Searches for single sneutrino production via R-parity violation at $\sqrt{s}$=189-209 GeV

A search for single sneutrino production under the assumption that R-parity is violated via a single dominant LLE coupling is presented. This search considers the process $e \gamma \;{\smash{\mathop{\longrightarrow}}}\;\tilde{\nu}_j l_k$ and is performed using the data collected by the ALEPH detector at centre-of-mass energies from 189 GeV up to 209 GeV. The observed candidate events are in agreement with Standard Model expectations and 95% confidence level upper limits on the LLE coupling are given as a function of the sneutrino mass.