Low-lying collective excitations in even-even vibrational and transitional nuclei may be described semiclassically as quadrupole running waves on the surface of the nucleus ("tidal waves"), and the observed vibrational-rotational behavior can be thought of as resulting from a rotating condensate of interacting d bosons. These concepts have been investigated by measuring lifetimes of the levels in the yrast band of the (102)Pd nucleus with the Doppler shift attenuation method. The extracted B(E2) reduced transition probabilities for the yrast band display a monotonic increase with spin, in agreement with the interpretation based on rotation-induced condensation of aligned d bosons.

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High spin states in the N =50 nucleus Tc were populated and studied using the reaction Zn ( 'P, 2p2n) Tc at a beam energy of 115 MeV. Gamma ray intensities and gamma-gamma coincidences were measured. Multipolarities of the transitions were extracted assuming stretched transitions. The positive and negative parity bands have been extended up to spins '2 + and 2, respectively. The proposed level scheme above J = 2 cannot be well understood on the basis of the spherical shell model calculations with valence protons occupying the (1f,/2, 2p3/2 2p, /2, 1g9/2) configuration space. The breaking of the N =50 neutron core appears to be a plausible mechanism for the observed high spin states.PACS number(s): 23.20.Lv, 23.20.En, 21.60.Cs, 27.60.+j

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