Study of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msup><mml:mi>e</mml:mi><mml:mo>+</mml:mo></mml:msup><mml:msup><mml:mi>e</mml:mi><mml:mo>−</mml:mo></mml:msup><mml:mo stretchy="false">→</mml:mo><mml:msup><mml:mi mathvariant="normal">Σ</mml:mi><mml:mn>0</mml:mn></mml:msup><mml:msup><mml:mover accent="true"><mml:mi mathvariant="normal">Σ</mml:mi><mml:mo stretchy="false">¯</mml:mo></mml:mover><mml:mn>0</mml:mn></mml:msup></mml:math> and <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msup><mml:mi mathvariant="normal">Σ</mml:mi><mml:mo>+</mml:mo></mml:msup><mml:msup><mml:mover accent="true"><mml:mi mathvariant="normal">Σ</mml:mi><mml:mo stretchy="false">¯</mml:mo></mml:mover><mml:mo>−</mml:mo></mml:msup></mml:math> by initial state radiation method at Belle
G. Gong, L. K. Li, Y. T. Zhang, W. B. Yan, I. Adachi, H. Aihara, S. Al Said, D. M. Asner, H. Atmacan, T. Aushev, R. Ayad, V. Babu, Sw. Banerjee, P. K. Behera, K. Belous, J. V. Bennett, M. Bessner, B. Bhuyan, T. Bilka, D. Biswas, A. Bobrov, D. Bodrov, J. Borah, A. Bożek, M. Bračko, P. Branchini, T. E. Browder, A. Budano, M. Campajola, D. Červenkov, M.-C. Chang, A. Chen, Y. Chen, B. G. Cheon, K. Chilikin, K. Cho, S.-J. Cho, S.-K. Choi, Y. Choi, S. Choudhury, D. Cinabro, S. Das, G. De Nardo, G. De Pietro, R. Dhamija, F. Di Capua, Z. Doležal, T. V. Dong, D. Epifanov, T. Ferber, D. Ferlewicz, B. G. Fulsom, R. Garg, V. Gaur, A. Garmash, A. Giri, P. Goldenzweig, B. Golob, E. Graziani, K. Gudkova, S. Halder, K. Hayasaka, H. Hayashii, M. T. Hedges, W.-S. Hou, C.-L. Hsu, K. Inami, N. Ipsita, A. Ishikawa, R. Itoh, M. Iwasaki, W. W. Jacobs, E.-J. Jang, S. Jia, Y. Jin, K. K. Joo, A. B. Kaliyar, K. H. Kang, T. Kawasaki, C. Kiesling, C. H. Kim, D. Y. Kim, Y.-K. Kim, K. Kinoshita, P. Kodyš, A. Korobov, S. Korpar, E. Kovalenko, P. Križan, P. Krokovny, R. Kumar, K. Kumara, Y.-J. Kwon, T. Lam, J. S. Lange, S. C. Lee, P. Lewis, C. Li, Y. Li, Y. B. Li
Abstract
The processes ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}{\mathrm{\ensuremath{\Sigma}}}^{0}{\overline{\mathrm{\ensuremath{\Sigma}}}}^{0}$ and ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}{\mathrm{\ensuremath{\Sigma}}}^{+}{\overline{\mathrm{\ensuremath{\Sigma}}}}^{\ensuremath{-}}$ are studied using initial-state-radiation events in a sample of $980\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ collected with the Belle detector at the KEKB asymmetric-energy ${e}^{+}{e}^{\ensuremath{-}}$ collider. The cross sections from the mass threshold to $3\text{ }\text{ }\mathrm{GeV}/{c}^{2}$ and the effective form factors of ${\mathrm{\ensuremath{\Sigma}}}^{0}$ and ${\mathrm{\ensuremath{\Sigma}}}^{+}$ are measured. In the charmonium region, we observe the decays $J/\ensuremath{\psi}\ensuremath{\rightarrow}{\mathrm{\ensuremath{\Sigma}}}^{0}{\overline{\mathrm{\ensuremath{\Sigma}}}}^{0}$ and $J/\ensuremath{\psi}\ensuremath{\rightarrow}{\mathrm{\ensuremath{\Sigma}}}^{+}{\overline{\mathrm{\ensuremath{\Sigma}}}}^{\ensuremath{-}}$ and determine the respective branching fractions.