The $^{23}$Na($α,p$)$^{26}$Mg reaction has been identified as having a significant impact on the nucleosynthesis of several nuclei between Ne and Ti in type-Ia supernovae, and of $^{23}$Na and $^{26}$Al in massive stars. The reaction has been subjected to renewed experimental interest recently, motivated by high uncertainties in early experimental data and in the statistical Hauser-Feshbach models used in reaction rate compilations. Early experiments were affected by target deterioration issues and unquantifiable uncertainties. Three new independent measurements instead are utilizing inverse kinematics and Rutherford scattering monitoring to resolve this. In this work we present directly measured angular distributions of the emitted protons to eliminate a discrepancy in the assumptions made in the recent reaction rate measurements, which results in cross sections differing by a factor of 3. We derive a new combined experimental reaction rate for the $^{23}$Na($α,p$)$^{26}$Mg reaction with a total uncertainty of 30% at relevant temperatures. Using our new $^{23}$Na($α,p$)$^{26}$Mg rate, the $^{26}$Al and $^{23}$Na production uncertainty is reduced to within 8%. In comparison, using the factor of 10 uncertainty previously recommended by the rate compilation STARLIB, $^{26}$Al and $^{23}$Na production was changing by more than a factor of 2. In type-Ia supernova conditions, the impact on production of $^{23}$Na is constrained to within 15%.
Uncertainties in the production of iron-group nuclides in core-collapse supernovae from Monte Carlo variations of reaction rates
Kogakuin University（工学院大学）；The University of Tokyo（东京大学）；RIKEN Pioneering Research Institute (PRI)（理化学研究所先导研究本部）；National Astronomical Observatory of Japan (NAOJ)（日本国立天文台）；North Carolina State University（北卡罗来纳州立大学）；University of Basel（巴塞尔大学）；University of Hertfordshire（赫特福德大学）
Reducing Uncertainties in the Production of the Gamma Emitting Nuclei 26Al, 44Ti, and 60Fe in Core Collapse Supernovae by Using Effective Helium Burning Rates
Implications for Type Ia Supernova Nucleosynthesis from an Experimentally Constrained $^{16}$O$(p,α)^{13}$N Reaction Rate
University of York（约克大学）；Northern Border University（北部边境大学）；Argonne National Laboratory（阿贡国家实验室）；Universidad de Granada（格拉纳达大学）；TRIUMF；University of Pittsburgh（匹兹堡大学）
