Toward open-shell nuclei with coupled-cluster theory

Jansen, G. R.; Hjorth‐Jensen, M.; Hagen, G.; Papenbrock, T.

doi:10.1103/physrevc.83.054306

Cited by 66 publications

(103 citation statements)

References 45 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For these calculations, we used the two-particles-attached equation-of-motion (2PA-EOM) method [8,33,45] including up to 3p−1h excitations on top of 16 O. While the A = 20 nuclei could in principle be accessed by twoparticle-removed equation-of-motion CCSD [8] relative to 22 O and 22 Si, since these closed-subshell nuclei are accessible via CCSD calculations, one finds significant underbinding when including up to 1p − 3h excitations. For N max = 6 calculations, the 2PA-EOM-CCSD results are lower in energy than the BCCD results by 2.04 MeV for 18 O and 2.51 MeV for 18 Ne.…”

Section: B Resultsmentioning

confidence: 99%

“…The grand canonical potential of Eq. (8), up to and including Ω [4] , displays fully antisymmetrized matrix elements whose explicit expressions in terms of matrix elements of the kinetic energy plus two-and three-body interactions, as well as of U and V matrices defining the reference Bogoliubov state, are pq + ∆ 3N…”

Section: Grand Canonical Potentialmentioning

confidence: 99%

“…The doubly magic 16 O nucleus provides a comparison to CCD and CCSD calculations, while the A = 18 nuclei will be compared to two-particle-attached equation-of-motion CCSD (2PA-EOM-CCSD) results [8,33,45].…”

Section: Proof-of-principle Calculations a Calculational Schemementioning

confidence: 99%

“…Ab initio many-body methods based on coupled cluster (CC) [1][2][3][4][5][6][7][8][9][10], self-consistent Dyson-Green's function (SCDyGF) [11][12][13][14][15] and in-medium similarity renormalization group (IMSRG) [16,17] techniques have been intensively developed in the last ten years to address nuclei up to mass A ∼ 130 [18]. However, these important developments have been limited until recently to doubly closed-(sub)shell nuclei plus those accessible via the addition and removal of one or two nucleons.…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Ab initioBogoliubov coupled cluster theory for open-shell nuclei

et al. 2015

Self Cite

View full text Add to dashboard Cite

Background: Ab initio many-body methods have been developed over the past ten years to address closed-shell nuclei up to mass A ∼ 130 on the basis of realistic two-and three-nucleon interactions. A current frontier relates to the extension of those many-body methods to the description of open-shell nuclei.Purpose: Several routes to address open-shell nuclei are currently under investigation, including ideas which exploit spontaneous symmetry breaking. Singly open-shell nuclei can be efficiently described via the sole breaking of U (1) gauge symmetry associated with particle-number conservation, as a way to account for their superfluid character. While this route was recently followed within the framework of self-consistent Green's function theory, the goal of the present work is to formulate a similar extension within the framework of coupled cluster theory.Methods: We formulate and apply Bogoliubov coupled cluster (BCC) theory, which consists of representing the exact ground-state wavefunction of the system as the exponential of a quasiparticle excitation cluster operator acting on a Bogoliubov reference state. Equations for the ground-state energy and the cluster amplitudes are derived at the singles and doubles level (BCCSD) both algebraically and diagrammatically. The formalism includes three-nucleon forces at the normal-ordered two-body level. The first BCCSD code is implemented in m-scheme, which will permit the treatment of doubly open-shell nuclei via the further breaking of SU (2) symmetry associated with angular momentum conservation.Results: Proof-of-principle calculations in an Nmax = 6 spherical harmonic oscillator basis are performed for 16,18,20 O, 18 Ne, and 20 Mg in the BCCD approximation with a chiral two-nucleon interaction, comparing to results obtained in standard coupled cluster theory when applicable. The breaking of U (1) symmetry is monitored by computing the variance associated with the particle-number operator. Conclusions:The newly developed many-body formalism increases the potential span of ab initio calculations based on single-reference coupled cluster techniques tremendously, i.e. potentially to reach several hundred additional mid-mass nuclei. The new formalism offers a wealth of potential applications and further extensions dedicated to the description of ground-and excited-states of open-shell nuclei. Short-term goals include the implementation of three-nucleon forces at the normal-ordered two-body level. Mid-term extensions include the approximate treatment of triple corrections and the development of the equation-of-motion methodology to treat both excited states and odd nuclei. Long-term extensions include exact restoration of U (1) and SU (2) symmetries.

show abstract

Section: B Resultsmentioning

confidence: 99%

Section: Grand Canonical Potentialmentioning

confidence: 99%

Section: Proof-of-principle Calculations a Calculational Schemementioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Ab initioBogoliubov coupled cluster theory for open-shell nuclei

et al. 2015

Self Cite

View full text Add to dashboard Cite

show abstract

“…The daughter nuclei 14 N and 22,24 F are computed via a novel generalization of the coupled-cluster equationof-motion approach [51][52][53]. We view the states of the daughter nuclei as isospin-breaking excitations |R ≡ R|HF of the coupled-cluster ground state, with…”

mentioning

confidence: 99%

Effects of Three-Nucleon Forces and Two-Body Currents on Gamow-Teller Strengths

et al. 2014

Self Cite

View full text Add to dashboard Cite

We optimize chiral interactions at next-to-next-to leading order to observables in two-and threenucleon systems, and compute Gamow-Teller transitions in 14 C and 22,24 O using consistent twobody currents. We compute spectra of the daughter nuclei 14 N and 22,24 F via an isospin-breaking coupled-cluster technique, with several predictions. The two-body currents reduce the Ikeda sum rule, corresponding to a quenching factor q 2 ≈ 0.84 − 0.92 of the axial-vector coupling. The half life of 14 C depends on the energy of the first excited 1 + state, the three-nucleon force, and the two-body current.

show abstract

No-Core Gamow Shell Model

Michel

Płoszajczak

2021

Gamow Shell Model

View full text Add to dashboard Cite

Toward open-shell nuclei with coupled-cluster theory

Cited by 66 publications

References 45 publications

Ab initioBogoliubov coupled cluster theory for open-shell nuclei

Ab initioBogoliubov coupled cluster theory for open-shell nuclei

Effects of Three-Nucleon Forces and Two-Body Currents on Gamow-Teller Strengths

No-Core Gamow Shell Model

Contact Info

Product

Resources

About