Showing papers by "Jie Meng published in 2022"
TL;DR: In this article , the deformed relativistic Hartree-Bogoliubov theory in continuum (DRHBc) with the density functional PC-PK1 was used to calculate the ground state properties of even-even nuclei with 8≤Z≤120 from the proton drip line to the neutron drip line.
44 citations
TL;DR: In this paper , the relativistic Hartree-Bogoliubov theory in continuum (DRHBc) was extended to even-even, odd-A and odd-odd nuclei.
Abstract: Background: One fascinating frontier in nuclear physics is the study of exotic nuclei. deformed relativistic Hartree-Bogoliubov theory in continuum (DRHBc), which simultaneously includes the nuclear superfluidity, deformation, and continuum effects, can provide proper descriptions for both stable and exotic nuclei. In Zhang, et al . [Phys. Rev. C 102, 024314 (2020)], the DRHBc theory based on the point-coupling density functionals was developed and the DRHBc calculation, previously accessible only for light nuclei, was extended for all even-even nuclei in the nuclear chart. The ground-state properties for the even-even nuclei with 8 ≤ Z ≤ 120 from the DRHBc calculations have been summarized in Zhang, et al . [At. Data Nucl. Data Tables 144, 101488 (2022)]. Purpose: The aim of this work is to extend the point-coupling DRHBc theory to odd- A and odd-odd nuclei and examine its applicability by taking odd- A Nd isotopes as examples. Method: In the DRHBc theory, the densities and potentials with axial deformation are expanded in terms of Legendre polynomials, and the relativistic Hartree-Bogoliubov equations are solved in a Dirac Woods-Saxon basis to include the continuum effects. For an odd- A or odd-odd nucleus, the blocking effect of unpaired nucleon(s) is taken into account with the equal filling approximation. To determine its ground state, an automatic blocking procedure is adopted, in which the orbital with the lowest quasiparticle energy is blocked during the iteration. This procedure is justified by comparing with the results from the orbital-fixed blocking calculations, in which the blocked orbital near the Fermi surface is fixed during the iteration. The ground states for both light and heavy nuclei can be provided by the automatic blocking procedure as the orbital-fixed blocking procedure, but with considerably reduced computational cost. Results: The numerical details for even-even nuclei, including the convergence on the energy cutoff, angular momentum cutoff and Legendre expansion, are found to be valid for odd- A and odd-odd nuclei as well. The ground-state properties of odd- A Nd available experimental data. This work paves the way to construct the DRHBc mass table including all even-even, odd- A and odd-odd nuclei in the nuclear chart.
10 citations
TL;DR: In this paper , the isotope shift of the ion crystal was measured precisely using laser-induced fluorescence from a sympathetically cooled large ion crystal and a King-plot analysis was performed based on the new measurement to obtain accurate atomic field shift $F$ and mass shift $K$ factors that have been cross-checked by state-of-the-art configuration interaction plus many-body perturbation theory.
Abstract: The accuracy of atomic isotope shift factors limits the extraction of nuclear charge radii from isotope shift measurements because determining these factors is experimentally and theoretically challenging. Here, the isotope shift of the ${\mathrm{Cd}}^{+}\phantom{\rule{4pt}{0ex}}5s{\phantom{\rule{0.16em}{0ex}}}^{2}{S}_{1/2}\ensuremath{\rightarrow}5p{\phantom{\rule{0.16em}{0ex}}}^{2}{P}_{3/2}$ transition is measured precisely using laser-induced fluorescence from a sympathetically cooled large ${\mathrm{Cd}}^{+}$ ion crystal. A King-plot analysis is performed based on the new measurement to obtain accurate atomic field shift $F$ and mass shift $K$ factors that have been cross-checked by state-of-the-art configuration interaction plus many-body perturbation theory. The nuclear charge radii (${R}_{\mathrm{ch}}$) of $^{100\text{--}130}\mathrm{Cd}$ extracted using these $F$ and $K$ values demonstrate a near fivefold precision increase in the neutron-rich region. This work proves that accurate extraction of ${R}_{\mathrm{ch}}$ from isotope shifts is possible. New ${R}_{\mathrm{ch}}$ values reveal hidden discrepancies with previous density functional predictions in the neutron-rich region and pose strong challenges to advancements in nuclear models.
5 citations
TL;DR: In this paper , two nearly degenerate positive-parity bands with the πg9/22⊗νg 9/2−1 configuration were identified in 81Kr. They are interpreted as chiral doublet bands and pseudospin-chiral triplet bands.
3 citations
TL;DR: In this article , the collective structures of a magnetic rotational structure with the π(f7/2)−1(p3/2f5/2)/4 configuration were discussed.
Abstract: The spectroscopy of Cu62 is studied via the Cr54(C12,1p3n)Cu62 fusion-evaporation reaction. On the basis of the γ−γ coincidence analysis, angular distributions from oriented states, and linear polarization measurement, three positive-parity and three negative-parity level sequences in Cu62 are observed, including two new γ-ray transitions and one new level. The collective structures are discussed in terms of the tilted axis cranking covariant density functional theory. Although not firmly confirmed in experiment, the properties of a magnetic rotational structure with the π(f7/2)−1(p3/2f5/2)2⊗ν(g9/2)1(p3/2f5/2)4 configuration have been discussed. Its angular momentum generation is probably due to the shears mechanism.2 MoreReceived 16 June 2021Revised 17 October 2021Accepted 11 January 2022DOI:https://doi.org/10.1103/PhysRevC.105.024305©2022 American Physical SocietyPhysics Subject Headings (PhySH)Research AreasCollective levelsElectromagnetic transitionsNuclear fusionNuclear structure & decaysTransfer reactionsProperties59 ≤ A ≤ 89TechniquesCollective modelsNuclear Physics
2 citations
TL;DR: In this article , a rotational band built on the 15/2− octupole state in Ge71 has been found to have strong E1 transitions and a well-behaved rotational sequence.
Abstract: The spectroscopy of Ge71 has been investigated via the fusion-evaporation reaction Ge74(α,α3n)Ge71. Collective structures including a rotational band built on the 15/2− octupole state in Ge71 have been established. The observation of strong E1 transitions and the well-behaved rotational sequence built on the 15/2− octupole state provide the first experimental evidence of an octupole rotational band in Ge isotopes, suggesting an enhanced octupole correlation around N=40 in the A≈70 region. A newly developed semimicroscopic cluster model provides a good description of the octupole characteristics of Ge71.Received 5 October 2020Revised 2 January 2021Accepted 24 June 2022DOI:https://doi.org/10.1103/PhysRevC.106.L011303©2022 American Physical SocietyPhysics Subject Headings (PhySH)Research AreasCollective levelsElectromagnetic transitionsNuclear structure & decaysNucleon distributionProperties59 ≤ A ≤ 89Nuclear Physics
2 citations
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TL;DR: In this paper , a finite amplitude method based on the deformed relativistic Hartree-Bogoliubov theory in continuum (DRHBc-FAM) is developed and applied to study isoscalar giant monopole resonance in exotic nuclei.
Abstract: Finite amplitude method based on the deformed relativistic Hartree-Bogoliubov theory in continuum (DRHBc-FAM) is developed and applied to study isoscalar giant monopole resonance in exotic nuclei. Validation of the numerical implementation is examined for 208 Pb. The isoscalar giant monopole resonances for even-even calcium isotopes from 40 Ca to the last bound neutron-rich nucleus 80 Ca are calculated, and a good agreement with the available experimental centroid energies is obtained for 40 − 48 Ca. For the exotic calcium isotopes, e.g., 68 Ca and 80 Ca, the DRHBc-FAM calculated results are closer to the energy weighted sum rule than the calculations on the harmonic oscillator basis, which highlights the advantages of DRHBc-FAM in describing giant resonances for exotic nuclei. In order to explore the soft monopole mode in the exotic nuclei, the giant monopole resonance for the deformed exotic nucleus 200 Nd is investigated, where the prolate shape and the oblate shape coexist. A soft monopole mode near 6.0 MeV is found in the prolate case, and another one near 4.5 MeV is found in the oblate case. The transition density of the soft monopole mode shows in phase or out-of-phase vibrations near the surface region, which is generated by quadrupole vibrations.
1 citations
TL;DR: In this article , the authors obtained the time differential perturbed angular distribution measurement performed with the electromagnet at IPN Orsay with an external magnetic field of 2.146 T at the target position was attained with GAMIPE reaction chamber surrounded by four high-purity germanium detectors.
Abstract: The $g$ factor of the isomeric $I={9}^{+}$ bandhead of the yrast states in $^{128}\mathrm{Cs}$ is obtained from the time differential perturbed angular distribution measurement performed with the electromagnet at IPN Orsay. An external magnetic field of 2.146 T at the target position was attained with GAMIPE reaction chamber surrounded by four high-purity germanium detectors, of which two were low-energy photon spectrometer type. The results are in accordance with $\ensuremath{\pi}{h}_{11/2}\ensuremath{\bigotimes}\ensuremath{
u}{h}_{11/2}^{\ensuremath{-}1}\phantom{\rule{4pt}{0ex}}I={9}^{+}$ bandhead assignment and are discussed in the context of chiral interpretation of the $^{128}\mathrm{Cs}$ nucleus as a composition of the odd proton, odd neutron, and even-even core with their angular momentum vectors. The obtained $g$-factor value was compared with predictions of the particle-rotor model. The experimental $g$ factor corresponds to the nonchiral geometry of the isomeric bandhead. This observation indicates the existence of the chiral critical frequency in $^{128}\mathrm{Cs}$ and may explain the absence of the chiral doublet members for $I<13\ensuremath{\hbar}$.
1 citations
TL;DR: In this paper , the authors proposed a method for determining whether a property ≤ A ≤ 189 is a property of a nuclear structure and decays, where A is the number of atoms in the nuclear chain.
Abstract: Received 5 June 2022DOI:https://doi.org/10.1103/PhysRevC.106.049901©2022 American Physical SocietyPhysics Subject Headings (PhySH)Research AreasElectromagnetic transitionsNuclear structure & decaysProperties150 ≤ A ≤ 189Nuclear Physics
TL;DR: In this paper , the isoscalar giant monopole resonance in axially deformed nuclei was studied by the quasiparticle finite amplitude method based on the covariant density functional theory.
Abstract: The isoscalar giant resonances for $^{86}\mathrm{Ge}$ are studied by the quasiparticle finite amplitude method based on the covariant density functional theory. In addition to the well-known monopole-quadrupole coupling that splits the isoscalar giant monopole resonance in axially deformed nuclei, a monopole-quadrupole-hexadecupole coupling is identified in the neutron-rich triaxially deformed nucleus $^{86}\mathrm{Ge}$, leading to the emergence of a distinct resonance peak at the low energy side of the isoscalar monopole strength function. The transition density of the triaxiality-induced resonance peak shows a strong interplay among monopole, quadrupole, and hexadecupole vibrations. The resonance peak responds to monopole, quadrupole, and hexadecupole perturbations simultaneously, which could be regarded as a fingerprint of the triaxiality in $^{86}\mathrm{Ge}$.
12 Dec 2022
TL;DR: In this paper , the authors propose a solution to solve the problem of the problem: this paper ] of "uniformity" and "uncertainty" of the solution.
Abstract: ,
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07 Jun 2022
TL;DR: In this article , the isoscalar giant resonances for 86 Ge were studied by the quasiparticle amplitude method based on the covariant density functional theory, and the resonance peak responses to monopole, quadrupole, and hexadecupole perturbations simultaneously were regarded as a print of the triaxiality in 86 Ge.
Abstract: The isoscalar giant resonances for 86 Ge are studied by the quasiparticle finite amplitude method based on the covariant density functional theory. In addition to the well-known monopole-quadrupole coupling that splits the isoscalar giant monopole resonance in axially deformed nuclei, a monopole-quadrupole-hexadecupole coupling is identified in the triaxially deformed nucleus 86 Ge, leading to the emergence of a distinct resonance peak at the low energy side of the isoscalar monopole strength function. The transition density of the triaxiality induced resonance peak shows a strong interplay among monopole, quadrupole, and hexadecupole vibrations. The resonance peak responses to monopole, quadrupole, and hexadecupole perturbations simultaneously, which could be regarded as a fingerprint of the triaxiality in 86 Ge.
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TL;DR: In this article , a new density-dependent point-coupling covariant density functional PCF-PK1 is proposed, where the exchange terms of the four-fermion terms are local and are taken into account with the Fierz transformation.
Abstract: A new density-dependent point-coupling covariant density functional PCF-PK1 is proposed, where the exchange terms of the four-fermion terms are local and are taken into account with the Fierz transformation. The coupling constants of the PCF-PK1 functional are determined by empirical saturation properties and ab initio equation of state and proton-neutron Dirac mass splittings for nuclear matter as well as the ground-state properties of selected spherical nuclei. The success of the PCF-PK1 is illustrated with properties of the infinite nuclear matter and finite nuclei including the ground-state properties and the Gamow-Teller resonances. In particular, the PCF-PK1 eliminates the spurious shell closures at Z = 58 and Z = 92, which exist commonly in many covariant density functionals without exchange terms. Moreover, the Gamow-Teller resonances are nicely reproduced without any adjustable parameters, and this demonstrates that a self-consistent description for the Gamow-Teller resonances can be achieved with the localized exchange terms in the PCF-PK1.
TL;DR: In this article , the authors proposed a method to estimate the probability of a single photon in the presence of an infinite number of photons, and demonstrated that it is possible to compute the probability.
Abstract: Received 25 August 2021DOI:https://doi.org/10.1103/PhysRevC.105.029903©2022 American Physical Society
TL;DR: In this article , two positive-and one negative-parity bands have been identified in As74 and interpreted as chiral doublet bands, which is supported by the triaxial particle rotor model.
Abstract: High-spin states in As74 were studied using the Ge74(He4,1p3n) reaction at beam energies of 58.6 and 62.6 MeV. Two positive- and one negative-parity bands have been identified in As74. The two positive-parity bands are interpreted as chiral doublet bands, which is supported by the triaxial particle rotor model. Three electric dipole transitions linking the yrast positive- and negative-parity bands were also observed in this work, suggesting the existence of octupole correlations in As74.Received 1 March 2022Revised 6 June 2022Accepted 27 October 2022DOI:https://doi.org/10.1103/PhysRevC.106.064302©2022 American Physical SocietyPhysics Subject Headings (PhySH)Research AreasCollective levelsCollective modelsNuclear structure & decaysProperties59 ≤ A ≤ 89TechniquesSpectrometers & spectroscopic techniquesNuclear Physics