Study of Key Ni 57 ( p , γ ) Cu 58 Resonances to Understand Ti 44 Nucleosynthesis in Supernovae

This is the authors' abstract. We don't add key points for this paper.

An important validation of nucleosynthesis models of core-collapse supernovae is the comparison of radioisotope predictions to abundances inferred from observations of γ rays emitted in remnants. One such isotope, ⁴⁴Ti, is especially sensitive to the ⁵⁷Ni(p,γ)⁵⁸Cu reaction rate. Despite this importance, no experimentally constrained rate exists for this reaction. It is thus crucial to determine this rate. GRETINA ORRUBA: Dual Detectors for Experimental Structure Studies (GODDESS) was used along with the first use of the Enge split-pole spectrograph at Notre Dame to measure structure properties of ⁵⁸Cu via the ⁵⁸Ni(³He,t)⁵⁸Cu reaction. The combined analysis of these complementary data sets allows for precise determination of ⁵⁸Cu level energies, and spins are constrained from analysis of the γ-ray decay. ⁴⁴Ti yields were found to change by over 25% compared to previous estimates in model calculations using the new experimentally constrained reaction rate.