缺中子铋同位素中的大形状摇摆

Large Shape Staggering in Neutron-Deficient Bi Isotopes.

作者信息

Barzakh A, Andreyev A N, Raison C, Cubiss J G, Van Duppen P, Péru S, Hilaire S, Goriely S, Andel B, Antalic S, Al Monthery M, Berengut J C, Bieroń J, Bissell M L, Borschevsky A, Chrysalidis K, Cocolios T E, Day Goodacre T, Dognon J-P, Elantkowska M, Eliav E, Farooq-Smith G J, Fedorov D V, Fedosseev V N, Gaffney L P, Garcia Ruiz R F, Godefroid M, Granados C, Harding R D, Heinke R, Huyse M, Karls J, Larmonier P, Li J G, Lynch K M, Maison D E, Marsh B A, Molkanov P, Mosat P, Oleynichenko A V, Panteleev V, Pyykkö P, Reitsma M L, Rezynkina K, Rossel R E, Rothe S, Ruczkowski J, Schiffmann S, Seiffert C, Seliverstov M D, Sels S, Skripnikov L V, Stryjczyk M, Studer D, Verlinde M, Wilman S, Zaitsevskii A V

机构信息

Petersburg Nuclear Physics Institute, NRC Kurchatov Institute, 188300 Gatchina, Russia.

Department of Physics, University of York, York YO10 5DD, United Kingdom.

出版信息

Phys Rev Lett. 2021 Nov 5;127(19):192501. doi: 10.1103/PhysRevLett.127.192501.

DOI:10.1103/PhysRevLett.127.192501

PMID:34797155

Abstract

The changes in the mean-square charge radius (relative to ^{209}Bi), magnetic dipole, and electric quadrupole moments of ^{187,188,189,191}Bi were measured using the in-source resonance-ionization spectroscopy technique at ISOLDE (CERN). A large staggering in radii was found in ^{187,188,189}Bi^{g}, manifested by a sharp radius increase for the ground state of ^{188}Bi relative to the neighboring ^{187,189}Bi^{g}. A large isomer shift was also observed for ^{188}Bi^{m}. Both effects happen at the same neutron number, N=105, where the shape staggering and a similar isomer shift were observed in the mercury isotopes. Experimental results are reproduced by mean-field calculations where the ground or isomeric states were identified by the blocked quasiparticle configuration compatible with the observed spin, parity, and magnetic moment.

摘要

利用位于欧洲核子研究中心（CERN）的ISOLDE的源内共振电离光谱技术，测量了¹⁸⁷、¹⁸⁸、¹⁸⁹、¹⁹¹Bi的均方电荷半径（相对于²⁰⁹Bi）、磁偶极矩和电四极矩的变化。在¹⁸⁷、¹⁸⁸、¹⁸⁹Biˡ中发现了半径的大幅交错，表现为¹⁸⁸Bi基态的半径相对于相邻的¹⁸⁷、¹⁸⁹Biˡ急剧增加。对于¹⁸⁸Biᵐ也观察到了大的同质异能位移。这两种效应都发生在相同的中子数N = 105处，在汞同位素中也观察到了形状交错和类似的同质异能位移。通过平均场计算再现了实验结果，其中基态或同质异能态由与观察到的自旋、宇称和磁矩兼容的阻塞准粒子构型确定。