Jet Multiplicity in Top-Quark Pair Events at CMS

TL;DR

This paper measures the distribution of additional jets in top-antitop events at CMS, comparing results with quantum chromodynamics predictions and providing insights into jet activity in top quark pair production.

Contribution

It introduces a method to associate jets with top decay products and measures the differential cross section as a function of jet multiplicity.

Findings

Measured the normalized differential cross section as a function of jet multiplicity.

Compared measurements with QCD predictions and found no significant deviations.

Quantified the fraction of events with no additional jets based on transverse momentum thresholds.

Abstract

The normalised differential top quark-antiquark production cross section is measured as a function of the jet multiplicity. Using a procedure to associate jets to decay products of the top quarks, the differential cross section of the ttbar production is determined as a function of the additional jet multiplicity. The fraction of events with no additional jets is measured as a function of the threshold required for the transverse momentum of the additional jet. The measurements are compared with predictions from perturbative quantum chromodynamics and no significant deviations are observed.