Probing the quenching of gA by single and double beta decays

J. SUHONEN; OSVALDO CIVITARESE

PHYSICS LETTERS B

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2013 vol. 725 p. 153 - 157

0370-2693

Ground-state-to-ground-state two-neutrino double beta (2 ν ββ ) decays and single beta (EC and β − ) decays are studied for the A = 100 ( 100 Mo? 100 Tc? 100 Ru), A = 116 ( 116 Cd? 116 In? 116 Sn) and A = 128 ( 128 Te? 128 I? 128 Xe) 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 ββ 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 ββ decays.