The capability of current and future measurements at low and high energy $e^{+}{e}^{-}$ colliders to probe for the existence of anomalous, $\mathrm{CP}$-conserving, $\tau \nu W$ dipole moment-type couplings is examined. At present, constraints on the universality of the $\tau$ charged and neutral current interactions as well as the shape of the $\tau \to \mathcal{l}$ energy spectrum provide the strongest bounds on such anomalous couplings. The presence of these dipole moments are shown to influence, e.g., the extraction of ${\alpha }_s{(m}_{\tau }^2)$ from $\tau$ decays and can lead to apparent violations of CVC expectations.

• Received 18 April 1997

DOI:https://doi.org/10.1103/PhysRevD.56.3074