Rivet analyses

title: D0_2015_I1324946

D0 measurement of the $\phi^*$ distribution of muon pairs with masses between 30 and 500 GeV in 10.4 fb-1

Experiment: D0 (Tevatron)

Inspire ID: 1324946

Status: VALIDATED

Authors: - Simone Amoroso

References: - Phys.Rev. D91 (2015) 072002 - DOI: 10.1103/PhysRevD.91.072002 - arXiv: 1410.8052

Beams: p- p+

Beam energies: (980.0, 980.0)GeV

Run details: - $Z/\gamma^*$ production with decays to muons.

D0 measurement of the distribution of the variable $\phi^*$ for muon pairs with masses between 30 and 500 GeV, using the complete run II data set collected at the Tevatron proton-antiproton collider. This corresponds to an integrated luminosity of $10.4 \text{fb}^{-1}$ at $\sqrt{s}=1.96$ TeV. The data are corrected for detector effects and presented in bins of dimuon rapidity and mass.

Source code:D0_2015_I1324946.cc

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

include "Rivet/Analysis.hh"

include "Rivet/Projections/DileptonFinder.hh"

include "Rivet/Projections/FinalState.hh"

namespace Rivet {

class D0_2015_I1324946 : public Analysis { public:

/// Constructor
RIVET_DEFAULT_ANALYSIS_CTOR(D0_2015_I1324946);


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

/// Book histograms and initialise projections before the run
void init() {
  DileptonFinder zfinder_mm(91.2 * GeV, 0.0,
                            Cuts::abseta < 2 && Cuts::pT > 15 * GeV && Cuts::abspid == PID::MUON,
                            Cuts::massIn(30 * GeV, 500 * GeV));
  declare(zfinder_mm, "zfinder_mm");

  book(_h_phistar_mm_peak_central, 1, 1, 1);
  book(_h_phistar_mm_peak_forward, 2, 1, 1);
  book(_h_phistar_mm_low_central, 3, 1, 1);
  book(_h_phistar_mm_low_forward, 4, 1, 1);
  book(_h_phistar_mm_high1, 5, 1, 1);
  book(_h_phistar_mm_high2, 6, 1, 1);
}


/// Perform the per-event analysis
void analyze(const Event& event) {

  //70<Mmm<105
  const DileptonFinder& zfinder_mm = apply<DileptonFinder>(event, "zfinder_mm");
  if (zfinder_mm.bosons().size() == 1) {
    Particles mm = zfinder_mm.constituents();
    std::sort(mm.begin(), mm.end(), cmpMomByPt);
    const FourMomentum& mminus = PID::charge3(mm[0].pid()) < 0 ? mm[0].momentum() : mm[1].momentum();
    const FourMomentum& mplus = PID::charge3(mm[0].pid()) < 0 ? mm[1].momentum() : mm[0].momentum();
    double phi_acop = M_PI - mapAngle0ToPi(mminus.phi() - mplus.phi());
    double costhetastar = tanh((mminus.eta() - mplus.eta()) / 2);
    double sin2thetastar = 1 - sqr(costhetastar);
    if (sin2thetastar < 0) sin2thetastar = 0;
    const double phistar = tan(phi_acop / 2) * sqrt(sin2thetastar);
    const FourMomentum& zmom = zfinder_mm.bosons()[0].momentum();
    if (zmom.mass() < 30 * GeV || zmom.mass() > 500 * GeV) vetoEvent;

    if (zmom.mass() > 70 && zmom.mass() < 100 && zmom.absrap() < 1.0)
      _h_phistar_mm_peak_central->fill(phistar);
    if (zmom.mass() > 70 && zmom.mass() < 100 && zmom.absrap() > 1.0 && zmom.absrap() < 2.0)
      _h_phistar_mm_peak_forward->fill(phistar);
    if (zmom.mass() > 30 && zmom.mass() < 60 && zmom.absrap() < 1.0)
      _h_phistar_mm_low_central->fill(phistar);
    if (zmom.mass() > 30 && zmom.mass() < 60 && zmom.absrap() > 1.0 && zmom.absrap() < 2.0)
      _h_phistar_mm_low_forward->fill(phistar);
    if (zmom.mass() > 160 && zmom.mass() < 300) _h_phistar_mm_high1->fill(phistar);
    if (zmom.mass() > 300 && zmom.mass() < 500) _h_phistar_mm_high2->fill(phistar);
  }
}


/// Normalise histograms etc., after the run
void finalize() {

  normalize(_h_phistar_mm_low_central);
  normalize(_h_phistar_mm_low_forward);
  normalize(_h_phistar_mm_peak_central);
  normalize(_h_phistar_mm_peak_forward);
  normalize(_h_phistar_mm_high1);
  normalize(_h_phistar_mm_high2);
}

/// @}

private:

/// @name Histograms
/// @{

Histo1DPtr _h_phistar_mm_low_central;
Histo1DPtr _h_phistar_mm_low_forward;
Histo1DPtr _h_phistar_mm_peak_central;
Histo1DPtr _h_phistar_mm_peak_forward;
Histo1DPtr _h_phistar_mm_high1;
Histo1DPtr _h_phistar_mm_high2;
/// @}

};

RIVET_DECLARE_PLUGIN(D0_2015_I1324946);

} ```