Observation of {upsilon}(2S){yields}{eta}{upsilon}(1S) and Search for Related Transitions

Journal Article · Fri Nov 07 00:00:00 EST 2008 · Physical Review Letters

DOI:https://doi.org/10.1103/PHYSREVLETT.101.192001· OSTI ID:21179887

He, Q; Insler, J; Muramatsu, H; Park, C S; Thorndike, E H; Yang, F ^[1]; Artuso, M; Blusk, S; Khalil, S; Li, J; Mountain, R; Nisar, S; Randrianarivony, K; Sultana, N; Skwarnicki, T; Stone, S; Wang, J C; Zhang, L M ^[2]; Bonvicini, G; Cinabro, D ^[3]

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1. University of Rochester, Rochester, New York 14627 (United States)
2. Syracuse University, Syracuse, New York 13244 (United States)
3. Wayne State University, Detroit, Michigan 48202 (United States)

We report the first observation of {upsilon}(2S){yields}{eta}{upsilon}(1S), with a branching fraction B=(2.1{sub -0.6}{sup +0.7}(stat){+-}0.3(syst))x10{sup -4} and a statistical significance 5.3{sigma}. Data were acquired with the CLEO III detector at the CESR e{sup +}e{sup -} symmetric collider. This is the first process observed involving a b-quark spin flip. For related transitions, 90% confidence limits in units of 10{sup -4} are B({upsilon}(2S){yields}{pi}{sup 0}{upsilon}(1S))<1.8, B({upsilon}(3S){yields}{eta}{upsilon}(1S))<1.8, B({upsilon}(3S){yields}{pi}{sup 0}{upsilon}(1S))<0.7, and B({upsilon}(3S){yields}{pi}{sup 0}{upsilon}(2S))<5.1.

• OSTI ID: 21179887
• Journal Information: Physical Review Letters, Vol. 101, Issue 19; Other Information: DOI: 10.1103/PhysRevLett.101.192001; (c) 2008 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 0031-9007
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
B QUARKS
BRANCHING RATIO
CESR STORAGE RING
ETA MESONS
MULTIPARTICLE SPECTROMETERS
PARTICLE IDENTIFICATION
SPIN FLIP