Bayesian predictions for A=6 nuclei using eigenvector continuation emulators

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 (chi EFT). We utilize eigenvector continuation and Bayesian methods to quantify uncertainties stemming from the many-body method, the chi EFT 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 N-max = 10 for Li-6. We find a slight underbinding of He-6 and Li-6, although consistent with experimental data given our theoretical error bars. As a result of incorporating correlated chi EFT-truncation errors we find more precise predictions (smaller error bars) for separation energies: S-d(Li-6) = 0.89 +/- 0.44 MeV, S-2n(He-6) = 0.20 +/- 0.60 MeV, and for the beta decay Q value: Q(beta-) (He-6) = 3.71 +/- 0.65 MeV. We conclude that our error bars can potentially be reduced further by extending the model space used by JUPITERNCSM.