rivet is hosted by Hepforge, IPPP Durham

Rivet analyses reference

TOPAZ_1995_I381900

Charged hadron spectra at 58 GeV
Experiment: TOPAZ (Tristan)
Inspire ID: 381900
Status: VALIDATED
Authors:
  • Peter Richardson
References:
  • Phys.Lett. B347 (1995) 171-178, 1995
Beams: e- e+
Beam energies: (29.0, 29.0) GeV
Run details:
  • e+ e- to hadrons

Measurement of the spectra for charged hadrons in $e^+e^-$ collisions at 58 GeV by the TOPAZ experiment at Tristan. The spectra for all charged hadrons, $\pi^\pm$, $K^\pm$ and $p,\bar{p}$ are included. The spectrum for $K^0,\bar{K}^0$ is also included

Source code: TOPAZ_1995_I381900.cc
 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
// -*- C++ -*-
#include "Rivet/Analysis.hh"
#include "Rivet/Projections/Beam.hh"
#include "Rivet/Projections/ChargedFinalState.hh"
#include "Rivet/Projections/UnstableParticles.hh"

namespace Rivet {


  /// @brief Add a short analysis description here
  class TOPAZ_1995_I381900 : public Analysis {
  public:

    /// Constructor
    DEFAULT_RIVET_ANALYSIS_CTOR(TOPAZ_1995_I381900);


    /// @name Analysis methods
    //@{

    /// Book histograms and initialise projections before the run
    void init() {

      // Initialise and register projections
      declare(Beam(), "Beams");
      declare(UnstableParticles(), "UFS");
      const ChargedFinalState cfs;
      declare(cfs, "CFS");

      // Book histograms
      book(_h_charged,1, 1, 1);
      book(_h_pi     ,2, 1, 1);
      book(_h_Kp     ,2, 1, 2);
      book(_h_proton ,2, 1, 3);
      book(_h_K0     ,3, 1, 1);
      book(_wSum,"TMP/wSum");
    }


    /// Perform the per-event analysis
    void analyze(const Event& event) {
      const ChargedFinalState& cfs = apply<ChargedFinalState>(event, "CFS");
      int nch = cfs.particles().size();
      if(nch<5) vetoEvent;
      // Get beams and average beam momentum
      const ParticlePair& beams = apply<Beam>(event, "Beams").beams();
      const double meanBeamMom = ( beams.first.p3().mod() +
                                   beams.second.p3().mod() ) / 2.0;
      MSG_DEBUG("Avg beam momentum = " << meanBeamMom);
      _wSum->fill();

      // neutral kaons
      const UnstableParticles& ufs = apply<UnstableParticles>(event, "UFS");
      for(const Particle & p : ufs.particles(Cuts::pid==130 || Cuts::pid==310)) {
	double xi = -log(p.p3().mod()/meanBeamMom);
	_h_K0->fill(xi);
      }
      // charged particles
      for(const Particle & p : cfs.particles()) {
	double xi = -log(p.p3().mod()/meanBeamMom);
	_h_charged->fill(xi);
	int id = abs(p.pid());
	if(id==211)
	  _h_pi->fill(xi);
	else if(id==321)
	  _h_Kp->fill(xi);
	else if(id==2212)
	  _h_proton->fill(xi);
      }
    }


    /// Normalise histograms etc., after the run
    void finalize() {
      scale(_h_charged,1./ *_wSum);
      scale(_h_pi     ,1./ *_wSum);
      scale(_h_Kp     ,1./ *_wSum);
      scale(_h_proton ,1./ *_wSum);
      scale(_h_K0     ,1./ *_wSum);
    }

    //@}


    /// @name Histograms
    //@{
    Histo1DPtr _h_charged,_h_pi,_h_Kp,_h_proton,_h_K0;
    CounterPtr _wSum;
    //@}


  };


  // The hook for the plugin system
  DECLARE_RIVET_PLUGIN(TOPAZ_1995_I381900);


}