Puzzles in charmed baryon semileptonic decays with $SU(3)_F$ flavor symmetry and lattice inputs

Abstract

Recent measurements of charmed-baryon semileptonic decays signal large tensions between experiment and theory, including $SU(3)_F$ analyses and lattice-quantum chromodynamics simulations. Possible sources of the discrepancy include the experimental normalization mode $Ξ_c^0 \to Ξ^- π^+$. Using lattice-QCD inputs in an $SU(3)_F$ analysis including first-order symmetry breaking, we predict ${\cal B}( Ξ_c^+ \to Σ^0 \ell^+ ν_\ell ) / {\cal B}( Ξ_c^+ \to Ξ^0 \ell^+ ν_\ell )=(2.6\pm0.3)\%, $ and ${\cal B}( Ξ_c^+ \to Λ\ell^+ ν_\ell )/{\cal B}( Ξ_c^+ \to Ξ^0 \ell^+ ν_\ell )=(1.1\pm0.1)\%, $ with $\ell^+=(e^+,μ^+)$. These ratios provide normalization-independent tests and may help clarify the origin of the present tension.