Yin, J. H.Li, Y. B.Won, E.Adachi, I.Aihara, H.Al Said, S.Asner, D. M.Aushev, T.Ayad, R.Babu, V.Banerjee, SwBehera, P.Belous, K.Bennett, J.Bessner, M.Bilka, T.Biswas, D.Bodrov, D.Bonvicini, G.Borah, J.Bozek, A.Bračko, M.Branchini, P.Browder, T. E.Budano, A.Červenkov, D.Chang, M. -C.Cheon, B. G.Chilikin, K.Cho, H. E.Cho, K.Choi, S. -K.Choi, Y.Choudhury, S.Cinabro, D.Cochran, J.Das, S.De Nardo, G.De Pietro, G.Dhamija, R.Di Capua, F.Dingfelder, J.Doležal, Z.Dong, T. V.Epifanov, D.Ferber, T.Ferlewicz, D.Fulsom, B. G.Gaur, V.Giri, A.Goldenzweig, P.Graziani, E.Gu, T.Guan, Y.Gudkova, K.Hadjivasiliou, C.Halder, S.Hara, T.Hayasaka, K.Hayashii, H.Herrmann, D.Hou, W. -S.Hsu, C. -L.Iijima, T.Ipsita, N.Ishikawa, A.Itoh, R.Iwasaki, M.Jacobs, W. W.Ji, Q. P.Jia, S.Jin, Y.Joo, K. K.Kahn, J.Kaliyar, A. B.Kawasaki, T.Kiesling, C.Kim, C. H.Kim, D. Y.Kim, K. -H.Kim, Y. -K.Kindo, H.Kinoshita, K.Kodyš, P.Korobov, A.Korpar, S.Kovalenko, E.Križan, P.Krokovny, P.Kuhr, T.Kumar, M.Kumar, R.Kumara, K.Lam, T.Lange, J. S.Lee, S. C.Li, L. K.Li, Y.Libby, J.Lieret, K.Lin, Y. -R.Liventsev, D.Masuda, M.Matsuda, T.Matvienko, D.Maurya, S. K.Meier, F.Merola, M.Metzner, F.Mizuk, R.Mohanty, G. B.Mussa, R.Nakamura, I.Narwal, D.Natkaniec, Z.Natochii, A.Nayak, L.Nayak, M.Nisar, N. K.Nishida, S.Ogawa, S.Ono, H.Oskin, P.Pakhlova, G.Pardi, S.Park, H.Park, J.Park, S. -H.Passeri, A.Patra, S.Paul, S.Pestotnik, R.Piilonen, Leo E.Podobnik, T.Prencipe, E.Prim, M. T.Rout, N.Russo, G.Sandilya, S.Sangal, A.Santelj, L.Savinov, V.Schnell, G.Schwanda, C.Seino, Y.Senyo, K.Shan, W.Shapkin, M.Sharma, C.Shiu, J. -G.Solovieva, E.Starič, M.Stottler, Z. S.Sumihama, M.Takizawa, M.Tanida, K.Tenchini, F.Tiwary, R.Uchida, M.Uglov, T.Unno, Y.Uno, S.Usov, Y.Vahsen, S. E.Varner, G.Vinokurova, A.Wang, D.Wang, E.Wang, M. -Z.Wang, X. L.Watanuki, S.Werbycka, O.Xu, X.Yabsley, B. D.Yan, W.Yang, S. B.Yelton, J.Yook, Y.Yuan, C. Z.Zhang, Z. P.Zhilich, V.Zhukova, V.2023-12-082023-12-082023-08-181126-6708https://hdl.handle.net/10919/117143<jats:title>A<jats:sc>bstract</jats:sc> </jats:title><jats:p>We measure the cross section of <jats:italic>e</jats:italic><jats:sup>+</jats:sup><jats:italic>e</jats:italic><jats:sup><jats:italic>−</jats:italic></jats:sup> → <jats:italic>η</jats:italic><jats:sub><jats:italic>c</jats:italic></jats:sub><jats:italic>J/ψ</jats:italic> at the Υ(<jats:italic>nS</jats:italic>)(<jats:italic>n</jats:italic> = 1–5) on-resonance and 10.52 GeV off-resonance energy points using the full data sample collected by the Belle detector with an integrated luminosity of 955 fb<jats:sup><jats:italic>−</jats:italic>1</jats:sup>. We also search for double charmonium production in <jats:italic>e</jats:italic><jats:sup>+</jats:sup><jats:italic>e</jats:italic><jats:sup><jats:italic>−</jats:italic></jats:sup> → <jats:italic>η</jats:italic><jats:sub><jats:italic>c</jats:italic></jats:sub><jats:italic>J/ψ</jats:italic> via initial state radiation near the <jats:italic>η</jats:italic><jats:sub><jats:italic>c</jats:italic></jats:sub><jats:italic>J/ψ</jats:italic> threshold. No evident signal of the double charmonium state is found, but evidence for the <jats:italic>e</jats:italic><jats:sup>+</jats:sup><jats:italic>e</jats:italic><jats:sup><jats:italic>−</jats:italic></jats:sup><jats:italic>→ η</jats:italic><jats:sub><jats:italic>c</jats:italic></jats:sub><jats:italic>J/ψ</jats:italic> process is found with a statistical significance greater than 3<jats:italic>.</jats:italic>3<jats:italic>σ</jats:italic> near the <jats:italic>η</jats:italic><jats:sub><jats:italic>c</jats:italic></jats:sub><jats:italic>J/ψ</jats:italic> threshold. The average cross section near the threshold is measured and upper limits of cross sections are set for other regions.</jats:p>Pages 121application/pdfenIn Copyright5106 Nuclear and Plasma Physics5107 Particle and High Energy Physics51 Physical Sciences4902 Mathematical physicsArticle - Refereedhttps://doi.org/10.1007/jhep08(2023)12120238Piilonen, Leo [0000-0001-6836-0748]1029-8479