1// -*- C++ -*-
 2#include "Rivet/Analysis.hh"
 3#include "Rivet/Projections/Beam.hh"
 4#include "Rivet/Projections/UnstableParticles.hh"
 5
 6namespace Rivet {
 7
 8
 9  /// @brief Xi_c*+ spectrum
10  class CLEOII_1996_I416471 : public Analysis {
11  public:
12
13    /// Constructor
14    RIVET_DEFAULT_ANALYSIS_CTOR(CLEOII_1996_I416471);
15
16
17    /// @name Analysis methods
18    /// @{
19    /// Book histograms and initialise projections before the run
20    void init() {
21      // projections
22      declare(Beam(), "Beams");
23      declare(UnstableParticles(), "UFS");
24      // book histos
25      book(_h_x,2,1,1);
26      book(_r,3,1,1);
27      book(_c_xi,"TMP/c_xi");
28    }
29
30    // Check for explicit decay into pdgids
31    bool isDecay(const Particle& mother, vector<int> ids) {
32      if(mother.pid()<0) {
33	for(unsigned int ix=0;ix<ids.size();++ix)
34	  ids[ix] *= -1;
35      }
36      // Trivial check to ignore any other decays but the one in question modulo photons
37      const Particles children = mother.children(Cuts::pid!=PID::PHOTON);
38      if (children.size()!=ids.size()) return false;
39      // Check for the explicit decay
40      return all(ids, [&](int i){return count(children, hasPID(i))==1;});
41    }
42
43    /// Perform the per-event analysis
44    void analyze(const Event& event) {
45      static const int idXi = 4324;
46      const ParticlePair& beams = apply<Beam>(event, "Beams").beams();
47      const double Emax = ( beams.first.p3().mod() + beams.second.p3().mod() ) / 2.0;
48      const double Pmax = sqrt(sqr(Emax)-sqr(2.645));
49      const UnstableParticles& ufs = apply<UnstableParticles>(event, "UFS");
50      for (const Particle& p : ufs.particles(Cuts::abspid==idXi)) {
51	double xp = p.momentum().p3().mod()/Pmax;
52	_h_x->fill(xp);
53	int sign = p.pid()/p.abspid();
54	if(isDecay(p,{sign*4132,sign*211})) {
55	  _r->fill(0.5);
56	}
57      }
58      unsigned int nxi = ufs.particles(Cuts::abspid==4132).size();
59      _c_xi->fill(nxi);
60    }
61
62
63    /// Normalise histograms etc., after the run
64    void finalize() {
65      normalize(_h_x,1,false);
66      scale(_r, 1./ *_c_xi);
67    }
68
69    /// @}
70
71
72    /// @name Histograms
73    /// @{
74    Histo1DPtr _h_x,_r;
75    CounterPtr _c_xi;
76    /// @}
77
78
79  };
80
81
82  RIVET_DECLARE_PLUGIN(CLEOII_1996_I416471);
83
84}