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

The CLEO Collaboration

We have measured the vector-pseudoscalar mass splitting $M(D_s^{\ast +})-M(D_s^{+})=144.22\pm 0.47\pm 0.37MeV$, significantly more precise than the previous world average. We minimize…