β-decay half-lives andβ-delayed neutron multiplicities of the neutron drip-line nuclei19B,22C,and23N

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