Search for the decay $K_L^0 \rightarrow 3\gamma$

Y. C. Tung; Y. B. Hsiung; J. K. Ahn; Y. Akune; V. Baranov; K. F. Chen; J. Comfort; M. Doroshenko; Y. Fujioka; T. Inagaki; S. Ishibashi; N. Ishihara; H. Ishii; E. Iwai; T. Iwata; I. Kato; S. Kobayashi; S. Komatsu; T. K. Komatsubara; A. S. Kurilin; E. Kuzmin; A. Lednev; H. S. Lee; S. Y. Lee; G. Y. Lim; J. Ma; T. Matsumura; A. Moisseenko; H. Morii; T. Morimoto; Y. Nakajima; T. Nakano; H. Nanjo; N. Nishi; J. Nix; T. Nomura; M. Nomachi; R. Ogata; H. Okuno; K. Omata; G. N. Perdue; S. Perov; S. Podolsky; S. Porokhovoy; K. Sakashita; T. Sasaki; N. Sasao; H. Sato; T. Sato; M. Sekimoto; T. Shimogawa; T. Shinkawa; Y. Stepanenko; Y. Sugaya; A. Sugiyama; T. Sumida; S. Suzuki; Y. Tajima; S. Takita; Z. Tsamalaidze; T. Tsukamoto; Y. Wah; H. Watanabe; M. L. Wu; M. Yamaga; T. Yamanaka; H. Y. Yoshida; Y. Yoshimura; Y. Zheng

doi:10.1103/physrevd.83.031101

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arXiv · 1011.4403

Search for the decay $K_L^0 \rightarrow 3\gamma$

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Abstract

We performed a search for the decay $K_L^0 \rightarrow 3\gamma$ with the E391a detector at KEK. In the data accumulated in 2005, no event was observed in the signal region. Based on the assumption of $K_L^0 \rightarrow 3\gamma$ proceeding via parity-violation, we obtained the single event sensitivity to be $(3.23\pm0.14)\times10^{-8}$, and set an upper limit on the branching ratio to be $7.4\times10^{-8}$ at the 90% confidence level. This is a factor of 3.2 improvement compared to the previous results. The results of $K_L^0 \rightarrow 3\gamma$ proceeding via parity-conservation were also presented in this paper.

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Y. C. Tung, Y. B. Hsiung, J. K. Ahn, Y. Akune, V. Baranov, K. F. Chen, J. Comfort, M. Doroshenko, Y. Fujioka, T. Inagaki, S. Ishibashi, N. Ishihara, H. Ishii, E. Iwai, T. Iwata, I. Kato, S. Kobayashi, S. Komatsu, T. K. Komatsubara, A. S. Kurilin, E. Kuzmin, A. Lednev, H. S. Lee, S. Y. Lee, G. Y. Lim, J. Ma, T. Matsumura, A. Moisseenko, H. Morii, T. Morimoto, Y. Nakajima, T. Nakano, H. Nanjo, N. Nishi, J. Nix, T. Nomura, M. Nomachi, R. Ogata, H. Okuno, K. Omata, G. N. Perdue, S. Perov, S. Podolsky, S. Porokhovoy, K. Sakashita, T. Sasaki, N. Sasao, H. Sato, T. Sato, M. Sekimoto, T. Shimogawa, T. Shinkawa, Y. Stepanenko, Y. Sugaya, A. Sugiyama, T. Sumida, S. Suzuki, Y. Tajima, S. Takita, Z. Tsamalaidze, T. Tsukamoto, Y. Wah, H. Watanabe, M. L. Wu, M. Yamaga, T. Yamanaka, H. Y. Yoshida, Y. Yoshimura, Y. Zheng. 2010-11-19. Search for the decay $K_L^0 \rightarrow 3\gamma$. https://doi.org/10.1103/physrevd.83.031101

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