First measurement of 25Al+p resonant scattering relevant to the astrophysical reaction 22Mg(α,p)25Al.

Type I X-ray bursts (XRBs) are the most frequently observed thermonuclear explosions in nature. The ²²Mg(α,p)²⁵Al reaction plays a critical role in XRB models. However, experimental information is insufficient to deduce a precise ²²Mg(α,p)²⁵Al reaction rate for the respective XRB temperature range. A new measurement of ²⁵Al+p resonant scattring was performed up to the astrophysically interested energy region of ²²Mg(α,p)²⁵Al. Several resonances were observed in the excitation functions, and their level properties have been determined based on an R-matrix analysis. In particular, proton widths and spin-parities of four natural-parity resonances above the α threshold of ²⁶Si, which can contribute the reaction rate of ²²Mg(α,p)²⁵Al, were first experimentally determined. [ABSTRACT FROM AUTHOR]