Advances in Higher-Order Perturbative Calculations for tt(X) production

by Luca Buonocore (CERN)

Wednesday 25 Jun 2025, 14:00 → 15:00 Europe/Zurich

In this talk, I will present recent theoretical advances in the study of top-antitop pair production, potentially in association with a color-singlet final state $X$. In the first part, I focus on $t\bar{t}X$ production with a veto on the transverse momentum ($p_T$) of the leading light jet. In the limit of small $p_T$, large logarithmic corrections arise that undermine the reliability of fixed-order perturbation theory. I will outline a factorization theorem for this observable and report on the computation of the soft function — the final missing ingredient required to achieve next-to-next-to-leading logarithmic prime (NNLL′) accuracy. In the second part, I will discuss ongoing work to go beyond the stable-top approximation by computing next-to-next-to-leading order (NNLO) corrections to the full decayed final state in leptonic channels: $p p \to b \bar{b} \ell^+ \nu_ell + \ell’^- \bar{\nu}_{\ell’}$. This includes the incorporation of off-shell effects and represents a significant step toward a fully realistic theoretical description of top-pair production at NNLO.