rivet is hosted by Hepforge, IPPP Durham

Rivet analyses reference

HRS_1988_I23360

Charm meson spectra in $e^+e^-$ collisions at 29 GeV
Experiment: HRS (PEP)
Inspire ID: 23360
Status: VALIDATED
Authors:
  • Peter Richardson
References:
  • Phys.Lett. B206 (1988) 551-556, 1988
Beams: e+ e-
Beam energies: (14.5, 14.5) GeV
Run details:
  • Hadronic e+e- events at $\sqrt{s} = 29.$ GeV

$D^{*\pm}$, $D^0,\bar{D}^0$ and $D^\pm$ meson momentum spectrum measured at $\sqrt{s} = 29.$ GeV using the HRS detector at PEP. Only the spectra are implemented, not the electroweak asymmetries.

Source code: HRS_1988_I23360.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
// -*- C++ -*-
#include "Rivet/Analysis.hh"
#include "Rivet/Projections/Beam.hh"
#include "Rivet/Projections/ChargedFinalState.hh"
#include "Rivet/Projections/UnstableParticles.hh"

namespace Rivet {


  /// @brief Charm meson spectra at 29 GeV
  class HRS_1988_I23360 : public Analysis {
  public:

    /// Constructor
    DEFAULT_RIVET_ANALYSIS_CTOR(HRS_1988_I23360);


    /// @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_Dstar1,1,1,1);
      book(_h_Dstar2,1,1,2);
      book(_h_D0    ,2,1,1);
      book(_h_Dp    ,2,1,2);
    }


    /// 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);

      const UnstableParticles& ufs = apply<UnstableParticles>(event, "UFS");
      for(const Particle & p : ufs.particles(Cuts::abspid==413 || Cuts::abspid==421 || Cuts::abspid==411 )) {
         double xE = p.E()/meanBeamMom;
	 int id = abs(p.pid());
	 if(id==413) {
	   _h_Dstar1->fill(xE);
	   _h_Dstar2->fill(xE);
	 }
	 else if(id==421) {
	   _h_D0->fill(xE);
	 }
	 else if(id==411) {
	   _h_Dp->fill(xE);
	 }
      }
    }


    /// Normalise histograms etc., after the run
    void finalize() {
      double fact = sqr(sqrtS())*crossSection()/sumOfWeights()/microbarn;
      scale(_h_Dstar1, fact);
      normalize(_h_Dstar2);
      scale(_h_D0,fact);
      scale(_h_Dp,fact);
    }

    //@}


    /// @name Histograms
    //@{
    Histo1DPtr _h_Dstar1,_h_Dstar2,_h_D0,_h_Dp;
    //@}


  };


  // The hook for the plugin system
  DECLARE_RIVET_PLUGIN(HRS_1988_I23360);


}