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Low energy hadronic contribution to the QED vacuum polarization

Recent improvements in the low energy e+e- annihilation data and their influence on the determination of the hadronic contribution to the running of the QED fine structure constant at m_Z are discussed. Using CMD-2 and KLOE measurements in the rho region we obtain Delta alpha(5)_had(s) = 0.02758 +/-...

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Detalles Bibliográficos
Autores principales: Burkhardt, H, Pietrzyk, B
Lenguaje:eng
Publicado: 2005
Materias:
Acceso en línea:https://dx.doi.org/10.1103/PhysRevD.72.057501
http://cds.cern.ch/record/847957
Descripción
Sumario:Recent improvements in the low energy e+e- annihilation data and their influence on the determination of the hadronic contribution to the running of the QED fine structure constant at m_Z are discussed. Using CMD-2 and KLOE measurements in the rho region we obtain Delta alpha(5)_had(s) = 0.02758 +/- 0.00035 at s = m_Z^2.