We briefly review how precise determinations of the strong coupling constant and of the heavy quark masses may be obtained from heavy quarkonium. Such determinations are competitive with heavy quark masses extraction from other systems and give an accurate value for the strong coupling constant at a relatively low energy scale. In particular we report about a recent determination of $\als$ from $\Gamma(\Upsilon(1S) \to \gamma X)/\Gamma(\Upsilon(1S) \to X)$ with CLEO data which includes color octet contributions and avoids model dependence in the extraction. The obtained value is $\als (M_{\Upsilon(1S)})= 0.184^{+0.015}_{-0.014}$, which corresponds to $\als(M_Z) = 0.119^{+0.006}_{-0.005}$. Future prospects for more precise extractions of the heavy quark masses and $\als$ are discussed.
Extraction of alpha(s) and m(Q) from Onia / N. Brambilla - In: Proceedings of the international workshop on charm physics : charm 2007, Cornell University, Ithaca, New York, 5-8 August 2007 / [a cura di] H. Mahlke, J. Napolitano. - [Ithaca, N.Y.] : [Cornell University], 2007. - pp. 113-121 (( convegno International Workshop on Charm Physics tenutosi a Ithaca, N.Y., USA nel 2007.
Extraction of alpha(s) and m(Q) from Onia
N. BrambillaPrimo
2007
Abstract
We briefly review how precise determinations of the strong coupling constant and of the heavy quark masses may be obtained from heavy quarkonium. Such determinations are competitive with heavy quark masses extraction from other systems and give an accurate value for the strong coupling constant at a relatively low energy scale. In particular we report about a recent determination of $\als$ from $\Gamma(\Upsilon(1S) \to \gamma X)/\Gamma(\Upsilon(1S) \to X)$ with CLEO data which includes color octet contributions and avoids model dependence in the extraction. The obtained value is $\als (M_{\Upsilon(1S)})= 0.184^{+0.015}_{-0.014}$, which corresponds to $\als(M_Z) = 0.119^{+0.006}_{-0.005}$. Future prospects for more precise extractions of the heavy quark masses and $\als$ are discussed.Pubblicazioni consigliate
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