Decay properties of states populated with the207Pb(n,n′γ)reaction and weak coupling in207Pb

Abstract

The properties of states in ${}^{207}\mathrm{Pb}$ populated with the ${(n,n}^{\ensuremath{'}}\ensuremath{\gamma})$ reaction have been studied. \ensuremath{\gamma}-ray excitation functions, angular distributions, and coincidences have been measured, and the lifetimes of many excited states were determined with the Doppler-shift attenuation method. A sextuplet of states near 3.2 MeV is interpreted as resulting from weak-coupling of the $\ensuremath{\nu}{f}_{5/2}^{\ensuremath{-}1}$ first excited state of ${}^{207}\mathrm{Pb}$ with the octupole phonon of the ${}^{208}\mathrm{Pb}$ core. A number of $E1$ transitions have been identified, and their reduced transition probabilities have been examined. The properties of low-lying levels in ${}^{207}\mathrm{Pb}$ have been studied in the framework of the particle-core coupling model.