Reanalysis of hyperon beta decay data on |F/D

We reanalyse hyperon beta decay data to extract the corresponding F and D values. We illustrate the possibility that flavour symmetry breaking effects may lead to a reduction of the F/D ratio. For proton and neutron our analyses suggests F/D = 0.49 ± 0.08 instead of F/D = 0.575 ± 0.016 which is generally used to analyse the spin data. Our smaller F/D value allows to fulfill the Ellis-Jaffe sum rule implying an unpolarized ss-sea.