We present our calculation of $D \to \pi$ and $D \to K$ semileptonic form factors in 2+1 flavor lattice QCD. We simulate three lattice cutoffs $a^{-1} \sim $ 2.5, 3.6 and 4.5 GeV with pion masses as low as 230 MeV. The Moebius domain-wall action is employed for both light and charm quarks. We present our results for the vector and scalar form factors and discuss their dependence on the lattice spacing, light quark masses and momentum transfer.

Weak Decays and Matrix Elements