Bound on the W-boson electric dipole moment.

Abstract

A $W$-boson electric dipole moment $\frac{{\ensuremath{\lambda}}_{W}e}{2{m}_{W}}$ can induce fermion electric dipole moments via quantum loop corrections. Updating an analysis by Salzman and Salzman, we estimate this effect and find that the current neutron-electric-dipole-moment bound $|{d}_{n}|<6\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}25}$ e cm implies (barring an unforeseen cancellation) $|{\ensuremath{\lambda}}_{W}|<1\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}3}$ or $|{d}_{W}|<{10}^{\ensuremath{-}19}$ e cm. On the basis of this constraint, we conclude that electricdipole-moment contributions to radiative $W$-boson processes must be very small and effectively undetectable.