N3LO NN interaction adjusted to light nuclei in ab exitu approach

Shirokov, A. M.; Shin, Ik Jae; Kim, Y.; Sosonkina, Masha; Maris, Pieter; Vary, James P.

doi:10.1016/j.physletb.2016.08.006

Cited by 121 publications

(135 citation statements)

References 43 publications

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“…The NN+3N(400) Hamiltonian [65,77] that was also used in Figs. 8 and 9 underestimates the experimentally known oxygen charge radii by about 10%, and misses the sharp increase for 18 O. The other shown interaction, NNLO sat [17] improves the situation significantly, in part because its LECs (cf.…”

Section: Ground-state Energies Along Isotopic Chains: the Oxygen Isotmentioning

confidence: 99%

Nuclear Structure from the In-Medium Similarity Renormalization Group

Hergert

Yao

Morris

et al. 2018

J. Phys.: Conf. Ser.

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Efforts to describe nuclear structure and dynamics from first principles have advanced significantly in recent years. Exact methods for light nuclei are now able to include continuum degrees of freedom and treat structure and reactions on the same footing, and multiple approximate, computationally efficient many-body methods have been developed that can be routinely applied for medium-mass nuclei. This has made it possible to confront modern nuclear interactions from Chiral Effective Field Theory, that are rooted in Quantum Chromodynamics with a wealth of experimental data.Here, we discuss one of these efficient new many-body methods, the In-Medium Similarity Renormalization Group (IMSRG), and its applications in modern nuclear structure theory. The IMSRG evolves the nuclear many-body Hamiltonian in second-quantized form through continuous unitary transformations that can be implemented with polynomial computational effort. Through suitably chosen generators, we drive the matrix representation of the Hamiltonian in configuration space to specific shapes, e.g., to implement a decoupling of lowand high-energy scales, or to extract energy eigenvalues for a given nucleus.We present selected results from Multireference IMSRG (MR-IMSRG) calculations of openshell nuclei, as well as proof-of-principle applications for intrinsically deformed medium-mass nuclei. We discuss the successes and prospects of merging the (MR-)IMSRG with many-body methods ranging from Configuration Interaction to the Density Matrix Renormalization Group, with the goal of achieving an efficient simultaneous description of dynamic and static correlations in atomic nuclei.

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Section: Ground-state Energies Along Isotopic Chains: the Oxygen Isotmentioning

confidence: 99%

Nuclear Structure from the In-Medium Similarity Renormalization Group

Hergert

Yao

Morris

et al. 2018

J. Phys.: Conf. Ser.

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“…We have generated theoretical data for 6 Li by performing ab initio NCSM calculations with the MFDn code [23][24][25], a hybrid MPI/OpenMP code for ab initio nuclear structure calculations, using the Daejeon16 NN interaction [26] and HO basis spaces up through the cutoff N max = 18. The dimension of the resulting manybody Hamiltonian matrix is about 2.8×10 9 at this cutoff.…”

Section: Introductionmentioning

confidence: 99%

Deep learning: Extrapolation tool forab initionuclear theory

Negoita¹,

Vary²,

Luecke³

et al. 2019

Phys. Rev. C

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Ab initio approaches in nuclear theory, such as the no-core shell model (NCSM), have been developed for approximately solving finite nuclei with realistic strong interactions. The NCSM and other approaches require an extrapolation of the results obtained in a finite basis space to the infinite basis space limit and assessment of the uncertainty of those extrapolations. Each observable requires a separate extrapolation and many observables have no proven extrapolation method. We propose a feed-forward artificial neural network (ANN) method as an extrapolation tool to obtain the ground-state energy and the ground-state point-proton root-mean-square (rms) radius along with their extrapolation uncertainties. The designed ANNs are sufficient to produce results for these two very different observables in 6 Li from the ab initio NCSM results in small basis spaces that satisfy the following theoretical physics condition: independence of basis space parameters in the limit of extremely large matrices. Comparisons of the ANN results with other extrapolation methods are also provided.

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“…10.14). The theoretical charge radii are about 10% smaller than the experimental charge radius of 16 O, R ch = 2.70 fm [159], and the sharp increase for 18 O is missing entirely. The variation of λ produces only a 0.2% change in the ground-state energies, but this is the result of a fine-tuned cancellation between induced 4N forces that are generated by the NN and 3N pieces of the Hamiltonian, and should not be seen as representative for chiral interactions in general.…”

Section: Example: the Oxygen Isotopic Chainmentioning

confidence: 99%

“…In principle, the LECs can be determined by matching calculations of the same observables in chiral EFT and (Lattice) QCD in the overlap region of the two theories. Since such a calculation is currently not feasible, they are fit to experimental data for low-energy QCD observables, typically in the πN, NN, and 3N sectors [6,7,17,18]. RG methods are natural companions for EFTs, because smoothly connect theories with different resolution scales and degrees of freedom [19,20].…”

Section: Introductionmentioning

confidence: 99%

In-Medium Similarity Renormalization Group Approach to the Nuclear Many-Body Problem

Hergert

Bogner

Lietz

et al. 2017

An Advanced Course in Computational Nuclear Physics

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We present a pedagogical discussion of Similarity Renormalization Group (SRG) methods, in particular the In-Medium SRG (IMSRG) approach for solving the nuclear manybody problem. These methods use continuous unitary transformations to evolve the nuclear Hamiltonian to a desired shape. The IMSRG, in particular, is used to decouple the ground state from all excitations and solve the many-body Schrödinger equation. We discuss the IM-SRG formalism as well as its numerical implementation, and use the method to study the pairing model and infinite neutron matter. We compare our results with those of Coupled cluster theory (Chapter 8), Configuration-Interaction Monte Carlo (Chapter 9), and the SelfConsistent Green's Function approach discussed in Chapter 11. The chapter concludes with an expanded overview of current research directions, and a look ahead at upcoming developments.

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N3LO NN interaction adjusted to light nuclei in ab exitu approach

Cited by 121 publications

References 43 publications

Nuclear Structure from the In-Medium Similarity Renormalization Group

Nuclear Structure from the In-Medium Similarity Renormalization Group

Deep learning: Extrapolation tool forab initionuclear theory

In-Medium Similarity Renormalization Group Approach to the Nuclear Many-Body Problem

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