  Spin dipole (SD) strengths for double beta-decay (DBD) nuclei were studied
experimentally for the first time by using measured cross sections of (3He,t)
charge exchange reactions (CERs). Then SD nuclear matrix elements (NMEs) for
low-lying 2- states were derived from the experimental SD strengths by
referring to the experimental GT (Gamow-Teller) and F (Fermi) strengths. They
are consistent with the empirical SD NMEs based on the quasi-particle model
with the empirical effective SD coupling constant. The CERs are used to
evaluate the SD NME, which is associated with one of the major components of
the neutrino-less DBD NME.
