Rivet analyses

title: CMS_2016_I1459051

Measurement of the inclusive jet cross-section in $pp$ collisions at $\sqrt{s} = 13~\TeV$

Experiment: CMS (LHC)

Inspire ID: 1459051

Status: VALIDATED

Authors: - Paolo Gunnellini

References: - Eur.Phys.J. C76 (2016) no.8, 451 - CERN-EP-2016-104 - Expt page: CMS-SMP-15-007

Beams: p+ p+

Beam energies: (6500.0, 6500.0)GeV

Run details: - Inclusive hard QCD at 13 TeV center-of-mass energy, and ptHat (or equivalent) greater than 90 GeV

A measurement of the double-differential inclusive jet cross section as a function of jet transverse momentum pT and absolute jet rapidity |y| is presented. The analysis is based on proton-proton collisions collected by the CMS experiment at the LHC at a centre-of-mass energy of 13 TeV. The data samples correspond to integrated luminosities of 71 and 44 pb-1 for |y| < 3 and 3.2 < |y| < 4.7, respectively. Jets are reconstructed with the anti-kt clustering algorithm for two jet sizes, R, of 0.7 and 0.4, in a phase space region covering jet pT up to 2 TeV and jet rapidity up to |y| = 4.7. Predictions of perturbative quantum chromodynamics at next-to-leading order precision, complemented with electroweak and nonperturbative corrections, are used to compute the absolute scale and the shape of the inclusive jet cross section. The cross-section difference in $R$, when going to a smaller jet size of 0.4, is best described by Monte Carlo event generators with next-to-leading order predictions matched to parton showering, hadronisation, and multiparton interactions. In the phase space accessible with the new data, this measurement provides a first indication that jet physics is as well understood at $\sqrt(s) = 13~\TeV$ as at smaller centre-of-mass energies.

Source code:CMS_2016_I1459051.cc

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

include "Rivet/Analysis.hh"

include "Rivet/Projections/FastJets.hh"

include "Rivet/Projections/FinalState.hh"

namespace Rivet {

/// Inclusive jet pT at 13 TeV class CMS_2016_I1459051 : public Analysis { public:

/// Constructor
RIVET_DEFAULT_ANALYSIS_CTOR(CMS_2016_I1459051);


/// Book histograms and initialize projections:
void init() {

  // Initialize the projections
  const FinalState fs;
  declare(FastJets(fs, JetAlg::ANTIKT, 0.4), "JetsAK4");
  declare(FastJets(fs, JetAlg::ANTIKT, 0.7), "JetsAK7");

  // Book sets of histograms, binned in absolute rapidity
  book(_hist_sigmaAK7, {0., 0.5, 1., 1.5, 2., 2.5, 3.});
  book(_hist_sigmaAK4, {0., 0.5, 1., 1.5, 2., 2.5, 3.});
  for (size_t i = 1; i < _hist_sigmaAK7->numBins() + 1; ++i) {
    book(_hist_sigmaAK7->bin(i), i, 1, 1);
    book(_hist_sigmaAK4->bin(i), 7 + i, 1, 1);
  }
  book(_hist_sigmaAK7Forward, 7, 1, 1);
  book(_hist_sigmaAK4Forward, 14, 1, 1);
}


/// Per-event analysis
void analyze(const Event& event) {

  // AK4 jets
  const FastJets& fjAK4 = apply<FastJets>(event, "JetsAK4");
  const Jets& jetsAK4 = fjAK4.jets(Cuts::ptIn(114 * GeV, 2200.0 * GeV) && Cuts::absrap < 4.7);
  for (const Jet& j : jetsAK4) {
    _hist_sigmaAK4->fill(j.absrap(), j.pT());
    if (inRange(j.absrap(), 3.2, 4.7)) _hist_sigmaAK4Forward->fill(j.pT());
  }

  // AK7 jets
  const FastJets& fjAK7 = apply<FastJets>(event, "JetsAK7");
  const Jets& jetsAK7 = fjAK7.jets(Cuts::ptIn(114 * GeV, 2200.0 * GeV) && Cuts::absrap < 4.7);
  for (const Jet& j : jetsAK7) {
    _hist_sigmaAK7->fill(j.absrap(), j.pT());
    if (inRange(j.absrap(), 3.2, 4.7)) _hist_sigmaAK7Forward->fill(j.pT());
  }
}


// Finalize
void finalize() {
  /// @note Extra division factor is the *signed* dy, i.e. 2*d|y|
  scale(_hist_sigmaAK4, crossSection() / picobarn / sumOfWeights() / 2.0);
  scale(_hist_sigmaAK7, crossSection() / picobarn / sumOfWeights() / 2.0);
  scale(_hist_sigmaAK4Forward, crossSection() / picobarn / sumOfWeights() / 3.0);
  scale(_hist_sigmaAK7Forward, crossSection() / picobarn / sumOfWeights() / 3.0);
  divByGroupWidth({_hist_sigmaAK4, _hist_sigmaAK7});
}


/// @name Histograms
/// @{
Histo1DGroupPtr _hist_sigmaAK4;
Histo1DGroupPtr _hist_sigmaAK7;
Histo1DPtr _hist_sigmaAK4Forward;
Histo1DPtr _hist_sigmaAK7Forward;
/// @}

};

RIVET_DECLARE_PLUGIN(CMS_2016_I1459051);

} ```