Β decay of neutron-rich 53-56Ca

β-decay properties of neutron-rich Ca isotopes have been obtained. Half-life values were determined for the first time for 54 Ca (86 ± 7 ms), 55 Ca (22 ± 2 ms), and 56 Ca (11 ± 2 ms). The half-life of 230 ± 60 ms deduced for 53 Ca is significantly longer than reported previously, where the decay chain 53 K → 53 Ca → 53 Sc was considered. A delayed y ray with an energy of 247 keV was identified following β decay of 54 Ca and is proposed to depopulate the 1+ 1 level in 34 Sc. The β-decay properties compare favorably with the results of shell-model calculations completed in the full pf space with the GXPF1 interaction. The half-lives of the neutron-rich Ca isotopes are also compared with gross β-decay theory. The systematic trend of the neutron-rich Ca half-lives is consistent with the presence of a subshell gap at N = 32.