Measurement of the direct photon spectrum in Y(1S) decays

Measurement of the direct photon spectrum in Y(1S) decays

Using data taken with the CLEO II detector at the Cornell Electron Storage Ring, we have determined the ratio of branching fractions: Rγ≡Γ(Y(1S)→γgg)/Γ(Y(1S)→ggg)=[2. 75±0.04(stat)±0.15(syst)]%. From this ratio, we have determined the QCD scale parameter ΛMS(defined in the modified minimal subtracti...

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書誌詳細
主要な著者: Nemati, B, Richichi, S, Ross, W, Skubic, P, Wood, M, Bishai, M, Fast, J, Gerndt, E, Hinson, J, Menon, N, Miller, D, Shibata, E, Shipsey, I, Yurko, M, Gibbons, L, Johnson, S, Kwon, Y, Roberts, S, Thorndike, E, Jessop, C, Lingel, K, Marsiske, H, Perl, M, Schaffner, S, Ugolini, D
フォーマット: Journal article
出版事項: 1997
その他の書誌記述
要約:Using data taken with the CLEO II detector at the Cornell Electron Storage Ring, we have determined the ratio of branching fractions: Rγ≡Γ(Y(1S)→γgg)/Γ(Y(1S)→ggg)=[2. 75±0.04(stat)±0.15(syst)]%. From this ratio, we have determined the QCD scale parameter ΛMS(defined in the modified minimal subtraction scheme) to be ΛMS=233±11±59 MeV, from which we determine a value for the strong coupling constant αs(MY(1S))=0.163±0.002±0.014, or αs(MZ)=0.110±0.001±0.007.

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