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

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, ^{44}Ti, is especially sensitive to the ^{57}Ni(p,γ)^{58}Cu 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 ^{58}Cu via the ^{58}Ni(^{3}He,t)^{58}Cu reaction. The combined analysis of these complementary data sets allows for precise determination of ^{58}Cu level energies, and spins are constrained from analysis of the γ-ray decay. ^{44}Ti yields were found to change by over 25% compared to previous estimates in model calculations using the new experimentally constrained reaction rate.