Next-to-leading-order predictions for t-channel single-top production at hadron colliders

TL;DR

This paper provides next-to-leading-order predictions for t-channel single-top production at hadron colliders, comparing different calculation approaches and assessing their agreement and accuracy.

Contribution

It introduces a NLO calculation starting from the 2->3 process with a non-zero b-quark mass and compares it to traditional 2->2 approaches with resummation techniques.

Findings

2->3 calculation is well-behaved and reliable.

Good agreement between 2->3 and 2->2 predictions.

Resummation of logarithms effectively approximates the full calculation.

Abstract

We present the predictions at next-to-leading order (NLO) in the strong coupling for the single-top cross section in the t channel at the Tevatron and the LHC. Our calculation starts from the 2 -> 3 Born amplitude g q -> t bbar q', keeping the b-quark mass non-zero. A comparison is performed with a traditional NLO calculation of this channel based on the 2 -> 2 Born process with a bottom quark in the initial state. In particular, the effect of using kinematic approximations and resumming logarithms of the form log(Q^2/m_b^2) in the 2 -> 2 process is assessed. Our results show that the 2 -> 3 calculation is very well behaved and in substantial agreement with the predictions based on the 2 -> 2 process.