= Semi-empirical mass errors can change beta-decay thresholds
<Beta decay> <Q values> depend on small differences between much larger atomic <masses>. A smooth <semi-empirical mass formula> can therefore approximate absolute masses reasonably while predicting the wrong sign for a MeV-scale decay threshold. <Nuclear pairing> explains offset even-even and odd-odd mass branches, but does not guarantee that every specific even-even neighbor lies below the intervening odd-odd nucleus. Measured masses or additional <nuclear shell> corrections are needed for quantitative threshold tests near a model's residual error scale.
Back to article page
