Eur. Phys. J. A (2007) 33: 247-250
https://doi.org/10.1140/epja/i2007-10473-7

HYP 2006

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

¹ 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

^* e-mail: m-ukai@phys.ed.gifu-u.ac.jp.

Received: 28 February 2007
Accepted: 7 July 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.