Restoring the valence-shell stabilization in Nd140

R D Kern ,D Rosiak,L Kaya,H De Witte,J Jolie,J G Cubiss,C Fransen,J M Keatings,M Stoyanova,N Warr,M Djongolov,A Blazhev,E Giannopoulos,G Rainovski,P Spagnoletti,V Karayonchev,P Reiter,V Werner,D Kocheva,O Möller,J Wiederhold,A Welker,L P Gaffney,M Scheck,N Pietralla,J Cederkäll,J Pakarinen,S Thiel,R Zidarova,K Gladnishki,P.-A Söderström,H Hess,A Boukhari,A Vogt,R Stegmann,Thilo Kroll ,J Snäll ,G O’neill

doi:10.1103/physrevc.102.041304

Abstract

A projectile Coulomb-excitation experiment was performed at the radioactive-ion beam facility HIE-ISOLDE at CERN to obtain E2 and M1 transition matrix elements of Nd140 using the multistep Coulomb-excitation code gosia. The absolute M1 strengths, B(M1;22+→21+)=0.033(8)μN2,B(M1;23+→21+)=0.26-0.10+0.11μN2, and B(M1;24+→21+)<0.04μN2, identify the 23+ state as the main fragment of the one-quadrupole-phonon proton-neutron mixed-symmetry state of Nd140. The degree of F-spin mixing in Nd140 was quantified with the determination of the mixing matrix element VF-mix<7-7+13keV.

Highlights

A projectile Coulomb-excitation experiment was performed at the radioactive-ion beam facility HIE-ISOLDE at CERN to obtain E 2 and M1 transition matrix elements of 140Nd using the multistep Coulomb-excitation code GOSIA
The basic framework for understanding the single-particle motion is provided by the nuclear shell model with the spinorbital interaction [1], which leads to the existence of discrete quantum states characterized by their total ( j) and orbital (l) angular momenta
The collective motion is a coherent movement of groups of few or many nucleons caused by the residual interaction, dominated by the proton-neutron interaction [2]

Summary

Rapid Communications

The basic framework for understanding the single-particle motion is provided by the nuclear shell model with the spinorbital interaction [1], which leads to the existence of discrete quantum states characterized by their total ( j) and orbital (l) angular momenta. The collective motion is a coherent movement of groups of few or many nucleons caused by the residual interaction, dominated by the proton-neutron interaction [2]. It reflects the many-body character of atomic. The interacting boson model (IBM) was introduced by Arima et al [5] as an effective approximation used to avoid this problem It represents a severe truncation of the shell model. In the IBM-1, no distinction between valence-proton and valence-neutron bosons is made and as a result they are interchangeable

Published by the American Physical Society

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