Proposals for Bottom Quark/Squark Renormalization in the Complex MSSM

TL;DR

This paper develops and tests various renormalization schemes for the bottom quark and squark sector in the complex MSSM, identifying the most robust methods and analyzing one-loop corrections to decay widths.

Contribution

It introduces and compares multiple renormalization schemes for the cMSSM bottom/squark sector, highlighting the most stable approaches and providing detailed one-loop decay width calculations.

Findings

No universal scheme is numerically acceptable across all parameters.

Two schemes, including 'm_b, A_b DRbar', show the most robustness.

One-loop corrections to decay widths are generally modest.

Abstract

We present a consistent renormalization of the top and bottom quark/squark sector of the MSSM with complex parameters (cMSSM). Various renormalization schemes are defined, analyzed analytically and tested numerically in the decays Stop_2 -> Sbot_i H+/W+ (i = 1,2). No scheme is found that produces numerically acceptable results over all the cMSSM parameter space, where problems occur mostly already for real parameters. Two schemes are identified that show the most robust behavior. A numerical analysis of the four partial stop decay widths is performed in our "preferred" scheme, "m_b, A_b DRbar". The full one-loop corrections to the corresponding partial decay widths are evaluated including hard QED and QCD radiation. We find mostly modest corrections at the one-loop level.