  The competition between alpha- and beta+/EC-decay modes is studied
systematically in nuclei along the alpha-decay chains following the synthesis
of superheavy nuclei with Z = 119 and Z = 120. A microscopic approach based on
deformed self-consistent Hartree-Fock mean-field calculations with Skyrme
forces and pairing correlations is used to describe the beta+ and electron
capture weak decays, whereas the alpha-decay is estimated from existing
phenomenological expressions. It is shown that alpha-decay is in most cases the
dominant decay mode, but interesting instances are identified where the
half-lives are comparable, opening the possibility of new pathways towards more
neutron-rich nuclei in this region.
