-decay of the new isotope Po; Probing prolate structures beyond the neutron mid-shell at N = 104

新同位体Poの崩壊; 中性子数104ミッドシェル領域のプロレート変形の解明

Andreyev, A. N.*; Antalic, S.*; Ackermann, D.*; Franchoo, S.*; Heberger, F. P.*; Hofmann, S.*; Huyse, M.*; Kojouharov, I.*; Kindler, B.*; Kuusiniemi, P.*; Lesher, S. R.*; Lommel, B.*; Mann, R.*; Mnzenberg, G.*; 西尾 勝久   ; Page, R. D.*; Ressler, J. J.*; Streicher, B.*; Saro, S.*; Sulignano, B.*; Van Duppen, P.*; Wiseman, D.*; Wyss, R.*

Andreyev, A. N.*; Antalic, S.*; Ackermann, D.*; Franchoo, S.*; Heberger, F. P.*; Hofmann, S.*; Huyse, M.*; Kojouharov, I.*; Kindler, B.*; Kuusiniemi, P.*; Lesher, S. R.*; Lommel, B.*; Mann, R.*; Mnzenberg, G.*; Nishio, Katsuhisa; Page, R. D.*; Ressler, J. J.*; Streicher, B.*; Saro, S.*; Sulignano, B.*; Van Duppen, P.*; Wiseman, D.*; Wyss, R.*

The new neutron-deficient isotope Po has been identified in the complete fusion reaction Ti+Sm Po+3n at the velocity filter SHIP of GSI. Striking features of the Po decay are the strongly-hindered decay to the spherical ground state and unhindered decay to a surprisingly low-lying deformed excited state at 286 keV in the daughter nucleus Pb. Based on the potential energy surface calculations, the Po ground state and the 286 keV excited state in Pb were interpreted as being of prolate origin.