Search

High-spin states in 198Tl were studied using the 197Au( $ \alpha$, 3 n) reaction. The level scheme was considerably extended including two new bands and several non-yrast levels. One of the new bands is possibly a chiral partner to the yrast $ \pi$ h9/2⊗ $ \nu$ i13/2 -1band. Two-quasiparticle-plus-triaxial-rotor model calculations suggest an aplanar orientation of the total angular momenta for these bands, thus supporting possible chirality. [ABSTRACT FROM AUTHOR]

The excited states in 198Tl populated in the 197Au(α,3n) reaction at a beam energy of 40 MeV were studied using two complementary experiments aimed at γ-ray spectroscopy at iThemba LABS, and at electron-γ spectroscopy at Orsay, respectively. The level scheme of 198Tl was extended and a weak side band feeding into the yrast πh9/2⊗i13/2 band was observed. The properties of these two bands are similar to these of the pairs of bands in the A = 130 mass region initially interpreted as chiral doublets. [ABSTRACT FROM AUTHOR]

The positrons and coincident gamma-rays following the pure Fermi 0+ → 0+ branch of β+-decay in14O were measured. The Doppler shift of the γ-quantum observed is sensitive to the beta-neutrino correlation coefficient, which is unity (α = 1) in the absence of scalar coupling. The interatomic interaction of recoiling daughters was noticed, which has prevented to obtain an improved result for scalar coupling despite of the excellent statistical accuracy of the measurement. At the same time, it was shown that the method described can be used as a very sensitive and flexible tool to probe the interatomic interactions in matter at the hundred eV energy level. Perspectives in this direction as well as the future angular-correlation experiments aimed to search for scalar coupling in beta-decay are discussed. [ABSTRACT FROM AUTHOR]

The decay of 123Ba to 123Cs has been studied with mass-separated sources. Singles spectra of γ-rays, X-rays and conversion electrons as well as γ - γ - t, γ - e − - t, and X - e − - t coincidences were recorded. A level scheme of 123Cs has been constructed including 26 new excited states and 82 transitions. The existence of a I π = 11/2−, T 1/2 = 1.7 s isomer, bandhead of the h 11/2 band, is confirmed. Its excitation energy equals 156.3 keV. A new T 1/2 = 114 ns isomer has been established at 232 keV using the in-beam recoil catcher technique. It is assigned to the I π = 9/2+ bandhead of the gpg 9/2 band. Collective bands based on the 1/2+ ground state and first 3/2+ excited state are proposed. The level structure is described in the frame of the interacting boson-fermion and core-quasiparticle coupling models. [ABSTRACT FROM AUTHOR]

A detailed analysis of the positive parity levels in odd iridium isotopes is carried out with an extended version of the Hecht and Satchler model. A satisfactory description ofIr positive parity states and their electromagnetic properties is obtained by coupling several Nilsson particle configurations to an asymmetric rotor. [ABSTRACT FROM AUTHOR]

The nucleus 146Tb was studied from in beam γγ-and conversion electron measurements. The level scheme was established up to ∼5MeV above the (πh11/2vd3/2−1)5−β-isomer. In addition to the known (πh11/2vh11/2−1)10+ E3-isomer, the 8+ and 11+ members of this configuration were located. The levels at the yrast line are dominated by the couplings of the πh11/2vh11/2−1 valence nucleons to the collective 3− octupole state and to the πh11/2d5/2−1 and πh11/2g7/2−1 particle-hole excitations of 146Gd. [ABSTRACT FROM AUTHOR]

The EUROGAMarray has been used to investigate the decay out of the yrast superdeformed (SD) band in Pb. Eigth single step decays from the lowest observed SD states to low-lying states at normal deformation (ND) have been identified. From this observation, the excitation energy (4877 ± 1.5 keV) and the spin (6) of the lowest observed SD state in Pb are established. [ABSTRACT FROM AUTHOR]

An isomeric state (T=4.0±0.2 ns, E=9.915 MeV, I=61/2) has been found in Tb by measuring the half-life of the K internal conversion line of the 184 keV E2 deexciting transition. The breaking of the neutron core is theoretically expected at that spin resulting in sizeable increase of the oblate deformation. [ABSTRACT FROM AUTHOR]