Speaker
Description
We present a holographic calculation of the semileptonic decays $B\to D$ and $B_s\to D_s$ within the AdS/QCD Softwall Model. Heavy-light mesons are described by normalizable bulk modes, while the flavor-changing current $J_\text{EW}^\mu=\bar{c}\,\gamma^\mu\,b$ is associated with a massless bulk vector field, motivated by the UV scaling dimension $\Delta=3$ of the QCD current. An effective bulk interaction yields the overlap integral from which we extract the holographic Isgur-Wise function $\xi(\omega)$, and the vector $f_+(q^2)$ and scalar $f_0(q^2)$ form factors. We also evaluate the Lepton Flavor Universality Ratios $R(D)$ and $R(D_s)$, comparing our predictions with lattice QCD and available experimental data. Finally, we discuss the limitations of the leading-order holographic description.
