DAMA/NaI results on spontaneous transition of nuclei to a superdense state

Thanks to the deeper experimental site, to the much larger exposure, to the effective shielding of the detectors and to the strong improvements in the detectors' radiopurity, the present search has achieved a much larger sensitivity than the pioneer experiment by Aleshin et al. in 1976. In particular, lower limits of order of 1023 y have been obtained on the lifetime of the process in 23Na and 127I (about three orders of magnitude higher than the previously available ones); the lower limits on the barrier potential U0, instead, have only been modestly improved because of their logarithmic dependence on the lifetime of the processes.