The 40Ca level scheme investigated with the 39K(p, γ) 40Ca reaction

Abstract

The 40Ca level scheme has been investigated via the 39K(p, γ) 40Ca reaction. A thin-target yield curve has been measured in the E P = 0.3–2.9 MeV energy region in which 113 resonances have been observed. Many of these resonances had not been observed previously. The γ-decay of 26 resonances has been studied in detail which yields for bound states and resonances (i) accurate excitation energies, (ii) branching ratios and upper limits for unobserved transitions, (iii) J π T assignments and, as a by-product, (iv) lifetimes from the observed Doppler shifts. The reaction Q-value has been determined as Q = 8328.28 ± 0.09 keV. The correspondence between T = 1 states in 40Ca and their parent states in 40K has been much improved. Shell-model calculations have been performed to describe many states of nuclei in the A = 37−41 region in a 16 O(1 s, 0 d) A−16− n (0 f, 1 p) n model space. Special attention has been paid to aspects of the cross-shell interaction.