1. Observation of aHΛΛ6eDouble Hypernucleus
- Author
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S. Torikai, J. Parker, M. Yosoi, J. H. Chung, N. Ushida, Hiroyuki Noumi, D.H. Davis, M. Mitsuhara, Tomoko Yoshida, Y. S. Iwata, Y. S. Ra, Fujio Takeutchi, Kazuma Nakazawa, Y. L. Lee, H. Torii, H. Shibuya, M. Sekimoto, K. S. Sim, C. O. Kim, Junji Tojo, Y. Nagase, K. M. Baik, Adam Rusek, H. Okabe, K. Oyama, S. J. Kim, Tomokazu Fukuda, Kazunuki Yamamoto, H. Akikawa, K. Imai, K. Arai, J. S. Song, J. K. Ahn, H. Tanaka, L. H. Zhu, T. Takahashi, B. Bassalleck, C. S. Yoon, T. Kouketsu, Shigeki Aoki, M. S. Chung, D.N. Tovee, Saewoong Bahk, Takayoshi Kawai, C. Nagoshi, Seok Kim, J. Y. Kim, J. W C McNabb, H. M. Park, N. Yasuda, K. Hoshino, H. Kanda, Masaharu Ieiri, K. Tanida, I. G. Park, Y. H. Iwata, Hirotaka Takahashi, J. T. Rhee, M. Kawasaki, M. Kaneko, S. Ogawa, P. K. Saha, D. Seki, C. J. Yoon, Y. Kondo, J. T. Yang, and A. K. Ichikawa
- Subjects
Physics ,Particle physics ,Excited state ,Hyperon ,General Physics and Astronomy ,Lambda ,Hypernucleus - Abstract
A double-hyperfragment event has been found in a hybrid-emulsion experiment. It is identified uniquely as the sequential decay of ${}_{\ensuremath{\Lambda}\ensuremath{\Lambda}}^{6}\mathrm{He}$ emitted from a ${\ensuremath{\Xi}}^{\ensuremath{-}}$ hyperon nuclear capture at rest. The mass of ${}_{\ensuremath{\Lambda}\ensuremath{\Lambda}}^{6}\mathrm{He}$ and the $\ensuremath{\Lambda}\ensuremath{-}\ensuremath{\Lambda}$ interaction energy $\ensuremath{\Delta}{B}_{\ensuremath{\Lambda}\ensuremath{\Lambda}}$ have been measured for the first time devoid of the ambiguities due to the possibilities of excited states. The value of $\ensuremath{\Delta}{B}_{\ensuremath{\Lambda}\ensuremath{\Lambda}}$ is $1.01\ifmmode\pm\else\textpm\fi{}{0.20}_{\ensuremath{-}0.11}^{+0.18}\phantom{\rule{0ex}{0ex}}\mathrm{MeV}$. This demonstrates that the $\ensuremath{\Lambda}\ensuremath{-}\ensuremath{\Lambda}$ interaction is weakly attractive.
- Published
- 2001
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