Search for lepton-flavor-violating tau decays to ℓα at Belle

作者：K. Uno, K. Hayasaka, K. Inami, H. Aihara, R. Ayad, S. Banerjee, K. Belous, J. V. Bennett, M. Bessner, D. Biswas, D. Bodrov, M. Bračko, P. Branchini, T. E. Browder, A. Budano, M. Campajola, K. Cho, S.-K. Choi, Y. Choi, S. Choudhury, G. De Nardo, G. De Pietro, F. Di Capua, J. Dingfelder, Z. Doležal, P. Ecker, D. Epifanov, T. Ferber, B. G. Fulsom, V. Gaur, A. Giri, P. Goldenzweig, E. Graziani, Y. Guan, K. Gudkova, C. Hadjivasiliou, T. Hara, H. Hayashii, D. Ricalde Herrmann, C.-L. Hsu, N. Ipsita, A. Ishikawa, R. Itoh, M. Iwasaki, W. W. Jacobs, Y. Jin, C. Kiesling, C. H. Kim, D. Y. Kim, K.-H. Kim, K. Kinoshita, P. Kodyš, A. Korobov, S. Korpar, E. Kovalenko, P. Krokovny, R. Kumar, K. Kumara, A. Kuzmin, Y.-J. Kwon, T. Lam, L. K. Li, Y. B. Li, L. Li Gioi, J. Libby, D. Liventsev, Yue Ma, M. Masuda, T. Matsuda, D. Matvienko, F. Meier, M. Merola, K. Miyabayashi, G. B. Mohanty, M. Nakao, H. Nakazawa, A. Natochii, M. Niiyama, S. Nishida, S. Ogawa, H. Ono, S. Pardi, J. Park, S.-H. Park, S. Patra, S. Paul, T. K. Pedlar, L. E. Piilonen, T. Podobnik, S. Prell, E. Prencipe, M. T. Prim, G. Russo, S. Sandilya, L. Šantelj, V. Savinov, G. Schnell, C. Schwanda, Y. Seino, K. Senyo, W. Shan, J.-G. Shiu, B. Shwartz, F. Simon, J. B. Singh, E. Solovieva, M. Starič, M. Sumihama, M. Takizawa, K. Tanida, F. Tenchini, K. Trabelsi, S. Uehara, T. Uglov, Y. Unno, S. Uno, M.-Z. Wang, E. Won, B. Yabsley, Y. Yook, C. Z. Yuan, L. Yuan, Y. Yusa, Z. P. Zhang, V. Zhilich · 发表于：Journal of High Energy Physics · 年份：2025 · DOI：10.1007/jhep08(2025)155 · 被引用次数：5 · 研究领域：Particle physics theoretical and experimental studies、Dark Matter and Cosmic Phenomena、Neutrino Physics Research

A bstract We report a search for the lepton-flavor-violating decays τ ± → ℓ ± α ( ℓ = e , μ ), where α is an undetected spin-0 particle, such as an axion-like particle using 736 × 10 6 tau lepton pairs collected by the Belle detector at the KEKB asymmetric-energy e + e − collider. We find no evidence of signal and obtain the most stringent upper limits on the branching fractions at 95% confidence level: $$\mathcal{B}$$ ( τ ± → e ± α ) < (0.4–6.4) × 10 − 4 and $$\mathcal{B}$$ ( τ ± → μ ± α ) < (0.2–3.5) × 10 − 4 at 95% confidence level for an α mass in the range 0.0 ≤ m α ≤ 1.6 GeV/ c 2 .