S-parameter, technimesons, and phase transitions in holographic tachyon DBI models

Abstract

We investigate some phenomenological aspects of the holographic models based on the tachyon Dirac-Born-Infeld action in anti--de Sitter space-time. These holographic theories model strongly interacting fermions and feature dynamical mass generation and symmetry breaking. We show that they can be viewed as models of holographic walking technicolor and compute the Peskin-Takeuchi $S$ parameter and masses of lightest technimesons for a variety of tachyon potentials. We also investigate the phase structure at finite temperature and charge density. Finally, we comment on the holographic Wilsonian renormalization group in the context of holographic tachyon Dirac-Born-Infeld models.