Microscopic description of vibrational states in deformed nuclei

Abstract

Microscopic description of the vibrational states with an energy up to 6 MeV in doubly even deformed nuclei is performed in the Quasiparticle-Phonon Nuclear Model. The QPNM Hamiltonian is constructed. New phonon operators consisting of electric and magnetic parts are introduced. The RPA equations are obtained for multipole and spin-multipole magnetic interactions. The Eλ and M L strength distributions are calculated. It is shown that the inclusion of isovector electric dipole interactions in addition to the octupole ones decreases by an order of magnitude the E1 transition probabilities to J π = 1 − with K = 0 and 1 states, thus bringing it closer to experimental data. Inclusion of spin-multipole isovector interactions as well as multipole interactions reduces 3–10 times the B(M2) and B(M3) values; the spin part of M2 and M3 transition operators is important. General properties of vibrational states in deformed nuclei are formulated. The effect of fragmentation of one-phonon states on distribution of Eλ and M L strength is investigated. The problem of many-quasiparticle components of the wave functions of neutron resonances is posed.