rivet is hosted by Hepforge, IPPP Durham

Rivet analyses reference

ARGUS_1990_I283027

Anti-deuteron production in $\Upsilon$ decays
Experiment: ARGUS (DORIS)
Inspire ID: 283027
Status: VALIDATED
Authors:
  • Peter Richardson
References:
  • Phys.Lett. B236 (1990) 102-108
Beams: * *
Beam energies: ANY
Run details:
  • Upsilon(1S) decays (originally e+e- production)

Measurement of the anti-deuteron spectrum in $\Upsilon(1S)$ decays. The measurement was original an average of both $\Upsilon(1S)$ and $\Upsilon(2S)$ decays but the $\Upsilon(2S)$ sample is rescaled to the $\Upsilon(1S)$.

Source code: ARGUS_1990_I283027.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
// -*- C++ -*-
#include "Rivet/Analysis.hh"
#include "Rivet/Projections/UnstableParticles.hh"

namespace Rivet {


  /// @brief anti-deuteron spectrum in upslion decays
  class ARGUS_1990_I283027 : public Analysis {
  public:

    /// Constructor
    DEFAULT_RIVET_ANALYSIS_CTOR(ARGUS_1990_I283027);


    /// @name Analysis methods
    ///@{

    /// Book histograms and initialise projections before the run
    void init() {
      // Initialise and register projections
      declare(UnstableParticles(), "UFS");
      // histograms
      book(_h_p,1,1,1);
      book(_w_ups,"TMP/w_ups");
    }


    /// Recursively walk the decay tree to find decay products of @a p
    void findDecayProducts(Particle mother, Particles& deut) {
      // deuteron id code
      static const long id = -1000010020;
      for(const Particle & p: mother.children()) {
	if(p.pid() == id) {
	  deut.push_back(p);
	}
	else if(!p.children().empty())
	  findDecayProducts(p, deut);
      }
    }

    
    /// Perform the per-event analysis
    void analyze(const Event& event) {
      for(const Particle & ups : apply<UnstableParticles>(event, "UFS").particles(Cuts::pid==553) ) {
	_w_ups->fill();
	Particles deut;
	findDecayProducts(ups, deut);
	if(deut.empty()) continue;
	LorentzTransform boost;
	if (ups.p3().mod() > 1*MeV)
	  boost = LorentzTransform::mkFrameTransformFromBeta(ups.momentum().betaVec());
	for(const Particle& p : deut) {
	  double mom = boost.transform(p.momentum()).p3().mod();
	  _h_p->fill(mom);
	}
      }
    }


    /// Normalise histograms etc., after the run
    void finalize() {
      // direct upsilon decays, i.e. to gg gamma and ggg so need to renormalize
      // factor and values from arxiv:0612019
      double Bmumu=0.0249, rhad = 3.56;
      double fact = 1.-(3.+rhad)*Bmumu;
      scale(_h_p, 1e5/fact / *_w_ups);
    }

    ///@}


    /// @name Histograms
    ///@{
    Histo1DPtr _h_p;
    CounterPtr _w_ups;
    ///@}


  };


  DECLARE_RIVET_PLUGIN(ARGUS_1990_I283027);

}