Real radiative decays of heavy pseudoscalar mesons

We report our ongoing lattice QCD study of radiative leptonic decays of the charged pseudoscalar mesons $D$, $D_s$, $B$, and $B_c\to \mathrm{\ell }{\nu }_{\mathrm{\ell }}\gamma$. We carry out our analysis on a single JLQCD ensemble with lattice spacing $a=0.044\text{ fm}$. This work is a step towards a complete QCD+QED lattice calculation of these modes, aimed at reducing theoretical uncertainties in the extraction of $\mathrm{\mid }{V}_{cd}\mathrm{\mid }$ and $\mathrm{\mid }{V}_{cs}\mathrm{\mid }$ and providing first-principles estimates of the corresponding form factors in the $B$ sector.