6533b81ffe1ef96bd1276f75

RESEARCH PRODUCT

Probing the quenching of gA by single and double beta decays

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Abstract Ground-state-to-ground-state two-neutrino double beta ( 2 ν β β ) decays and single beta (EC and β − ) decays are studied for the A = 100 (100Mo 100Tc 100Ru), A = 116 (116Cd 116In 116Sn) and A = 128 (128Te 128I 128Xe) nuclear systems by using the proton–neutron quasiparticle random-phase approximation exploiting realistic effective interactions in very large single-particle bases. The aim of this exercise is to see if both the single-beta and double-beta decay observables related to the ground states of the initial, intermediate and final nuclei participant in the decays can be described simultaneously by changing the value of the axial-vector coupling constant g A . In spite of the very different responses to single and 2 ν β β decays of the considered nuclear systems, the obtained results point consistently to a quenched effective value of g A that is (slightly) different for the single and 2 ν β β decays.