MSSM Higgs sector at the one-loop level

Abstract

This work provides an elementary introduction to the Higgs sector renormalisation within the Minimal Supersymmetric Standard Model (MSSM) framework. The main aim of the paper is to clarify some technical details that are usually omitted in the existing literature. The MSSM tree-level relation m ²_h + m ²_H = m ²_A + m ²_Z is renormalised using the standard technique of direct computation of the relevant one-loop Feynman diagrams. The calculation is performed within the unitary gauge and the definition of the renormalised parameters is briefly reviewed. The expected cancellation of ultraviolet divergences is explicitly checked and the well-known leading-log term is recovered. All the necessary ingredients of the computations are summarized in the appendices which makes the work more self-contained.