Chargino-sneutrino production in electron-photon collisions

We study the production of charginos and sneutrinos in electron-photon collisions ${(e}^{-}\gamma \to {\tilde{\chi }}_j^{-}{\tilde{\nu }}_e)$ within the minimal supersymmetric standard model. The high energy photons can be generated by Compton backscattering of intense laser pulses off one of the beams of the Next Linear Collider. This process could offer a significant opportunity to identify sneutrinos, which exclusively decay invisibly into a neutrino and the LSP, since the cross sections are two orders of magnitude higher than for the radiative production of invisible sneutrinos ${(e}^{+}{e}^{-}\to \tilde{\nu }\overline{\tilde{\nu }}\gamma )$. For three scenarios of gaugino-Higgsino mixing the cross sections and polarization asymmetries are computed and the resulting signatures are compared with the SM background.