Lifetime measurements of first excited states in 16,18C

Abstract

The electric quadrupole transition from the first 2+ state to the ground 0+ state in 18C was studied through lifetime measurement by an upgraded recoil shadow method applied to inelastically scattered radioactive 18C nuclei. The measured mean lifetime is 18.9 +/- 0.9 (stat) +/- 4.4 (syst) ps, corresponding to a B(E2;2+ -> 0+) value of 4.3 +/- 0.2 +/- 1.0 e2fm4, or about 1.5 Weisskopf units. The mean lifetime of the first 2+ state in 16C was remeasured to be 18.0 +/- 1.6 +/- 4.7 ps, about four times shorter than the value reported previously. The discrepancy between the two results was resolved by incorporating the gamma-ray angular distribution measured in this work into the previous measurement. These transition strengths are hindered compared to the empirical transition strengths, indicating that the anomalous hindrance observed in 16C persists in 18C.

Submitted to Physical Review C; 26 pages with 13 figures

References in corpus (2)

• Three-body model calculations for 16C nucleus
• Microscopic shell-model description of the exotic nucleus ^{16}C

Cited by in corpus (12)

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• Proton radii of Be, B, and C isotopes
• Hindered proton collectivity in 28S: Possible magic number at Z=16
• Shell evolution in neutron-rich carbon isotopes: Unexpected enhanced role of neutron-neutron correlation
• Complete Glauber calculations for proton-nucleus inelastic cross sections
• alpha clustering and neutron-skin thickness of carbon isotopes
• Ab initio no-core shell model study of neutron-rich ${}^{18,19,20}$C isotopes
• Probing the quadrupole transition strength of 15C via deuteron inelastic scattering
• Quadrupole dynamics of carbon isotopes and 10Be
• Breakup effects in the ${}^{16}\mathrm{C}+p$ and ${}^{16}\mathrm{C}+d$ reactions
• Unbound states in 17C and p-sd shell-model interactions