Scalar mesons in holographic walking technicolor

Abstract

We study the spectrum of scalar mesons in the holographic dual of walking technicolor, obtained by embedding D7–D7¯ probe branes in a certain type IIB background. The scalar mesons arise from fluctuations of the probe techniflavor 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–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.