Spin-induced quenching of the radiative decay of quasibound Li I quartets above the 1s2s3S (Li+) threshold

The authors have measured the lifetimes of quasibound Li quartets below the 1s2s 3 S (Li + ) threshold to be in excellent agreement with calculations. Quasibound quartets above this limit decay faster than suggested by available calculations, which have only included radiative decay. The results are interpreted as an increase in the autoionisation rates of about two orders of magnitude at this limit.