beta-decay half-lives and beta-delayed neutron multiplicities of the neutron drip-line nuclei B-19, C-22, and N-23

Beta-decay properties of the neutron drip-line nuclei B-19, C-22, and N-23 have been studied using projectile fragments from 95 MeV/nucleon Ar-40 ions incident on a Ta-nat target. The beta-decay half-lives of C-22 and N-23 have been determined for the first time to be 6.1(-1.2)(+1.4) and 14.1(-1.5)(+1.2) ms, respectively. The half-life of B-19 was reinvestigated, resulting in a new value of 2.92+/-0.13 ms. The beta-delayed neutron multiplicities have also been determined to be P-1n=71.8(-9.1)(+8.3)%, P-2n=16.0(-4.8)(+5.6)% for B-19, P-1n=61(-13)(+14)% for C-22, and P-1n=42.2(-6.5)(+6.3)%, P-2n=8.0(-3.4)(+3.8)% for N-23. The results are compared with theoretical predictions.