A new result of investigations of the hyperfine structure (hfs) anomaly in Be
isotopes is presented. The hfs constant for 11Be is obtained by using the
core plus neutron type wave function: ∣2s21​​>+∣1d25​​×2+;1/2+>. A large hfs anomaly of 11Be is found, which is mainly due
to a large radius of the halo single particle state.Comment: 14 pages, Late