rivet is hosted by Hepforge, IPPP Durham

Rivet analyses reference

CLEO_2007_I728872

Spectrum of $\phi$ mesons in $\Upsilon(4S)$ and $\Upsilon(5S)$ decays
Experiment: CLEO (CESR)
Inspire ID: 728872
Status: VALIDATED
Authors:
  • Peter Richardson
References:
  • Phys.Rev. D75 (2007) 012002
Beams: * *
Beam energies: ANY
Run details:
  • Any process producing $\Upsilon(4S)$ or $\Upsilon(5S)$, original $e^+e^-$

Measurement of the $\phi$ meson spectrum in $\Upsilon(4S)$ and $\Upsilon(5S)$ decays by CLEO, only the spectra are included not the conclusions on $B_s$ production drawn from them.

Source code: CLEO_2007_I728872.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
93
94
95
// -*- C++ -*-
#include "Rivet/Analysis.hh"
#include "Rivet/Projections/UnstableParticles.hh"

namespace Rivet {


  /// @brief Add a short analysis description here
  class CLEO_2007_I728872 : public Analysis {
  public:

    /// Constructor
    DEFAULT_RIVET_ANALYSIS_CTOR(CLEO_2007_I728872);


    /// @name Analysis methods
    //@{

    /// Book histograms and initialise projections before the run
    void init() {

      // Initialise and register projections
      declare(UnstableParticles(), "UFS");

      // Book histograms
      book(_h_4S, 1, 1, 5);
      book(_h_5S, 2, 1, 5);
      book(_c_4S, "/TMP/N4S");
      book(_c_5S, "/TMP/N5S");
    }

    void findDecayProducts(const Particle & p, Particles & phi) {
      for(const Particle & child : p.children()) {
	if(child.pid()==333)
	  phi.push_back(child);
	else if(!child.children().empty())
	  findDecayProducts(child,phi);
      }
    }
    
    /// Perform the per-event analysis
    void analyze(const Event& event) {
      // Find the Upsilons among the unstables
      const UnstableParticles& ufs = apply<UnstableParticles>(event, "UFS");
      Particles upsilons = ufs.particles(Cuts::pid==300553 || Cuts::pid==400553);
      for (const Particle& ups : upsilons) {
        LorentzTransform cms_boost;
        if (ups.p3().mod() > 1*MeV)
          cms_boost = LorentzTransform::mkFrameTransformFromBeta(ups.momentum().betaVec());
	Particles phis;
        findDecayProducts(ups, phis);

	if(ups.pid()==300553)
	  _c_4S->fill();
	else
	  _c_5S->fill();

	for(const Particle & phi : phis) {
          FourMomentum p2 = cms_boost.transform(phi.momentum());
	  double x = 2.*p2.p3().mod()/ups.mass();
	if(ups.pid()==300553)
	  _h_4S->fill(x);
	else
	  _h_5S->fill(x);
	}
      }
    }


    /// Normalise histograms etc., after the run
    void finalize() {
      if(_h_4S->effNumEntries()!=0)
	scale(_h_4S   ,100./ *_c_4S);
      if(_h_5S->effNumEntries()!=0)
	scale(_h_5S   ,100./ *_c_5S);
    }

    //@}


    /// @name Histograms
    //@{
    Histo1DPtr _h_4S,_h_5S;
    CounterPtr _c_4S,_c_5S;
    //@}


  };


  // The hook for the plugin system
  DECLARE_RIVET_PLUGIN(CLEO_2007_I728872);


}