分类: 物理学 >> 核物理学 提交时间: 2016-09-07
摘要: We report new measurements of the total cross sections for e+e−→Υ(nS)π+π− (n = 1, 2, 3) and e+e−→bb¯ from a high-luminosity fine scan of the region s√=10.63-11.05 GeV with the Belle detector. We observe that the Υ(nS)π+π− spectra have little or no non-resonant component and extract from them the masses and widths of Υ(10860) and Υ(11020) and their relative phase. We find M10860=(10891.1±3.2+0.6−1.7) MeV/c2 and Γ10860=(53.7+7.1−5.6+1.3−5.4) MeV and report first measurements M11020=(10987.5+6.4−2.5+9.0−2.1) MeV/c2, Γ11020=(61+9−19+2−20) MeV, and ϕ11020−ϕ10860=(−1.0±0.4+1.4−0.1) rad.