Observation of X(3872)→J/ψγ and Search for X(3872)→ψ'γ in B Decays

• Published in: Physical review letters 2011-08, Vol.107 (9)
• Main Authors: Bhardwaj, V., Trabelsi, K., Olsen, Stephen L., Adachi, I., Adamczyk, K., Asner, David M., Aulchenko, V., Aushev, T., Bakich, A. M., Barberio, E., Belous, K., Bhuyan, Bipul, Bondar, A., Brodzicka, J., Browder, Thomas E., Chen, A., Chen, P., Cheon, B. G., Cho, K., Choi, Y., Dolezal, Z., Eidelman, S., Epifanov, D., Gaur, Vipin, Gabyshev, N., Golob, B., Hayashii, H., Horii, Y., Hoshi, Y., Hou, W. S., Hsiung, Y. B., Hyun, H. J., Iijima, T., Ishikawa, A., Iwabuchi, Masaya, Iwasaki, Y., Iwashita, T., Joshi, N. J., Kang, J. H., Kiesling, C., Kim, H. O., Kim, J. H., Kim, K. T., Kim, M. J., Kim, S. K., Kim, Y. J., Ko, Byeong Rok, Kobayashi, Nakako, Krizan, P., Kumar, R., Kumita, T., Lange, J. S., Lee, S. H., Li, Y., Lim, C. L., Matvienko, D., Miyata, H., Mizuk, R., Mohanty, G. B., Mussa, Roberto, Nakano, E., Nishida, Shohei, Nitoh, O., Nozaki, T., Ohshima, T., Okuno, S., Onuki, Y., Pakhlova, Galina, Pestotnik, R., Petric, Marko, Piilonen, Leo E., Rohrken, Markus, Sakai, K., Seon, O., Shebalin, V., Shibata, T. A., Shiu, Jing-Ge, Smerkol, P., Sohn, Young-Soo, Sokolov, Anatoly, Solovieva, E., Stanic, S., Tatishvili, Gocha, Teramoto, Y., Uehara, S., Uglov, T., Unno, Yuji, Uno, S., Usov, Y., Varner, Gary, Vossen, Anslem G., Wang, X. L., Watanabe, Y., Yabsley, B. D., Yamashita, Y., Yuan, C. Z., Zhang, C. C., Zhang, Z. P., Zhulanov, V., Zupanc, A.
• Format: Article
• Language: English
• Subjects: Observation of X J/ and search for X ′ in B decays
• ISSN: 0031-9007; 1079-7114
• DOI: 10.1103/PhysRevLett.107.091803

We report a study of B (J/ψγ)K and B (ψ'γ)K decay modes using 772 × 106 BB events collected at the (4S) resonance with the Belle detector at the KEKB energy-asymmetric e⁺e⁻ collider. We observe X(3872) J/ψγ and report the first evidence for χc2 → J/ψγ in B→(Xcc₋γ)K decays, while in a search for X(3872)→ψ'γ no significant signal is found. We measure the branching fractions, B(B± X(3872)K±)B(X(3872) J/ψγ) = (1.78+0.48-0.44±0.12)×10⁻⁶, B(B± ! χc2K±)= (1.11+0.36 -0.34 ± 0.09) × 10⁻⁵, B(B± X (3872)K±)B(X(3872) ψ'γ) < 3.45 × 10⁻⁶ (upper limit at 90% C.L.) and also provide upper limits for other searches.