J. W. Tape

The lifetime of the 3.74 MeV (3−) state of 40Ca

Abstract The mean life of the 3.74 MeV (3 − ) excited state of 40 Ca has been directly measured by a particle-gamma delayed coincidence technique. A mean life τ = 59 ± 5 ps was obtained, corresponding to a transition strength B (E3) = 31 ± 3 W.u.

Electric monopole transitions in Ca 40

The E0 pair decay branching ratio (GAMMA/sub ..pi..//GAMMA) for the 5.21-MeV 0/sup +/ fifth excited state of /sup 40/Ca was measured. The state was excited by inelastic proton scattering. The e/sup -/-e/sup +/ pairs were detected in two ..delta..E-E scintillation telescopes in coincidence with backscattered protons. A branching ratio limit of 1.4 x 10/sup -3/ was determined which corresponds to a monopole strength rho .. 0/sup +//sub 2/)/(2/sup +//sub 2/ ..-->.. 0/sup +//sub 1/)) = (2.1 +- 0.1) x 10/sup -2/ for the decay of 5.25-MeV 2/sup +/ state was measured and corresponds to a B (E2) = (3.5 +- 0.6) e/sup 2/ fm/sup 4/. (AIP)

Electric monopole transitions in /sup 40/Ca. [E0 pair decay branching ratio]

The E0 pair decay branching ratio (GAMMA/sub ..pi..//GAMMA) for the 5.21-MeV 0/sup +/ fifth excited state of /sup 40/Ca was measured. The state was excited by inelastic proton scattering. The e/sup -/-e/sup +/ pairs were detected in two ..delta..E-E scintillation telescopes in coincidence with backscattered protons. A branching ratio limit of 1.4 x 10/sup -3/ was determined which corresponds to a monopole strength rho .. 0/sup +//sub 2/)/(2/sup +//sub 2/ ..-->.. 0/sup +//sub 1/)) = (2.1 +- 0.1) x 10/sup -2/ for the decay of 5.25-MeV 2/sup +/ state was measured and corresponds to a B (E2) = (3.5 +- 0.6) e/sup 2/ fm/sup 4/. (AIP)

The 4.61 and 5.15 MeV levels of 48Ca

Abstract Particle-γ angular-correlation and lifetime studies of the fourth and fifth excited states of 48 Ca give E x = 4.613 MeV, J π = 3 (+) , τ m = 1.8±0.6 ps and E x = 5.152 MeV, J π = (5 − ) τ m = 2.21±0.04 ns respectively. The properties of the first five excited states of 48 Ca are discussed with reference to recent shell-model calculations; no compelling evidence of collective structure is indicated.