New-generation Monte Carlo shell model for the K computer era

Shimizu, Noritaka; Abe, Takashi; Tsunoda, Y.; Utsuno, Yutaka; Yoshida, Takahiro; Mizusaki, T.; Honma, Michio; Otsuka, Takaharu

doi:10.1093/ptep/pts012

Cited by 149 publications

(195 citation statements)

References 75 publications

Supporting

Mentioning

187

Contrasting

Order By: Relevance

“…The spectrum of states in 70 Ni was calculated with the Monte-Carlo shell model (MCSM) using the A3DA interaction [33]. Here, the full f pg 9/2 d 5/2 model space for both protons and neutrons was employed, allowing for the breaking of the πf 7/2 shell below Z = 28.…”

Section: Discussionmentioning

confidence: 99%

“…The delineation of levels up to several MeV in excitation energy in these nuclei is an important step towards providing a firmer understanding of their properties through comparisons with modern theoretical models. Much of this effort has been concentrated thus far on 68 Ni itself, with substantial improvements made to the level scheme [30][31][32] and deduced decay rates [12,31], as well as with comparisons of the data with Monte-Carlo shellmodel (MCSM) calculations [33,34]. The latter have provided strong evidence for coexisting spherical, oblate, and prolate shapes in this nucleus [12,13].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Identification of deformed intruder states in semi-magicNi70

et al. 2015

View full text Add to dashboard Cite

The structure of semi-magic 70 28 Ni 42 was investigated following complementary multinucleontransfer and secondary fragmentation reactions. Changes to the higher-spin, presumed negativeparity states based on observed γ-ray coincidence relationships result in better agreement with shell-model calculations using effective interactions in the neutron f 5/2 pg 9/2 model space. The second 2 + and (4 + ) states, however, can only be successfully described when proton excitations across the Z = 28 shell gap are included. Monte-Carlo shell-model calculations suggest that the latter two states are part of a prolate-deformed intruder sequence, establishing an instance of shape coexistence at low excitation energies similar to that observed recently in neighboring 68 Ni.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Identification of deformed intruder states in semi-magicNi70

et al. 2015

View full text Add to dashboard Cite

show abstract

“…The analysis of the oscillator excitations will be useful for developing and improving a truncation scheme for the model space in, e.g., ab initio NCSM [1], importance-truncated NCSM [17,18], the symmetry-adapted no-core shell model [19], the Monte Carlo shell model [20], as well as a model approach such as the tensor-optimized shell model [21].…”

Section: Introductionmentioning

confidence: 99%

Harmonic-oscillator excitations of precise few-body wave functions

Horiuchi

Suzuki

2014

Phys. Rev. C

View full text Add to dashboard Cite

A method for calculating the occupation probability of the number of harmonic-oscillator (HO) quanta is developed for a precise few-body wave function obtained in a correlated Gaussian basis. The probability distributions of two-to four-nucleon wave functions obtained by using different nucleon-nucleon (NN) interactions are analyzed to gain insight into the characteristic behavior of the various interactions. Tensor correlations as well as short-range correlations play a crucial role in enhancing the probability of high HO excitations. For the excited states of 4 He, the interaction dependence is much less because high HO quanta are mainly responsible for describing the relative-motion function between the 3N + N ( 3 H + p and 3 He + n) clusters.

show abstract

“…In particular, it became possible to assess transition probabilities between states of different shapes, and to search for retarded decays which would be the signature of a shape-isomerlike structure. Monte Carlo shell model (MCSM) studies [23][24][25][26] have been performed for the neutron-rich 68-78 Ni isotopes and coexistence of low-lying spherical, oblate, and strongly deformed prolate shapes has been found in 68 Ni and 70 Ni [17,18]. A significant hindrance for the E2 transition deexciting the prolate deformed 0 þ state was predicted in 68 Ni only.…”

mentioning

confidence: 99%

Multifaceted Quadruplet of Low-Lying Spin-Zero States in Ni66 : Emergence of Shape Isomerism in Light Nuclei

Leoni¹,

Fornal²,

Mărginean³

et al. 2017

Phys. Rev. Lett.

View full text Add to dashboard Cite

þ states, pointing to the oblate, spherical, and prolate nature of the consecutive excitations. In addition, they account for the hindrance of the E2 decay from the prolate 0 þ 4 to the spherical 2 þ 1 state, although overestimating its value. This result makes 66 Ni a unique nuclear system, apart from 236;238 U, in which a retarded γ transition from a 0 þ deformed state to a spherical configuration is observed, resembling a shape-isomerlike behavior. DOI: 10.1103/PhysRevLett.118.162502 The concept of potential energy surface (PES) is central in many areas of physics. Usually, the PES displays the potential energy of the system as a function of its geometry. As an example, the PES of a molecule expressed in such coordinates as bond length, valence angles, etc., can be used for finding the minimum energy shape or calculating chemical reaction rates [1]. The idea of potential energy surface in deformation space has also been widely applied to the nucleus at a given spin. For an even-even nucleus at spin 0, the lowest PES minimum corresponds to the ground state (g.s.), while there may exist additional (secondary) minima in which excited 0 þ states can reside: they can be interpreted as ground states of different shapes [2][3][4][5][6]. When a secondary minimum is separated from the main minimum by a high barrier, in the extreme case a long-lived isomer, called shape isomer, can be formed [7]. Shape isomerism at spin zero, so far, has clearly been observed only in actinide nuclei -these isomers decay mainly by fission, and in two cases only, 236 U and 238 U, by very retarded γ-ray branches [8][9][10][11].The existence of shape isomers in lighter systems has been a matter of debate for a long time. Already in the 1980s, a study based on microscopic Hartree-Fock plus BCS calculations, in which a large number of nuclei was surveyed, identified ten isotopes in which a deformed 0 þ state is separated from a spherical structure by a significantly high barrier:66 Ni and 68 Ni, 190;192 Pt, 206;208;210 Os, and 194;196;214

show abstract

New-generation Monte Carlo shell model for the K computer era

Cited by 149 publications

References 75 publications

Identification of deformed intruder states in semi-magicNi70

Identification of deformed intruder states in semi-magicNi70

Harmonic-oscillator excitations of precise few-body wave functions

Multifaceted Quadruplet of Low-Lying Spin-Zero States in Ni66 : Emergence of Shape Isomerism in Light Nuclei

Contact Info

Product

Resources

About