Issue Eur. Phys. J. A Volume 33, Number 3, September 2007 HYP 2006 Page(s) 247 - 250 DOI 10.1140/epja/i2007-10473-7 Published online 03 September 2007

Eur. Phys. J. A 33, 247-250 (2007)
DOI: 10.1140/epja/i2007-10473-7

Observation of the 7 MeV excited spin-flip and non-spin-flip partners in ¹⁶ _ΛO by γ -ray spectroscopy

M. Ukai¹, S. Ajimura², H. Akikawa³, D. E. Alburger⁴, A. Banu⁵, R. E. Chrien⁴, G. B. Franklin⁶, J. Franz⁷, O. Hashimoto¹, T. Hayakawa², H. Hotchi⁴, K. Imai³, T. Kishimoto², M. May⁴, D. J. Millener⁴, S. Minami², Y. Miura¹, T. Miyoshi¹, K. Mizunuma¹, T. Nagae⁸, S. N. Nakamura¹, K. Nakazawa⁹, Y. Okayasu¹, P. Pile⁴, B. P. Quinn⁶, A. Rusek⁴, Y. Sato⁸, R. Sutter⁴, H. Takahashi³, L. Tang¹⁰, H. Tamura¹, K. Tanida¹¹, L. Yuan¹⁰ and S. H. Zhou<sup>12

1</sup>  Department of Physics, Tohoku University, 980-8578, Sendai, Japan
²  Department of Physics, Osaka University, 560-0043, Toyonaka, Japan
³  Department of Physics, Kyoto University, 606-8502, Kyoto, Japan
⁴  Brookhaven National Laboratory, 11973, Upton, NY, USA
⁵  GSI, D-64291, Darmstadt, Germany
⁶  Carnegie Mellon University, 15213, Pittsburgh, PA, USA
⁷  Department of Physics, University of Freiburg, D-79104, Freiburg, Germany
⁸  Institute of Particle and Nuclear Studies, KEK, 305-0801, Tsukuba, Japan
⁹  Department of Physics, Gifu University, 501-1193, Gifu, Japan
¹⁰  Department of Physics, Hampton University, 23668, VA, USA
¹¹  RIKEN, 351-0198, Wako, Japan
¹²  Department of Physics, CIAE, P. O. Box 275(80), 102413, Beijing, China

m-ukai@phys.ed.gifu-u.ac.jp.

(Received 28 February 2007 / Published online 3 September 2007)

Abstract

We have observed three γ -ray transitions in _Λ ¹⁶ O from both 7MeV excited spin-flip and non-spin-flip partners ( 2^-, 1^- ₂ to the ground-state doublet ( 1^- ₁, 0^- via the ¹⁶O(K ^-,π^-) reaction. The 7MeV excitation energies of the spin-doublet members ( 2^-, 1^- ₂ were determined to be 6784±4±4 keV and 6562±1±2 keV, respectively, and thus the spacing was obtained to be 222±4±5 keV. This is the first observation of the spin-flip state directly populated by the ( K ^-,π^- reaction. Moreover, such directly populated spin-flip and non-spin-flip partners were resolved for the first time.

Key words: 21.80.+a Hypernuclei -- 23.20.Lv γ transitions and level energies -- 13.75.Ev Hyperon-nucleon interactions

Correspondence: m-ukai@phys.ed.gifu-u.ac.jp.


© Società Italiana di Fisica, Springer-Verlag 2007

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