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TOPAZ_1993_I361661

Measurement of event shapes at $E_{\text{CMS}}=58$ GeV
Experiment: TOPAZ (Tristan)
Inspire ID: 361661
Status: VALIDATED
Authors:
  • Peter Richardson
References:
  • Phys.Lett. B304 (1993) 373-380, 1993
Beams: e- e+
Beam energies: (29.0, 29.0) GeV
Run details:
  • e+ e- to hadrons

Measurement of the hadronic event shapes in $e^+e^-$ collisions by TOPAZ at 58 GeV.

Source code: TOPAZ_1993_I361661.cc
 1// -*- C++ -*-
 2#include "Rivet/Analysis.hh"
 3#include "Rivet/Projections/FinalState.hh"
 4#include "Rivet/Projections/Thrust.hh"
 5#include "Rivet/Projections/FastJets.hh"
 6#include "Rivet/Projections/Hemispheres.hh"
 7
 8namespace Rivet {
 9
10
11  /// @brief Thrust, heavy jet mass, and y3 at 58 GeV
12  class TOPAZ_1993_I361661 : public Analysis {
13  public:
14
15    /// Constructor
16    RIVET_DEFAULT_ANALYSIS_CTOR(TOPAZ_1993_I361661);
17
18
19    /// @name Analysis methods
20    //@{
21
22    /// Book histograms and initialise projections before the run
23    void init() {
24
25      const FinalState fs;
26      declare(fs, "FS");
27      declare(FastJets(fs, FastJets::DURHAM, 0.7), "DurhamJets");
28      const Thrust thrust(fs);
29      declare(thrust, "Thrust");
30      declare(Hemispheres(thrust), "Hemispheres");
31
32      // Book histograms
33      book(_h_thrust, 1, 1, 1);
34      book(_h_rho   , 2, 1, 1);
35      book(_h_y23   , 3, 1, 1);
36
37    }
38
39
40    /// Perform the per-event analysis
41    void analyze(const Event& event) {
42      // First, veto on leptonic events by requiring at least 4 charged FS particles
43      const FinalState& fs = apply<FinalState>(event, "FS");
44      const size_t numParticles = fs.particles().size();
45      // Even if we only generate hadronic events, we still need a cut on numCharged >= 2.
46      if (numParticles < 2) {
47        MSG_DEBUG("Failed leptonic event cut");
48        vetoEvent;
49      }
50      // thrust
51      const Thrust& thrust = apply<Thrust>(event, "Thrust");
52      _h_thrust->fill(-log(1.-thrust.thrust()));
53      // jet mass
54      const Hemispheres& hemi = apply<Hemispheres>(event, "Hemispheres");
55      _h_rho->fill(-log(hemi.scaledM2high()));
56      // Jets
57      const FastJets& durjet = apply<FastJets>(event, "DurhamJets");
58      if(numParticles>=3)
59        if (durjet.clusterSeq()) _h_y23->fill(-log(durjet.clusterSeq()->exclusive_ymerge_max(2)));
60    }
61
62
63    /// Normalise histograms etc., after the run
64    void finalize() {
65
66      normalize(_h_thrust);
67      normalize(_h_rho);
68      normalize(_h_y23); 
69
70    }
71
72    //@}
73
74
75    /// @name Histograms
76    //@{
77    Histo1DPtr _h_thrust,_h_rho,_h_y23;
78    //@}
79
80
81  };
82
83
84  // The hook for the plugin system
85  RIVET_DECLARE_PLUGIN(TOPAZ_1993_I361661);
86
87
88}