Neutralinos from Chargino Decays in the Complex MSSM

TL;DR

This paper provides a comprehensive one-loop calculation of chargino decay widths in the complex MSSM, emphasizing the importance of higher-order corrections for accurate predictions at colliders.

Contribution

It presents the first full one-loop evaluation of chargino decay modes involving neutralinos and W bosons in the cMSSM, including all relevant decay channels and QED radiation effects.

Findings

Higher-order corrections can reach ±10% in decay widths.

Corrections significantly impact the interpretation of neutralino production.

Results are crucial for collider experiments like the LHC and future linear colliders.

Abstract

We review the evaluation of 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 SM gauge bosons. The evaluation of the decay widths is based on a full one-loop calculation including hard and soft QED radiation. Here we focus on the decays involving the Lightest Supersymmetric Particle (LSP), i.e. the lightest neutralino, or a heavier neutralino and a W boson. The higher-order corrections of the chargino decay widths can easily reach a level of \pm 10%, translating into corrections of similar size in the respective branching ratios. These corrections are important for the correct interpretation of LSP and heavier neutralino production at the LHC and at a future linear e+e- collider.