Rivet analyses

title: CDF_2009_I856131

Z rapidity measurement

Experiment: CDF (Tevatron Run 2)

Inspire ID: 856131

Status: VALIDATED

Authors: - Frank Siegert

References: - arXiv: 0908.3914

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

```c++ // -- C++ --

include "Rivet/Analysis.hh"

include "Rivet/Projections/DileptonFinder.hh"

include "Rivet/Projections/FinalState.hh"

namespace Rivet {

/// @brief CDF Z boson rapidity measurement class CDF_2009_I856131 : public Analysis { public:

/// Constructor
RIVET_DEFAULT_ANALYSIS_CTOR(CDF_2009_I856131);


/// @name Analysis methods
/// @{

/// Book histograms and initialise projections before the run
void init() {

  /// Initialise and register projections here
  // this seems to have been corrected completely for all selection cuts,
  // i.e. eta cuts and pT cuts on leptons.
  DileptonFinder zfinder(91.2 * GeV, 0.2, Cuts::abspid == PID::ELECTRON,
                         Cuts::massIn(66 * GeV, 116 * GeV));
  declare(zfinder, "DileptonFinder");


  /// Book histograms here
  book(_h_xs, 1, 1, 1);
  book(_h_yZ, 2, 1, 1);
}


/// Perform the per-event analysis
void analyze(const Event& event) {
  const DileptonFinder& zfinder = apply<DileptonFinder>(event, "DileptonFinder");
  if (zfinder.bosons().size() == 1) {
    _h_yZ->fill(fabs(zfinder.bosons()[0].rapidity()));
    _h_xs->fill(1960);
  }
  else {
    MSG_DEBUG("no unique lepton pair found.");
  }
}


/// Normalise histograms etc., after the run
void finalize() {
  scale(_h_xs, crossSection() / picobarn / sumOfWeights());
  // Data seems to have been normalized for the avg of the two sides
  // (+ve & -ve rapidity) rather than the sum, hence the 0.5:
  scale(_h_yZ, 0.5 * crossSection() / picobarn / sumOfWeights());
}

/// @}

private:

/// @name Histograms
/// @{
Histo1DPtr _h_yZ;
BinnedHistoPtr<int> _h_xs;
/// @}

};

RIVET_DECLARE_PLUGIN(CDF_2009_I856131);

} ```