Precision Measurement of $D_s^{\ast +}$-$D_s^{+}$ Mass Difference

BESIII Collaboration, M. Ablikim, M. N. Achasov +684

We measure the mass difference between $D_s^{\ast +}$ and $D_s^{+}$, $\Delta m_s$, using the decay chain $D_s^{\ast +}\to D_s^{+}(\to K^{+}{K}^{-}{\pi }^{+}){\pi }^0$, utilizing $e^{+}{e}^{-}$ annihi…