Soft Gluon Resummation in $t$-channel single top quark production at the LHC

TL;DR

This paper performs a detailed resummation of soft gluon effects in t-channel single top quark production at the LHC, highlighting the importance of color coherence and proposing experimental tests.

Contribution

It introduces a next-to-leading logarithm resummation formalism for soft gluon radiation in single top production, including color coherence effects and experimental observables.

Findings

Soft gluon effects are significant in forward jet regions.

Color coherence impacts the distribution predictions.

The proposed observable $\

Abstract

We present a detailed phenomenological study of the multiple soft gluon radiation for the $t$-channel single top and anti-top quark production at the Large Hadron Collider (LHC). By applying the transverse momentum dependent factorization formalism, large logarithms introduced by small total transverse momentum $q_\perp$ of the single-top (anti-top) plus one-jet final state system are resummed to all orders in the expansion of the strong interaction coupling at the accuracy of Next-to-Leading Logarithm. We discuss various kinematical distributions which are sensitive to this effect and find that soft gluon radiation become more important when the final state jet is required to be in the forward region. We show that the main difference from PYTHIA prediction lies on the inclusion of the exact color coherence effect between the initial and final states in our resummation calculation. We further propose to apply the experimental observable $\phi^*$ to test the effect of multiple gluon radiation in the single-top and anti-top events. The bottom quark mass effect and jet rapidity distribution are also discussed.