1// -*- C++ -*-
 2#include "Rivet/Analysis.hh"
 3#include "Rivet/Projections/FinalState.hh"
 4#include "Rivet/Projections/ChargedFinalState.hh"
 5#include "Rivet/Projections/FastJets.hh"
 6
 7namespace Rivet {
 8
 9
10  /// D0 dijet angular distributions
11  class D0_2009_I824127 : public Analysis {
12  public:
13
14    RIVET_DEFAULT_ANALYSIS_CTOR(D0_2009_I824127);
15
16
17    /// @name Analysis methods
18    /// @{
19
20    // Book histograms
21    void init() {
22      FinalState fs;
23      FastJets conefinder(fs, JetAlg::D0ILCONE, 0.7);
24      declare(conefinder, "ConeFinder");
25
26      book(_h_chi_dijet, {250., 300., 400., 500., 600., 700., 800., 900., 1000., 1100., 1960.});
27      for (auto& b : _h_chi_dijet->bins()) {
28        book(b, b.index(), 1, 1);
29      }
30    }
31
32
33    /// Do the analysis
34    void analyze(const Event & e) {
35
36      const Jets& jets = apply<JetFinder>(e, "ConeFinder").jetsByPt();
37      if (jets.size() < 2) vetoEvent;
38
39      FourMomentum j0(jets[0].momentum());
40      FourMomentum j1(jets[1].momentum());
41      double y0 = j0.rapidity();
42      double y1 = j1.rapidity();
43
44      if (fabs(y0+y1)>2) vetoEvent;
45
46      double mjj = FourMomentum(j0+j1).mass();
47      double chi = exp(fabs(y0-y1));
48      if(chi<16.)  _h_chi_dijet->fill(mjj, chi);
49    }
50
51
52    /// Finalize
53    void finalize() {
54      normalize(_h_chi_dijet);
55    }
56
57    /// @}
58
59
60  private:
61
62    /// @name Histograms
63    /// @{
64    Histo1DGroupPtr _h_chi_dijet;
65    /// @}
66
67  };
68
69
70
71  RIVET_DECLARE_ALIASED_PLUGIN(D0_2009_I824127, D0_2009_S8320160);
72
73}