1// -*- C++ -*-
 2#include "Rivet/Analysis.hh"
 3#include "Rivet/Projections/UnstableParticles.hh"
 4
 5namespace Rivet {
 6
 7
 8  /// @brief anti-deuteron spectrum in upslion decays
 9  class ARGUS_1990_I283027 : public Analysis {
10  public:
11
12    /// Constructor
13    RIVET_DEFAULT_ANALYSIS_CTOR(ARGUS_1990_I283027);
14
15
16    /// @name Analysis methods
17    ///@{
18
19    /// Book histograms and initialise projections before the run
20    void init() {
21      // Initialise and register projections
22      declare(UnstableParticles(), "UFS");
23      // histograms
24      book(_h_p,1,1,1);
25      book(_w_ups,"TMP/w_ups");
26    }
27
28
29    /// Recursively walk the decay tree to find decay products of @a p
30    void findDecayProducts(Particle mother, Particles& deut) {
31      // deuteron id code
32      static const long id = -1000010020;
33      for(const Particle & p: mother.children()) {
34	if(p.pid() == id) {
35	  deut.push_back(p);
36	}
37	else if(!p.children().empty())
38	  findDecayProducts(p, deut);
39      }
40    }
41
42    
43    /// Perform the per-event analysis
44    void analyze(const Event& event) {
45      for(const Particle & ups : apply<UnstableParticles>(event, "UFS").particles(Cuts::pid==553) ) {
46	_w_ups->fill();
47	Particles deut;
48	findDecayProducts(ups, deut);
49	if(deut.empty()) continue;
50	LorentzTransform boost;
51	if (ups.p3().mod() > 1*MeV)
52	  boost = LorentzTransform::mkFrameTransformFromBeta(ups.momentum().betaVec());
53	for(const Particle& p : deut) {
54	  double mom = boost.transform(p.momentum()).p3().mod();
55	  _h_p->fill(mom);
56	}
57      }
58    }
59
60
61    /// Normalise histograms etc., after the run
62    void finalize() {
63      // direct upsilon decays, i.e. to gg gamma and ggg so need to renormalize
64      // factor and values from arxiv:0612019
65      double Bmumu=0.0249, rhad = 3.56;
66      double fact = 1.-(3.+rhad)*Bmumu;
67      scale(_h_p, 1e5/fact / *_w_ups);
68    }
69
70    ///@}
71
72
73    /// @name Histograms
74    ///@{
75    Histo1DPtr _h_p;
76    CounterPtr _w_ups;
77    ///@}
78
79
80  };
81
82
83  RIVET_DECLARE_PLUGIN(ARGUS_1990_I283027);
84
85}