Chargino Decays in the Complex MSSM: A Full One-Loop Analysis

TL;DR

This paper provides a comprehensive one-loop calculation of chargino decay widths in the complex MSSM, including all relevant channels and radiative corrections, crucial for accurate collider phenomenology.

Contribution

It presents the first full one-loop analysis of chargino decays in the cMSSM, incorporating all decay channels and QED radiation effects, with results ready for implementation in FeynHiggs.

Findings

Corrections to decay widths involving the LSP can reach ±10%.

Corrections to Higgs decay channels are slightly smaller, affecting branching ratios.

Results are essential for interpreting LSP and Higgs signals at colliders.

Abstract

We evaluate two-body decay modes of charginos in the Minimal Supersymmetric Standard Model with complex parameters (cMSSM). Assuming heavy scalar quarks we take into account all decay channels involving charginos, neutralinos, (scalar) leptons, Higgs bosons and Standard Model gauge bosons. The evaluation of the decay widths is based on a full one-loop calculation including hard and soft QED radiation. Special attention is paid to decays involving the Lightest Supersymmetric Particle (LSP), i.e. the lightest neutralino, or a neutral or charged Higgs boson. The higher-order corrections of the chargino decay widths involving the LSP can easily reach a level of about \pm 10%, while the corrections to the decays to Higgs bosons are slightly smaller, translating into corrections of similar size in the respective branching ratios. These corrections are important for the correct interpretation of LSP and Higgs production at the LHC and at a future linear e+e- collider. The results will be implemented into the Fortran code FeynHiggs.