Rivet analyses

title: CMS_2026_I3136278

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++ // -- 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);

} ```