Sumario: | The integrated statistical rates for superallowed 0+-0+ β-transitions evaluated according to the most widely used methods proposed by Behrens-Jänecke-Bühring and Towner-Hardy are compared. It is shown that both calculations are in essential agreement up to mass A=38. However, for heavier nuclei there is a discrepancy. The disagreement, which increases with increasing Z, ranges from 0.07% for 42Sc to as much as 0.13% for 54Co and is larger than the errors attached to f-values due to uncertainties in W0 (these being about 0.03-0.04%). Moreover, such differences are either comparable to or even larger than the uncertainties in t and δc. The disagreement is attributed to the different evaluations of the second-forbidden nuclear matrix elements. The choice of the parameters used in both methods is also discussed. © 1983.
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