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.

R., B., D., B., D., D., P., G., C., G., J. P., L., et al. (1998). Measurement of the axial-vector tau spectral functions and determination of alpha(s)(M_tau(2)) from hadronic tau decays. THE EUROPEAN PHYSICAL JOURNAL. C, PARTICLES AND FIELDS, 4(3), 409-431 [10.1007/s100520050217].

Measurement of the axial-vector tau spectral functions and determination of alpha(s)(M_tau(2)) from hadronic tau decays

CIOCCI, MARIA AGNESE;MARROCCHESI, PIER SIMONE;
1998-01-01

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.
1998
R., B., D., B., D., D., P., G., C., G., J. P., L., et al. (1998). Measurement of the axial-vector tau spectral functions and determination of alpha(s)(M_tau(2)) from hadronic tau decays. THE EUROPEAN PHYSICAL JOURNAL. C, PARTICLES AND FIELDS, 4(3), 409-431 [10.1007/s100520050217].
File in questo prodotto:
Non ci sono file associati a questo prodotto.

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11365/41502
 Attenzione

Attenzione! I dati visualizzati non sono stati sottoposti a validazione da parte dell'ateneo