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*0 spectrum
10  class CLEOII_1995_I397770 : public Analysis {
11  public:
12
13    /// Constructor
14    RIVET_DEFAULT_ANALYSIS_CTOR(CLEOII_1995_I397770);
15
16
17    /// @name Analysis methods
18    /// @{
19
20    /// Book histograms and initialise projections before the run
21    void init() {
22      // projections
23      declare(Beam(), "Beams");
24      declare(UnstableParticles(), "UFS");
25      // book histos
26      book(_h_x,2,1,1);
27      book(_r,3,1,1);
28      book(_c_xi,"TMP/c_xi");
29    }
30
31    // Check for explicit decay into pdgids
32    bool isDecay(const Particle& mother, vector<int> ids) {
33      if(mother.pid()<0) {
34	for(unsigned int ix=0;ix<ids.size();++ix)
35	  ids[ix] *= -1;
36      }
37      // Trivial check to ignore any other decays but the one in question modulo photons
38      const Particles children = mother.children(Cuts::pid!=PID::PHOTON);
39      if (children.size()!=ids.size()) return false;
40      // Check for the explicit decay
41      return all(ids, [&](int i){return count(children, hasPID(i))==1;});
42    }
43
44    /// Perform the per-event analysis
45    void analyze(const Event& event) {
46      static const int idXi = 4314;
47      const ParticlePair& beams = apply<Beam>(event, "Beams").beams();
48      const double Emax = ( beams.first.p3().mod() + beams.second.p3().mod() ) / 2.0;
49      const double Pmax = sqrt(sqr(Emax)-sqr(2.645));
50      const UnstableParticles& ufs = apply<UnstableParticles>(event, "UFS");
51      for (const Particle& p : ufs.particles(Cuts::abspid==idXi)) {
52	double xp = p.momentum().p3().mod()/Pmax;
53	_h_x->fill(xp);
54	int sign = p.pid()/p.abspid();
55	if(isDecay(p,{sign*4232,-sign*211})) {
56	  _r->fill("10.5"s);
57	}
58      }
59      unsigned int nxi = ufs.particles(Cuts::abspid==4232).size();
60      _c_xi->fill(nxi);
61    }
62
63    /// Normalise histograms etc., after the run
64    void finalize() {
65      normalize(_h_x);
66      scale(_r, 1./ *_c_xi);
67    }
68    /// @}
69
70
71    /// @name Histograms
72    /// @{
73    Histo1DPtr _h_x;
74    BinnedHistoPtr<string> _r;
75    CounterPtr _c_xi;
76    /// @}
77
78
79  };
80
81
82  RIVET_DECLARE_PLUGIN(CLEOII_1995_I397770);
83
84}