Prolate shape of 140Ba from a first combined Doppler-shift and Coulomb-excitation measurement at the REX-ISOLDE facility

Background: Quadrupole moments of excited nuclear states are important observables for geometrically interpreting nuclear structure in terms of deformed shapes, although data are scarce and sometimes ambiguous, in particular, in neutron-rich nuclides. Purpose: A measurement was performed for determi...

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Detalles Bibliográficos
Autores: Bauer, C.; Behrens, T.; Bildstein, V.; Blazhev, A.; Bruyneel, B.; Butterworth, J.; Clément, E.; Coquard, L.; Egido de los Ríos, José Luis; Ekström, A.; Fitzpatrick, C. R.; Fransen, C.; Gernhäuser, R.; Habs, D.; Hess, H.; Leske, J.; Kröll, T.; Krücken, R.; Lutter, R.; Marley, P.; Möller, T.; Otsuka, T.; Patronis, N.; Petts, A.; Pietralla, N.; Rodríguez, T. R.; Shimizu, N.; Stahl, C.; Stefanescu, I.; Stora, T.; Thirolf, P. G.; Voulot, D.; Van De Walle, J.; Warr, N.; Wenander, F.; Wiens, A.
Tipo de documento: Artículo
Fecha de publicación:2012
País:España
Institución:Universidad Autónoma de Madrid
Repositorio:Biblos-e Archivo. Repositorio Institucional de la UAM
Lenguaje:Inglés
OAI Identifier:oai:repositorio.uam.es:10486/668444
Acceso en línea:http://hdl.handle.net/10486/668444
https://dx.doi.org/10.1103/PhysRevC.86.034310
Nivel de acceso:Acceso abierto
Palabra clave:Física
Descripción
Sumario:Background: Quadrupole moments of excited nuclear states are important observables for geometrically interpreting nuclear structure in terms of deformed shapes, although data are scarce and sometimes ambiguous, in particular, in neutron-rich nuclides. Purpose: A measurement was performed for determining the spectroscopic quadrupole moment of the 21+ state of 140Ba in order to clarify the character of quadrupole deformation (prolate or oblate) of the state in its yrast sequence of levels. Method: We have utilized a new combined technique of lifetime measurement at REX-ISOLDE and MINIBALL using the Doppler-shift attenuation method (DSAM) and a reorientation analysis of Coulomb-excitation yields. Results: On the basis of the new lifetime of τ(21+)=10.4-0.8+2.2 ps the electric quadrupole moment was determined to be Q(21+)=-0.52(34) eb, indicating a predominant prolate deformation. Conclusions: This finding is in agreement with beyond-mean-field calculations using the Gogny D1S force and with results from the Monte Carlo shell-model approach