Study of the change from walking to non-walking behavior in a vectorial gauge theory as a function ofNf

Masafumi Kurachi, Robert Shrock
2006 Journal of High Energy Physics  
We study a vectorial gauge theory with gauge group SU(Nc) and a variable number, Nf, of massless fermions in the fundamental representation of this group. Using approximate solutions of Schwinger-Dyson and Bethe-Salpeter equations, we calculate meson masses and investigate how these depend on Nf. We focus on the range of Nf extending from near the boundary with a non-Abelian Coulomb phase, where the theory exhibits a slowly running ("walking") gauge coupling, toward smaller values where the
more » ... alues where the theory has non-walking behavior. Our results include determinations of the masses of the lowest-lying flavor-adjoint mesons with J^{PC} = 0^{-+}, 1^{--}, 0^{++}, and 1^{++} (the generalized \pi, \rho, a0, and a1). Related results are given for flavor-singlet mesons and for the generalization of f_\pi. These results give insight into the change from walking to non-walking behavior in a gauge theory, as a function of Nf .
doi:10.1088/1126-6708/2006/12/034 fatcat:elbygoxqtbhxbicj36pzer57di