Finite-width effects on threshold corrections to squark and gluino production

TL;DR

This paper investigates how finite decay widths of squarks and gluinos affect threshold resummation calculations for their production at the LHC, finding that moderate widths do not significantly alter higher-order corrections.

Contribution

It demonstrates that for moderate decay widths, zero-width approximations with bound-state contributions remain valid, clarifying the impact of finite-width effects on threshold resummation.

Findings

Higher-order soft and Coulomb corrections are well-described by zero-width calculations for Gamma/m < 5%

Finite-width effects introduce uncertainties comparable to higher-order calculation ambiguities

Bound-state resonances below threshold are important for accurate cross section predictions

Abstract

We study the implication of finite squark and gluino decay widths for threshold resummation of squark and gluino production cross sections at the LHC. We find that for a moderate decay width (Gamma/m < 5%) higher-order soft and Coulomb corrections are appropriately described by NLL calculations in the zero-width limit including the contribution from bound-state resonances below threshold, with the remaining uncertainties due to finite-width effects of a similar order as the ambiguities of threshold-resummed higher-order calculations.