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Rivet analyses reference

DM2_1983_I190558

Cross section for $e^+e^-\to p\bar{p}$ between 1.975 and 2.250 GeV
Experiment: DM2 (DCI)
Inspire ID: 190558
Status: VALIDATED
Authors:
  • Peter Richardson
References:
  • Nucl.Phys. B224 (1983) 379, 1983
Beams: e+ e-
Beam energies: ANY
Run details:
  • e+e- to hadrons

Source code: DM2_1983_I190558.cc
 1// -*- C++ -*-
 2#include "Rivet/Analysis.hh"
 3#include "Rivet/Projections/FinalState.hh"
 4#include "Rivet/Projections/FastJets.hh"
 5
 6namespace Rivet {
 7
 8
 9  /// @brief Add a short analysis description here
10  class DM2_1983_I190558 : public Analysis {
11  public:
12
13    /// Constructor
14    RIVET_DEFAULT_ANALYSIS_CTOR(DM2_1983_I190558);
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(_nproton, "TMP/proton");
28    }
29
30
31    /// Perform the per-event analysis
32    void analyze(const Event& event) {
33      const FinalState& fs = apply<FinalState>(event, "FS");
34      if(fs.particles().size()!=2) vetoEvent;
35      for (const Particle& p : fs.particles()) {
36	if(abs(p.pid())!=PID::PROTON) vetoEvent;
37      }
38      _nproton->fill();
39    }
40
41
42    /// Normalise histograms etc., after the run
43    void finalize() {
44      double sigma = _nproton->val();
45      double error = _nproton->err();
46      sigma *= crossSection()/ sumOfWeights() /nanobarn;
47      error *= crossSection()/ sumOfWeights() /nanobarn; 
48      Scatter2D temphisto(refData(1, 1, 1));
49      Scatter2DPtr mult;
50      book(mult, 1, 1, 1);
51      for (size_t b = 0; b < temphisto.numPoints(); b++) {
52	const double x  = temphisto.point(b).x();
53	pair<double,double> ex = temphisto.point(b).xErrs();
54	pair<double,double> ex2 = ex;
55	if(ex2.first ==0.) ex2. first=0.0001;
56	if(ex2.second==0.) ex2.second=0.0001;
57	if (inRange(sqrtS()/MeV, x-ex2.first, x+ex2.second)) {
58	  mult->addPoint(x, sigma, ex, make_pair(error,error));
59	}
60	else {
61	  mult->addPoint(x, 0., ex, make_pair(0.,.0));
62	}
63      }
64    }
65
66    //@}
67
68
69    /// @name Histograms
70    //@{
71    CounterPtr _nproton;
72    //@}
73
74
75  };
76
77
78  // The hook for the plugin system
79  RIVET_DECLARE_PLUGIN(DM2_1983_I190558);
80
81
82}