Measurement of the differential $t$-channel production cross-section of single top quarks and top antiquarks at $\sqrt{s} = $13 TeV with the ATLAS detector

TL;DR

This paper measures the differential cross-sections of single top quark and antiquark production at 13 TeV using ATLAS data, comparing results with theoretical models and constraining new physics via effective field theory.

Contribution

It provides the first detailed differential measurements of single top quark production at 13 TeV and tests various theoretical predictions against experimental data.

Findings

Results agree with theoretical predictions within uncertainties

Constraints set on four-fermion operator contributions

Differential cross-sections as functions of top quark kinematics

Abstract

Differential production cross-sections of single top quarks and top antiquarks are measured in proton-proton collisions at a centre-of-mass energy $\sqrt{s} = $13 TeV. The full Run-2 dataset collected by the ATLAS detector at the LHC in the years 2015-2018 is used. The differential cross-sections are measured as a function of the transverse momentum and absolute rapidity of the top (anti)quark. The measurement results are compared to predictions obtained from fixed order calculations, different matrix-element event generators and different parton distribution function sets. The results agree with the theoretical predictions within the measurement uncertainties. An effective field theory interpretation of the measurement sets constraints on the contribution of the four-fermion operator $O_{Qq}^{3,1}$.