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 Spectrum for D_s2+
10  class ARGUS_1995_I397794 : public Analysis {
11  public:
12
13    /// Constructor
14    RIVET_DEFAULT_ANALYSIS_CTOR(ARGUS_1995_I397794);
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_rate1,1,1,1);
27      book(_h_rate2,1,2,1);
28      book(_h_x,2,1,1);
29    }
30
31
32    /// Perform the per-event analysis
33    void analyze(const Event& event) {
34      static const int idDs2 = 435;
35      // Get beams and average beam momentum
36      const ParticlePair& beams = apply<Beam>(event, "Beams").beams();
37      const double Emax = ( beams.first.p3().mod() + beams.second.p3().mod() ) / 2.0;
38      const double Pmax = sqrt(sqr(Emax)-sqr(2.625));
39      const UnstableParticles& ufs = apply<UnstableParticles>(event, "UFS");
40      for (const Particle& p : ufs.particles(Cuts::abspid==idDs2)) {
41	double xp = p.momentum().p3().mod()/Pmax;
42	_h_x->fill(xp);
43	int sign = p.pid()/p.abspid();
44	if(p.children().size()!=2) continue;
45	if(p.children()[0].pid()==sign*421 &&
46	   p.children()[1].pid()==sign*321) {
47	  _h_rate1->fill(xp);
48	  _h_rate2->fill(xp);
49	}
50	else if(p.children()[1].pid()==sign*421 &&
51		p.children()[0].pid()==sign*321) {
52	  _h_rate1->fill(xp);
53	  _h_rate2->fill(xp);
54	}
55      }
56    }
57
58
59    /// Normalise histograms etc., after the run
60    void finalize() {
61      normalize(_h_x);
62      scale(_h_rate1,0.3*crossSection()/sumOfWeights()/picobarn);
63      scale(_h_rate2,crossSection()/sumOfWeights()/picobarn);
64    }
65
66    /// @}
67
68
69    /// @name Histograms
70    /// @{
71    Histo1DPtr _h_x,_h_rate1,_h_rate2;
72    /// @}
73
74
75  };
76
77
78  RIVET_DECLARE_PLUGIN(ARGUS_1995_I397794);
79
80}