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JADE_1984_I202785

Spectrum for $D^{*+}$ production in $e^+e^-$ collisions at $E_{\text{CMS}}=34.4$
Experiment: JADE (Petra)
Inspire ID: 202785
Status: VALIDATED
Authors:
  • Peter Richardson
References:
  • Phys.Lett. 104B (1981) 325-329
Beams: e+ e-
Beam energies: (17.2, 17.2) GeV
Run details:
  • e+ e- to hadrons

Measurement of the $D^{*+}$ momentum spectrum in $e^+e^-$ collisions for a centre-of-mass energy of 34.4 GeV by the JADE experiment at Petra. The angular distribution is also measured.

Source code: JADE_1984_I202785.cc
 1// -*- C++ -*-
 2#include "Rivet/Analysis.hh"
 3#include "Rivet/Projections/UnstableParticles.hh"
 4#include "Rivet/Projections/Beam.hh"
 5
 6namespace Rivet {
 7
 8
 9  /// @brief D*+ production at 34.4 GeV
10  class JADE_1984_I202785 : public Analysis {
11  public:
12
13    /// Constructor
14    RIVET_DEFAULT_ANALYSIS_CTOR(JADE_1984_I202785);
15
16
17    /// @name Analysis methods
18    //@{
19
20    /// Book histograms and initialise projections before the run
21    void init() {
22      declare(Beam(), "Beams");
23      declare(UnstableParticles(), "UFS");
24
25      // Book histograms
26      book(_h_x    , 1, 1, 1);
27      book(_h_theta, 3, 1, 1);
28    }
29
30
31    /// Perform the per-event analysis
32    void analyze(const Event& event) {
33      
34      // Get beams and average beam momentum
35      const ParticlePair& beams = apply<Beam>(event, "Beams").beams();
36      const double meanBeamMom = ( beams.first.p3().mod() +
37                                   beams.second.p3().mod() ) / 2.0;
38      MSG_DEBUG("Avg beam momentum = " << meanBeamMom);
39      Vector3 axis = beams.first.pid() == PID::EMINUS ?
40	beams.first.p3().unit() : beams.second.p3().unit();
41      const UnstableParticles& ufs = apply<UnstableParticles>(event, "UFS");
42      for (const Particle& p : ufs.particles(Cuts::abspid==413)) {
43	double modp = p.p3().mod();
44	double xE =p.E()/meanBeamMom;
45	_h_x->fill(xE);
46	if(xE>0.4&&p.pid()>0) {
47	  _h_theta->fill(p.p3().dot(axis)/modp);
48	}
49      }
50    }
51
52
53    /// Normalise histograms etc., after the run
54    void finalize() {
55
56      normalize(_h_theta,33.6,false); // normalize to data
57      scale(_h_x, crossSection()/microbarn/sumOfWeights()*sqr(sqrtS()));
58
59    }
60
61    //@}
62
63
64    /// @name Histograms
65    //@{
66    Histo1DPtr _h_x, _h_theta;
67    //@}
68
69
70  };
71
72
73  // The hook for the plugin system
74  RIVET_DECLARE_PLUGIN(JADE_1984_I202785);
75
76
77}