Rivet analyses

Dijet angular distributions in pp collisions at $\sqrt{s} = 7$ TeV

Experiment: CMS (LHC)

Inspire ID: 1090423

Status: VALIDATED

Authors: - A. Hinzmann

References: - JHEP 05 (2012) 055 - DOI: 10.1007/JHEP05(2012)055 - arXiv: 1202.5535

Beams: p+ p+

Beam energies: (3500.0, 3500.0)GeV

Run details: - QCD events with dijet mass greater 400 GeV

Measurement of dijet angular distributions in proton-proton collisions at a center-of-mass energy of 7 TeV. The data sample has a total integrated luminosity of 2.2 inverse femtobarns, recorded by the CMS experiment at the LHC. Normalized dijet angular distributions have been measured for dijet invariant masses from 0.4 TeV to above 3 TeV.

Source code:CMS_2012_I1090423.cc

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

namespace Rivet {


  class CMS_2012_I1090423 : public Analysis {
  public:

    RIVET_DEFAULT_ANALYSIS_CTOR(CMS_2012_I1090423);

    void init() {

      FinalState fs;
      FastJets antikt(fs, JetAlg::ANTIKT, 0.5);
      declare(antikt, "ANTIKT");

      book(_h_chi_dijet, {400., 600., 800., 1000., 1200., 1500., 1900., 2400., 3000., 7000.});
      for (auto& b : _h_chi_dijet->bins()) {
        book(b, _h_chi_dijet->numBins() - b.index() + 1, 1, 1);
      }
    }


    void analyze(const Event& event) {
      const Jets& jets = apply<JetFinder>(event, "ANTIKT").jetsByPt();
      if (jets.size() < 2) vetoEvent;

      const double y0 = jets[0].rapidity();
      const double y1 = jets[1].rapidity();
      if (fabs(y0+y1)/2 > 1.11) vetoEvent;

      const double chi = exp(fabs(y0-y1));
      if (chi > 16) vetoEvent;

      const FourMomentum jj = jets[0].momentum() + jets[1].momentum();
       _h_chi_dijet->fill(jj.mass(), chi);
    }


    void finalize() {
      normalize(_h_chi_dijet);
    }


  private:

    Histo1DGroupPtr _h_chi_dijet;

  };



  RIVET_DECLARE_PLUGIN(CMS_2012_I1090423);

}