Rivet analyses referenceDM2_1988_I262690Cross section for $e^+e^-\to K^+K^-$ between 1.35 and 2.4 GeVExperiment: DM2 (DCI) Inspire ID: 262690 Status: VALIDATED Authors:
Beam energies: ANY Run details:
Measurement of the cross section for $e^+e^-\to K^+K^-$ at energies between 1.35 and 2.4 GeV Source code: DM2_1988_I262690.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 DM2_1988_I262690 : public Analysis {
11 public:
12
13 /// Constructor
14 RIVET_DEFAULT_ANALYSIS_CTOR(DM2_1988_I262690);
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 /// Normalise histograms etc., after the run
44 void finalize() {
45 double sigma = _nkaon->val();
46 double error = _nkaon->err();
47 sigma *= crossSection()/ sumOfWeights() /nanobarn;
48 error *= crossSection()/ sumOfWeights() /nanobarn;
49 Scatter2D temphisto(refData(1, 1, 1));
50 Scatter2DPtr mult;
51 book(mult, 1, 1, 1);
52 for (size_t b = 0; b < temphisto.numPoints(); b++) {
53 const double x = temphisto.point(b).x();
54 pair<double,double> ex = temphisto.point(b).xErrs();
55 pair<double,double> ex2 = ex;
56 if(ex2.first ==0.) ex2. first=0.0001;
57 if(ex2.second==0.) ex2.second=0.0001;
58 if (inRange(sqrtS()/MeV, x-ex2.first, x+ex2.second)) {
59 mult->addPoint(x, sigma, ex, make_pair(error,error));
60 }
61 else {
62 mult->addPoint(x, 0., ex, make_pair(0.,.0));
63 }
64 }
65 }
66
67 //@}
68
69
70 /// @name Histograms
71 //@{
72 CounterPtr _nkaon;
73 //@}
74
75
76 };
77
78
79 // The hook for the plugin system
80 RIVET_DECLARE_PLUGIN(DM2_1988_I262690);
81
82
83}
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