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新山 雅之 所属 京都産業大学 理学部 物理科学科 職種 教授 |
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| 発行・発表の年月 | 2019/05 |
| 形態種別 | その他 |
| 査読 | 査読あり |
| 標題 | Observation of a new structure near 10.75 GeV in the energy dependence of the $e^+e^-\toΥ(nS)π^+π^-$ ($n=1,2,3$) cross sections |
| 執筆形態 | その他 |
| 著者・共著者 | R. Mizuk,A. Bondar,I. Adachi,H. Aihara,D. M. Asner,V. Aulchenko,T. Aushev,R. Ayad,I. Badhrees,S. Bahinipati,A. M. Bakich,P. Behera,C. Beleño,M. Berger,V. Bhardwaj,T. Bilka,J. Biswal,A. Bozek,M. Bračko,T. E. Browder,M. Campajola,L. Cao,D. Červenkov,A. Chen,B. G. Cheon,K. Chilikin,H. E. Cho,K. Cho,S. -K. Choi,Y. Choi,D. Cinabro,S. Cunliffe,N. Dash,G. De Nardo,F. Di Capua,S. Di Carlo,Z. Doležal,T. V. Dong,S. Eidelman,D. Epifanov,J. E. Fast,T. Ferber,B. G. Fulsom,V. Gaur,A. Garmash,A. Giri,P. Golden |
| 概要 | We report a new measurement of the $e^+e^-\to\Upsilon(nS)\pi^+\pi^-$
($n=1,2,3$) 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 $M=(10752.7\pm5.9\,^{+0.7}_{-1.1})\,$MeV/$c^2$ and $\Gamma=(35.5^{+17.6}_{-11.3}\,^{+3.9}_{-3.3})\,$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 $e^+e^-\to\Upsilon(1S)\pi^+\pi^-$ process at the energy 10.52 GeV, which is below the $B\bar{B}$ threshold. |
| DOI | 10.1007/JHEP10(2019)220 |