English

Experimentally well-constrained masses of $^{27}$P and $^{27}$S: Implications for studies of explosive binary systems

Nuclear Experiment 2020-01-15 v2

Abstract

The mass of 27^{27}P was predicted to impact the X-ray burst (XRB) model predictions of burst light curves and the composition of the burst ashes. To address the uncertainties and inconsistencies in the reported 27^{27}P masses in literature, a wealth of information has been extracted from the β\beta-decay spectroscopy of the drip-line nucleus 27^{27}S. We determine the most precise mass excess of 27^{27}P to date to be 659(9)-659(9)~keV, which is 63~keV (2.3σ\sigma) higher than the AME2016 recommended value of 722(26)-722(26)~keV. The experimentally unknown mass excess of 27^{27}S was estimated to be 17030(400)~keV in AME2016, and we constrain this mass to be 17678(77)~keV based on the measured β\beta-delayed two-proton energy. In the temperature region of (0.060.3)(0.06-0.3)~GK, the 26^{26}Si(p,γ)27(p,\gamma)^{27}P reaction rate determined in this work is significantly lower than the rate recommended in the reaction rate libraries, up to two orders of magnitude around 0.1~GK. The impact of these newly determined masses and well-constrained rate on the modeling of the explosive astrophysical scenarios has been explored by hydrodynamic nova and post-processing XRB models. No substantial change was found in the nova contribution to the synthesis of galactic 26^{26}Al or in the XRB energy generation rate, but we found that the calculated abundances of 26^{26}Al and 26^{26}Si at the last stage of XRB are increased by a factor of 2.4. We also conclude that 27^{27}S is not a significant waiting point in the rapid proton capture process.

Keywords

Cite

@article{arxiv.1809.02980,
  title  = {Experimentally well-constrained masses of $^{27}$P and $^{27}$S: Implications for studies of explosive binary systems},
  author = {L. J. Sun and X. X. Xu and S. Q. Hou and C. J. Lin and J. José and J. Lee and J. J. He and Z. H. Li and J. S. Wang and C. X. Yuan and F. Herwig and J. Keegans and T. Budner and D. X. Wang and H. Y. Wu and P. F. Liang and Y. Y. Yang and Y. H. Lam and P. Ma and F. F. Duan and Z. H. Gao and Q. Hu and Z. Bai and J. B. Ma and J. G. Wang and F. P. Zhong and C. G. Wu and D. W. Luo and Y. Jiang and Y. Liu and D. S. Hou and R. Li and N. R. Ma and W. H. Ma and G. Z. Shi and G. M. Yu and D. Patel and S. Y. Jin and Y. F. Wang and Y. C. Yu and Q. W. Zhou and P. Wang and L. Y. Hu and X. Wang and H. L. Zang and P. J. Li and Q. Q. Zhao and L. Yang and P. W. Wen and F. Yang and H. M. Jia and G. L. Zhang and M. Pan and X. Y. Wang and H. H. Sun and Z. G. Hu and R. F. Chen and M. L. Liu and W. Q. Yang and Y. M. Zhao and H. Q. Zhang},
  journal= {arXiv preprint arXiv:1809.02980},
  year   = {2020}
}