W+W−pair production in two-photon collisions and the magnetic moment of theW±bosons

We consider the process $\gamma \gamma \to W^{+}{W}^{-}$ for arbitrary values of the $W^{\pm }$ boson magnetic moment ${\mu }_W=\left(\frac{e}{2M_W}\right)(1+\kappa )$. The angular distribution, at sufficiently high energy, is extremely sensitive to the magnetic-moment parameter $\kappa$, with the standard value $\kappa =1\mathrm{}$ clearly distinguished from other values. This process is then inserted into $e^{+}{e}^{-}\to e^{+}{e}^{-}{W}^{+}{W}^{-}$, using the equivalent-photon approximation, and we evaluate the angular distribution measured in the $W^{+}{W}^{-}$ center-of-mass frame. The sensitivity to $\kappa$ can be retained only if one puts a lower cutoff on the $W^{\pm }$ boson energies.