Probing t-channel single top-quark and antiquark production via differential cross-section measurements at s=13 TeV with the ATLAS detector

The differential production cross-sections of single top quarks and top antiquarks produced via the t -channel process are measured in proton-proton collisions at s = 13 TeV at the LHC with the full Run 2 ATLAS dataset corresponding to an integrated luminosity of 140 f b − 1 . The cross-sections are measured as a function of the transverse momentum and absolute rapidity of the top quark ( tq ) and top antiquark ( t ¯ q ) at parton level. In addition, for the first time, the differential ratio of the tq to t ¯ q cross-sections is presented. The results are compared to theoretical predictions from fixed-order calculations, various event generators, and different PDF sets. An interpretation in the framework of an effective field theory (EFT) is performed to constrain the Wilson coefficient C Q q 3 , 1 of the four-fermion operator.