Remarks on measurement of the decay ${\Xi }_b^{-}\to {\Lambda }_b{\pi }^{-}$

Abstract

The interpretation of the recent observation by LHCb of a heavy-flavor-conserving and strangeness-changing decay ${\Xi }_b^{-}\to {\Lambda }_b{\pi }^{-}$ in terms of the branching fraction for the decay suffers from the uncertainty in the yield of the ${\Xi }_b^{-}$ hyperons relative to that of the ${\Lambda }_b$. It is pointed out here that this relative yield can be determined with a significantly reduced uncertainty by measuring within the same experimental conditions the decays related by the flavor $SU(3)$ symmetry and/or the heavy quark symmetry, such as ${\Xi }_b\to J/\psi \Xi$, ${\Lambda }_b\to J/\psi \Lambda$, or ${\Xi }_b^{-}\to {\Xi }_c^0\ell \nu$, ${\Lambda }_b\to {\Lambda }_c\ell \nu$.

Comments: 4 pages