The long debate on the possible existence of neutral nuclei has been recently revived by the application of a new experimental approach, which lead to the observation of few events consistent with the formation of a bound4n in the breakup of14Be. The description of these events by a resonant (low‐energy)4n state is discussed. Finally, the preliminary results of an experiment measuring the breakup reaction (12Be, 2&agr;4n) are presented. © 2004 American Institute of Physics