rivet is hosted by Hepforge, IPPP Durham

Rivet analyses reference

BESII_2004_I622224

Charged particle momentum distributions for energies between 2.2 and 4.8 GeV
Experiment: BESII (BEPC)
Inspire ID: 622224
Status: VALIDATED
Authors:
  • Peter Richardson
References:
  • Phys.Rev. D69 (2004) 072002, 2004
Beams: e+ e-
Beam energies: (1.1, 1.1); (1.3, 1.3); (1.5, 1.5); (1.6, 1.6); (2.3, 2.3); (2.4, 2.4) GeV
Run details:
  • e+e- to hadrons. Beam energy must be specified as analysis option "ENERGY" when rivet-merging samples.

Charged particle momentum distributions for energies between 2.2 and 4.8 GeV. Beam energy must be specified as analysis option "ENERGY" when rivet-merging samples.

Source code: BESII_2004_I622224.cc
 1// -*- C++ -*-
 2#include "Rivet/Analysis.hh"
 3#include "Rivet/Projections/ChargedFinalState.hh"
 4
 5namespace Rivet {
 6
 7
 8  /// @brief Charged particle spectra between 2.2 and 4.8 GeV
 9  class BESII_2004_I622224 : public Analysis {
10  public:
11
12    /// Constructor
13    RIVET_DEFAULT_ANALYSIS_CTOR(BESII_2004_I622224);
14
15
16    /// @name Analysis methods
17    //@{
18
19    /// Book histograms and initialise projections before the run
20    void init() {
21      const ChargedFinalState fs;
22      declare(fs, "FS");
23      unsigned int iloc(0);
24      if(isCompatibleWithSqrtS(2.2 , 1E-3))
25	iloc = 1;
26      else if(isCompatibleWithSqrtS(2.6 , 1E-3))
27	iloc = 2;
28      else if(isCompatibleWithSqrtS(3.0 , 1E-3))
29	iloc = 3;
30      else if(isCompatibleWithSqrtS(3.2 , 1E-3))
31	iloc = 4;
32      else if(isCompatibleWithSqrtS(4.6 , 1E-3))
33	iloc = 5;
34      else if(isCompatibleWithSqrtS(4.8 , 1E-3))
35	iloc = 6;
36      else
37	MSG_ERROR("Beam energy not supported!");
38      assert(iloc!=0);
39      book(_h_ln, iloc   ,1,1);
40      book(_h_weight, "TMP/Weight");
41    }
42
43
44    /// Perform the per-event analysis
45    void analyze(const Event& event) {
46      const ChargedFinalState& fs = apply<ChargedFinalState>(event, "FS");
47      if(fs.particles().size()==2 &&
48	 abs(fs.particles()[0].pid())==13 &&
49	 abs(fs.particles()[1].pid())==13) vetoEvent;
50      for (const Particle& p : fs.particles()) {
51	const Vector3 mom3 = p.p3();
52	double pp = mom3.mod();
53	double xi = -log(2.*pp/sqrtS());
54	_h_ln->fill(xi);
55      }
56      _h_weight->fill();
57    }
58
59
60    /// Normalise histograms etc., after the run
61    void finalize() {
62      scale(_h_ln,1./_h_weight->sumW());
63    }
64
65    //@}
66
67
68    /// @name Histograms
69    //@{
70    Histo1DPtr _h_ln;
71    CounterPtr _h_weight;
72    //@}
73
74
75  };
76
77
78  // The hook for the plugin system
79  RIVET_DECLARE_PLUGIN(BESII_2004_I622224);
80
81
82}