Measurements of the Absolute Branching Fraction of the Semileptonic Decay ${\mathbf{\Xi }}^{-}\to \mathbf{\Lambda }{\mathbf{e}}^{-}{\bar{\nu }}_{\mathbf{e}}$ and the Axial Charge of the ${\mathbf{\Xi }}^{-}$

BESIII Collaboration, M. Ablikim, M. N. Achasov +685

Using $(10087\pm 44)\times 10^6$ $J/\psi$ events collected with the BESIII detector, we study the semileptonic decay ${\Xi }^{-}\to \Lambda e^{-}{\bar{\nu }}_e$ for the first time at an electron-…