| 1. |
- Wesolowski, S., et al.
(författare)
-
Rigorous constraints on three-nucleon forces in chiral effective field theory from fast and accurate calculations of few-body observables
- 2021
-
Ingår i: Physical Review C. - 2469-9985 .- 2469-9993. ; 104:6
-
Tidskriftsartikel (refereegranskat)abstract
- We explore the constraints on the three-nucleon force (3NF) of chiral effective field theory (χEFT) that are provided by bound-state observables in the A=3 and A=4 sectors. Our statistically rigorous analysis incorporates experimental error, computational method uncertainty, and the uncertainty due to truncation of the χEFT expansion at next-to-next-to-leading order. A consistent solution for the H3 binding energy, the He4 binding energy and radius, and the H3β-decay rate can only be obtained if χEFT truncation errors are included in the analysis. The β-decay rate is the only one of these that yields a nondegenerate constraint on the 3NF low-energy constants, which makes it crucial for the parameter estimation. We use eigenvector continuation for fast and accurate emulation of no-core shell model calculations of the few-nucleon observables. This facilitates sampling of the posterior probability distribution, allowing us to also determine the distributions of the parameters that quantify the truncation error. We find a χEFT expansion parameter of Q=0.33±0.06 for these observables.
|
|
| 2. |
- Drut, J. E., et al.
(författare)
-
Toward ab initio density functional theory for nuclei
- 2010
-
Ingår i: Progress in Particle and Nuclear Physics. - 0146-6410. ; 64:1, s. 120-168
-
Tidskriftsartikel (refereegranskat)abstract
- We survey approaches to non-relativistic density functional theory (DFT) for nuclei using progress toward ob initio DFT for Coulomb systems as a guide. Ab initio DFT starts with a microscopic Hamiltonian and is naturally formulated using orbital-based functionals, which generalize the conventional 'local density plus gradients' form. The orbitals satisfy single-particle equations with multiplicative (local) potentials. The DFT functionals can be developed starting from internucleon forces using wavefunction-based methods or by Legendre transform via effective actions. We describe known and unresolved issues for applying these formulations to the nuclear many-body problem and discuss how ab initio approaches can help improve empirical energy density functionals. (C) 2009 Elsevier B.V. All rights reserved.
|
|
| 3. |
- Bogner, S. K., et al.
(författare)
-
Density matrix expansion for low-momentum interactions
- 2009
-
Ingår i: European Physical Journal A. - 1434-601X .- 1434-6001. ; 39:2, s. 219-241
-
Tidskriftsartikel (refereegranskat)abstract
- A first step toward a universal nuclear energy density functional based on low-momentum interactions is taken using the density matrix expansion (DME) of Negele and Vautherin. The DME is adapted for non-local momentum space potentials and generalized to include local three-body interactions. Different prescriptions for the three-body DME are compared. Exploratory results are given at the Hartree-Fock level, along with a roadmap for systematic improvements within an effective action framework for the Kohn-Sham density functional theory.
|
|
