Semileptonic decays Λc+ → Λ+ν (=e,μ) in the covariant quark model and comparison with the new absolute branching fraction measurements of Belle and BESIII

We present precise theoretical predictions for the absolute branching fractions of Λb→Λc ell nu decays in the covariant confined quark model. This study is motivated by two recent and accurate measurements of the absolute branching fractions of Λc→ pKpi and Λc → Λ e nu by the Belle Collaboration at the KEKB and by the BESIII Collaboration at the BEPCII. Our predictions for the branching fractions are consistent with both experimental results. We also provide detailed numerical results for differential decay distributions and polarization observables.