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Search for a light pseudoscalar particle in the decay $K^0_L \to \pi^0 \pi^0 X$ (2008) |
- Tung, Y. C.,
- Hsiung, Y. B.,
- Wu, M. L.,
- Chen, K. F.,
- Ahn, J. K.,
- Akune, Y.,
- Baranov, V.,
- Comfort, J.,
- Doroshenko, M.,
- Fujioka, Y.,
- Inagaki, T.,
- Ishibashi, S.,
- Ishihara, N.,
- Ishii, H.,
- Iwai, E.,
- Iwata, T.,
- Kato, I.,
- Kobayashi, S.,
- Komatsubara, T. K.,
- Kurilin, A. S.,
- Kuzmin, E.,
- Lednev, A.,
- Lee, H. S.,
- Lee, S. Y.,
- Lim, G. Y.,
- Ma, J.,
- Matsumura, T.,
- Moisseenko, A.,
- Morii, H.,
- Morimoto, T.,
- Nakano, T.,
- Nanjo, H.,
- Nix, J.,
- Nomura, T.,
- Nomachi, M.,
- Ogata, R.,
- Okuno, H.,
- Omata, K.,
- Perdue, G. N.,
- Podolsky, S.,
- Sakashita, K.,
- Sasaki, T.,
- Sasao, N.,
- Sato, H.,
- Sato, T.,
- Sekimoto, M.,
- Shinkawa, T.,
- Sugaya, Y.,
- Sugiyama, A.,
- Sumida, T.,
- Suzuki, S.,
- Tajima, Y.,
- Takita, S.,
- Tsamalaidze, Z.,
- Tsukamoto, T.,
- Wah, Y.,
- Watanabe, H.,
- Yamaga, M.,
- Yamanaka, T.,
- Yoshida, H. Y.,
- Yoshimura, Y.,
- Zheng, Y.
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Abstract |
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We performed a search for a light pseudoscalar particle $X$ in the decay $K_L^0->pi0pi0X$, $X->\gamma\gamma$ with the E391a detector at KEK. Such a particle with a mass of 214.3 MeV/$c^2$ was suggested by the HyperCP experiment. We found no evidence for $X$ and set an upper limit on the product branching ratio for $K_L^0->pi0pi0X$, $X->\gamma\gamma$ of $2.4 \times 10^{-7}$ at the 90% confidence level. Upper limits on the branching ratios in the mass region of $X$ from 194.3 to 219.3 MeV/$c^2$ are also presented..
Comment: 5 pages, 5 figures |
Publication details |
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