
^{20}C (1998TI06)(Not illustrated) ^{20}C has been observed in heavy ion projectile fragmentation reactions (1987GI05, 1990MU06, 1991MU19) and in protoninduced targetfragmentation reactions (1987VI13, 1988MU08, 1993WOZZ). The atomic mass excess is 37.560 ± 0.200 MeV (1995AU04). It is then stable with respect to ^{19}C + n and ^{18}C + 2n by 3.3 and 3.5 MeV, respectively. βdelayed neutron emission has been observed (1987GI05, 1990MU06, 1991MU19). The half life and neutron emission probability have been measured to be τ_{1/2} = 16^{+14}_{7} ms, P_{n} = 50 ± 30 (1989LE16) and τ_{1/2} = 14^{+6}_{5} ms, P_{n} = 72 ± 14 (1990MU06). Shell model calculations for exotic light nuclei are described in (1988POZS, 1993PO11). Shell model interactions constructed for the 0p1s0d nuclear shell model space are reported in (1992WA22). Selfconsistent calculations of light nuclei using the density functional method are reported in (1990LO11). See also the calculation of ground state properties reported in (1996GR21, 1996RE19), and see (1996SH13) for a description of a simple model of neutron "halo nuclei" applied to ^{20}C. Microscopic calculations of betadecay halflives for 6 ≤ Z ≤ 108 neutronrich nuclei are reported in (1990ST08). See also (1987SN01, 1993SA16, 1994HA39).
