Magnetic moment of weak bosons produced in pp and pp-bar collisions

We suggest that the reactions $\mathrm{pp}\ensuremath{\rightarrow}{W}^{\ifmmode\pm\else\textpm\fi{}}\ensuremath{\gamma}X$ and $p\overline{p}\ensuremath{\rightarrow}{W}^{\ifmmode\pm\else\textpm\fi{}}\ensuremath{\gamma}X$ are good candidates for measuring the magnetic moment parameter $\ensuremath{\kappa}$ in ${\ensuremath{\mu}}_{W}=(\frac{e}{2{M}_{W}})(1+\ensuremath{\kappa})$. The angular distribution of the $W$ bosons in $p\overline{p}\ensuremath{\rightarrow}{W}^{\ifmmode\pm\else\textpm\fi{}}\ensuremath{\gamma}X$ is particularly sensitive to this parameter. For the gauge-theory value of $\ensuremath{\kappa}=1$, we have found a peculiar zero in $\frac{d\ensuremath{\sigma}(d\overline{u}\ensuremath{\rightarrow}{W}^{\ensuremath{-}}\ensuremath{\gamma})}{d}cos\ensuremath{\theta}$ at $cos\ensuremath{\theta}=\ensuremath{-}\frac{1}{3}$, the location of this zero depending on the quark charge through $cos\ensuremath{\theta}=\ensuremath{-}(1+2{Q}_{d})$. A similar zero occurs in $\frac{d\ensuremath{\sigma}(u\overline{d}\ensuremath{\rightarrow}{W}^{+}\ensuremath{\gamma})}{d}cos\ensuremath{\theta}$. We can offer no explanation for this behavior.