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## Rivet analyses reference

### ATLAS_2014_I1288706

Measurement of the low-mass Drell-Yan differential cross section at 7 TeV
Experiment: ATLAS (LHC)
Inspire ID: 1288706
Status: VALIDATED
Authors:
• Elena Yatsenko
References:
Beams: p+ p+
Beam energies: (3500.0, 3500.0) GeV
Run details:
• Run with inclusive $Z$ events, with $Z/\gamma^*$ decays to electrons and/or muons at $\sqrt{s} = 7$ TeV.

Measurements of the differential cross section for the process $Z/\gamma^\ast \rightarrow l$ $(l = e, \mu)$ as a function of dilepton invariant mass in pp collisions at $\sqrt{s} = 7$ TeV. The measurement is performed in the $e$ and $\mu$ channels for invariant masses between 26 GeV and 66 GeV in the fiducial region $p_\text{T}^\text{leading} > 15$ GeV, $p_\text{T}^\text{subleading} > 12$ GeV, $|\eta| < 2.4$ using an integrated luminosity of 1.6 $\text{fb}^{-1}$. The analysis is extended to invariant masses as low as 12 GeV in the muon channel within a fiducal region of $p_\text{T}^\text{leading} > 9$ GeV, $p_\text{T}^\text{subleading} > 6$ GeV, $|\eta| < 2.4$ with 35 $\text{pb}^{-1}$.

Source code: ATLAS_2014_I1288706.cc
  1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 // -*- C++ -*- #include "Rivet/Analysis.hh" #include "Rivet/Projections/FinalState.hh" #include "Rivet/Projections/ZFinder.hh" #include "Rivet/Particle.fhh" namespace Rivet { class ATLAS_2014_I1288706 : public Analysis { public: /// Constructor ATLAS_2014_I1288706() : Analysis("ATLAS_2014_I1288706") { _sumw_ext_mu_dressed = 0; _sumw_mu_dressed = 0; _sumw_el_dressed = 0; } /// @name Analysis methods //@{ /// Book histograms and initialise projections before the run void init() { // Set up projections FinalState fs; ZFinder zfinder_ext_dressed_mu(fs, Cuts::abseta<2.4 && Cuts::pT>6.0*GeV, PID::MUON, 12.0*GeV, 66.0*GeV, 0.1); declare(zfinder_ext_dressed_mu, "ZFinder_ext_dressed_mu"); ZFinder zfinder_dressed_mu(fs, Cuts::abseta<2.4 && Cuts::pT>12*GeV, PID::MUON, 26.0*GeV, 66.0*GeV, 0.1); declare(zfinder_dressed_mu, "ZFinder_dressed_mu"); ZFinder zfinder_dressed_el(fs, Cuts::abseta<2.4 && Cuts::pT>12*GeV, PID::ELECTRON, 26.0*GeV, 66.0*GeV, 0.1); declare(zfinder_dressed_el, "ZFinder_dressed_el"); _hist_ext_mu_dressed = bookHisto1D(1, 1, 1); // muon, dressed level, extended phase space _hist_mu_dressed = bookHisto1D(2, 1, 1); // muon, dressed level, nominal phase space _hist_el_dressed = bookHisto1D(2, 1, 2); // electron, dressed level, nominal phase space } /// Perform the per-event analysis void analyze(const Event& event) { const double weight = event.weight(); const ZFinder& zfinder_ext_dressed_mu = apply(event, "ZFinder_ext_dressed_mu"); const ZFinder& zfinder_dressed_mu = apply(event, "ZFinder_dressed_mu" ); const ZFinder& zfinder_dressed_el = apply(event, "ZFinder_dressed_el" ); fillPlots(zfinder_ext_dressed_mu, _hist_ext_mu_dressed, 9*GeV, weight); fillPlots(zfinder_dressed_mu, _hist_mu_dressed, 15*GeV, weight); fillPlots(zfinder_dressed_el, _hist_el_dressed, 15*GeV, weight); } /// Helper function to fill the histogram if a Z is found with the required lepton cuts void fillPlots(const ZFinder& zfinder, Histo1DPtr hist, double leading_pT, double weight) { if (zfinder.bosons().size() != 1) return; const FourMomentum el1 = zfinder.rawParticles()[0]; const FourMomentum el2 = zfinder.rawParticles()[1]; if (el1.pT() < leading_pT && el2.pT() < leading_pT) return; const double mass = zfinder.bosons()[0].mass(); hist->fill(mass/GeV, weight); } /// Normalise histograms etc., after the run void finalize() { scale(_hist_ext_mu_dressed, crossSection()/sumOfWeights()); scale(_hist_mu_dressed, crossSection()/sumOfWeights()); scale(_hist_el_dressed, crossSection()/sumOfWeights()); } //@} private: // Data members like post-cuts event weight counters go here double _sumw_ext_mu_dressed, _sumw_mu_dressed, _sumw_el_dressed; /// Histograms Histo1DPtr _hist_ext_mu_dressed, _hist_mu_dressed, _hist_el_dressed; }; // The hook for the plugin system DECLARE_RIVET_PLUGIN(ATLAS_2014_I1288706); }