A study of17N levels andT=3/2 multiplets in mass 17 nuclei

Search for 2p decay of the first excited state of Ne17

“…This is a borromean nucleus: its 16 F subsystem is unbound with S p ( 16 F) = −535 keV. The situation with 17 Ne separation energies is highly analogous to that with the "classical" two-neutron halo nucleus 6 He and thus the question about the existence of the two-proton halo in 17 Ne was formulated in Ref. [4].…”

“…The intrigue of this problem is enhanced by the fact that the 17 Ne nucleus is probably the only realistic candidate to possess a two-proton halo as in heavier proton dripline systems the specific spatial extension of the valence nucleon wave functions should be suppressed by the Coulomb interaction. The issue of two-proton halo in 17 Ne was discussed in the theory papers [5,6] and experimental works [7,8].…”

“…The radiative absorption of two protons (2p capture) is known to be a possible bypath for this waiting point [9]. The so far unknown 2p decay width of the first excited state of 17 Ne (E * = 1288 keV, J π = 3/2 − ) makes a key point for solving the bypass problem of the 15O waiting point.o this issue. Taking into account this (previously omitted) state in the calculation of the resonant radiative capture rate strongly modified the corresponding rate in a broad temperature range around 0.15 GK [10].…”

“…In this work we address the subject of the extremely weak 2p decay branch of the first excited 3/2 − state of 17 Ne which is known [2,3] to predominantly undergo γ decay to the ground state. Below in Section II we discuss some issues of the 17 Ne study in general and then return to the subject of measuring the extremely small Γ part /Γ γ ratio in Section III.…”

“…Below in Section II we discuss some issues of the 17 Ne study in general and then return to the subject of measuring the extremely small Γ part /Γ γ ratio in Section III. Further in this work, we study experimentally the 1 H( 18 Ne, d) 17 Ne reaction and derive a new upper limit for the Γ 2p /Γ γ ratio of the 3/2 − state. Instead of the invariant mass method to determine the 2p-decay rate we use the novel combined mass method to provide better experimental resolution.…”