On the Charge-Dependent Matrix Element Between the 9.516 MeV 4+ T = 1 Level and the 8.439 MeV 4+ T = 0 Level of 24Mg

Abstract

A recent measurement of the ß - y circular polarization asymmetry parameter A on the isospinforbidden ß + decay of the ground state of 24Al to the 8.438 MeV 4+ T= 0 state of 24Mg yields a charge-dependent matrix element ⟨ VCD⟩Mg between the 9.516 MeV 4+ T = 1 state and the 8.439 MeV 4+ T = 0 state of 24Mg of (106 ± 40) keV, which is the largest measured value obtained so far in ß decay. Our calculation using Nilsson’s wavefunctions and a spherical Coulomb potential results in a value of 87 keV for ⟨ VCD⟩Mg . Variation of the value of ⟨ VCD⟩Mg against the deformation parameter ß shows that theory agree very well with the measured ⟨ VCD⟩Mg for ß around 0.5.