Lifetimes and structures of low-lying negative-parity states of Po209

Microscopic structure of the one-phonon 2+ states of Po208

“…This result may point out to some inaccuracy in the matrix elements of our effective interaction, and in particular of the neutron-proton ones. A similar conclusion was reached for the off-diagonal matrix elements of the proton-neutron effective interaction in [39], where results of 209 Po were discussed.…”

“…In order to study the low-energy states of 208 Po and in particular to investigate the structure of the yrast and yrar 2 + states, we have performed shell-model calculations by considering 208 Pb as closed core and by using the model space spanned by the 2p 3/2 , 2p 1/2 , 1f 7/2 , 1f 5/2 , 0h 9/2 , 0i 13/2 orbitals for the 2 protons valence particles and the 2 neutrons valence holes. Results are obtained by using the shell-model code KSHELL [38] and adopting the same theoretical framework of our previous study of 209 Po [39]. More precisely, the two-body matrix elements of the effective Hamiltonian are derived by means of the Q-box folded-diagram approach [40] starting from the realistic CD-Bonn nucleon-nucleon potential [41] renormalized by way of the V low−k approach [42].…”

“…The proton and neutron one-body component of the effective Hamiltonian are set by reference to the experimental spectrum of 209 Bi [43] and 207 Pb [44], respectively. More details are presented in [39]. In this paper we also briefly discussed our choice of the effective charges and effective gyromagnetic factors, whose values are reported here for completeness, e π = 1.5e, e ν = 0.92e,…”

Timing characteristics of the R13089-100 photomultiplier tube coupled with 1.5" × 1.5" CeBr3 scintillators and its application in lifetime measurements

“…The lifetimes of the low lying states in 209 Po have been reported very recently [31], using LaBr 3 (Ce) and HPGe detectors. In the present work, the lifetime of the 11/2 − state has been measured using two 1.5 × 1.5 CeBr 3 detectors.…”

“…It can be seen that the lifetime measured from the present work is in good agreement with that reported in ref. [31], in which 1.5 ×1.5 LaBr 3 (Ce) scintillators were used along with HPGe detectors. It may be noted that, because of the selection of 239 keV as the feeder transition in the present work, instead of 790 keV (as considered in ref.…”