Alberto Prades Ibanez - DIS2026 - Proceedings in CDS - Highlights on top quark properties and mass measurements with the ATLAS detector

This contribution covers four recent measurements of top-quark properties by the ATLAS Collaboration using $140~\\mathrm{fb}^{-1}$ of $\\sqrt{s} = 13~\\mathrm{TeV}$ LHC proton--proton collision data. Two top-quark mass determinations are presented: a measurement based on the reconstruction of a $J/\\psi \\rightarrow \\mu^{+}\\mu^{-}$ decay in $t\\bar{t}$ events, and a pole mass extraction from mass from a differential cross-section in dileptonic $t\\bar{t}+1$ jet events. Furthermore, the first direct measurement of the CKM matrix element $|V_{cb}|$ at the weak scale is performed using hadronic $W$-boson decays in $t\\bar{t}$ events. Finally, Effective Field Theory constraints are derived from four-dimensional angular distributions in $t$-channel single-top-quark production. Together, these results show the broad scope of the top-quark physics program, demonstrating its versatility not only for determining fundamental Standard Model parameters and exploring flavor physics, but also as a powerful probe for new physics.