Abstract
The 15O(α,γ)19Ne reaction is responsible for breakout from the hot CNO cycle in type I x-ray bursts. Understanding the properties of resonances between Ex=4 and 5 MeV in 19Ne is crucial in the calculation of this reaction rate. The spins and parities of these states are well known, with the exception of the 4.14- and 4.20-MeV states, which have adopted spin-parities of 9/2− and 7/2−, respectively. γ-ray transitions from these states were studied using triton-γ−γ coincidences from the 19F(3He,tγ)19Ne reaction measured with the GODDESS (Gammasphere ORRUBA Dual Detectors for Experimental Structure Studies) at Argonne National Laboratory. The observed transitions from the 4.14- and 4.20-MeV states provide strong evidence that the Jπ values are actually 7/2− and 9/2−, respectively. These assignments are consistent with the values in the 19F mirror nucleus and in contrast to previously accepted assignments.
