Evidence for the Existence of Two-Phonon Collective Excitations in Deformed Nuclei

Kπ=0+andGarrett1, Kadi2, Li3 et al. 1997Phys. Rev. Lett.824460View full textAdd to dashboardCite

“…2 1 g ͒͞ B͑E2; 2 1 g ! 0 1 gs ͒ 1.3 6 0.4 is less than the expected harmonic value of 2.8, but is not unlike the value of 1.5 observed [1] in 168 Er. For the 1943 keV level, the B͑E2; 0 1 !…”

“…The recent measurement [1] of enhanced E2 transitions from a level at 2055 keV in 168 Er, interpreted as the K p 4 1 two-phonon g vibration ͑4 1 gg ͒, has not silenced the controversy which is now centered on the magnitude of the two-g-phonon component in the wave function needed to reproduce the enhanced E2 rate and the extent to which these states appear in other nuclei [2][3][4][5][6][7]. Following the discovery of the 4 1 gg state in 168 Er, attempts [2] were made to locate candidates for these states in other nuclei, mainly by considering branching ratios and energy systematics.…”

Algebraic Collective Model Description of 166Er

“…The former, 5 0 + state, has thus been identified as a K = 0 + double-γ vibration [5] and the latter has been interpreted as a K = 4 + double-γ vibration. Interestingly, a large range of anharmonicities of these double-γ vibrations is observed [6][7][8][9]. These states and their anharmonicities are of a great interest since they provide a stringent test of nuclear models.…”

Two-phononγ-vibrational states in rotating triaxial odd-Anuclei

“…The description in terms of the interacting boson model was improved by Yoshinaga et al [10] by introducing the g boson. The definite experimental evidence, the absolute B(E2) value between the K = 4 2γ candidate and the 1γ, that proves that the K = 4 state is really the 2γ was given by means of γ ray induced Doppler broadening following neutron capture by Börner et al [11] and using Coulomb excitation by Oshima et al [12] and Härtlein et al [13].…”