or via $t$- and $u$-channel squark exchange. DY production of neutralinos only occurs in the case of a noticeable contribution of higgsinos and even then the cross sections are quite small. In contrast, $Z,\gamma\to{\widetilde{W}}^{+}\,{\widetilde{W}}^{-}$ has quite a large cross section. The same is true for $W^{\pm}\to{\widetilde{W}}^{\pm}\,{\widetilde{W}}^{0}$. For $m_{{\widetilde{W}}^{\pm}}\lesssim3\,m_{{{\widetilde{\tau}}}_{\text{R}}}$ the DY production of ${\widetilde{W}}^{+}\,{\widetilde{W}}^{-}$ can exceed $Z,\gamma\to{{\widetilde{\tau}}}^{+}_{\text{R}}\,{{\widetilde{\tau}}}^{-}_{\text{R}}$. If the charginos are more higgsino-like the cross sections become lower, $m_{{\widetilde{H}}^{\pm}}\lesssim2\,m_{{{\widetilde{\tau}}}_{\text{R}}}$ is required for a competing or dominant higgsino production. The production via squarks in the $t$- and $u$-channel introduces an additional dependence on the squark masses. However, the cross sections are roughly the same as the corresponding production via DY only if $m_{{\widetilde{q}}}\simeq m_{{\widetilde{W}}}$. Thus, for larger squark masses the $t$- and $u$-channel squark contributions become subleading. According to these considerations, one should keep in mind the chargino production via DY, which can become an important channel, especially in the case of a light wino.

Let us finally consider the production of colored sparticles. Since the LHC is a proton-proton collider, at leading order $\mathcal{O}(\alpha_{s}^{2})$ squark-pair, gluino-pair and squark-gluino production each allow a variety of diagrams that include the initial states $gg$, $qg$ and $qq$, which are the dominant hadronic channels at 