Ab initio estimation of $E2$ strengths in ${}^8$Li and its neighbors by normalization to the measured quadrupole moment

Abstract

For electric quadrupole ($E2$) observables, which depend on the large-distance tails of the nuclear wave function, ab initio no-core configuration interaction (NCCI) calculations converge slowly, making meaningful predictions challenging to obtain. Nonetheless, the calculated values for different $E2$ matrix elements, particularly those involving levels with closely-related structure (e.g., within the same rotational band) are found to be robustly proportional. This observation suggests that a known value for one observable may be used to determine the overall scale of $E2$ strengths, and thereby provide predictions for others. In particular, we demonstrate that meaningful predictions for $E2$ transitions may be obtained by calibration to the ground-state quadrupole moment. We test this approach for well-measured low-lying $E2$ transitions in ${}^7$Li and ${}^9$Be, then provide predictions for transitions in ${}^8$Li and ${}^9$Li. In particular, we address the $2^{+}\to 1^{+}$ transition in ${}^8$Li, for which the reported measured strength exceeds ab initio Green's function Monte Carlo (GFMC) predictions by over an order of magnitude.

10 pages, 8 figures

References in corpus (10)

• Similarity Renormalization Group for Nucleon-Nucleon Interactions
• Improved chiral nucleon-nucleon potential up to next-to-next-to-next-to-leading order
• Local three-nucleon interaction from chiral effective field theory
• Convergence in the no-core shell model with low-momentum two-nucleon interactions
• Emergence of rotational bands in ab initio no-core configuration interaction calculations of the Be isotopes
• Emergent Sp(3,R) dynamical symmetry in the nuclear many-body system from an ab initio description
• First Measurement of the $B(E2;3/2^{-}\to 1/2^{-})$ Transition Strength in ${}^7$Be: Testing Ab Initio Predictions for $A=7$ Nuclei
• Quadrupole moments and proton-neutron structure in p-shell mirror nuclei
• Natural orbitals for the ab initio no-core configuration interaction approach
• Accelerating quantum many-body configuration interaction with directives

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• Quadrupole dynamics of carbon isotopes and 10Be
• Robust ab initio predictions for dimensionless ratios of E2 and radius observables. II. Estimation of E2 transition strengths by calibration to the charge radius
• Robust ab initio predictions for dimensionless ratios of E2 and radius observables. I. Electric quadrupole moments and deformation
• Three-body structures of low-lying nuclear states of ${}^8$Li