Scalar Mesons in Holographic Walking Technicolor

TL;DR

This paper investigates the scalar meson spectrum in a holographic model of walking technicolor, revealing near-degeneracy with vector mesons and stability of the embedding, suggesting possible underlying symmetries.

Contribution

It provides the first explicit calculation of scalar meson spectra in this holographic walking technicolor model, showing near-degeneracy with vector mesons and stability of the D7-anti-D7 embedding.

Findings

Scalar meson spectrum computed and found stable.

Mass splitting between scalar and vector mesons is subleading.

Near-degeneracy suggests possible approximate symmetry.

Abstract

We study the spectrum of scalar mesons in the holographic dual of walking technicolor, obtained by embedding D7 - anti-D7 probe branes in a certain type IIB background. The scalar mesons arise from fluctuations of the probe techniflavour branes and complement the (axial-)vector meson spectra that we investigated in earlier work. By explicitly finding the spectrum of scalar masses, we show that the nonsupersymmetric D7 - anti-D7 embedding is stable with respect to such fluctuations. Interestingly, it turns out that the mass splitting between the scalar and vector meson spectra is of subleading order in a small parameter expansion. It is noteworthy that this near-degeneracy may not be entirely due to a small amount of supersymmetry breaking and thus could indicate the presence of some other (approximate) symmetry in the problem.