Münster 2011 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

HK: Fachverband Physik der Hadronen und Kerne

HK 9: Struktur und Dynamik von Kernen II

HK 9.9: Vortrag

Montag, 21. März 2011, 18:45–19:00, O-1

Search for one-phonon mixed-symmetry states in the radioactive nucleus ¹⁴⁰Nd — •Georgi Rainovski^1,2, Kalin Gladnishki², Pavel Petkov^3,4, Jan Jolie³, Norbert Pietralla¹, Andrey Blazhev³, Antoaneta Damyanova², Miroslav Danchev², Alfred Dewald³, Christoph Fransen³, Matthias Hackstein³, Doycho Karagyozov², Oliver Möller¹, Thomas Pissulla³, Michael Reese¹, Wolfram Rother³, and Rositsa Topchiyska² — ¹Institut für Kernphysik, Technische Universität Darmstadt, D-64289 Darmstadt, Germany — ²Faculty of Physics, St. Kliment Ohridski University of Sofia, 1164 Sofia, Bulgaria — ³Institut für Kernphysik, Universität zu Köln, D-50937 Köln, Germany — ⁴Bulgarian Academy of Sciences, Institute for Nuclear Research and Nuclear Energy, 1784 Sofia, Bulgaria

Low-spin excited states of ¹⁴⁰Nd have been studied via the ¹⁴⁰Ce(³He,3n)¹⁴⁰Nd reaction. The data show that one of the candidates for the one-phonon mixed symmetry state of ¹⁴⁰Nd, namely the 2₃⁺ state at 2140 keV with an effective lifetime of 220(90) fs, exhibits a fast M1 decay to the 2₁⁺ state. Thus this state can be considered, at least, as a fragment of the one-phonon MSS of ¹⁴⁰Nd. This is the first example where mixed symmetry character is tentatively assigned to a state of an unstable nucleus from the mass A ≈ 140 region based on the data on absolute M1 transition rates. However, the data are not conclusive on whether this decay exhausts the total M1 strength or whether the one-phonon mixed symmetry state of ¹⁴⁰Nd is fragmented.