High spin states in 128^{128}Ba

High spin states in 128Ba have been investigated with the fusion–evaporation reaction 96Zr(36S,4n)128Ba at a beam energy of 150 MeV with the GASP-spectrometer at INFN in Legnaro, Italy. The level scheme could be extended to higher spins and six-quasiparticle states have been observed. The deduced alignments are compared to the predictions of previously reported cranked shell model calculations. (Springer

Collectivity of the intruder bands in 114Sn

For the investigation of the collectivity and the structure of the intruder bands with positive and negative parity in 114Sn, coincidence lifetime measurements using the recoil distance Doppler shift (RDDS) and the Doppler-shift attenuation (DSA) methods were performed at the GASP spectrometer at the INFN-Laboratori in Legnaro. Excited nuclear states were populated with the reaction 100Mo(18O,4n)114Sn. For analysis the differential decay curve method was used in the \u3b3\u3b3-coincidence mode. In total 31 lifetimes could be obtained, belonging to 11 and 13 states in the positive- and negative-parity intruder bands, respectively, and to 7 spherical states. This work enhances our knowledge of low-lying collectivity among the Sn isotopes near the mid-shell region

High Spin States in 128Ba

High spin states in Ba-128 have been investigated with the fusion-evaporation reaction Zr-96 (S-36, 4n)Ba-128 at a beam energy of 150 MeV with the GASP-spectrometer at INFN in Legnaro, Italy. The level scheme could be extended to higher spins and six-quasiparticle states have been observed. The deduced alignments are compared to the predictions of previously reported cranked shell model calculations

Lowest four-quasiparticle magnetic dipole band in 128^{128}Ba

The four-quasiparticle magnetic dipole band in 128Ba has been investigated with the 96Zr(36S,4n)128Ba reaction at the GASP spectrometer of the Laboratori Nazionali di Legnaro. Linking transitions to the previously known positive parity states have been observed for the first time in this mass region and new transitions on top of the band have been found. The experimental results are compared to previously made tilted axis cranking calculations. (APS

In-beam M1 and E2 transition rates and collective structures in 128^{128}Ba

Subpicosecond mean lifetimes of eight excited states in 128 Ba populated via the 96 Zr( 36 S,4n) reaction were measured by the Doppler-shift attenuation (DSA) technique using a line-shape analysis. The differential decay-curve method (DDCM) was applied for the lifetime determination. The B (E2) values in the yrast band indicate that the first band-crossing is with a proton S-band. The configuration πh 11 2 d 5 2 of the negative-parity semi-decoupled bands is confirmed by the measured B (E2, I → I − 2) and B (M1, I → I − 1) transition strengths. The higher-lying “dipole” band in 128 Ba can be described as a high- K four-quasiparticle band built on the prolate configuration (πh 11 2 d 5 2 ) ⊗ (νh 11 2 g 7 2 ) . (Elsevier

In-band M1 and E2 transition rates and collective structures in 128Ba

Subpicosecond mean lifetimes of eight excited states in 128Ba populated via the 96Zr(36S,4n) reaction were measured by the Doppler-shift attenuation (DSA) technique using a line-shape analysis. The differential decay-curve method (DDCM) was applied for the lifetime determination. The B(E2) values in the yrast band indicate that the first band-crossing is with a proton S-band. The configuration View the MathML source of the negative-parity semi-decoupled bands is confirmed by the measured B(E2, I \u2192 I 12 2) and B(M1, I \u2192 I 12 1) transition strengths. The higher-lying \u201cdipole\u201d band in 128Ba can be described as a high-K four-quasiparticle band built on the prolate configuration View the MathML source

Detailed angular correlation analysis with 4π\pi spectrometers : spin determinations and multipolarity mixing measurements in 128^{128}Ba

We analyze for the first time the full γγ directional correlations from oriented states (DCO) in an experiment performed with the GASP detector array. Our analysis is based on a transformation of the directional information into expansion coefficients of an orthogonal basis. With this method, which we call SpeeDCO (spectral expansion of DCO), the complete DCO information is concentrated in 12 γγ coincidence spectra. The analysis is applicable to all detector arrays which uniformly cover the solid angle. We show that the complete DCO information can be used for a reliable and unique determination of spins and multipolarity mixing ratios in weakly populated bands. We were able to establish the spins and the positive parity of the ΔI=1 “M1 band” in 128Ba and multipolarity mixing ratios of nine M1/E2 in-band transitions were derived as well. The measured values are in good agreement with those expected for a high-K rotational band. (APS