1// -*- C++ -*-
 2#include "Rivet/Analysis.hh"
 3#include "Rivet/Projections/UnstableParticles.hh"
 4#include "Rivet/Projections/Beam.hh"
 5
 6namespace Rivet {
 7
 8
 9  /// @brief Add a short analysis description here
10  class TASSO_1986_I230950 : public Analysis {
11  public:
12
13    /// Constructor
14    RIVET_DEFAULT_ANALYSIS_CTOR(TASSO_1986_I230950);
15
16
17    /// @name Analysis methods
18    /// @{
19
20    /// Book histograms and initialise projections before the run
21    void init() {
22
23      // Initialise and register projections
24      declare(Beam(), "Beams");
25      declare(UnstableParticles(), "UFS");
26
27      // Book histograms
28      book(_h_p, 1, 1, 1);
29      book(_h_x, 2, 1, 1);
30
31    }
32
33
34    /// Perform the per-event analysis
35    void analyze(const Event& event) {
36      // Get beams and average beam momentum
37      const ParticlePair& beams = apply<Beam>(event, "Beams").beams();
38      const double meanBeamMom = ( beams.first.p3().mod() + beams.second.p3().mod() ) / 2.0;
39      MSG_DEBUG("Avg beam momentum = " << meanBeamMom);
40
41      for (const Particle& p : apply<UnstableParticles>(event, "UFS").
42	     particles(Cuts::pid==PID::PI0)) {
43      double modp = p.p3().mod();
44      double xE = p.E()/meanBeamMom;
45      double beta = modp/p.E();
46      _h_p->fill(modp);
47      _h_x->fill(xE, 1./beta);
48      }
49    }
50
51
52    /// Normalise histograms etc., after the run
53    void finalize() {
54      scale(_h_p, crossSection()/nanobarn/sumOfWeights());
55      scale(_h_x, sqr(sqrtS())*crossSection()/microbarn/sumOfWeights());
56    }
57
58    /// @}
59
60
61    /// @name Histograms
62    /// @{
63    Histo1DPtr _h_p, _h_x;
64    /// @}
65
66
67  };
68
69
70  RIVET_DECLARE_PLUGIN(TASSO_1986_I230950);
71
72
73}