Observation of Anomalous {upsilon}(1S){pi}{sup +}{pi}{sup -} and {upsilon}(2S){pi}{sup +}{pi}{sup -} Production near the {upsilon}(5S) Resonance

Journal Article · Fri Mar 21 04:00:00 EDT 2008 · Physical Review Letters

DOI:https://doi.org/10.1103/PHYSREVLETT.100.112001· OSTI ID:21123761

Chen, K -F; Hou, W -S; Chang, P; Chao, Y; Hsiung, Y B; Lin, S -W; Shiu, J -G; Ueno, K; Wang, C C; Wang, M -Z ^[1]; Shapkin, M; Sokolov, A; Belous, K ^[2]; Adachi, I; Brodzicka, J; Haba, J; Hazumi, M; Itoh, R; Iwasaki, Y; Katayama, N ^[3]

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1. Department of Physics, National Taiwan University, Taipei (China)
2. Institute of High Energy Physics, Protvino (Russian Federation)
3. High Energy Accelerator Research Organization (KEK), Tsukuba (Japan)

We report the first observation of e{sup +}e{sup -}{yields}{upsilon}(1S){pi}{sup +}{pi}{sup -}, {upsilon}(2S){pi}{sup +}{pi}{sup -}, and first evidence for e{sup +}e{sup -}{yields}{upsilon}(3S){pi}{sup +}{pi}{sup -}, {upsilon}(1S)K{sup +}K{sup -}, near the peak of the {upsilon}(5S) resonance at {radical}(s){approx}10.87 GeV. The results are based on a data sample of 21.7 fb{sup -1} collected with the Belle detector at the KEKB e{sup +}e{sup -} collider. Attributing the signals to the {upsilon}(5S) resonance, the partial widths {gamma}({upsilon}(5S){yields}{upsilon}(1S){pi}{sup +}{pi}{sup -})=0.59{+-}0.04(stat){+-}0.09(syst) MeV and {gamma}({upsilon}(5S){yields}{upsilon}(2S){pi}{sup +}{pi}{sup -})=0.85{+-}0.07(stat){+-}0.16(syst) MeV are obtained from the observed cross sections. These values exceed by more than 2 orders of magnitude the previously measured partial widths for dipion transitions between lower {upsilon} resonances.

• OSTI ID: 21123761
• Journal Information: Physical Review Letters, Journal Name: Physical Review Letters Journal Issue: 11 Vol. 100; ISSN 0031-9007; ISSN PRLTAO
• Country of Publication: United States
• Language: English

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