1// -*- C++ -*-
 2#include "Rivet/Analysis.hh"
 3#include "Rivet/Projections/FinalState.hh"
 4#include "Rivet/Projections/FastJets.hh"
 5
 6namespace Rivet {
 7
 8
 9  /// @brief CDF dijet angular distributions
10  class CDF_1996_I423414 : public Analysis {
11  public:
12
13    RIVET_DEFAULT_ANALYSIS_CTOR(CDF_1996_I423414);
14
15
16    /// @name Analysis methods
17    /// @{
18
19    /// Book histograms and initialise projections before the run
20    void init() {
21      FinalState fs(Cuts::abseta < 4.2);
22      declare(FastJets(fs, JetAlg::CDFJETCLU, 0.7), "Jets");
23
24      book(_h_chi, {241., 300., 400., 517., 625., 1800.},
25                   {"d01-x01-y01", "d01-x01-y02", "d01-x01-y03", "d01-x01-y04", "d01-x01-y05"});
26      book(_h_ratio,  2, 1, 1);
27      book(_htmp_chi_above_25 ,"TMP/chiabove25", refData(2, 1, 1));
28      book(_htmp_chi_below_25 ,"TMP/chibelow25", refData(2, 1, 1));
29    }
30
31
32    /// Perform the per-event analysis
33    void analyze(const Event& event) {
34
35      Jets jets = apply<FastJets>(event, "Jets").jetsByPt(Cuts::pT > 50.0*GeV);
36      if (jets.size() < 2) vetoEvent;
37
38      const FourMomentum jet1 = jets[0].momentum();
39      const FourMomentum jet2 = jets[1].momentum();
40      const double eta1 = jet1.eta();
41      const double eta2 = jet2.eta();
42      const double chi = exp(fabs(eta1 - eta2));
43      if (fabs(eta2) > 2.0 || fabs(eta1) > 2.0 || chi > 5.0) vetoEvent;
44
45      double m = FourMomentum(jet1 + jet2).mass();
46      _h_chi->fill(m, chi);
47
48      // Fill ratio numerator or denominator depending on chi value
49      ((chi > 2.5) ? _htmp_chi_above_25 : _htmp_chi_below_25)->fill(m/GeV);
50    }
51
52
53    /// Normalise histograms etc., after the run
54    void finalize() {
55      normalize(_h_chi);
56      divide(_htmp_chi_below_25, _htmp_chi_above_25, _h_ratio);
57    }
58
59    /// @}
60
61
62  private:
63
64    /// @name Histograms
65    /// @{
66    Histo1DGroupPtr _h_chi;
67    Histo1DPtr _htmp_chi_above_25, _htmp_chi_below_25;
68    Estimate1DPtr _h_ratio;
69    /// @}
70
71  };
72
73
74
75  RIVET_DECLARE_ALIASED_PLUGIN(CDF_1996_I423414, CDF_1996_S3418421);
76
77}