Differential top quark cross section results from the ATLAS and CMS experiments

TL;DR

This work surveys differential top-quark cross-section measurements from ATLAS and CMS across $t\\bar{t}$ production in single-lepton and dilepton final states, boosted topologies, and WbWb interference, as well as single-top $t$-channel production. It combines advanced reconstruction, including resolved and boosted top tagging, kinematic fits, and unfolding (e.g., TUnfold, Iterative Bayesian), with detailed comparisons to fixed-order and beyond-NLO QCD predictions. A core finding is that, although NNLO QCD and related generators improve agreement in many observables, no current model describes all bins or high-mass tails across the full phase space, underscoring the need for further theoretical and PDF refinements. The results place valuable constraints on parton distribution functions and MC modeling, guiding future top-quark mass and PDF extractions and informing Run 3 analyses with larger data sets.

Abstract

This report summarizes recent results of differential top quark cross section measurements performed by the ATLAS and CMS experiments. The $t\bar{t}$ process is studied as well as the production of single (anti-)top quarks and the interference with other Standard Model processes of the same final state. State-of-the-art theory predictions are compared to the data. No theory model is able to describe the data across all bins, but an improved description of the data when moving to predictions in higher orders in perturbative QCD can be observed.