One often compiles the allowed beta decay in terms of a logft which stands for log$_{10}$ of the \( ft_{1/2} \) value.

The values of the coupling constants for Fermi decay, \( g_{V} \), and Gamow-Teller decay, \( g_{A} \) are obtained as follows. For a \( 0^{+} \rightarrow 0^{+} \) nuclear transition \( B(GT)=0 \), and for a transition between \( T=1 \) analogue states with \( B(F)=2 \) we find $$ C = 2 t_{1/2} f. $$ The partial half-lives and \( Q \) values for several \( 0^{+} \rightarrow 0^{+} \) analogue transitions have been measured to an accuracy of about one part in 10000. With phase space factors one obtains $$ C = 6170(4) $$ This result, together with the value of \( K_{o} \) can be used to obtain \( g_{V} \).