Spin Assignments of Superdeformed Bands in Europium
- Received Date: 2000-01-04
- Accepted Date: 1900-01-01
- Available Online: 2001-02-05
Abstract: A comprehensive investigation of the superdeformed bands observed in 142,143,144,147Eu was given. The fluctuation in the transition energies has been removed. The smoothed transition energies were fitted by the ab-expression or its modification. The spins of these bands, except for band 4 of 147Eu, have been assigned conclusively. The exit spin in 143Eu was proud to be 29/2, different from that asserted to be determined experi- mentally but remains to be confirmed. The corresponding values in 142Eu and 144Eu(a) are 21 and 28, lower than those proposed in the literature by 6 and 8 units, respectively. Two pairs of superdeformed bands in 147 Eu, i. e. bands 1,5 and bands 2,3 were proposed to be signature partners. The exit spins are 53/2 and 63/2 for the former pair, and 43/2 and 41/2 for the latter pair. In addition, both of them have a rather large de-coupling constant(≈-1), implying they are of K=1/2 and built on the single particle level ν[651]↓ or π[530] ↑. This assignment may be helpful for the studies of the so-called identical bands and pseudospin problem. The signature partner pairs observed in 144,148Eu are not included in the investigation.