Experimentally well-constrained masses of P-27 and S-27: Implications for studies of explosive binary systems
Experimentally well-constrained masses of P-27 and S-27: Implications for studies of explosive binary systems
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实验上良好约束的 27P 和 27S 质量：对爆炸性二元系统研究的启示
DOI：
10.1016/j.physletb.2020.135213
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发表时间：
2020
影响因子：
4.4
通讯作者：
Wu C.
中科院分区：
文献类型：
--
作者：
Sun L. J.;Xu X. X.;Hou S. Q.;Lin C. J.;Jose J.;Lee J.;He J. J.;Li Z. H.;Wang J. S.;Yuan C. X.;Herwig F.;Keegans J.;Budner T.;Wang D. X.;Wu H. Y.;Liang P. F.;Yang Y. Y.;Lam Y. H.;Ma P.;Duan F. F.;Gao Z. H.;Hu Q.;Bai Z.;Ma J. B.;Wang J. G.;Zhong F. P.;Wu C.
预计27 P的质量会影响X射线暴（XRB）模型对爆发光变曲线和爆发灰烬成分的预测，但在报道的27 P质量中仍然存在很大的不确定性和不一致性。我们使用27 S的β衰变光谱确定了迄今为止27 P最精确的质量过剩为− 659（9）keV，比2016年原子质量评估中推荐的值高出63 keV（2.3σ），精确度高出3倍。根据新的27P质量，用Monte Carlo方法重新计算了Si 26（p，γ）27P反应速率及其不确定度。根据测量的β延迟双质子能量和库仑位移能量关系，我们还估计了27 S的未知质量过剩为17678（77）keV。这些良好的约束质量和反应速率的爆炸性天体物理的场景建模的影响进行了研究后处理XRB和流体动力学新星模型。与基于数据库质量和速率的模型计算相比，爆发灰烬中A= 26的丰度增加了2.4倍，而XRB能量产生速率或光变曲线没有发现实质性变化。我们的计算还表明，27 S在快速质子俘获过程中不是一个重要的等待点，Si 26（p，γ）27 P反应速率的变化也不足以影响先前关于新星对银河系26 Al合成贡献的结论。
The mass of 27 P is expected to impact the X-ray burst (XRB) model predictions of burst light curves and the composition of the burst ashes, but large uncertainties and inconsistencies still exist in the reported 27 P masses. We have used the β-decay spectroscopy of 27 S to determine the most precise mass excess of 27 P to date to be− 659 (9) keV, which is 63 keV (2.3σ) higher and a factor of 3 more precise than the value recommended in the 2016 Atomic Mass Evaluation. Based on the new 27 P mass, the Si 26 (p, γ) 27 P reaction rate and its uncertainty were recalculated using Monte Carlo techniques. We also estimated the previously unknown mass excess of 27 S to be 17678 (77) keV, based on the measured β-delayed two-proton energy and the Coulomb displacement energy relations. The impact of these well-constrained masses and reaction rates on the modeling of the explosive astrophysical scenarios has been investigated by post-processing XRB and hydrodynamic nova models. Compared to the model calculations based on the masses and rates from databases, the abundance of A= 26 in the burst ashes is increased by a factor of 2.4, while no substantial change was found in the XRB energy generation rate or the light curve. Our calculation also suggests that 27 S is not a significant waiting point in the rapid proton capture process, and the change of the Si 26 (p, γ) 27 P reaction rate is not sufficiently large to affect the conclusion previously drawn on the nova contribution to the synthesis of galactic 26 Al.