Reevaluation of thermonuclear reaction rate of ⁵⁰Fe(p, γ)⁵¹Co

The thermonuclear rate of the ⁵⁰Fe(p, γ)⁵¹Co reaction in the Type I X-ray bursts(XRBs) temperature range has been reevaluated based on a recent precise mass measurement at CSRe Lanzhou, where the proton separation energy S_P = 142 ± 77 keV has been determined firstly for the ⁵¹Co nucleus. Comparing to the previous theoretical predictions, the experimental S_p value has much smaller uncertainty. Based on the nuclear shell model and mirror nuclear structure information, we have calculated two sets of thermonuclear rates for the ⁵⁰Fe(p, γ)⁵¹Co reaction by utilizing the experimental S_p value. It shows that the statistical-model calculations are not ideally applicable for this reaction primarily because of the low density of low-lying excited states in ⁵¹Co. In this work, we recommend that a set of new reaction rates based on the mirror structure of ⁵¹Cr should be incorporated in future astrophysical network calculations. (authors)