1// -*- C++ -*-
 2#include "Rivet/Analysis.hh"
 3#include "Rivet/Projections/UnstableParticles.hh"
 4#include "Rivet/Tools/Random.hh"
 5
 6namespace Rivet {
 7
 8
 9  /// @brief Direct photon spectrum in upslion decay
10  class CLEOIII_2006_I701217 : public Analysis {
11  public:
12
13    /// Constructor
14    RIVET_DEFAULT_ANALYSIS_CTOR(CLEOIII_2006_I701217);
15
16
17    /// @name Analysis methods
18    /// @{
19
20    /// Book histograms and initialise projections before the run
21    void init() {
22      // projections
23      declare(UnstableParticles(Cuts::pid==553 ||
24				Cuts::pid==100553 ||
25				Cuts::pid==200553), "UFS");
26      // histos
27      for(unsigned int ix=0; ix<3; ++ix) {
28        book(_h[ix], 1+ix, 1,1);
29      }
30    }
31
32
33    /// Perform the per-event analysis
34    void analyze(const Event& event) {
35      // Find the Upsilons among the unstables
36      for (const Particle& ups : apply<UnstableParticles>(event, "UFS").particles()) {
37      	unsigned int nhadron(0);
38      	Particles photons;
39      	for (const Particle & child : ups.children()) {
40      	  if (PID::isHadron(child.pid())) {
41      	    ++nhadron;
42          }
43      	  else if (child.pid()==PID::PHOTON) {
44      	    photons.push_back(child);
45          }
46      	}
47        if (nhadron==0 || photons.empty()) continue;
48        LorentzTransform boost;
49        if (ups.p3().mod() > 1*MeV) {
50          boost = LorentzTransform::mkFrameTransformFromBeta(ups.momentum().betaVec());
51        }
52        unsigned int iups = ups.pid()/100000;
53        for (const Particle & gamma : photons) {
54          double E = boost.transform(gamma.momentum()).E();
55          double sigma = 0.01*E*(0.6*pow(E,-0.7309)+1.14-0.01*E);
56	        E = randnorm(E,sigma);
57          _h[iups]->fill(2.*E/ups.mass());
58        }
59      }
60    }
61
62
63    /// Normalise histograms etc., after the run
64    void finalize() {
65      normalize(_h, 1.0, false);
66    }
67
68    /// @}
69
70
71    /// @name Histograms
72    /// @{
73    Histo1DPtr _h[3];
74    /// @}
75
76
77  };
78
79
80  RIVET_DECLARE_PLUGIN(CLEOIII_2006_I701217);
81
82}