Eur. Phys. J. A (2007) 33: 255-258
https://doi.org/10.1140/epja/i2007-10478-2

HYP 2006

Decay asymmetry in non-mesonic weak decay of light Λ -hypernuclei

¹ High Energy Accelerator Research Organization, 305-0801, Tsukuba, Ibaraki, Japan
² Department of Physics, Osaka University, 560-0043, Osaka, Japan
³ Gesellschaft für Schwerionenforschung mbH (GSI), D-64291, Darmstadt, Germany
⁴ Department of Physics, Seoul National University, 151-742, Seoul, Korea
⁵ Department of Engineering Science, Osaka Electro-Communication University, 572-8530, Osaka, Japan
⁶ Department of Physics, Tohoku University, 980-8578, Sendai, Japan
⁷ Department of Physics, University of Tokyo, 113-0033, Tokyo, Japan
⁸ Nishina Center for Accelerator-Based Science, RIKEN, 351-0198, Wako, Saitama, Japan
⁹ Korea Research Institute of Standards and Science (KRISS), 305-600, Daejeon, Korea
¹⁰ Japan Atomic Energy Agency, 319-1184, Tokai, Ibaraki, Japan
¹¹ Department of Physics, Kyoto University, 606-8502, Kyoto, Japan
¹² Gifu University, 501-1193, Gifu, Japan

^* e-mail: tmaruta@post.kek.jp.

Received: 28 February 2007
Accepted: 7 July 2007
Published online: 7 September 2007

Abstract

The proton decay asymmetry, α^NM _p , of the polarized Λ -hypernuclei, ⁵ _ΛHe , ¹² _ΛC and ¹¹ _ΛB , has been investigated to understand the reaction mechanism of the non-mesonic weak-decay process. These Λ -hypernuclei were produced in the highest statistics ever via the (π⁺, K ⁺) reaction at 1.05GeV/c by using the SKS spectrometer at KEK 12GeV PS. The results show that the α^NM _p are very small for these s -shell and p -shell hypernuclei.