Automatised full one-loop renormalisation of the MSSM II: The chargino-neutralino sector, the sfermion sector and some applications

TL;DR

This paper presents an automated on-shell renormalisation framework for the chargino-neutralino and sfermion sectors of the MSSM, enabling precise one-loop calculations for collider and astrophysics processes.

Contribution

It introduces a fully automated code, SloopS, for on-shell renormalisation of key MSSM sectors, including new insights into mixing angle and tan(beta) renormalisation schemes.

Findings

Numerical comparison of SloopS with existing literature results.

Analysis of tan(beta) scheme dependence on physical observables.

Loop corrections to neutralino and sfermion masses and collider processes.

Abstract

An on-shell renormalisation programme for the chargino/neutralino and the sfermion sectors within the Minimal Supersymmetric Standard Model as implemented in a fully automated code, SloopS, for the calculation of one-loop processes at the colliders and in astrophysics, is presented. This is a sequel to our study in arXiv:0807.4668 [hep-ph] where an on-shell renormalisation of the Higgs (and the gauge/fermion) sector is performed. The issue of mixing is treated in a unified and coherent manner in all these sectors, in particular we give some new insight into the renormalisation of the mixing angle in the sfermion sector and like with the Higgs sector and the issue of tan(beta) we discuss different schemes. We also perform numerical comparisons between our code SloopS and different results found in the literature. In particular we consider loop corrections to the neutralino and sfermion masses, chargino pair production and stau pair production in e^{+}e^{-} colliders, as well as a few decays of the heavier chargino. For all these observables, we analyse the tan(beta) scheme dependence using different definitions of this parameter and comment on the impact of using different renormalisation of the mixing parameter in the sfermion sector.