1// -*- C++ -*-
 2#include "Rivet/Analysis.hh"
 3#include "Rivet/Projections/ZFinder.hh"
 4
 5namespace Rivet {
 6
 7  /// @ D0 Run I Z \f$ p_\perp \f$ in Drell-Yan events
 8  /// @author Simone Amoroso
 9  class D0_2000_I503361 : public Analysis {
10  public:
11
12    /// Constructor
13    RIVET_DEFAULT_ANALYSIS_CTOR(D0_2000_I503361);
14
15
16    /// @name Analysis methods
17    //@{
18
19    /// Book histograms and initialise projections before the run
20    void init() {
21
22      ///  Initialise and register projections here
23      ZFinder zfinder(FinalState(), Cuts::open(), PID::ELECTRON, 75*GeV, 105*GeV, 0.0*GeV, ZFinder::ClusterPhotons::NONE);
24      declare(zfinder, "ZFinder");
25
26
27      book(_hist_zpt ,1, 1, 1);
28    }
29
30
31    /// Perform the per-event analysis
32    void analyze(const Event& event) {
33      /// @todo Do the event by event analysis here
34      const ZFinder& zfinder = apply<ZFinder>(event, "ZFinder");
35      if (zfinder.bosons().size() != 1) {
36        MSG_DEBUG("Num e+ e- pairs found = " << zfinder.bosons().size());
37	vetoEvent;
38      }
39      const FourMomentum& pZ = zfinder.bosons()[0].momentum();
40      if (pZ.mass2() < 0) {
41	MSG_DEBUG("Negative Z mass**2 = " << pZ.mass2()/GeV2 << "!");
42	vetoEvent;
43      }
44
45      MSG_DEBUG("Dilepton mass = " << pZ.mass()/GeV << " GeV");
46      _hist_zpt->fill(pZ.pT());
47
48    }
49
50
51    /// Normalise histograms etc., after the run
52    void finalize() {
53      scale(_hist_zpt, crossSection()/picobarn/sumOfWeights());
54    }
55
56    //@}
57
58
59  private:
60
61    /// @name Histograms
62    //@{
63    Histo1DPtr _hist_zpt;
64    //@}
65
66
67  };
68
69
70
71  // The hook for the plugin system
72  RIVET_DECLARE_PLUGIN(D0_2000_I503361);
73
74}