Basic modes in nuclear collective motion

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The following outcome has been obtained by this international collaboration involving three major institutions.1) The Q-phonon scheme originally introduced for even-even nuclei s extended to odd-A nuclei. In particular, the structure of the supersymmetry of U(6|4) has been clarified. To be more precise, eigenstates within the same representation space were shown, in the previous study, to be produced by acting the quadrupole operator of U(6|4) on the ground state of each representation. In the present study, eigenstates are shown to be produced between different representations by utilizing supersymmetric operators. The Q-phonon theory has been extended to other supersymmetric cases like U(6|12) and U(6|20).2) The so-called beta vibrational state is shown to be a mixture of multi beta-gamma excitations, in particular, that of the beta excitation and double gamma excitation. This trend is found to be consistent with experimental data taken by the Koeln and Yale groups.3) The mixed symmetry states of 2+ and 3+ are studied by extending the idea of the Q-phonon. Many godd candidates of such states are found by the Koeln group for Mo, Xe, Ba and Pt regions.4) A possible link between different representations of O(6) is suggested.5) High spin states sre studied for Xe and Ba isotopes including experimental data from the Koeln group.