Factorization and resummation of s-channel single top quark production

TL;DR

This paper develops a theoretical framework using SCET to factorize and resum s-channel single top quark production, quantifying the effects on cross sections and scale dependence at Tevatron and LHC.

Contribution

It introduces a novel factorization and resummation approach for s-channel single top production using SCET and momentum space formalism.

Findings

Resummation enhances NLO cross sections by 3-5%.

Significantly reduces scale dependence at Tevatron.

No improvement in scale dependence at LHC.

Abstract

In this paper we study the factorization and resummation of s-channel single top quark production in the Standard Model at both the Tevatron and the LHC. We show that the production cross section in the threshold limit can be factorized into a convolution of hard function, soft function and jet function via soft-collinear-effective-theory (SCET), and resummation can be performed using renormalization group equation in the momentum space resummation formalism. We find that in general, the resummation effects enhance the Next-to-Leading-Order (NLO) cross sections by about $3%-5%$ at both the Tevatron and the LHC, and significantly reduce the factorization scale dependence of the total cross section at the Tevatron, while at the LHC we find that the factorization scale dependence has not been improved, compared with the NLO results.