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 ${ \rm e} \gamma { \smash{ \mathop{ \to}}} \tilde{ \nu}\ell$ 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 $\mathrm{ pb}^{ -1}$. 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.
Categories: hep-ex