Zero-jettiness resummation for top-quark pair production at the LHC

Abstract

Abstract We study the resummation of the 0-jettiness resolution variable T $$ \mathcal{T} $$ 0 for the top-quark pair production process in hadronic collisions. Starting from an effective theory framework we derive a factorisation formula for this observable which allows its resummation at any logarithmic order in the T $$ \mathcal{T} $$ 0 → 0 limit. We then calculate the O $$ \mathcal{O} $$ (α s ) corrections to the soft function matrices and, by employing renormalisation group equation methods, we obtain the ingredients for the resummation formula up to next-to-next-to-leading logarithmic (NNLL) accuracy. We study the impact of these corrections to the 0-jettiness distribution by comparing predictions at different accuracy orders: NLL, NLL′, NNLL and approximate NNLL′ ( NNLL a ′ $$ {\mathrm{NNLL}}_{\mathrm{a}}^{\prime } $$ ). We match these results to the corresponding fixed order calculations both at leading order and next-to-leading order for the t t ¯ $$ \overline{t} $$ +jet production process, obtaining the most accurate prediction of the 0-jettiness distribution for the top-quark pair production process at NNLL a ′ $$ {\mathrm{NNLL}}_{\mathrm{a}}^{\prime } $$ +NLO accuracy.

Keywords

• NLO Computations
• QCD Phenomenology