Search for 2p decay of the first excited state of Ne-17

Structure of nuclei located near and beyond the drip-lines plays important role in the explosive astrophysical processes. The problem of two-proton decay of the Ne-17 first excited state is a good example of such situation. The two-proton radiative capture is a possible bypass of the O-15 waiting point in the rp-process. The rate of this process drastically depends on the value of the weak 2p-decay branch which is anticipated for the first excited state of Ne-17. The first excited state of Ne-17 (J(pi) = 3/2(-)), located only 344 keV above the 2p decay threshold, has extremely small Gamma(2p)/Gamma(gamma) branching ratio for which only upper limit was obtained experimentally. In the recent experiment at the ACCULINNA fragment-separator at the 2p decay of the low-lying states of Ne-17 was studied. The use of the p(Ne-18, d)Ne-17 transfer reaction in combination with a novel combined-mass method allow us to set a new limit for the decay ratio of the Ne-17 3/2(-) state, Gamma(2p)/Gamma(gamma) <= 0.016(3)%, that is about fifty times lesser than the existing value. The proposed method is promising tool to search for 2p-decay partial width at a level of Gamma(2p)/Gamma(gamma) approximate to 10(-6).