Comparison of superdeformed bands in61Znand60Zn: Possible evidence for

Abstract

The yrast superdeformed band in 61 Zn has been established using 28 Si( 36 Ar, 2pn) 61 Zn and 40 Ca( 29 Si, 2␣) 61 Zn fusion-evaporation reactions. The excitation energy of this band was determined via two transitions that link this band to the normally deformed states. Lifetime analysis of this band resulted in a quadrupole moment of Q t ϭ3.0Ϯ 0.4 0.5 e b, which corresponds to a deformation of ␤ 2 ϭ0.50Ϯ 0.06 0.07 . A comparison of the J (2) dynamical moments of inertia of the yrast superdeformed band in 61 Zn with those in 60 Zn shows a nearly complete blocking of the observed alignment in 60 Zn, indicating that Tϭ0 proton-neutron pair correlations may be present in 60 Zn. ͓S0556-2813͑99͒51109-6͔

Single-particle and collective excitations in63Ni

“…III). Figure 7(c) extends the I x vs ω comparison further with selected bands in 60 Zn (SD in [53]), 61 Zn (SD in [54]), 62 Zn (SD in [55] and SD1 in [56]), and 65 Zn (SD1 in [52]). Since the 65 Zn SD1 band has not yet been firmly linked to the lowerlying states, the spin value of 33/2 proposed by Yu et al [52] for the bandhead was adopted.…”

“…From the discussion above, it is clear that an interpretation within the framework adopted for the description of most of the collective bands observed in the Ni [32,33,35,37,39,41] and Zn [52][53][54][55][56] isotopic chains is warranted. Hence, calculations were performed within the configuration-dependent cranked Nilsson-Strutinsky (CNS) model with the formalism described in Refs.…”

“…Specifically, much attention has been devoted to documenting the evolution of shell structure with neutron number N in nuclei located above doubly-magic 48 Ca. In neutron-rich 52 Ca [1], 54 Ti [2], and 56 Cr [3], a new subshell gap was established at N = 32, based on systematic studies of 2 + 1 energies and B(E2;2 + 1 →0 + 1 ) transition strengths [4][5][6][7]. Indications of an N = 34 subshell closure have been found in 54 Ca [8].…”

“…In neutron-rich 52 Ca [1], 54 Ti [2], and 56 Cr [3], a new subshell gap was established at N = 32, based on systematic studies of 2 + 1 energies and B(E2;2 + 1 →0 + 1 ) transition strengths [4][5][6][7]. Indications of an N = 34 subshell closure have been found in 54 Ca [8]. It is by now well established that the monopole part of the tensor force plays a central role in the development of these two gaps [9][10][11][12].…”

T=0neutron-proton pairing correlations in the superdeformed rotational bands around60Zn

“…However, unexpectedly, the SD band in the doubly-magic SD nucleus 60 Zn deviates strongly from the theoretical predictions. This has been tentatively interpreted as an effect of the simultaneous alignment of the g 9/2 neutrons and protons [9], or as a manifestation of the T =0 n-p correlations [10]. In the present paper we perform the first calculations based on these two assumptions.…”