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EnglishAn analysis based on 124000 selected tau pairs recorded by the ALEPH detector at LEP provides the vector (V) and axial-vector (A) spectral functions of hadronic tau decays together with their total widths. This allows the evaluation of finite energy chiral sum rules that are weighted integrals over the (V - A) spectral functions. In addition, a precise measurement of alpha(s) along with a determination of nonperturbative contributions at the tau mass scale is performed. The experimentally and theoretically most robust determination of alpha(s)(M-tau(2)) is obtained from the (V + A) fit that yields alpha(s)(M-tau(2)) = 0.334 +/- 0.022 giving alpha(s)(M-Z(2)) = 0.1202 +/- 0.0027 after the extrapolation to the mass of the Z boson. The approach of the Operator Product Expansion (OPE) is tested experimentally studying the evolution of the tau hadronic widths to masses smaller than the tau mass.
| Titolo: | Measurement of the axial-vector tau spectral functions and determination of alpha(s)(M-tau(2)) from hadronic tau decays |
| Autori: | |
| Data di pubblicazione: | 1998 |
| Rivista: | |
| Abstract: | An analysis based on 124000 selected tau pairs recorded by the ALEPH detector at LEP provides the vector (V) and axial-vector (A) spectral functions of hadronic tau decays together with their total widths. This allows the evaluation of finite energy chiral sum rules that are weighted integrals over the (V - A) spectral functions. In addition, a precise measurement of alpha(s) along with a determination of nonperturbative contributions at the tau mass scale is performed. The experimentally and theoretically most robust determination of alpha(s)(M-tau(2)) is obtained from the (V + A) fit that yields alpha(s)(M-tau(2)) = 0.334 +/- 0.022 giving alpha(s)(M-Z(2)) = 0.1202 +/- 0.0027 after the extrapolation to the mass of the Z boson. The approach of the Operator Product Expansion (OPE) is tested experimentally studying the evolution of the tau hadronic widths to masses smaller than the tau mass. |
| Handle: | http://hdl.handle.net/11384/4416 |
| Appare nelle tipologie: | 1.1 Articolo in rivista |
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