Light quark mass dependence of the $D$ and $D_s$ decay constants

L. S. Geng, M. Altenbuchinger, W. Weise

We study the light quark mass dependence of the $D$ and $D_s$ meson decay constants, $f_D$ and $f_{D_s}$, using a covariant formulation of chiral perturbation theory ($\chi$PT) at nex…