Mass splittings inΣbandΣb*

The charged ${\Sigma }_b$ and ${\Sigma }_b^{*}$ states have recently been reported by the CDF Collaboration. The relation of their reported charge-averaged masses to expectations based on the quark model is reviewed briefly. A relation is proved among the $\Delta I=1$ electromagnetic mass differences ${\Sigma }_1\equiv M({\Sigma }^{+})-M({\Sigma }^{-})$, ${\Sigma }_1^{*}\equiv M({\Sigma }^{*+})-M({\Sigma }^{*-})$, ${\Sigma }_{b1}\equiv M({\Sigma }_b^{+})-M({\Sigma }_b^{-})$, and ${\Sigma }_{b1}^{*}\equiv M({\Sigma }_b^{*+})-M({\Sigma }_b^{*-})$. The relation is ${\Sigma }_{b1}^{*}-{\Sigma }_{b1}=(m_s/m_b)({\Sigma }_1^{*}-{\Sigma }_1)$, leading to the expectation ${\Sigma }_{b1}^{*}-{\Sigma }_{b1}=0.40\pm 0.07\mathrm{MeV}$.