declare(FinalState(), "FS");
25
26      // Book histograms
27      book(_nkaon, "TMP/kaon");
28
29    }
30
31
32    /// Perform the per-event analysis
33    void analyze(const Event& event) {
34      const FinalState& fs = apply<FinalState>(event, "FS");
35      if(fs.particles().size()!=2) vetoEvent;
36      for (const Particle& p : fs.particles()) {
37	if(abs(p.pid())!=PID::KPLUS) vetoEvent;
38      }
39      _nkaon->fill();
40
41    }
42
43
44    /// Normalise histograms etc., after the run
45    void finalize() {
46      double sigma = _nkaon->val();
47      double error = _nkaon->err();
48      sigma *= crossSection()/ sumOfWeights() /nanobarn;
49      error *= crossSection()/ sumOfWeights() /nanobarn;
50	Scatter2D temphisto(refData(1, 1, 1));
51	Scatter2DPtr  mult;
52        book(mult, 1, 1, 1);
53	for (size_t b = 0; b < temphisto.numPoints(); b++) {
54	  const double x  = temphisto.point(b).x();
55	  pair<double,double> ex = temphisto.point(b).xErrs();
56	  pair<double,double> ex2 = ex;
57	  if(ex2.first ==0.) ex2. first=0.0001;
58	  if(ex2.second==0.) ex2.second=0.0001;
59	  if (inRange(sqrtS()/GeV, x-ex2.first, x+ex2.second)) {
60	    mult->addPoint(x, sigma, ex, make_pair(error,error));
61	  }
62	  else {
63	    mult->addPoint(x, 0., ex, make_pair(0.,.0));
64	  }
65	} 
66
67    }
68
69    //@}
70
71
72    /// @name Histograms
73    //@{
74    CounterPtr _nkaon;
75    //@}
76
77
78  };
79
80
81  // The hook for the plugin system
82  RIVET_DECLARE_PLUGIN(BABAR_2013_I1238807);
83
84
85}