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 22 Mg( α ,p) 25 Al reaction plays a critical role in XRB models. However, experimental information is insufficient to deduce a precise 22 Mg( α ,p) 25 Al reaction rate for the respective XRB temperature range. A new measurement of 25 Al+p resonant scattring was performed up to the astrophysically interested energy region of 22 Mg( α ,p) 25 Al. 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 26 Si, which can contribute the reaction rate of 22 Mg( α ,p) 25 Al, were first experimentally determined.