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TOPAZ_1993_I353845

Cross section in $e^+e^-\to$hadrons for energies between 57.37 and 59.84 GeV
Experiment: TOPAZ (Tristan)
Inspire ID: 353845
Status: VALIDATED
Authors:
  • Peter Richardson
References:
  • Phys.Lett. B304 (1993) 373-380, 1993
Beams: e- e+
Beam energies: ANY
Run details:
  • e+ e- to hadrons and e+ e- to mu+ mu-

Measurement of the hadronic cross section in $e^+e^-$ collisions by TOPAZ for energies between 57.37 and 59.84 GeV. The individual hadronic and muonic cross sections are also outputted to the yoda file so that ratio $R$ can be recalculated if runs are combined.

Source code: TOPAZ_1993_I353845.cc
 1// -*- C++ -*-
 2#include "Rivet/Analysis.hh"
 3#include "Rivet/Projections/FinalState.hh"
 4
 5namespace Rivet {
 6
 7
 8  /// @brief Add a short analysis description here
 9  class TOPAZ_1993_I353845 : public Analysis {
10  public:
11
12    /// Constructor
13    RIVET_DEFAULT_ANALYSIS_CTOR(TOPAZ_1993_I353845);
14
15
16    /// @name Analysis methods
17    //@{
18
19    /// Book histograms and initialise projections before the run
20    void init() {
21      // Initialise and register projections
22      declare(FinalState(), "FS");
23
24      // Book histograms
25      book(_c_hadrons, "/TMP/sigma_hadrons");
26      book(_c_muons, "/TMP/sigma_muons");
27    }
28
29
30    /// Perform the per-event analysis
31    void analyze(const Event& event) {
32      const FinalState& fs = apply<FinalState>(event, "FS");
33
34      map<long,int> nCount;
35      int ntotal(0);
36      for (const Particle& p : fs.particles()) {
37	nCount[p.pid()] += 1;
38	++ntotal;
39      }
40      // mu+mu- + photons
41      if(nCount[-13]==1 and nCount[13]==1 &&
42	 ntotal==2+nCount[22])
43	_c_muons->fill();
44      // everything else
45      else
46	_c_hadrons->fill();
47    }
48
49
50    /// Normalise histograms etc., after the run
51    void finalize() {
52      double fact = crossSection()/ sumOfWeights() /picobarn;
53      for(unsigned int ix=2;ix<5;ix+=2) {
54	double sigma,error;
55	if(ix==2) {
56	  sigma = _c_hadrons->val()*fact;
57	  error = _c_hadrons->err()*fact;
58	}
59	else {
60	  sigma = _c_muons  ->val()*fact;
61	  error = _c_muons  ->err()*fact;
62	}
63	Scatter2D temphisto(refData(ix, 1, 1));
64	Scatter2DPtr mult;
65	book(mult, ix, 1, 1);
66	for (size_t b = 0; b < temphisto.numPoints(); b++) {
67	  const double x  = temphisto.point(b).x();
68	  pair<double,double> ex = temphisto.point(b).xErrs();
69	  pair<double,double> ex2 = ex;
70	  if(ex2.first ==0.) ex2. first=0.0001;
71	  if(ex2.second==0.) ex2.second=0.0001;
72	  if (inRange(sqrtS()/GeV, x-ex2.first, x+ex2.second)) {
73	    mult   ->addPoint(x, sigma, ex, make_pair(error,error));
74	  }
75	  else {
76	  mult   ->addPoint(x, 0., ex, make_pair(0.,.0));
77	  }
78	}
79      }
80    }
81
82    //@}
83
84
85    /// @name Histograms
86    //@{
87    CounterPtr _c_hadrons, _c_muons;
88    //@}
89
90
91  };
92
93
94  // The hook for the plugin system
95  RIVET_DECLARE_PLUGIN(TOPAZ_1993_I353845);
96
97
98}