Strong couplings and form factors of charmed mesons in holographic QCD

Abstract

We extend the two-flavor hard-wall holographic model of Erlich, Katz, Son and Stephanov [Phys.\ Rev.\ Lett.\ {\bf 95}, 261602 (2005)] to four flavors to incorporate strange and charm quarks. The model incorporates chiral and flavor symmetry breaking and provides a reasonable description of masses and weak decay constants of a variety of scalar, pseudoscalar, vector and axial-vector strange and charmed mesons. In particular, we examine flavor symmetry breaking in the strong couplings of the $\rho$ meson to the charmed $D$ and $D^{\ast }$ mesons. We also compute electromagnetic form factors of the $\pi$, $\rho$, $K$, $K^{\ast }$, $D$ and $D^{\ast }$ mesons. We compare our results for the $D$ and $D^{\ast }$ mesons with lattice QCD data and other nonperturbative approaches.

Comments: 18 pages, 8 figures. V3: Added 3 new references. Version published in Phys. Rev. D