Holographic Renormalisation and the Electroweak Precision Parameters

TL;DR

This paper investigates how holographic renormalisation affects an AdS/QCD-inspired model of electroweak symmetry breaking, providing a well-defined framework for calculating precision parameters and deriving physical bounds.

Contribution

It introduces a holographic renormalisation procedure for an AdS/QCD model with electroweak symmetry breaking, ensuring physical quantities are UV cut-off independent.

Findings

Boundary counterterms enable UV-finite two-point functions.

Precision electroweak parameters are computed and bounds established.

Large-N scaling behavior is analyzed.

Abstract

We study the effects of holographic renormalisation on an AdS/QCD inspired description of dynamical electroweak symmetry breaking. Our model is a 5D slice of AdS_5 geometry containing a bulk scalar and SU(2) times SU(2) gauge fields. The scalar field obtains a VEV which represents a condensate that triggers electroweak symmetry breaking. Fermion fields are constrained to live on the UV brane and do not propagate in the bulk. The two-point functions are holographically renormalised through the addition of boundary counterterms. Measurable quantities are then expressed in terms of well defined physical parameters, free from any spurious dependence on the UV cut-off. A complete study of the precision parameters is carried out and bounds on physical quantities derived. The large-N scaling of results is discussed.