Journal Article

Observation of a new structure near 10.75 GeV in the energy dependence of the e+e−→ ϒ (nS)π+π− (n = 1, 2, 3) cross sections

Shebalin, V., Jin, Y., Ye, H., Nakao, M., Hayashii, H., Sanuki, T., Kim, K. T., Starič, M., Gaur, V., Hayasaka, K., Onuki, Y., Yang, S. B., Kinoshita, K., Dong, T.V., Cunliffe, S., Kawasaki, T., Kodyš, P., Kim, S. H., Usov, Y., MacQueen, C., Joffe, D., Doležal, Z., Sumiyoshi, T., Kroeger, R., Cinabro, D., Nisar, N. K., Chilikin, K., Di Capua, F., Sokolov, A., Itoh, R., Unno, Y., Mori, T., Natkaniec, Z., Nakano, T., Yuan, C. Z., Ferber, T., Miyata, H., Garmash, A., Zhang, Z. P., Bozek, A., Strube, J. F., Pakhlov, P., Beleño, C., Epifanov, D., Gioi, L. Li, Ogawa, S., Schneider, O., Paul, S., Oskin, P., Hara, T., Inami, K., Schwanda, C., Karyan, G., Pang, T., Kang, K. H., Ono, H., Popov, V., Shwartz, B., Hartbrich, O., Mohanty, G. B., Fulsom, B. G., Ritter, M., Aushev, T., Nishida, S., Lange, J. S., Wang, M.-Z., Hou, W.-S., De Nardo, G., Jacobs, W. W., Schnell, G., Bilka, T., Savinov, V., Fast, J. E., Krokovny, P., Eidelman, S., Berger, M., Bhardwaj, V., Wang, B., Križan, P., Asner, D. M., Iwasaki, Y., Pestotnik, R., Inguglia, G., Salehi, M., Schueler, J., Kotchetkov, D., Lieret, K., Nishimura, K., Červenkov, D., Rostomyan, A., Luo, T., Kichimi, H., Lee, S. C., Niiyama,

2019

Overview

A bstract We report a new measurement of the e + e − → ϒ( nS ) π + π − ( n = 1 , 2 , 3) cross sections at energies from 10 . 52 to 11 . 02 GeV using data collected with the Belle detector at the KEKB asymmetric-energy e + e − collider. We observe a new structure in the energy dependence of the cross sections; if described by a Breit-Wigner function its mass and width are found to be M = 10752.7 ± 5.9 − 1.1 + 0.7 MeV / c 2 and Γ = 35.5 − 11.3 − 3.3 + 17.6 + 3.9 MeV, where the first error is statistical and the second is systematic. The global significance of the new structure including systematic uncertainty is 5.2 standard deviations. We also find evidence for the e + e − → ϒ (1 S ) π + π − process at the energy 10 . 52 GeV, which is below the B B ¯ threshold.

• Publisher: Springer Berlin Heidelberg,Springer Nature B.V,Springer Berlin,SpringerOpen
• Subject: Classical and Quantum Gravitation / Cross-sections / Dependence / e+-e- Experiments / Elementary Particles / High energy physics / Physics / Physics and Astronomy / Quantum Field Theories / Quantum Field Theory / Quantum Physics / Quarkonium / Regular Article - Experimental Physics / Relativity Theory / Spectroscopy / String Theory