1// -*- C++ -*-
 2#include "Rivet/Analysis.hh"
 3#include "Rivet/Projections/UnstableParticles.hh"
 4
 5namespace Rivet {
 6
 7
 8  /// @brief phi and D_s spectra at 29 GeV
 9  class HRS_1985_I213242 : public Analysis {
10  public:
11
12    /// Constructor
13    RIVET_DEFAULT_ANALYSIS_CTOR(HRS_1985_I213242);
14
15
16    /// @name Analysis methods
17    ///@{
18
19    /// Book histograms and initialise projections before the run
20    void init() {
21      declare(UnstableParticles(), "UFS");
22      book(_h_phi,1,1,1);
23      book(_h_Ds ,2,1,1);
24    }
25
26
27    /// Perform the per-event analysis
28    void analyze(const Event& event) {
29      UnstableParticles ufs = apply<UnstableParticles>(event,"UFS");
30      for(const Particle & p : ufs.particles(Cuts::abspid==431 ||
31					     Cuts::pid==333)) {
32      	double xE = 2.*p.E()/sqrtS();
33      	Vector3 mom3 = p.p3();
34        const double energy = p.E();
35      	double modp = mom3.mod();
36      	double beta = modp/energy;
37	if(p.pid()==333) 
38	  _h_phi->fill(xE,1./beta);
39	else
40	  _h_Ds ->fill(xE,1./beta);
41      }
42    }
43
44
45    /// Normalise histograms etc., after the run
46    void finalize() {
47      // PDG 2020 D_s phi pi br
48      double br=0.045;
49      scale( _h_phi, sqr(sqrtS())*crossSection()/nanobarn/sumOfWeights());
50      scale( _h_Ds , br*sqr(sqrtS())*crossSection()/nanobarn/sumOfWeights());
51    }
52
53    ///@}
54
55
56    /// @name Histograms
57    ///@{
58    Histo1DPtr _h_phi,_h_Ds;
59    ///@}
60
61
62  };
63
64
65  RIVET_DECLARE_PLUGIN(HRS_1985_I213242);
66
67}