1// -*- C++ -*-
 2#include "Rivet/Analysis.hh"
 3#include "Rivet/Projections/DileptonFinder.hh"
 4
 5namespace Rivet {
 6
 7
 8  /// @brief D0 Run I Z \f$ p_\perp \f$ in Drell-Yan events
 9  ///
10  /// @author Simone Amoroso
11  class D0_2000_I503361 : public Analysis {
12  public:
13
14    /// Constructor
15    RIVET_DEFAULT_ANALYSIS_CTOR(D0_2000_I503361);
16
17
18    /// @name Analysis methods
19    /// @{
20
21    /// Book histograms and initialise projections before the run
22    void init() {
23
24      ///  Initialise and register projections here
25      DileptonFinder zfinder(91.2*GeV, 0.0, Cuts::abspid == PID::ELECTRON, Cuts::massIn(75*GeV, 105*GeV));
26      declare(zfinder, "DileptonFinder");
27
28      book(_hist_zpt ,1, 1, 1);
29    }
30
31
32    /// Perform the per-event analysis
33    void analyze(const Event& event) {
34      /// @todo Do the event by event analysis here
35      const DileptonFinder& zfinder = apply<DileptonFinder>(event, "DileptonFinder");
36      if (zfinder.bosons().size() != 1) {
37        MSG_DEBUG("Num e+ e- pairs found = " << zfinder.bosons().size());
38        vetoEvent;
39      }
40      const FourMomentum& pZ = zfinder.bosons()[0].momentum();
41      if (pZ.mass2() < 0) {
42        MSG_DEBUG("Negative Z mass**2 = " << pZ.mass2()/GeV2 << "!");
43        vetoEvent;
44      }
45
46      MSG_DEBUG("Dilepton mass = " << pZ.mass()/GeV << " GeV");
47      _hist_zpt->fill(pZ.pT());
48
49    }
50
51
52    /// Normalise histograms etc., after the run
53    void finalize() {
54      scale(_hist_zpt, crossSection()/picobarn/sumOfWeights());
55    }
56
57    /// @}
58
59
60  private:
61
62    /// @name Histograms
63    /// @{
64    Histo1DPtr _hist_zpt;
65    /// @}
66
67
68  };
69
70
71
72  RIVET_DECLARE_PLUGIN(D0_2000_I503361);
73
74}