The definition of the halo radius

Last modification: 1996/3/25

We define the halo radius as the radius r at which angle-averaged mass density is 0.16 x 10^-5 fm^-3, which is about 10^-4 of the nuclear matter density: Note that the nucleon halo, being composed of only two nucleons, has much lower density than the nucleon skin.

We also define the halo thickness as the halo radius subtracted by 1.2 x A^1/3 fm.

According to these definitions, the halo radius (thickness) in the salient case of ¹¹Li is 11.2 fm (8.5 fm) while the neutron skin thickness in our definition is only 1.9 fm (from Fig. 4 of Ref. [TS90] and Fig. 4 of Ref. [Sa92]).