2021/08/30 by T. Djärv, A. Ekström, C. Forssén +1 · 1 citation
Physics and Astronomy · #nucl-th #nucl-ex #physics.data-an
paper · pdf · doi:10.1103/physrevc.105.014005
published as Phys. Rev. C 105, 014005 (2022) · 13 pages, 9 figures
arxiv created 2021/08/30 · arxiv updated 2022/02/04
We make ab initio predictions for the A = 6 nuclear level scheme based on two- and three-nucleon interactions up to next-to-next-to-leading order in chiral effective field theory (χEFT). We utilize eigenvector continuation and Bayesian methods to quantify uncertainties stemming from the many-body method, the χEFT truncation, and the low-energy constants of the nuclear interaction. The construction and validation of emulators is made possible via the development of JupiterNCSM -- a new M-scheme no-core shell model code that uses on-the-fly Hamiltonian matrix construction for efficient, single-node computations up to Nmax = 10 for 6Li. We find a slight underbinding of 6He and 6Li, although consistent with experimental data given our theoretical error bars. As a result of incorporating a correlated χEFT-truncation errors we find more precise predictions (smaller error bars) for separation energies: Sd(6Li) = 0.89 ± 0.44 MeV, S2n(6He) = 0.20 ± 0.60 MeV, and for the beta decay Q-value: Qβ-(6He) = 3.71 ± 0.65 MeV. We conclude that our error bars can potentially be reduced further by extending the model space used by JupiterNCSM.