Threshold resummation for pair production of coloured heavy (s)particles at hadron colliders

TL;DR

This paper develops a NNLL resummation formalism for pair production of heavy coloured particles at hadron colliders, improving theoretical predictions by including soft and Coulomb effects and their interference.

Contribution

It introduces a novel factorization and resummation approach for heavy coloured particle pair production near threshold at NNLL accuracy, including bound state effects.

Findings

Resummation increases cross section predictions by 4-20%.

Scale dependence is significantly reduced.

Results are applicable to squark-antisquark production at LHC and Tevatron.

Abstract

We derive a factorization formula for the production of pairs of heavy coloured particles in hadronic collisions near the production threshold that establishes factorization of soft and Coulomb effects. This forms the basis for a combined resummation of Coulomb and soft corrections, including the non-trivial interference of the two effects. We develop a resummation formalism valid at NNLL accuracy using the momentum-space approach to soft gluon resummation. We present numerical results for the NLL resummed squark-antisquark production cross section at the LHC and Tevatron, including also the contribution of squark-antisquark bound states below threshold. The total correction on top of the next-to-leading order approximation is found to be sizeable, and amounts to (4-20)% in the squark mass region 200 GeV-3 TeV at the 14 TeV LHC. The scale dependence of the total cross section is also reduced.