Eur. Phys. J. A (2005) 24: 1-4
https://doi.org/10.1140/epja/i2004-10126-5

Observation of negative-parity high-spin states of ⁶⁸As

¹ II. Physikalisches Institut, Universität Göttingen, 37073, Göttingen, Germany
² Institute for Nuclear Research and Nuclear Energy, BAS, 1784, Sofia, Bulgaria
³ Institut für Kernphysik, Universität zu Köln, 50937, Köln, Germany
⁴ Horia-Hulubei National Institute for Physics and Nuclear Engineering, P.O. Box MG-6, Bucharest, Romania
⁵ Laboratori Nazionali di Legnaro, INFN, 35020, Legnaro (Padova), Italy
⁶ Institut de Recherches Subatomiques, CNRS-IN2P3, 67037, Strasbourg, France
⁷ Sezione di Padova, INFN, Padova, Italy
⁸ Instituto de Estructura de la Materia, Consejo Superior de Investigaciones Cientificas, 28006, Madrid, Spain
⁹ Departamento de Fisica Teórica, Universidad Autónoma de Madrid, 28049, Madrid, Spain
¹⁰ Institut für Kern- und Hadronenphysik, FZ Rossendorf, 01314, Dresden, Germany
¹¹ Department of Physics, Royal Institute of Technology, 10405, Stockholm, Sweden

Received: 2 December 2004
Accepted: 14 January 2005
Published online: 21 January 2005

Abstract

The neutron-deficient nucleus ⁶⁸As was populated at high spin in two experiments using the reaction ⁴⁰Ca(³²S, 3pn) at beam energies of 105 and 95 MeV. A self-supporting and a gold-backed, highly enriched ⁴⁰Ca target were used. Gamma rays were detected with the EUROBALL array, combined with the charged-particle detector array EUCLIDES and the Neutron Wall. The ⁶⁸As level scheme was considerably extended, especially at negative parity and many previous spin-parity assignments were confirmed or rejected. The total-Routhian-surface (TRS) calculations find shape coexistence and γ softness for the negative- and positive-parity states, respectively.