High spin states of 86Zr.

Abstract

The level scheme of $^{86}\mathrm{Zr}$ was studied by in-beam measurements on \ensuremath{\gamma} transitions in the $^{60}\mathrm{Ni}$${(}^{29}$Si,2pn\ensuremath{\gamma}${)}^{86}$Zr reaction and by helium-jet studies of delayed \ensuremath{\gamma}-ray activity from the $^{58}\mathrm{Ni}$${(}^{32}$S,3pn${)}^{86}$Nb(\ensuremath{\beta} +/EC${)}^{86}$Zr reaction. In the latter study, measurements consisted of \ensuremath{\gamma}-\ensuremath{\gamma} and \ensuremath{\beta}-\ensuremath{\gamma} coincidences, excitation functions, and a lifetime determination. An $^{86}\mathrm{Nb}$ decay scheme was obtained which suggests ${J}^{\ensuremath{\pi}}$${=5}^{+}$ for the $^{86}\mathrm{Nb}$ ground state. The in-beam study consisted of \ensuremath{\gamma}-\ensuremath{\gamma} coincidences, excitation functions, angular distributions, and lifetime measurements via both Doppler shift attenuation and recoil distance methods. The high-spin decay scheme and level lifetimes obtained from the in-beam studies suggest intrinsic modes of excitation rather than the collective behavior seen in $^{84}\mathrm{Zr}$.