Article
Physics, Nuclear
Jing Guo, C. F. Chen, Xian-Rong Zhou, Q. B. Chen, H-J Schulze
Summary: The AA pairing effects in spherical and deformed multi-A hyperisotopes have been investigated using the Skyrme-Hartree-Fock approach. The results show the presence of magic numbers -S = 2, 8, 18, 20, 34, 58, 68, and 70 in spherical hyperisotopes, and additional possible magic numbers -S = 4, 6, 10, 14, 26, 30, and 32 in deformed hyperisotopes, which are sensitive to quadrupole deformation.
Article
Physics, Nuclear
D. Negrea, N. Sandulescu, D. Gambacurta
Summary: This study analyzes the contribution of isovector and isoscalar proton-neutron pairing to the binding energies of even-even nuclei with N - Z = 0, 2, 4 and atomic mass 20 < A < 100. The binding energies are calculated using a mean-field approach coupled with a Skyrme-type functional and a zero-range isovector-isoscalar pairing force. The pairing force is treated in the framework of the quartet condensation model (QCM) which preserves particle number and isospin exactly. The interdependence of pairing and deformation is taken into account through self-consistent Skyrme-HF + QCM calculations in the intrinsic system. It is shown that the binding energies do not change significantly when the isoscalar pairing is activated, which can be attributed to the less attractive off-diagonal matrix elements of the isoscalar force and the competition between isoscalar and isovector pairing channels.
Article
Astronomy & Astrophysics
Ikuko Hamamoto
Summary: This study interprets the recent observation of halo phenomena in F-29 as evidence for the prolate deformation of the ground state of F-29 using a simple model based on spherical and deformed Woods-Saxon potentials. The strong preference of particular shape by the proton numbers 8 and 9, together with the energy difference between neutron orbits in oxygen isotopes, seems to play an important role in the phenomena of oxygen neutron drip line anomaly.
Article
Astronomy & Astrophysics
K. Zhao, Z. Liu, F. S. Zhang, N. Wang
Summary: The study found that the production cross sections for n-rich N=126 residual fragments are several times larger in the U-238 + Pt-198 reaction system than in the Xe-136 + Pt-198 system due to larger cross sections and lower excitation energies of primary fragments. In both systems, N=126 semi-magic residues are produced via neutron emission in the decay of primary fragments, surviving in semi-central collisions with lower excitation energies.
Article
Physics, Nuclear
Varinderjit Singh, J. E. Johnstone, R. Giri, S. Hudan, J. Vadas, R. T. DeSouza, D. Ackermann, A. Chbihi, Q. Hourdille, A. Abbott, C. Balhoff, A. Hannaman, A. B. McIntosh, M. Sorensen, Z. Tobin, A. Wakhle, S. J. Yennello, M. A. Famiano, K. W. Brown, C. Santamaria, J. Lubian, H. O. Soler, B. Carlson
Summary: The study found that shell effects have a significant impact on fusion cross sections of mid-mass nuclei, with different neutron shell structures leading to different outcomes. The use of a more realistic density model can more accurately describe experimental measurements, although it still tends to overpredict closed-shell nuclei.
Article
Physics, Multidisciplinary
Jiawei Chen, Junchen Pei, Yu Qiang, Jihuai Chi
Summary: The fission properties of neutron-rich nuclei Cf-278 and Cf-286 near the end point of the r-process are studied using microscopic self-consistent approaches. Fission barriers and potential energy surfaces are obtained through constrained static Skyrme Hartree-Fock-BCS calculations. Fission fragments are studied through dynamical time-dependent Hartree-Fock+BCS calculations. The results show that Cf-286 has an octupole deformation at the ground state, which can increase the fission barrier height and significantly enhance the spontaneous fission half-life. No very asymmetric fission channels predicted by semi-empirical models are found in our results.
CHINESE PHYSICS LETTERS
(2023)
Review
Physics, Multidisciplinary
B. Gnoffo, S. Pirrone, G. Politi, G. Cardella, E. De Filippo, E. Geraci, C. Maiolino, N. S. Martorana, A. Pagano, E. V. Pagano, M. Papa, F. Risitano, F. Rizzo, P. Russotto, M. Trimarchi
Summary: An investigation plan is presented to study different clustering and molecular states in neutron rich isotopes of Lithium, Beryllium, Boron and Carbon, using experimental facilities at INFN-Laboratori Nazionali del Sud. The high intensities of exotic beams provided by the FRAISE facility and the use of high-performance experimental apparatus, such as the detectors CHIMERA, FARCOS, and NArCOS, will enable high statistics and new information on known states and new states to be obtained.
FRONTIERS IN PHYSICS
(2022)
Article
Physics, Nuclear
T. Huang, D. Seweryniak, B. B. Back, P. C. Bender, M. P. Carpenter, P. Chowdhury, R. M. Clark, P. A. Copp, X-T He, R. D. Herzberg, D. E. M. Hoff, H. Jayatissa, T. L. Khoo, F. G. Kondev, G. Morgan, C. Morse, A. Korichi, T. Lauritsen, C. Muller-Gatermann, D. H. Potterveld, W. Reviol, A. M. Rogers, S. Saha, G. Savard, K. Sharma, S. Stolze, S. Waniganeththi, G. L. Wilson, J. Wu, Y-F Xu, S. Zhu
Summary: The study investigated the products of the 203,205Tl(50Ti, 2n) fusion-evaporation reactions using the Argonne Gas-Filled Analyzer, discovering new single-proton Nilsson states in the previously unknown isotope 251Lr. Furthermore, a more detailed analysis of the alpha decay of 253Lr was conducted.
Article
Physics, Nuclear
Eunja Ha, Seonghyun Kim, Myung-Ki Cheoun, H. Sagawa
Summary: In this study, the roles of the tensor force on the pairing correlations in the ground-state structure of certain nuclei were investigated using a deformed BCS model and the Brueckner G matrix derived from the charge-dependent Bonn potential. The focus was on the neutron-proton pairing and the spin-triplet even tensor force, with detailed analyses on the attractive and repulsive channels. The tensor force was found to be crucial in interpreting experimental data of a two-nucleon knockout reaction from C-12.
Article
Nuclear Science & Technology
En-Bo Huo, Ke-Ran Li, Xiao-Ying Qu, Ying Zhang, Ting-Ting Sun
Summary: The possible exotic nuclear properties in neutron-rich Ca, Ni, Zr, and Sn isotopes were studied using the continuum Skyrme Hartree-Fock-Bogoliubov theory and the Green's function method. The effects of pairing correlation, couplings with continuum, and blocking effects were properly considered. The study found that the neutron-rich isotopes show different properties depending on the criteria used for neutron drip line prediction, and the presence of unpaired odd neutron leads to lower neutron pairing energies in odd-A nuclei compared to neighbor-ing even-even nuclei. Possible halo structures were predicted in neutron-rich Ca, Ni, and Sn isotopes, characterized by significant deviations from the traditional r ? A(1/3) rule and diffuse spatial density distributions. The contributions of various partial waves to the neutron density were analyzed, and it was found that orbitals near the Fermi surface, particularly those with small angular momenta, significantly affect the extended nuclear density and large rms radii. The evolution of the number of neutrons above the Fermi surface as a function of mass number A is consistent with the pairing energy, supporting the important role of pairing correlation in halo phenomena.
NUCLEAR SCIENCE AND TECHNIQUES
(2023)
Article
Physics, Nuclear
N. Yu Shirikova, A. Sushkov, R. Jolos
Summary: The Coriolis matrix elements responsible for the mixing of different nuclear states were calculated for Gd and Dy isotopes using the Quasiparticle Phonon Model. The results showed significant values for these matrix elements, indicating potential deviations from Alaga rules. This suggests that Gd isotopes are suitable for studying M1 transitions from the 1(+) state to the states of the ground band.
EUROPEAN PHYSICAL JOURNAL A
(2022)
Article
Physics, Nuclear
Cong Pan, Myung-Ki Cheoun, Yong-Beom Choi, Jianmin Dong, Xiaokai Du, Xiao-Hua Fan, Wei Gao, Lisheng Geng, Eunja Ha, Xiao-Tao He, Jinke Huang, Kun Huang, Seonghyun Kim, Youngman Kim, Chang-Hwan Lee, Jenny Lee, Zhipan Li, Zhi-Rui Liu, Yiming Ma, Jie Meng, Myeong-Hwan Mun, Zhongming Niu, Panagiota Papakonstantinou, Xinle Shang, Caiwan Shen, Guofang Shen, Wei Sun, Xiang-Xiang Sun, Jiawei Wu, Xinhui Wu, Xuewei Xia, Yijun Yan, To Chung Yiu, Kaiyuan Zhang, Shuangquan Zhang, Wei Zhang, Xiaoyan Zhang, Qiang Zhao, Ruyou Zheng, Shan-Gui Zhou
Summary: This paper extends the point-coupling DRHBc theory to odd -A and odd-odd nuclei and examines its applicability by calculating the ground-state properties of odd -A Nd isotopes. The results show good agreement with experimental data, paving the way for constructing a DRHBc mass table that includes all even-even, odd -A, and odd-odd nuclei in the nuclear chart.
Article
Astronomy & Astrophysics
Kamila Sieja
Summary: This study gains new insights into the structure of Sr isotopes in the region of N=60 through experimental studies on excited levels, transition strengths, and spectroscopic factors. A classic shell model is used to describe the structure of Sr isotopes, and spectroscopic factors are computed to understand the evolution of low-energy excitations. The origin of deformation at N=60 is mentioned in the context of shell model and Monte Carlo shell model calculations.
Article
Physics, Multidisciplinary
Fakeha Farooq, Jameel-Un Nabi, Ramoona Shehzadi
Summary: This study reports the key nuclear properties of weak beta-decay processes on Yttrium isotopes in the mass number range A = 101-108. Results show good agreement between experimental data and theoretical works, which may be helpful for r-process simulations in astrophysical scenarios.
Article
Physics, Nuclear
Jing Geng, Wen Hui Long
Summary: This article introduces the significance of unstable nuclei in nuclear science, with a focus on the effects of deformation and pairing correlations on nuclear structure. By introducing a new model, the axially deformed relativistic Hartree-Fock-Bogoliubov model, the reliable description of unstable nuclei can be achieved.
Correction
Physics, Multidisciplinary
Wataru Horiuchi, Toru Sato, Yuichi Uesaka, Kenichi Yoshida
PROGRESS OF THEORETICAL AND EXPERIMENTAL PHYSICS
(2022)
Article
Physics, Multidisciplinary
Hana Gil, Nobuo Hinohara, Chang Ho Hyun, Kenichi Yoshida
Summary: This study demonstrates that the KIDS functional can appropriately describe the ground-state properties of nuclei and reduce the discrepancy from experimental data by adjusting the parameter of symmetry energy.
JOURNAL OF THE KOREAN PHYSICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Kenichi Yoshida
Summary: The ground-state moments of inertia (MoI) have been investigated for approximately 1700 even-even nuclei from the proton drip line to the neutron drip line up to Z=120 and N=184. The cranked Hartree-Fock-Bogoliubov equation is solved using the Skyrme and pairing energy density functionals. The results show that the MoI greatly increase near the drip line, while the deformation is not as strong as estimated by the empirical relation.
Article
Physics, Multidisciplinary
Wataru Horiuchi, Toru Sato, Yuichi Uesaka, Kenichi Yoshida
Summary: We have derived complete formulas for allowed and first-forbidden transitions of nuclear beta decay, taking into account recoil-order and induced currents up to next-to-leading order. By exploiting the conservation of vector current for multipole operators of natural-parity transitions, the meson exchange current for the vector current is minimized. The formulas are applicable to various beta-decay processes. As a numerical demonstration, we have applied the formulas to the beta decay of a neutron-rich nucleus Sn-160. The next-to-leading order corrections amount to 10-20% of the total decay rate, while induced currents alter the rate by at most 5%.
PROGRESS OF THEORETICAL AND EXPERIMENTAL PHYSICS
(2023)
Article
Physics, Nuclear
Kenichi Yoshida, Yifei Niu, Futoshi Minato
Summary: This study investigates the influence of nuclear shape changes on the beta-decay half-life by calculating the half-lives of neutron-rich nuclei. The results show that the beta-decay half-life can be a reliable indicator of shape-phase transition, as a sudden shortening of half-lives is found when the nuclear shape changes.
Article
Physics, Nuclear
N. Hizawa, K. Hagino, K. Yoshida
Summary: In this paper, we apply the dynamical generator coordinate method (DGCM) with a conjugate momentum to study nuclear collective excitation. By constructing a numerically workable scheme for a general one-body operator, we investigate the quadrupole vibration of O-16 using the Gogny D1S interaction. Our results show that both the ground state energy and the excitation energies are lowered compared to the conventional GCM, indicating the relevance of the conjugate momentum in collective motions.
Article
Physics, Nuclear
A. Yagi, A. Odahara, H. Nishibata, R. Lozeva, C-B Moon, S. Nishimura, K. Yoshida, N. Yoshinaga, C. Watanabe, K. Higashiyama, T. Shimoda, R. Daido, Y. Fang, P. S. Lee, B. Moon, P. Doornenbal, G. Lorusso, P-A Soderstrom, T. Sumikama, H. Watanabe, T. Isobe, H. Baba, H. Sakurai, F. Browne, Z. Patel, S. Rice, L. Sinclair, J. Wu, Z. Y. Xu, R. Yokoyama, T. Kubo, N. Inabe, H. Suzuki, N. Fukuda, D. Kameda, H. Takeda, D. S. Ahn, Y. Shimizu, D. Murai, F. L. Bello Garrote, J-M Daugas, F. Didierjean, E. Ideguchi, S. Iimura, T. Ishigaki, H. S. Jung, T. Komatsubara, Y. K. Kwon, C. S. Lee, S. Morimoto, M. Niikura, I Nishizuka, K. Tshoo
Summary: The structure of the neutron-rich N = 86 isotope Xe-140 was investigated using beta-gamma spectroscopy, revealing two new beta-decay isomers. Comparisons between experimental results and theoretical calculations were made to discuss the nuclear structures of low-lying states in Xe-140.
Article
Physics, Nuclear
K. Uzawa, K. Hagino, K. Yoshida
Summary: This study investigates the applicability of the generator coordinate method (GCM) as a microscopic theory for cluster radioactivities of heavy nuclei. The results show that the experimental decay rates can be accurately reproduced using this method, and the potential for further development in studying cluster decays of heavy nuclei is discussed.
Article
Physics, Nuclear
Kenichi Yoshida
Summary: In this study, the authors directly solve the coordinate-space cranked Skyrme-Hartree-Fock-Bogoliubov equation to describe the yrast states in weakly bound nuclei. They first demonstrate the method with a numerical calculation for the ground-state band in a medium-mass nucleus, and then apply it to neutron-rich even-N Mg isotopes. The analysis reveals that the appearance of the significantly low I-pi = 2(+) state in Mg-40 is mainly due to the suppression of pairing. The calculation also predicts that the 2(+) state in Mg-42 appears as high in energy as in Mg34-38, while the triaxial deformation is enhanced in nonzero spin states. This numerical framework provides a practical approach for systematically investigating the near yrast states and revealing unique structures in drip-line nuclei.
Article
Physics, Nuclear
Kenichi Yoshida
Summary: This study investigates the SD configurations in Zn-60, Zn-62, and Ge-64 and explores the different roles of energy gaps at particle numbers 30 and 32. The results show that the SD structures in Zn-62 are unique, where the negative-parity SD states have lower energy than the positive-parity ones.
Article
Physics, Nuclear
Kenichi Yoshida, Yusuke Tanimura
Summary: The study investigates the impact of the pn-pair interaction in the T = 0, S = 1 channel on low-lying SD transitions in nuclei, finding that the effect depends on the spatial overlap of the pn pair and the angular momentum of the valence nucleons. The dynamical S = 1 pairing is effective even for SD states, particularly in transitions involving high-l orbitals with the same principal quantum number.
Article
Physics, Nuclear
Kenichi Yoshida
Summary: In this study, isotopic dependence of collectivity in Ca and Ni isotopes generated by spin-dependent interactions was investigated through isovector-spin-flip excitations. By considering responses in the neutral and charge-exchange channels, the collective shift and the formation of giant resonances were explained. The evolution of IV-spin susceptibility and the role of residual interactions and dynamic pairing effects were also discussed.
Correction
Physics, Multidisciplinary
Kenichi Yoshida
PROGRESS OF THEORETICAL AND EXPERIMENTAL PHYSICS
(2021)
Article
Physics, Nuclear
N. Hizawa, K. Hagino, K. Yoshida
Summary: In this study, an extension of the generator coordinate method (GCM) was discussed by simultaneously using a collective coordinate and its conjugate momentum as generator coordinates. The dynamical GCM (DGCM) method proposed by Goeke and Reinhard was followed, showing that it can be considered as an extension of the double projection method for the center of mass motion. An application of DGCM to investigate particle number projection was then conducted, where a linear superposition of BCS states with different mean particle numbers was used to significantly lower the ground state energy, especially for magic nuclei with zero pairing gap in the BCS approximation.
Article
Physics, Multidisciplinary
Haruki Kasuya, Kenichi Yoshida
Summary: It is shown that the lowest-energy solution of the Hartree-Fock-Bogoliubov equation has even particle-number parity if time-reversal symmetry is conserved in the Hamiltonian. By employing a time-reversal antisymmetric constraint operator to the Hamiltonian, a method for solving the HFB equation to describe the ground state of odd-mass nuclei is rigorously established. Numerical analysis on neutron-rich Mg isotopes demonstrates the anomalous increase in the matter radius of Mg-37 can be well described within the framework of the nuclear energy density functional method, revealing the deformed halo structure.
PROGRESS OF THEORETICAL AND EXPERIMENTAL PHYSICS
(2021)