First lifetime measurement of dipole collective bands in neutron-deficient lead nuclei

Abstract

Lifetimes of states in two ΔI=1 bands in ${}_{}{}^{198}{}_{}{}^{}\mathrm{Pb}$ have been measured using the Doppler-shift attenuation method. The in-band reduced transition probabilities are ∼1–2 Weisskopf units assuming magnetic dipole transitions. The measured lifetimes in conjunction with the partial level scheme support an oblate collective interpretation for these structures.