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CDF_2009_I856131

Z rapidity measurement
Experiment: CDF (Tevatron Run 2)
Inspire ID: 856131
Status: VALIDATED
Authors:
  • Frank Siegert
References: Beams: p- p+
Beam energies: (980.0, 980.0) GeV
Run details:
  • $p \bar{p} \to e^+ e^-$ + jets at 1960 GeV. Needs mass cut on lepton pair to avoid photon singularity, looser than $66 < m_{ee} < 116$ GeV

CDF measurement of the total cross section and rapidity distribution, $\mathrm{d}\sigma/\mathrm{d}y$, for $q\bar{q}\to \gamma^{*}/Z\to e^{+}e^{-}$ events in the $Z$ boson mass region ($66<M_{ee}<116$ GeV/c$^2$) produced in $p\bar{p}$ collisions at $\sqrt{s}=1.96$ TeV with 2.1 fb$^{-1}$ of integrated luminosity.

Source code: CDF_2009_I856131.cc
 1// -*- C++ -*-
 2#include "Rivet/Analysis.hh"
 3#include "Rivet/Projections/FinalState.hh"
 4#include "Rivet/Projections/ZFinder.hh"
 5
 6namespace Rivet {
 7
 8
 9  /// @brief CDF Z boson rapidity measurement
10  class CDF_2009_I856131 : public Analysis {
11  public:
12
13    /// @name Constructors etc.
14    //@{
15
16    /// Constructor
17    RIVET_DEFAULT_ANALYSIS_CTOR(CDF_2009_I856131);
18
19    //@}
20
21
22  public:
23
24    /// @name Analysis methods
25    //@{
26
27    /// Book histograms and initialise projections before the run
28    void init() {
29
30      /// Initialise and register projections here
31      // this seems to have been corrected completely for all selection cuts,
32      // i.e. eta cuts and pT cuts on leptons.
33      ZFinder zfinder(FinalState(), Cuts::open(), PID::ELECTRON,
34                      66*GeV, 116*GeV, 0.2, ZFinder::ClusterPhotons::NODECAY, ZFinder::AddPhotons::YES);
35      declare(zfinder, "ZFinder");
36
37
38      /// Book histograms here
39      book(_h_xs ,1, 1, 1);
40      book(_h_yZ ,2, 1, 1);
41
42    }
43
44
45    /// Perform the per-event analysis
46    void analyze(const Event& event) {
47      const ZFinder& zfinder = apply<ZFinder>(event, "ZFinder");
48      if (zfinder.bosons().size() == 1) {
49        _h_yZ->fill(fabs(zfinder.bosons()[0].rapidity()));
50        _h_xs->fill(1960);
51      } else {
52        MSG_DEBUG("no unique lepton pair found.");
53      }
54
55    }
56
57
58    /// Normalise histograms etc., after the run
59    void finalize() {
60      scale(_h_xs, crossSection()/sumOfWeights());
61      // Data seems to have been normalized for the avg of the two sides
62      // (+ve & -ve rapidity) rather than the sum, hence the 0.5:
63      scale(_h_yZ, 0.5*crossSection()/sumOfWeights());
64    }
65
66    //@}
67
68
69  private:
70
71    /// @name Histograms
72    //@{
73    Histo1DPtr _h_yZ;
74    Histo1DPtr _h_xs;
75    //@}
76
77  };
78
79
80
81  // The hook for the plugin system
82  RIVET_DECLARE_PLUGIN(CDF_2009_I856131);
83
84}