Interplay between sequential and prompt two-proton decay from the first excited state of Ne 16

The first excited, J(pi) = 2(+) state of Ne-16 at E* = 1.69(2) MeV is well populated in neutron knockout reactions with a Ne-17 beam and the correlations between the momenta of the three final fragments following 2p decay were measured. The correlation pattern showed aspects of both sequential and diprotonlike decay, which were reproduced in three-body O-14 + p + p calculations. These calculations suggest that interference between these processes is responsible for the observed features which can be described in terms of a "tethered decay mechanism." The intrinsic width of this state was constrained to be from 100 to 250 keV. Higher excited states populating the N-13 + p + p + p exit channel were found at E* = 8.37(10) and 10.76(20) MeV.