Article

Lifetime measurements and shape coexistence in<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mmultiscripts><mml:mi mathvariant="normal">Dy</mml:mi><mml:mprescripts/><mml:none/><mml:mrow><mml:mn>144</mml:mn></mml:mrow></mml:mmultiscripts></mml:math>

M. G. ProcterSchuster Laboratory, University of Manchester, Manchester M13 9PL, United KingdomD. M. CullenSchuster Laboratory, University of Manchester, Manchester M13 9PL, United KingdomC. ScholeyDepartment of Physics, University of Jyväskylä, FIN-40014 Jyväskylä, FinlandB. NiclasenSchuster Laboratory, University of Manchester, Manchester M13 9PL, United KingdomPaolo MasonSchuster Laboratory, University of Manchester, Manchester M13 9PL, United KingdomS. V. RigbySchuster Laboratory, University of Manchester, Manchester M13 9PL, United KingdomJ. A. DareSchuster Laboratory, University of Manchester, Manchester M13 9PL, United KingdomΑ. DewaldInstitut für Kernphysik, Universität zu Köln, D-50937 Köln, GermanyP. T. GreenleesDepartment of Physics, University of Jyväskylä, FIN-40014 Jyväskylä, FinlandH. IwasakiInstitut für Kernphysik, Universität zu Köln, D-50937 Köln, GermanyU. JakobssonDepartment of Physics, University of Jyväskylä, FIN-40014 Jyväskylä, FinlandPeter G. JonesDepartment of Physics, University of Jyväskylä, FIN-40014 Jyväskylä, FinlandR. JulinDepartment of Physics, University of Jyväskylä, FIN-40014 Jyväskylä, FinlandS. JuutinenDepartment of Physics, University of Jyväskylä, FIN-40014 Jyväskylä, FinlandS. KetelhutDepartment of Physics, University of Jyväskylä, FIN-40014 Jyväskylä, FinlandM. LeinoDepartment of Physics, University of Jyväskylä, FIN-40014 Jyväskylä, FinlandN. M. LumleySchuster Laboratory, University of Manchester, Manchester M13 9PL, United KingdomO. MöllerInstitut für Kernphysik, Technische Universität Darmstadt, D-64289 Darmstadt, GermanyM. NymanDepartment of Physics, University of Jyväskylä, FIN-40014 Jyväskylä, FinlandP. PeuraInstitut für Kernphysik, Universität zu Köln, D-50937 Köln, GermanyTh. PissullaInstitut für Kernphysik, Universität zu Köln, D-50937 Köln, GermanyA. PuurunenDepartment of Physics, University of Jyväskylä, FIN-40014 Jyväskylä, FinlandP. RahkilaDepartment of Physics, University of Jyväskylä, FIN-40014 Jyväskylä, FinlandW. RotherInstitut für Kernphysik, Universität zu Köln, D-50937 Köln, GermanyP. RuotsalainenDepartment of Physics, University of Jyväskylä, FIN-40014 Jyväskylä, FinlandJ. SarénDepartment of Physics, University of Jyväskylä, FIN-40014 Jyväskylä, FinlandJ. SorriDepartment of Physics, University of Jyväskylä, FIN-40014 Jyväskylä, FinlandJ. UusitaloDepartment of Physics, University of Jyväskylä, FIN-40014 Jyväskylä, Finland

Physical Review Cjournal2010lv

ABI

Abstract

The known level scheme of $^{144}\mathrm{Dy}$ has been extended and lifetime measurements have been made with the recoil-distance Doppler-shift method. Reduced transition probabilities and deformations have been determined for four low-lying transitions. These states form part of the first observed band crossing, giving information on the change in nuclear deformation resulting from the rearrangement of ${h}_{11/2}$ protons in the nucleus. Two bands built upon excited ${10}^{+}$ states have been assigned $\ensuremath{\pi}({h}_{11/2}){}^{2}$ prolate and $\ensuremath{\nu}({h}_{11/2}){}^{\ensuremath{-}2}$ oblate configurations with $\ensuremath{\tau}=12(2)\text{ps}$ and $0.01<\ensuremath{\tau}\ensuremath{\lesssim}16\text{ns}$, respectively. These long lifetimes are reasoned to be a result of shape coexistence at low energy and moderate spin. A known four-quasiparticle dipole band has been extended to higher spin and lifetime measurements suggest a long-lived bandhead state. In this case, the excited states in the band may be consistent with a shears model interpretation of a magnetic dipole rotor. However, the measured $B(M1)/B(E2)$ branching ratios reveal a larger than expected deformed rotational component compared with that in the analogous band in the lower mass isotone $^{142}\mathrm{Gd}$.

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Topics

Nuclear physics research studies Atomic and Molecular Physics Advanced Chemical Physics Studies

Identifiers

DOI: 10.1103/physrevc.81.054320

Citations and references

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