High spin states in stable nucleus 84Sr

Abstract

High spin states of 84 Sr were populated through the reaction 70 Zn( 18 O, 4n) 84 Sr at 75 MeV beam energy. Measurement of excitation function, γ-γ coincidences, directional correlation from oriented state (DCO) ratios and γ-transition intensities were performed using eight anticompton HPGe detectors and one planar HPGe detector. Based on the measured results, a new level scheme of 84 Sr was established in which 12 new states and nearly 30 new γ-transitions were identified in the present work. The positive-parity states of the new level scheme were compared with the results from calculations in the framework of the projected shell model (PSM). One negative-parity band was extended to spin I π =19 − and it can be found that in the high spin states, the γ-transition energies show the nature of signature staggering. The negative-parity band levels are in good agreement with deformed configuration-mixing shell model (DCM) calculations.high spin states, γ-γ coincidence, DCO ratio, level scheme, PSM

Indications of octupole correlation in 84Sr

“…It is reported in [34] that N = 45 and 46 provide a transitional point for the nuclei near Z = 38. Therefore, the 84 Sr is a transitional nucleus and, can exhibit rotational and vibrational features together.…”

“…This band is built upon the K π = 3 − band-head with I π = 3 − [32, 46] and is re-investigated in the present study for octupole correlation. In the previous study of this band, the spin and parity were assigned based on the angular distribution and correlation measurements [32,34,36]. In our study, polarization asymmetry (Δ) measurements were also carried out to find the multipole character of intra-and inter-connecting γ-ray transitions.…”

“…Previously, the low-lying states of this nucleus were investigated via the β-decay, (p,t) and (α,a¢) reactions [29][30][31]. The intermediate states were studied via the 76 Ge( 12 C,4n) [32], 85 Rb(p,2n) [33], and 70 Zn( 18 O,4n) [34] reactions. The 51 V( 36 S,p2n), 52 Cr( 36 S,2p2n) and 59 Co( 28 Si,3p) reactions [35,36] were employed to obtain the transition probabilities of intermediate states by the Doppler Shift Attenuation Method (DSAM).…”