1. Observation of $e^+e^- \to \gamma \chi_{c1}$ and search for $e^+e^- \to \gamma \chi_{c0}, \gamma \chi_{c2},$ and $\gamma\eta_c$ at $\sqrt{s}$ near 10.6 GeV at Belle
- Author
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Jia, S., Wang, X. L., Aushev, T., Li Gioi, L., Libby, J., Liptak, Z., Liventsev, D., Lu, P.-C., Lubej, M., MacNaughton, J., Masuda, M., Matsuda, T., Matvienko, D., Ayad, R., Merola, M., Miyata, H., Mizuk, R., Mori, T., Mussa, R., Nakano, E., Nakao, M., Nath, K. J., Nayak, M., Nisar, N. K., Babu, V., Nishida, S., Ogawa, S., Olsen, S. L., Ono, H., Onuki, Y., Ostrowicz, W., Pakhlova, G., Pal, B., Pardi, S., Paul, S., Bansal, V., Pedlar, T. K., Pestotnik, R., Piilonen, L. E., Popov, V., Prencipe, E., Ritter, M., Rostomyan, A., Russo, G., Sakai, Y., Salehi, M., Behera, P., Sandilya, S., Santelj, L., Sanuki, T., Savinov, V., Schneider, O., Schnell, G., Schueler, J., Schwanda, C., Seino, Y., Senyo, K., Beleño, C., Sevior, M. E., Shibata, T.-A., Shiu, J.-G., Simon, F., Sokolov, A., Solovieva, E., Starič, M., Stottler, Z. S., Strube, J. F., Sumiyoshi, T., Berger, M., Sutcliffe, W., Takizawa, M., Tanida, K., Tao, Y., Tenchini, F., Uchida, M., Uehara, S., Uglov, T., Unno, Y., Uno, S., Bhuyan, B., Urquijo, P., Usov, Y., Van Tonder, R., Varner, G., Varvell, K. E., Vorobyev, V., Waheed, E., Wang, B., Wang, C. H., Wang, M.-Z., Bilka, T., Wang, P., Watanuki, S., Widmann, E., Won, E., Yamamoto, H., Yang, S. B., Ye, H., Yin, J. H., Yusa, Y., Zhang, Z. P., Biswal, J., Zhilich, V., Zhukova, V., Zhulanov, V., Belle Collaboration, Shen, C. P., Bobrov, A., Bozek, A., Bračko, M., Browder, T. E., Cao, L., Červenkov, D., Chang, P., Chekelian, V., Chen, A., Cheon, B. G., Yuan, C. Z., Chilikin, K., Cho, K., Choi, S.-K., Choi, Y., Choudhury, S., Cinabro, D., Cunliffe, S., Dash, N., Di Carlo, S., Doležal, Z., Adachi, I., Dong, T. V., Eidelman, S., Epifanov, D., Fast, J. E., Ferber, T., Frey, A., Fulsom, B. G., Garg, R., Gaur, V., Gabyshev, N., Aihara, H., Garmash, A., Gelb, M., Giri, A., Goldenzweig, P., Greenwald, D., Haba, J., Hayasaka, K., Hayashii, H., Hou, W.-S., Hsu, C.-L., Al Said, S., Iijima, T., Inami, K., Inguglia, G., Ishikawa, A., Itoh, R., Iwasaki, M., Iwasaki, Y., Jacobs, W. W., Jin, Y., Joffe, D., Asner, D. M., Kahn, J., Kaliyar, A. B., Karyan, G., Kawasaki, T., Kichimi, H., Kiesling, C., Kim, D. Y., Kim, H. J., Kim, J. B., Kim, S. H., Atmacan, H., Kinoshita, K., Kodyš, P., Korpar, S., Kotchetkov, D., Križan, P., Kroeger, R., Krokovny, P., Kuhr, T., Kulasiri, R., Kumar, R., Aulchenko, V., Kuzmin, A., Kwon, Y.-J., Lalwani, K., Lange, J. S., Lee, I. S., Lee, J. Y., Lee, S. C., Li, C. H., Li, L. K., Li, Y. B., Laboratoire de l'Accélérateur Linéaire (LAL), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Belle, and Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11)
- Subjects
Born approximation ,exclusive reaction ,measured [channel cross section] ,photon: spectrum ,BELLE ,annihilation [electron positron] ,electron positron: annihilation ,10.58 GeV-cms ,+photon+chi%2Fc0%283415%29%22">electron positron --> photon chi/c0(3415) ,channel cross section: upper limit ,chi/c1(3510) ,High Energy Physics - Experiment ,energy dependence ,chi/c2(3555) ,KEK-B ,[PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex] ,tree approximation ,Particle Physics Experiments ,ddc:530 ,+photon+chi%2Fc1%283510%29%22">electron positron --> photon chi/c1(3510) ,chi/c0(3415) ,+photon+chi%2Fc2%283555%29%22">electron positron --> photon chi/c2(3555) ,BES ,upper limit [channel cross section] ,electron positron: colliding beams ,spectrum [photon] ,High Energy Physics - Phenomenology ,[PHYS.HPHE]Physics [physics]/High Energy Physics - Phenomenology [hep-ph] ,colliding beams [electron positron] ,channel cross section: measured ,experimental results - Abstract
Using data samples of 89.5~fb$^{-1}$, 711.0~fb$^{-1}$, and 121.4~fb$^{-1}$ collected with the Belle detector at the KEKB asymmetric-energy $e^+e^-$ collider at center-of-mass energies 10.52 GeV, 10.58 GeV, and 10.867 GeV, respectively, we study the exclusive reactions $e^+e^-\to\gamma\chi_{cJ}$ ($J = 0,~1,~2$) and $e^+e^-\to\gamma\eta_c$. A significant $\gamma \chi_{c1}$ signal is observed for the first time at $\sqrt{s}=10.58$ GeV with a significance of $5.1\sigma$ including systematic uncertainties. No significant excesses for $\gamma \chi_{c0}$, $\gamma \chi_{c2}$, and $\gamma \eta_c$ final states are found, and we set 90\% credibility level upper limits on the Born cross sections ($\sigma_{\rm B}$) at 10.52 GeV, 10.58 GeV, and 10.867~GeV. Together with cross sections measured by BESIII at lower center-of-mass energies, the energy dependency of $\sigma_{\rm B}(e^+e^-\to\gamma\chi_{c1})$ is obtained., Comment: 8 pages, 4 figures
- Published
- 2018
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