Soft gluon resummation for associated squark-electroweakino production at the LHC

TL;DR

This paper develops a threshold resummation method at NLL accuracy for squark-electroweakino production at the LHC, improving prediction precision by including soft gluon effects and reducing theoretical uncertainties.

Contribution

It provides analytical results for process-dependent soft anomalous dimensions and hard matching coefficients, and implements NLO+NLL calculations in the Resummino program.

Findings

NLL contributions increase cross sections by 2-6%.

Scale dependence reduces from ±10% to below ±5%.

Results are applicable to scenarios with non-universal squark masses.

Abstract

We perform a threshold resummation calculation for the associated production of squarks and electroweakinos at the LHC to the next-to-leading logarithmic (NLL) accuracy. Analytical results for the process-dependent soft anomalous dimension and the hard matching coefficient are presented. The resummed results are matched to fixed-order predictions at next-to-leading order (NLO) in QCD, which are generalised to scenarios with non-universal squark masses and mixings. Numerically, the NLL contributions increase the total NLO cross section by $2\%$ to $6\%$ for squark masses ranging from 1 TeV to 3 TeV, respectively, and they reduce the dependence of the predictions on the factorisation and renormalisation scales from typically $\pm10\%$ to below $\pm5\%$. Our NLO and NLO+NLL calculations have been implemented in the publicly available program Resummino.