Evidence of octupole-phonons at high spin in Pb-207

Ralet, D.; CLEMENT, E.; Georgiev, G.; Stuchbery, A.; REJMUND, M.; VAN ISACKER, R.; DE FRANCE, G.; LEMASSON, A.; Ljungvall, J.; Michelagnoli, C.; NAVIN, A.; BALABANSKI, D.; Atanasova, L.; BLAZHEV, A.; BOCCHI, G.; Carroll, R.; Dudouet, J.; DUPONT, E.; FORNA, B.; Franchoo, S.; Fransen, C.; MUELLER-GATERMANN, C.; Goasduff, A.; Gadea, A.; JOHN, P.; KOCHEVA, D.; KONSTANTINOPOULOS, T.; KORICHI, A.; Kusoglu, Aslı; LENZI, S.; Leoni, S.; LOZEVA, R.; MAJ, A.; PEREZ, R.; PIETRALLA, N.; Shand, C.; Stezowski, O.; WILMSEN, D.; Yordanov, D.; BARRIENTOS, D.; BEDNARCZYK, R.; Birkenbach, B.; Boston, A.; Boston, H.; BURROWS, I.; Cederwall, B.; CIEMALA, M.; COLLADO, J.; CRESPI, F.; Cullen, D.; EBERTH, H.; GOUPIL, J.; Harkness, L.; Hess, H.; Jungclaus, A.; Korten, W.; Labiche, M.; Menegazzo, R.; Mengoni, D.; Million, B.; Nyberg, J.; Podolyak, Zs; PULLIA, A.; QUINTANA ARNES, B.; Recchia, F.; REITER, R.; SAILLANT, F.; SALSAC, M.; SANCHIS, E.; THEISEN, C.; DOBON, J.; Wieland, O.

doi:10.1016/j.physletb.2019.134797

Evidence of octupole-phonons at high spin in Pb-207

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Ralet D., CLEMENT E., Georgiev G., Stuchbery A. E., REJMUND M., VAN ISACKER R., ...More

PHYSICS LETTERS B, vol.797, 2019 (SCI-Expanded)

Publication Type: Article / Article
Volume: 797
Publication Date: 2019
Doi Number: 10.1016/j.physletb.2019.134797
Journal Name: PHYSICS LETTERS B
Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
Keywords: AGATA spectrometer, gamma-Ray tracking, VAMOS plus plus spectrometer, Plunger device, Nuclear deformation, Octupole phonon, NUCLEAR-DATA SHEETS, VIBRATIONAL-STATE, EXCITATION, SEARCH, DECAY
Istanbul University Affiliated: Yes

Abstract

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 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. Crown Copyright (C) 2019 Published by Elsevier B.V.