Rivet analyses

Measurement of dijet angular distributions and search for beyond the standard model physics in proton-proton collisions at sqrt(s)=13 TeV

Experiment: CMS (CERN LHC)

Inspire ID: 3136278

Status: VALIDATED

Authors: - cms-pag-conveners-exo@cern.ch - Andreas Hinzmann

References: - arXiv: 2603.25458 - CMS EXO-24-011 - submitted to JHEP

Beams: p+ p+

Beam energies: (6500.0, 6500.0)GeV

Run details: - Hard QCD process with a pT cut of 200 GeV on sub-leading jet is recommended.

A measurement is presented of dijet angular distributions in proton-proton collisions at TeV, using data collected with the CMS detector at the CERN LHC and corresponding to an integrated luminosity of 138/fb. The data are compared with predictions from perturbative quantum chromodynamics at next-to-next-to-leading order, including electroweak corrections.

Source code:CMS_2026_I3136278.cc

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

namespace Rivet {


  /// @brief Dijet angular distributions at 13 TeV
  class CMS_2026_I3136278 : public Analysis {
  public:

    RIVET_DEFAULT_ANALYSIS_CTOR(CMS_2026_I3136278);

    void init() {
      FinalState fs(Cuts::abseta < 5 && Cuts::pT > 0*GeV);
      declare(FastJets(fs, JetAlg::ANTIKT, 0.4, JetMuons::ALL, JetInvisibles::NONE), "JetsAK4");
      
      book(_h_chi_dijet,{3000.,3600.,4200.,4800.,5400.,6000.,7000.,13000.});
      for (auto& b : _h_chi_dijet->bins()) {
        book(b, b.index() + 11, 1, 1);
      }
    }

    void analyze(const Event& event) {
      const Jets jets = apply<FastJets>(event, "JetsAK4").jetsByPt(Cuts::pT > 200*GeV);
      if (jets.size() < 2) vetoEvent;
      const double y0 = jets[0].rapidity();
      const double y1 = jets[1].rapidity();
      if (std::abs(y0+y1)/2 > 1.11) vetoEvent;
      const double chi = std::exp(std::abs(y0-y1));
      if (chi > 16) vetoEvent;
      const FourMomentum jj = jets[0].momentum() + jets[1].momentum();
      _h_chi_dijet->fill(jj.mass()/GeV, chi);
    }


    void finalize() {
      normalize(_h_chi_dijet);
    }


  private:

    Histo1DGroupPtr _h_chi_dijet;

  };



  // The hook for the plugin system
  RIVET_DECLARE_PLUGIN(CMS_2026_I3136278);

}