Breakout from the hot CNO cycle:: The 18F(p,γ) vs 18F(p,α) branching ratio

We have studied the properties of low-lying F-18+p resonances as excited states in Ne-19. Three new levels have been found in the range 0 less than or equal to E(c.m.)less than or equal to 1 MeV just above the F-18+p threshold, and partial decay widths and isospin-mirror connections are suggested to known states in F-19 for each of the nine states in this energy range. The properties of these resonances have been used to calculate the reaction rate N-A(sigma v) for the F-18(p,gamma)Ne-19 and F-18(p,alpha)O-15 reactions in the temperature range 10(8)<T<10(9). A comparison of these rates indicates that in this temperature range, the O-14(alpha,p)F-17(p,gamma)Ne-18(e(+)nu)F-18(p, gamma)Ne-19 reaction sequence is not as fast as the(15)O(alpha, gamma)Ne-19 reaction. [S0556-2813(98)06305-5].