1// -*- C++ -*-
 2#include "Rivet/Analysis.hh"
 3#include "Rivet/Projections/UnstableParticles.hh"
 4
 5namespace Rivet {
 6
 7
 8  /// @brief B -> D_s X
 9  class CLEOII_1996_I401599 : public Analysis {
10  public:
11
12    /// Constructor
13    RIVET_DEFAULT_ANALYSIS_CTOR(CLEOII_1996_I401599);
14
15
16    /// @name Analysis methods
17    /// @{
18
19    /// Book histograms and initialise projections before the run
20    void init() {
21      // projections
22      declare(UnstableParticles(Cuts::pid==300553),"UFS");
23      // histograms
24      book(_h, 2,1,1);
25    }
26
27    void findDecay(const Particle& parent, Particles& Ds) {
28      for (const Particle& p : parent.children()) {
29        if (p.abspid()==431) {
30          Ds.push_back(p);
31        }
32        else if (p.abspid()==PID::PIPLUS ||
33          p.abspid()==PID::KPLUS  ||
34          p.pid()==PID::PI0 ||
35          p.pid()==PID::K0S) {
36          continue;
37        }
38        else if(!p.children().empty()) {
39          findDecay(p,Ds);
40        }
41      }
42    }
43
44    /// Perform the per-event analysis
45    void analyze(const Event& event) {
46      const UnstableParticles& ufs = apply<UnstableParticles>(event, "UFS");
47      for (const Particle & p : ufs.particles()) {
48        const LorentzTransform boost = LorentzTransform::mkFrameTransformFromBeta(p.mom().betaVec());
49        for (const Particle & B:p.children()) {
50          if (B.abspid()!=511 && B.abspid()!=521) continue;
51          Particles Ds;
52          findDecay(B,Ds);
53          for (const Particle & p2 : Ds) {
54            const double x = boost.transform(p2.mom()).p3().mod()/sqrt(0.25*sqr(p.mass())-sqr(p2.mass()));
55            _h->fill(x);
56          }
57        }
58      }
59    }
60
61
62    /// Normalise histograms etc., after the run
63    void finalize() {
64      normalize(_h, 1.0, false);
65    }
66
67    /// @}
68
69
70    /// @name Histograms
71    /// @{
72    Histo1DPtr _h;
73    /// @}
74
75
76  };
77
78
79  RIVET_DECLARE_PLUGIN(CLEOII_1996_I401599);
80
81}