Measurements of the $\tau$ Mass and Mass Difference of the ${\tau }^{+}$ and ${\tau }^{-}$} at BaBar

The BaBar Collaboration, B. Aubert

We present the result from a precision measurement of the mass of the $\tau$ lepton, $M_{\tau }$, based on $423f{b}^{-1}$ of data recorded at the ${\rm Y}(4S)$ resonance with the BaBar detector. U…