Q_EC Measurement of ^{124,125,127-130}La

For neutron-deficient ^{124,125,127-130}La, Q_EC measurement has been performed by determining β⁺-ray maximum energies. The radioactive sources were prepared by on-line mass-separation following the fusion-evaporation reactions ^92,natMo(³⁶Ar, 3pxn). The β⁺-rays were measured with an HPGe detector in β - γ coincidence mode in which γ-rays were detected with another HPGe detector for specifying an excited state in daughter nucleus. By unfolding the β⁺-ray spectra using experimental response functions, the Q_EC-values of ^{124,125,127,130}La were newly obtained, and those of ^128,129La were improved in their accuracy. The Q_EC-values obtained and the resulting atomic masses are compared with theoretical predictions. The results of half-life calculation and two-neutron separation energies using the experimental Q_EC-values are also discussed.