The mean life of the second 0+ state in 42Ca

The mean life of the second excited state in ⁴²Ca (1.84 MeV, O⁺) was measured by a direct electronic timing technique to be 558 ± 8 ps. This result compares with a previous measurement of 480 ± 30 ps which yields a high B(E2) value. The present result gives a B(E2; 0₂⁺ 1.84 MeV → 2₁⁺ 1.52 MeV) value of 484 e² · fm⁴ or 55 single-particle units; the theoretical implications of this are discussed.The accurate mean life was extracted using a convoluted function to describe both the inherent time resolution of the experimental system and the exponential decay of the state of interest.