TY  - JOUR
AU  - Ralet, D. et al
AU  - Gadea, A.
AU  - Perez, R. M.
PY  - 2019
DA  - 2019//
TI  - Evidence of octupole-phonons at high spin in Pb-207<bold> </bold>
T2  - Phys. Lett. B
JO  - Physics Letters B
SP  - 134797
EP  - 6pp
VL  - 797
PB  - Elsevier
KW  - AGATA spectrometer
KW  - gamma-Ray tracking
KW  - VAMOS plus plus spectrometer
KW  - Plunger device
KW  - Nuclear deformation
KW  - Octupole phonon
AB  - A lifetime measurement of the 19/2(-) state in Pb-207 has been performed using the Recoil Distance Doppler-Shift (RDDS) method. The nuclei of interest were produced in multi-nucleon transfer reactions induced by a Pb-208 beam impinging on a Mo-100 enriched target. The beam-like nuclei were detected<bold> </bold>and identified in terms of their atomic mass number in the VAMOS++ spectrometer while the prompt gamma rays were detected by the AGATA tracking array. The measured large reduced transition probability B(E3, 19/2(-) -> 13/2(+)) = 40(8) W.u. is the first indication of the octupole phonon at high spin in Pb-207. An analysis in terms of a particle-octupole-vibration coupling model indicates that the measured B(E3) value in Pb-207 is compatible with the contributions from single-phonon and single particle E3 as well as E3 strength arising from the double-octupole-phonon 6(+) state, all adding coherently. A crucial aspect of the coupling model, namely the strong mixing between single-hole and the phonon-hole states, is confirmed in a realistic shell-model calculation.
SN  - 0370-2693
UR  - https://doi.org/10.1016/j.physletb.2019.134797
DO  - 10.1016/j.physletb.2019.134797
LA  - English
N1  - WOS:000488071200015
ID  - Ralet_etal2019
ER  -