Is there a bound Lambda-n-n ?

The HypHI Collaboration at GSI argued recently for a (Lambda-n-n) bound state from the observation of its two-body (t + pi-) weak-decay mode. We derive constraints from several hypernuclear systems, in particular from the A=4 hypernuclei with full consideration of (Lambda N <–> Sigma N) coupling, to rule out a bound (Lambda-n-n).