  High resolution experimental data has been obtained for the
40,42,44,48Ca(3He,t)Sc charge exchange reaction at 420 MeV beam energy, which
favors the spin-isospin excitations. The measured angular distributions were
analyzed for each state separately, and the relative spin dipole strength has
been extracted for the first time. The low-lying spin-dipole strength
distribution in 40Sc shows some interesting periodic gross feature. It
resembles to a soft, dumped multi-phonon vibrational band with $\hbar\omega$=
1.8 MeV, which might be associated to pairing vibrations around $^{40}$Ca.
