New results on the hadronic contributions to alpha(M(Z)**2) and to (g-2)(mu)
May, 199816 pages
Published in:
- Phys.Lett.B 435 (1998) 427-440
e-Print:
- hep-ph/9805470 [hep-ph]
Report number:
- LAL-98-38
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Abstract: (Elsevier)
We reevaluate the dispersion integrals of the leading order hadronic contributions to the running of the QED fine structure constant α ( s ) at s = M Z 2 , and to the anomalous magnetic moments of the muon and the electron. Finite-energy QCD sum rule techniques complete the data from e + e − annihilation and τ decays at low energy and at the c c ̄ threshold. Global quark-hadron duality is assumed in order to resolve the integrals using the Operator Product Expansion wherever it is applicable. We obtain Δα had ( M Z 2 ) =(276.3±1.6)×10 −4 yielding α −1 ( M Z 2 )=128.933±0.021, and a μ had =(692.4±6.2)×10 −10 with which we find for the complete Standard Model prediction a μ SM =(11 659 159.6±6.7)×10 −10 . For the electron, the hadronic contribution reads a e had =(187.5±1.8)×10 −14 . The following formulae express our results on the running of α at M Z 2 as a function of the input value for α s ( M Z 2 ) and its error: Δα had (M Z 2 )=(249.8+221α s (M Z 2 )±1.5±221Δα s (M Z 2 ))×10 −4 , α −1 (M Z 2 )=129.297−3.03α s (M Z 2 )±0.020±3Δα s (M Z 2 ) .Note:
- 16 pages, 3 figures
- fundamental constant: fine structure
- Z0: mass
- muon: magnetic moment
- vacuum polarization: hadronic
- dispersion relation
- spectral representation: moment
- quantum chromodynamics
- sum rule: finite energy
- duality: quark hadron
- operator product expansion
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