TY - JOUR
T1 - Low-lying structures of exotic sc isotopes and the evolution of the N = 34 subshell closure
AU - Steppenbeck, D.
AU - Takeuchi, S.
AU - Aoi, N.
AU - Doornenbal, P.
AU - Matsushita, M.
AU - Wang, H.
AU - Baba, H.
AU - Go, S.
AU - Lee, J.
AU - Matsui, K.
AU - Michimasa, S.
AU - Motobayashi, T.
AU - Nishimura, D.
AU - Otsuka, T.
AU - Sakurai, H.
AU - Shiga, Y.
AU - Söderström, P. A.
AU - Sumikama, T.
AU - Taniuchi, R.
AU - Utsuno, Y.
AU - Valiente-Dobón, J. J.
AU - Yoneda, K.
N1 - Funding Information:
aRIKEN Nishina Center, 2-1, Hirosawa, Wako, Saitama 351-0198, Japan bDepartment of Physics, Tokyo Institute of Technology, Meguro, Tokyo 152-8551, Japan cResearch Center for Nuclear Physics, University of Osaka, Ibaraki, Osaka 567-0047, Japan dCenter for Nuclear Study, University of Tokyo, Hongo, Bunkyo, Tokyo 113-0033, Japan eDepartment of Physics, University of Tokyo, Hongo, Bunkyo, Tokyo 113-0033, Japan fDepartment of Physics, Tokyo University of Science, Noda, Chiba 278-8510, Japan gDepartment of Physics, Rikkyo University, Toshima, Tokyo 171-8501, Japan hDepartment of Physics, Tohoku University, Sendai, Miyagi 980-8578, Japan iJapan Atomic Energy Agency, Tokai, Ibaraki 319-1195, Japan jInstituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Legnaro, Legnaro 35020, Italy E-mail: steppenbeck@riken.jp
Publisher Copyright:
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PY - 2016
Y1 - 2016
N2 - Recent investigations of exotic nuclei with N = 32 and 34 have highlighted the presence of sizable subshell closures at these neutron numbers that are absent in stable isotones. Indeed, the development of the shell gap at N = 32 is now well established from studies along the calcium, titanium, and chromium isotopic chains and, more recently, below the Z = 20 core in potassium and argon isotones. The onset of a new subshell closure at N = 34 was reported in 54Ca owing to the relatively high energy of its first 2+ state. On the theoretical side, the development of these neutron subshell gaps has been discussed, for example, in the framework of tensor-force-driven shell evolution; as protons are removed from the πf72 orbital, the vf52 state becomes progressively less bound and shifts up in energy relative to the vp32-vp12 spin-orbit partners. However, it was also reported that no significant N = 34 subshell gap exists in titanium, despite the fact that an inversion of the vf52 and vp12 orbitals has been noted. Thus, the strength of the N = 34 subshell closure in the scandium isotopes, which lie between calcium and titanium, provides additional insight on the migration of the vf52 orbital in exotic nuclei. In the present work, the low-lying structures of the neutron-rich isotopes 54Sc, 55Sc, and 56Sc - investigated using in-beam γ-ray spectroscopy with fast radioactive projectiles - will be presented, and the evolution of the N = 34 subshell closure will be further examined. The results will be compared to modern shell-model calculations applied within the pf shell.
AB - Recent investigations of exotic nuclei with N = 32 and 34 have highlighted the presence of sizable subshell closures at these neutron numbers that are absent in stable isotones. Indeed, the development of the shell gap at N = 32 is now well established from studies along the calcium, titanium, and chromium isotopic chains and, more recently, below the Z = 20 core in potassium and argon isotones. The onset of a new subshell closure at N = 34 was reported in 54Ca owing to the relatively high energy of its first 2+ state. On the theoretical side, the development of these neutron subshell gaps has been discussed, for example, in the framework of tensor-force-driven shell evolution; as protons are removed from the πf72 orbital, the vf52 state becomes progressively less bound and shifts up in energy relative to the vp32-vp12 spin-orbit partners. However, it was also reported that no significant N = 34 subshell gap exists in titanium, despite the fact that an inversion of the vf52 and vp12 orbitals has been noted. Thus, the strength of the N = 34 subshell closure in the scandium isotopes, which lie between calcium and titanium, provides additional insight on the migration of the vf52 orbital in exotic nuclei. In the present work, the low-lying structures of the neutron-rich isotopes 54Sc, 55Sc, and 56Sc - investigated using in-beam γ-ray spectroscopy with fast radioactive projectiles - will be presented, and the evolution of the N = 34 subshell closure will be further examined. The results will be compared to modern shell-model calculations applied within the pf shell.
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M3 - Conference article
AN - SCOPUS:85034579363
VL - 2016-September
JO - Proceedings of Science
JF - Proceedings of Science
SN - 1824-8039
M1 - 030
T2 - 26th International Nuclear Physics Conference, INPC 2016
Y2 - 11 September 2016 through 16 September 2016
ER -