High-K isomersin extreme conditions

() P.M. Walker (Surrey, )() C.A. Bertulani (TAMUC)20124

OutlineIntroduction of high-K isomersModelCalculations 1. extreme shape 2. extreme mass 3. extreme lifetimeSummary

P.M. Walker & G.D. Dracoulis,Nature 399, 35 (1999).Nuclear isomers: Long-lived excited states (10-9 s)Introduction

A well-known example:IntroductionFermi Surfaceneutronproton7/2[514]9/2[624]9/2[514]7/2[404]

ModelConfiguration-constrained calculationsof potential-energy surfacesF.R. Xu et al., Phys. Lett. B 435, 257 (1998).Standard liquid drop modelStrutinsky shell correction calculated fromWoods-Saxon potential and Lipkin-Nogami pairingtraced byNuclear shape parametrizationTRIAXIAL

ModelPotential-energy surfaces of high-K statesH.L. Liu et al., Phys. Rev. C 83, 011303(R) (2011).H.L. Liu et al., Eur. Phys. J. A. 47, 135 (2011).

High-K shape isomerP. Limkilde & G. SlettenNucl. Phys. A 199(1973)504extreme shape

|Ecal. Eexp.| < 400 keV

Configurations suggestedfor the first timeCalculationsHigh-K shape isomers livelonger than the correspondingK=0 shape isomers

shape isomerhigh-K shape isomeric statesoftrigideasy to fissionhard to fissionshort lifetimelong lifetimeT1/2=37psT1/2=34nsT1/2=40psT1/2=0.18ms236Pu242CmCalculationsH.L. Liu et al., Eur. Phys. J. A. 47, 135 (2011).

Effects of 6 deformations on heaviest high-K isomers?I. Muntian et al.,Phys. Lett. B500, 241 (2001).extreme mass

R.-D. Herzberg et al.Nature 442(2006)896S.K. Tandel et al.Phys. Rev. Lett.97(2006)082502Hessberger et al.Eur. Phys. J. A43(2010)55R.M. Clark et al.Phys. Lett. B 690(2010)192-qp isomer4-qp isomerJYFLANLGSILBNL

CalculationsRemarkable and stable 6 deformationsIncreased bindingdue to 6 deformationsSolid lines: Cal. with 6Dashed lines: Cal. without 6

CalculationsComparison between exp. and cal.Single-particle levelsH.L. Liu et al., Phys. Rev. C 83, 011303(R) (2011).

P.M. Walker & G.D. Dracoulis, Hyperfine Interact. 135, 83 (2001).extreme lifetime

Softness against triaxial deformationfacilitates the tunneling decay through triaxial shapes.P. Chowdhury et al., Nucl. Phys. A 485, 136 (1988).

H.L. Liu et al., Phys. Rev. C 83, 067303 (2011).CalculationsK=18+ isomeric state in 188Hf:moderately robust against triaxialdistortion

SummaryExtension of the model with the inclusion of high-order deformations

Explanation of the long life-time of the high-K shape isomers in actinide nuclei

Significantly improved description of heaviest high-K isomers with 6 deformation

New insight into the occurrence of long-lived isomer in neutron-rich Hf

Thank you!