Rotational bands in the doubly odd nucleus 134Pr

The band structures of the doubly odd ¹³⁴Pr nucleus has been investigated via the ¹¹⁹Sn( ¹⁹F,4n) ¹³⁴Pr and ¹¹⁰Pd( ²⁸Si,p3n) ¹³⁴Pr reactions at beam energies of 87 and 130 MeV, respectively. The three previously known rotational bands based on the π[541] {3}/{2 ^-}(α=± {1}/{2})⊗ν[514] {9}/{2 ^-} and π[423] {5}/{2 ⁺}⊗ν[514] {9}/{2 ^-} configurations have been extended to higher spins. The difference of ≈2ħ in the experimental alignment of the bands based on the signature partners of the [541] {3}/{2 ^-}h{11}/{2} proton orbital is discussed in terms of shape coexistence and coupling with the γ-phonon but no consistent interpretation can be found. A new band consisting of quadrupole transitions has also been identified and linked unambiguously to the low-lying levels of the yrast band. Total routhian surface and cranked shell model calculations suggest a (π h_{11}/{2}) ³⊗ν[530] {1}/{2 ^-} configuration for this band. The experimental ratios of reduced transition probabilities {B( M1) }/{B( E2) } of the various rotational structures are compared to the theoretical values obtained from a semiclassical model and from the two-particle plus triaxial-rotor model.