Search for R-parity violating production of single sneutrinos in ee collisions at $\sqrt{s}$ = 189-209 GeV

Abstract. A search for single sneutrino production under the assumption that R-parity is violated via a single dominant $LL\bar{E}$ coupling is presented. This search considers the process ${\rm e} \gamma \rightarrow \tilde{\nu}\ell$ and is performed using the data collected by the ALEPH detector at centre-of-mass energies from 189 GeV up to 209 GeV corresponding to an integrated luminosity of 637.1 pb-1. The numbers of observed candidate events are in agreement with Standard Model expectations and 95% confidence level upper limits on five of the $LL\bar{E}$ couplings are given as a function of the assumed sneutrino mass.