Alpha decay ofPb186andHg

Abstract

Fine structure in the o. decay of mass-separated Pb and Hg has been studied at the GSI on-line mass separator. Alpha singles spectra as well as a-x-t and a-e-t coincidence events were collected. The o. decay of Pb revealed feeding to a low-lying 0+ state at 328(12) keV inHg.This state can be interpreted as being the bandhead of the deformed rotational band observed previously in in-beam studies. In the a decay of Hg, feeding towards the Srst excited 2+ state at 153 keV and the 0~+ state at 478 keV in Pt was observed. The hindrance factor of the a decay towards the excited 0+ state gives information about the particle-hole character of the states connected in the a decay. A two-level mixing calculation is introduced. From the fixing in Pt and the a-decay hindrance factors, small mixing is deduced for ground states of neutron-de6cient Hg and Pb nuclei.

Shape coexistence in180Hg studied through theβdecay of180Tl

“…The existence of isomerism in 180 Tl could possibly be verified via a β-γ study. [3,12,[20][21][22]. The filled triangles show the states identified in this work.…”

Shape coexistence in the light Po isotopes

“…The di erence as compared to refs. [46,47] lies in the value we chose for the ratio A=T 4 /T 1 . In the Pairing Vibration Model this ratio should be p 2 in absolute value, since it compares the transition from the two-phonon to the one-phonon state with the transition from a one-phonon to the zero-phonon state.…”

“…The predictions of the Pairing Vibration Model can beapplied not only to estimate the energies of multi-particle multi-hole states, but also to the analysis of the hindrance factors measured in decay in this region [25,45,46]. A schematic decay process connecting the ground-state of a parent A Po n ucleus with the ground-state and intruder state of the daughter A 4 Pb nucleus is shown in gure 8.…”

“…We used the method outlined in refs. [46,47] to estimate the mixing between the 4p-2h and the ground-state con guraton in the Po isotopes as a function of the experimental hindrance factors and the mixing between the 2p-2h and the ground-state in the corresponding Pb daughters. The di erence as compared to refs.…”

The Structure of Nuclei Far from Stability

“…[13]. The Woods-Saxon potential was used to describe the deformed mean field, and the same potential has been used to describe the neighboring even-even Pt and Hg nuclei [14] as well as single-proton bandheads in this region [15].…”