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L3_1995_I381046

Production of $B^*$ mesons at LEP1
Experiment: L3 (LEP)
Inspire ID: 381046
Status: VALIDATED
Authors:
  • Peter Richardson
References:
  • Phys.Lett. B345 (1995) 589-597, 1995
Beams: e- e+
Beam energies: ANY
Run details:
  • e+e- to hadrons

The ratio of vector to pseudoscalar for $B$ meson production at LEP1.

Source code: L3_1995_I381046.cc
 1// -*- C++ -*-
 2#include "Rivet/Analysis.hh"
 3#include "Rivet/Projections/ChargedFinalState.hh"
 4#include "Rivet/Projections/UnstableParticles.hh"
 5
 6namespace Rivet {
 7
 8
 9  /// @brief B* production
10  class L3_1995_I381046 : public Analysis {
11  public:
12
13    /// Constructor
14    RIVET_DEFAULT_ANALYSIS_CTOR(L3_1995_I381046);
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(ChargedFinalState(), "FS");
25      declare(UnstableParticles(), "UFS");
26
27      // Book histograms
28      book(_c_bStar, "/TMP/cbStar", refData<YODA::BinnedEstimate<string>>(1,1,1));
29      book(_c_B    , "/TMP/cB", refData<YODA::BinnedEstimate<string>>(1,1,1));
30
31    }
32
33
34    /// Perform the per-event analysis
35    void analyze(const Event& event) {
36      // First, veto on leptonic events by requiring at least 4 charged FS particles
37      const FinalState& fs = apply<FinalState>(event, "FS");
38      const size_t numParticles = fs.particles().size();
39
40      // Even if we only generate hadronic events, we still need a cut on numCharged >= 2.
41      if (numParticles < 2) {
42        MSG_DEBUG("Failed leptonic event cut");
43        vetoEvent;
44      }
45      MSG_DEBUG("Passed leptonic event cut");
46
47      for (const Particle& p : apply<UnstableParticles>(event, "UFS").particles(Cuts::abspid==513 or Cuts::abspid==523 or
48									       Cuts::abspid==511 or Cuts::abspid==521)) {
49        // count number of Bs not from mixing or B*
50        if (p.abspid()==511 || p.abspid()==521) {
51          if (p.parents()[0].abspid()==p.abspid()) continue;
52          if (p.parents()[0].abspid()==513 || p.parents()[0].abspid()==523) continue;
53          _c_B->fill(Ecm);
54        }
55        else {
56          _c_bStar->fill(Ecm);	// B*
57        }
58      }
59
60    }
61
62
63    /// Normalise histograms etc., after the run
64    void finalize() {
65      // no of B*/B+B*
66      BinnedEstimatePtr<string> h1;
67      book(h1,1,1,1);
68      *h1 = *_c_bStar / (*_c_bStar + *_c_B);
69    }
70
71    /// @}
72
73
74    /// @name Histograms
75    /// @{
76    BinnedHistoPtr<string> _c_bStar, _c_B;
77    const string Ecm = "91.2";
78    /// @}
79
80
81  };
82
83
84  RIVET_DECLARE_PLUGIN(L3_1995_I381046);
85
86
87}