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JADE_1981_I166363

Spectra for anti-protons and $\bar{\Lambda}^0$ at 34 GeV
Experiment: JADE (Petra)
Inspire ID: 166363
Status: VALIDATED
Authors:
  • Peter Richardson
References:
  • Phys.Lett. 104B (1981) 325-329
Beams: e+ e-
Beam energies: (17.0, 17.0) GeV
Run details:
  • e+ e- to hadrons

Measurement of the anti-proton and $\bar{\Lambda}^0$ momentum spectrum in $e^+e^-$ collisions for a centre-of-mass energy of 34 GeV by the JADE experiment at Petra. Useful as not summed over particle and antiparticle, only the antibaryons are included.

Source code: JADE_1981_I166363.cc
 1// -*- C++ -*-
 2#include "Rivet/Analysis.hh"
 3#include "Rivet/Projections/FinalState.hh"
 4#include "Rivet/Projections/UnstableParticles.hh"
 5
 6namespace Rivet {
 7
 8
 9  /// @brief pbar and lambdabar at 34 GeV
10  class JADE_1981_I166363 : public Analysis {
11  public:
12
13    /// Constructor
14    RIVET_DEFAULT_ANALYSIS_CTOR(JADE_1981_I166363);
15
16
17    /// @name Analysis methods
18    //@{
19
20    /// Book histograms and initialise projections before the run
21    void init() {
22
23      // Initialise and register projections
24      declare(FinalState(), "FS");
25      declare(UnstableParticles(), "UFS");
26
27      // Book histograms
28      book(_h_pbar     , 1, 1, 1);
29      book(_h_lambdabar, 2, 1, 1);
30
31    }
32
33
34    /// Perform the per-event analysis
35    void analyze(const Event& event) {
36      // at least 5 charged FS particles
37      const FinalState& fs = apply<FinalState>(event, "FS");
38      const size_t numParticles = fs.particles().size();
39
40      if (numParticles < 3) {
41        MSG_DEBUG("Failed leptonic event cut");
42        vetoEvent;
43      }
44      MSG_DEBUG("Passed leptonic event cut");
45
46      for (const Particle& p : apply<UnstableParticles>(event, "UFS").particles(Cuts::pid==-2212 or Cuts::pid==-3122)) {
47	if(p.pid()==-2212)
48	  _h_pbar->fill(p.p3().mod());
49	else
50	  _h_lambdabar->fill(p.p3().mod());
51      }
52
53    }
54
55
56    /// Normalise histograms etc., after the run
57    void finalize() {
58      scale(_h_pbar     , crossSection()/nanobarn/sumOfWeights());
59      scale(_h_lambdabar, crossSection()/nanobarn/sumOfWeights());
60    }
61
62    //@}
63
64
65    /// @name Histograms
66    //@{
67    Histo1DPtr  _h_pbar, _h_lambdabar;
68    //@}
69
70
71  };
72
73
74  // The hook for the plugin system
75  RIVET_DECLARE_PLUGIN(JADE_1981_I166363);
76
77
78}