L.C. Rohana Wijewardhana
(University of Cincinnati (US))
We study the spectrum of vector and scalar mesons in the holographic dual of a walking gauge theory , obtained by embedding D7 - anti-D7 probe branes in a certain type IIB background. We show that there is a nontrivial relation that needs to be satisfied in order for axial-vector modes to exist The scalar mesons arise from fluctuations of the probe flavour branes and complement the (axial-)vector meson spectra. 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. We also estimate the Peskin Takeuchi S parameter of this theory and show that it is positive definite.
This is joint work of L.Anguelova, P.Suranyi and L.C.R.Wijewardhana.
Will be presented by L.C.R.Wijewardhana.
Published in (1)Nucl.Phys.B852:39-60,2011.
e-Print: arXiv:1105.4185 [hep-th]
Submitted to Nuclear Physics B.