Analyzing lepton flavor universality in the decays $Lambda_btoLambda_c^{(ast)}(frac12^pm,frac32^-) + ell,bar u_ell$

Lepton flavor universality can be tested in the semileptonic decays $Lambda_bto Lambda_c^{(ast)}$ where $Lambda_c^{(ast)}$ denotes either the ground state $Lambda_c(2286)$ (with $J^P=1/2^+$) or its orbital excitations $Lambda_c(2595)$ (with $J^P=1/2^-$) and $Lambda_c(2625)$ (with $J^P=3/2^-$). We calculate the differential decay rates as well as the branching fractions of these decays for both tauonic and muonic modes with form factors obtained from a covariant confined quark model previously developed by us. We present results for the rate ratios of the tauonic and muonic modes which provide important tests of lepton flavor universality in forthcoming experiments.