rivet is hosted by Hepforge, IPPP Durham

Rivet analyses reference

CMS_2011_S8957746

Event shapes at 7 TeV
Experiment: CMS (LHC)
Inspire ID: 886332
Status: VALIDATED
Authors:
  • Hendrik Hoeth
References: Beams: p+ p+
Beam energies: (3500.0, 3500.0) GeV
Run details:
  • pp QCD interactions at 7000 GeV. Particles with c*tau>10mm are stable.

Central transverse Thrust and Minor have been measured in proton-proton collisions at $\sqrt{s} = 7$ TeV, with a data sample collected with the CMS detector at the LHC. The sample corresponds to an integrated luminosity of 3.2 inverse picobarns. Input for the variables are anti-$k_t$ jets with $R = 0.5$.

Source code: CMS_2011_S8957746.cc
  1// -*- C++ -*-
  2#include "Rivet/Analysis.hh"
  3#include "Rivet/Projections/FinalState.hh"
  4#include "Rivet/Projections/FastJets.hh"
  5#include "Rivet/Projections/Thrust.hh"
  6
  7namespace Rivet {
  8
  9
 10  /// Event shapes at 7 TeV
 11  class CMS_2011_S8957746 : public Analysis {
 12  public:
 13
 14    RIVET_DEFAULT_ANALYSIS_CTOR(CMS_2011_S8957746);
 15
 16
 17    /// Initialization, called once before running
 18    void init() {
 19      // Projections
 20      const FastJets jets(FinalState((Cuts::etaIn(-5.0, 5.0))), FastJets::ANTIKT, 0.5);
 21      declare(jets, "Jets");
 22
 23      // Book histograms
 24      book(_hist_T_90  ,1, 1, 1);
 25      book(_hist_m_90  ,2, 1, 1);
 26      book(_hist_T_125 ,3, 1, 1);
 27      book(_hist_m_125 ,4, 1, 1);
 28      book(_hist_T_200 ,5, 1, 1);
 29      book(_hist_m_200 ,6, 1, 1);
 30    }
 31
 32
 33    void analyze(const Event& event) {
 34      const double weight = 1.0;
 35      const Jets& jets = apply<FastJets>(event, "Jets").jetsByPt(30.0*GeV);
 36      if (jets.size() < 2 ||
 37          fabs(jets[0].eta()) >= 1.3 ||
 38          fabs(jets[1].eta()) >= 1.3 ||
 39          jets[0].pT() < 90*GeV) {
 40        vetoEvent;
 41      }
 42      std::vector<Vector3> momenta;
 43      for (const Jet& j : jets) {
 44        if (j.abseta() < 1.3) {
 45          Vector3 mom = j.p3();
 46          mom.setZ(0.0);
 47          momenta.push_back(mom);
 48        }
 49      }
 50      if (momenta.size() == 2) {
 51        // We need to use a ghost so that Thrust.calc() doesn't return 1.
 52        momenta.push_back(Vector3(1e-10*MeV, 0., 0.));
 53      }
 54      Thrust thrust;
 55      thrust.calc(momenta);
 56
 57      // The lowest bin also includes the underflow:
 58      const double T = max(log(1-thrust.thrust()), -12.0);
 59      const double M = max(log(thrust.thrustMajor()), -6.0);
 60      if (jets[0].pT()/GeV > 200) {
 61        _hist_T_200->fill(T, weight);
 62        _hist_m_200->fill(M, weight);
 63      } else if (jets[0].pT()/GeV > 125) {
 64        _hist_T_125->fill(T, weight);
 65        _hist_m_125->fill(M, weight);
 66      } else if (jets[0].pT()/GeV > 90) {
 67        _hist_T_90->fill(T, weight);
 68        _hist_m_90->fill(M, weight);
 69      }
 70    }
 71
 72
 73    void finalize() {
 74      normalize(_hist_T_90);
 75      normalize(_hist_m_90);
 76      normalize(_hist_T_125);
 77      normalize(_hist_m_125);
 78      normalize(_hist_T_200);
 79      normalize(_hist_m_200);
 80    }
 81
 82
 83  private:
 84
 85    /// @{
 86    Histo1DPtr _hist_T_90;
 87    Histo1DPtr _hist_m_90;
 88    Histo1DPtr _hist_T_125;
 89    Histo1DPtr _hist_m_125;
 90    Histo1DPtr _hist_T_200;
 91    Histo1DPtr _hist_m_200;
 92    /// @}
 93
 94  };
 95
 96
 97
 98  RIVET_DECLARE_ALIASED_PLUGIN(CMS_2011_S8957746, CMS_2011_I886332);
 99
100}