Measurement of the strong coupling constant αs and the vector and axial-vector spectral functions in hadronic tau decays

Kartvelishvili, Vakhtang (1999) Measurement of the strong coupling constant αs and the vector and axial-vector spectral functions in hadronic tau decays. European Physical Journal C: Particles and Fields, 7 (4). pp. 571-593. ISSN 1434-6044

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Abstract

The spectral functions of the vector current and the axial-vector current have been measured in hadronic ττ decays using the OPAL detector at LEP. Within the framework of the Operator Product Expansion a simultaneous determination of the strong coupling constant αsαs , the non-perturbative operators of dimension 6 and 8 and of the gluon condensate has been performed. Different perturbative descriptions have been compared to the data. The Contour Improved Fixed Order Perturbation Theory gives αs(m2τ)=0.348±0.009exp±0.019theoαs(mτ2)=0.348±0.009exp±0.019theo at the ττ -mass scale and αs(m2Z)=0.1219±0.0010exp±0.0017theoαs(mZ2)=0.1219±0.0010exp±0.0017theo at the Z0Z0 -mass scale. The values obtained for αs(m2Z)αs(mZ2) using Fixed Order Perturbation Theory or Renormalon Chain Resummation are 2.3% and 4.1% smaller, respectively. The ‘running’ of the strong coupling between s0≃1.3GeV2s0≃1.3GeV2 and s0=m2τs0=mτ2 has been tested from direct fits to the integrated differential hadronic decay rate Rτ(s0)Rτ(s0) . A test of the saturation of QCD sum rules at the ττ -mass scale has been performed.

Item Type:
Journal Article
Journal or Publication Title:
European Physical Journal C: Particles and Fields
Uncontrolled Keywords:
/dk/atira/pure/subjectarea/asjc/2200/2201
Subjects:
ID Code:
82585
Deposited By:
Deposited On:
02 Nov 2016 15:12
Refereed?:
Yes
Published?:
Published
Last Modified:
04 Apr 2020 03:58