[en] Measurements of the differential cross sections and asymmetries in the inelastic scattering of 20.4 MeV polarized protons from ¹⁴⁸,¹⁵⁰,¹⁵²,¹⁵⁴Sm have been used to investigate the collective properties of these nuclei, i.e. the vibrator-rotator phase transition, the deformations and the density moments. Experimental results included data for both the positive-parity states 0₁⁺,2₁⁺,(4₁⁺,6₁⁺) and the negative parity states 1₁^-,3₁^-,5₁^-, which systematics gives more reliability to the extracted physical quantities of interest. Phenomenological optical potentials have been carefully evaluated following the lines of a generalized optical model developed in this work. (Auth.)