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Rivet analyses reference

FENICE_1994_I377833

Cross section for $e^+e^-\to p\bar{p}$ between 1.9 and 2.44 GeV
Experiment: FENICE (ADONE)
Inspire ID: 377833
Status: VALIDATED
Authors:
  • Peter Richardson
References:
  • Phys.Lett. B334 (1994) 431-434, 1994
Beams: e+ e-
Beam energies: ANY
Run details:
  • e+e- to hadrons

Measurement of the cross section for $e^+e^-\to p\bar{p}$ between 1.9 and 2.44 GeV.

Source code: FENICE_1994_I377833.cc
 1// -*- C++ -*-
 2#include "Rivet/Analysis.hh"
 3#include "Rivet/Projections/FinalState.hh"
 4#include "Rivet/Projections/UnstableParticles.hh"
 5
 6namespace Rivet {
 7
 8
 9  /// @brief Add a short analysis description here
10  class FENICE_1994_I377833 : public Analysis {
11  public:
12
13    /// Constructor
14    RIVET_DEFAULT_ANALYSIS_CTOR(FENICE_1994_I377833);
15
16
17    /// @name Analysis methods
18    //@{
19
20    /// Book histograms and initialise projections before the run
21    void init() {
22      // Initialise and register projections
23      declare(FinalState(), "FS");
24      declare(UnstableParticles(), "UFS");
25      book(_nProton,  "/TMP/nProton" );
26    }
27
28
29    /// Perform the per-event analysis
30    void analyze(const Event& event) {
31      const FinalState& fs = apply<FinalState>(event, "FS");
32      // total hadronic and muonic cross sections
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 && nCount[2212]==1 && nCount[-2212]==1)
40	_nProton->fill();
41    }
42
43
44    /// Normalise histograms etc., after the run
45    void finalize() {
46      double fact = crossSection()/ sumOfWeights() /nanobarn;
47      double sigma = _nProton->val()*fact;
48      double error = _nProton->err()*fact;
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(sqr(sqrtS()/GeV), 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 _nProton;
73    //@}
74
75
76  };
77
78
79  // The hook for the plugin system
80  RIVET_DECLARE_PLUGIN(FENICE_1994_I377833);
81
82
83}