Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - Measurement of the spectral functions of axial - vector hadronic tau decays and determination of alpha(S)(M**2(tau))
AU - ALEPH Collaboration, The
AU - Barate, R.
AU - Betteridge, Andrew
AU - Bowdery, Christopher
AU - Colrain, Paul
AU - Finch, Alexander
AU - Foster, Frank
AU - Hughes, Gareth
AU - Jones, Roger
AU - Williams, Mark
PY - 1998/7
Y1 - 1998/7
N2 - An analysis based on 124 000 selected τ pairs recorded by the ALEPH detector at LEP provides the vector (V) and axial-vector (A) spectral functions of hadronic τ 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 αs along with a determination of nonperturbative contributions at the τ mass scale is performed. The experimentally and theoretically most robust determination of αs(M2τ) is obtained from the (V+A) fit that yields αs(M2τ)=0.334±0.022 giving αs(M2Z)=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 τ hadronic widths to masses smaller than the τ mass.
AB - An analysis based on 124 000 selected τ pairs recorded by the ALEPH detector at LEP provides the vector (V) and axial-vector (A) spectral functions of hadronic τ 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 αs along with a determination of nonperturbative contributions at the τ mass scale is performed. The experimentally and theoretically most robust determination of αs(M2τ) is obtained from the (V+A) fit that yields αs(M2τ)=0.334±0.022 giving αs(M2Z)=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 τ hadronic widths to masses smaller than the τ mass.
U2 - 10.1007/s100520050217
DO - 10.1007/s100520050217
M3 - Journal article
VL - 4
SP - 409
EP - 431
JO - The European Physical Journal C (EPJ C) - Particles and Fields
JF - The European Physical Journal C (EPJ C) - Particles and Fields
SN - 1434-6052
IS - 3
ER -