Selectron studies ate−e−ande+e−colliders

Selectrons may be studied in both $e^{-}{e}^{-}$ and $e^{+}{e}^{-}$ collisions at future linear colliders. Relative to $e^{+}{e}^{-},$ the $e^{-}{e}^{-}$ mode benefits from negligible backgrounds and $\beta$ threshold behavior for identical selectron pair production, but suffers from luminosity degradation and increased initial state radiation and beamstrahlung. We include all of these effects and compare the potential for selectron mass measurements in the two modes. The virtues of the $e^{-}{e}^{-}$ collider far outweigh its disadvantages. In particular, the selectron mass may be measured to $100\hspace{0.5em}\mathrm{MeV}$ with a total integrated luminosity of $1\hspace{0.5em}{\mathrm{fb}}^{-1},$ while more than $100\hspace{0.5em}{\mathrm{fb}}^{-1}$ is required in $e^{+}{e}^{-}$ collisions for similar precision.