Rivet analyses

Measurement of differential $Z/\gamma^*$ pT

Experiment: D0 (Tevatron Run 2)

Inspire ID: 856972

Status: VALIDATED

Authors: - Flavia Dias - Gavin Hesketh - Frank Siegert

References: - arXiv: 1006.0618

Beams: p- p+

Beam energies: (980.0, 980.0)GeV

Run details: - $p \bar{p} \to \mu^+ \mu^-$ + jets at 1960~GeV. Needs mass cut on lepton pair to avoid photon singularity, looser than $65 < m_{\mu\mu} < 115$ GeV. Restrict $Z/\gamma^*$ mass range to roughly $50~\text{GeV}/c^2 < m_{\mu\mu} < 120~\text{GeV}/c^2$ for efficiency. Weighted events and kinematic sampling enhancement can help to fill the pT tail.

Cross section as a function of pT of the Z boson decaying into muons in $p \bar{p}$ collisions at $\sqrt{s}$ = 1.96 TeV, based on an integrated luminosity of 0.97 fb$^{-1}$.

Source code:D0_2010_I856972.cc

// -*- C++ -*-
#include "Rivet/Analysis.hh"
#include "Rivet/Projections/DileptonFinder.hh"
#include "Rivet/Projections/FinalState.hh"

namespace Rivet {


  /// @brief Measurement of Z(->muon muon) pT differential cross-section
  ///
  /// @author Flavia Dias
  class D0_2010_I856972 : public Analysis {
  public:

    RIVET_DEFAULT_ANALYSIS_CTOR(D0_2010_I856972);


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

    /// Add projections and book histograms
    void init() {
      Cut cut = Cuts::abseta < 1.7 && Cuts::pT > 15 * GeV;
      DileptonFinder zfinder(91.2 * GeV, 0.2, cut && Cuts::abspid == PID::MUON,
                             Cuts::massIn(65 * GeV, 115 * GeV));
      declare(zfinder, "DileptonFinder");

      book(_h_Z_pT_normalised, 1, 1, 1);
      book(_h_Z_pT_xs, 2, 1, 1);
    }


    // Do the analysis
    void analyze(const Event& e) {
      const DileptonFinder& zfinder = apply<DileptonFinder>(e, "DileptonFinder");
      if (zfinder.bosons().size() == 1) {
        double ZpT = zfinder.bosons()[0].pT() / GeV;
        _h_Z_pT_normalised->fill(ZpT);
        _h_Z_pT_xs->fill(ZpT);
      }
    }


    /// Finalize
    void finalize() {
      normalize(_h_Z_pT_normalised);
      scale(_h_Z_pT_xs, crossSection() / picobarn / sumOfWeights());
    }

    /// @}


  private:

    /// @name Histogram
    Histo1DPtr _h_Z_pT_normalised;
    Histo1DPtr _h_Z_pT_xs;
  };


  RIVET_DECLARE_ALIASED_PLUGIN(D0_2010_I856972, D0_2010_S8671338);

}

Aliases: - D0_2010_S8671338