The excitation energy systematics of πh11/2×νh11/2 yrast bands of odd-odd isotopes 118– 132Cs are studied, and as a result of this study we suggest that the spin values of lowest observed states of yrast bands of 118,122,124,126,128Cs be reassigned as 8, 9, 9, 9, and 10, respectively. These new spin assignments are also supported by the argument of alignment additivity. [S0556-2813(98)02309-7]

High-spin states in 158Ho have been studied through the 152Sm(11B,5n) 158Ho reaction at a beam energy of 60 MeV. In addition to the previously known yrast band, three new rotational bands, namely, the {p7/2－[523]×n3/2－[521]}Kπ=5+ ground-state band, the {p7/2+[404] ×n3/2+[651]} Kπ=5+ band, and the {p7/2－[523]×n11/2－[505]}Kπ=9+ band, are proposed. The yrast band is connected to the ground-state band, and its configuration is reassigned as the {p7/2－[523]×n3/2+ [651]}Kπ=5－ rather than the {p7/2－[523]×n5/2+ [642]}Kπ=6－. On the basis of the present experimental study, the spin values of the member states of the yrast band turn out to be larger by three units with respect to the earlier tentative spin assignments and in agreement with the latest spin assignments based on the arguments of the level energy systematics and the alignment additivity. [S0556-2813(99)04006-6]

High spin states of odd-odd nucleus 124Cs have been studied following the 116Sn(11B,3n) reaction at a beam energy of 45 MeV. The previously reported isolated rotational bands are connected to each other by various linking transitions and to the 11 ground state through different decay paths. The spin of the lowest observed state in the πh11/2×νh11/2 yrast band is determined to be 9\, which is two units larger than that suggested by the latest in-beam study and confirms the spin assignment proposed by a recent systematics study on spin assignment and signature inversion of the πh11/2×νh11/2 bands in odd-odd isotopes 118-132Cs.

High spin states of 122Cs are reinvestigated through the 116Sn (10B; 4n)122Cs reaction at the beam energy of 54 MeV. Two new levels are added to the lower side of the most strongly populated band and the previously proposed 488 keV linking transition between the two observed bands is replaced by the 95 keV linking transition. As a result of these new observations, it becomes reasonable to assign the most strongly populated band in 122Cs as the πh11/2×νh11/2 yrast band.

The level states of the nucleus 124Cs have been populated through the 116Sn(11B,3n) reaction at a beam energy of 45 MeV, provided by the HI-13 tandem accelerator of the China Institute of Atomic Energy. A number of low-lying states are constructed. The level states in the πh11/2×νg7/2 side band are extended down to lower spin by one h. The level energies and spins in the rotational bands are determined through the establishment of various connections, which confirm the spin assignment of the yrast band in 124Cs based on excitation energy systematics. It is revealed that with the present spin assignment, theπh11/2×νg7/2 side band shows signature inversion at low-spin region and the inversion occurs at a spin of about 16h.