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 $hbaromega$= 1.8 MeV, which might be associated to pairing vibrations around $^{40}$Ca.
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