States in O22 via β decay of N22

The energy-level structure of {sup 22}O with the recently identified N=14 subshell closure was investigated by the beta decay of {sup 22}N for the first time. A beta-delayed-neutron, time-of-flight measurement revealed six new neutron transitions attributed to the beta decay of {sup 22}N. One- and two-beta-delayed neutron decay of {sup 22}N, with emission probabilities of 33(3)% and 12(3)%, respectively, were observed to correspond to four new negative-parity states in {sup 22}O. The half-life of {sup 22}N beta decay was determined to be 20(2) ms. Three gamma-ray transitions in {sup 22}O and single gamma rays in {sup 21}O and {sup 20}O were observed following the beta decay of {sup 22}N. The observation of large Gamow-Teller strength for a highly excited state in {sup 22}O indicates a halo structure for {sup 22}N. A comparison of results with shell-model predictions showed overall poor agreement. The measured P{sub n} values of {sup 24}O and {sup 25}F components of the secondary beam showed an enhancement relative to the P{sub n} values of adjacent oxygen and fluorine isotopes, providing additional evidence for the N=14 closed subshell.