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PLUTO_1979_I140818

Hadronic cross section in $e^+e^-$ collisions for energies between 9.4 to 9.48
Experiment: PLUTO (PETRA)
Inspire ID: 140818
Status: VALIDATED
Authors:
  • Peter Richardson
References:
  • Z.Phys. C1 (1979) 343, 1979
Beams: e- e+
Beam energies: ANY
Run details:
  • e+ e- to hadrons and e+ e- to mu+ mu- (for normalization)

Measurement of the hadronic cross section in $e^+e^-$ collisions for energies between 9.4 to 9.48 GeV.

Source code: PLUTO_1979_I140818.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 PLUTO_1979_I140818 : public Analysis {
10  public:
11
12    /// Constructor
13    RIVET_DEFAULT_ANALYSIS_CTOR(PLUTO_1979_I140818);
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      // counters for R
24      book(_c_hadrons, "/TMP/sigma_hadrons");
25    }
26
27
28    /// Perform the per-event analysis
29    void analyze(const Event& event) {
30      const FinalState& fs = apply<FinalState>(event, "FS");
31
32      map<long,int> nCount;
33      int ntotal(0);
34      unsigned int nCharged(0);
35      for (const Particle& p : fs.particles()) {
36	nCount[p.pid()] += 1;
37	++ntotal;
38	if(PID::isCharged(p.pid())) ++nCharged;
39      }
40      // mu+mu- + photons
41      if(nCount[-13]==1 and nCount[13]==1 &&
42	 ntotal==2+nCount[22])
43	vetoEvent;
44      // everything else
45      else {
46	_c_hadrons->fill();
47      }
48
49    }
50
51
52    /// Normalise histograms etc., after the run
53    void finalize() {
54      double fact = crossSection()/ sumOfWeights() /nanobarn;
55      double sig_h = _c_hadrons->val()*fact;
56      double err_h = _c_hadrons->err()*fact;
57      Scatter2D temphisto(refData(2, 1, 1));
58      Scatter2DPtr hadrons;
59      book(hadrons, 2, 1, 1);
60      for (size_t b = 0; b < temphisto.numPoints(); b++) {
61	const double x  = temphisto.point(b).x();
62	pair<double,double> ex = temphisto.point(b).xErrs();
63	pair<double,double> ex2 = ex;
64	if(ex2.first ==0.) ex2. first=0.0001;
65	if(ex2.second==0.) ex2.second=0.0001;
66	if (inRange(sqrtS()/GeV, x-ex2.first, x+ex2.second)) {
67	  hadrons->addPoint(x, sig_h, ex, make_pair(err_h,err_h));
68	}
69	else {
70	  hadrons->addPoint(x, 0., ex, make_pair(0.,.0));
71	}
72      }
73    }
74
75    //@}
76
77
78    /// @name Histograms
79    //@{
80    CounterPtr _c_hadrons;
81    //@}
82
83
84  };
85
86
87  // The hook for the plugin system
88  RIVET_DECLARE_PLUGIN(PLUTO_1979_I140818);
89
90
91}