Eur. Phys. J. A (2018) 54: 59
https://doi.org/10.1140/epja/i2018-12496-3

Regular Article - Experimental Physics

Yrare low-spin positive-parity states in N = 88 ₆₆ ¹⁵⁴ Dy

¹ University of Johannesburg, Physics Department, P.O. Box 524, 2006, Auckland Park, South Africa
² iThemba LABS, National Research Foundation, P.O. Box 722, 7129, Somerset West, South Africa
³ University of Western Cape, Physics Department, P/B X17, ZA7535, Bellville, South Africa
⁴ University of Zululand, Physics Department, P/B X1001, 3886, KwaDlangezwa, South Africa
⁵ Stellenbosch University, Physics Department, P/B X1, 7602, Matieland, South Africa
⁶ Rhodes University, Physics Department, P.O. Box 94, 6140, Grahamstown, South Africa
⁷ UM-DAE Centre for Excellence in Basic Sciences, Kalina, 400098, Mumbai, India

^* e-mail: zimbageo@yahoo.com

Received: 19 May 2017
Accepted: 14 March 2018
Published online: 17 April 2018

Abstract

Low-spin positive-parity yrare states of ₆₆ ¹⁵⁴ Dy₈₈ were established using the ¹⁵⁵Gd(³He,4n) reaction at a beam energy of MeV. The AFRODITE spectrometer array at iThemba LABS was used to record coincidences and measure DCO ratios and polarisation asymmetries. The band has been observed up to spin in the odd spins and to in the even spins. The staggering parameter S(I) of the band is compared to that found in other N = 88 isotones. Different behaviour of S(I) with increasing spin is observed for each of the isotones. We conjecture that the variation in S(I) is mainly due to mixing of the even-spin states with the same spin and parity states in neighbouring rotational bands. A second band has been established up to a spin of in the even spins. We suggest that this is a band based on the state at keV.