W^+Z and W^+γ^* Backgrounds to Strong W^+W^+ Scattering at the LHC

Because of inevitable blind spots at high rapidity and low transverse momentum, the process $\overline qq \rightarrow l^+ l^- \ l^{+} \nu$ provides a surprisingly large background to the $W^+W^+ \rightarrow l^+ \nu \ l^+ \nu$ signal associated with strong $WW$ scattering. Previous calculations of the total background are approximately doubled, and the estimate of the ``no-lose'' luminosity at the LHC to observe manifestations of the electroweak symmetry breaking mechanism is increased to between $\sim 100$ and $\sim 140$ fb$^{-1}$.