1993/04/30 by Bob Holdom, B. Holdom, Randy Lewis +2 · 1 citation
Physics and Astronomy · #High-Energy Particle Collisions Research #Particle physics theoretical and experimental studies #Quantum Chromodynamics and Particle Interactions #hep-ph
paper · pdf · doi:10.1007/bf01577545
published as Z. Phys. C63 (1994) 71-76 · 12 pages of LaTeX plus 3 uuencoded postscript figures, UTPT-93-7
arxiv created 1994/02/18 · openalex publication_date 1994/03/01 · arxiv updated 2009/11/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
A simple model for the hadronic contribution to the photon vacuum polarization function Πhad(q2), for spacelike momenta, is presented. For small momenta, the two loop contribution from the pseudoscalar meson octet is computed from the chiral Lagrangian. The light quark contribution (which at low momentum gives the \cal O(q6) counterterm in the chiral Lagrangian) is calculated within a relativistic constituent quark model incorporating the momentum dependence of the quark mass. The perturbative gluons of QCD are included in a standard fashion. The total result is close to an estimate of Πhad(q2) that is obtained directly from e+e-→ hadrons data. We further use our results for Πhad(q2) to calculate the \cal O(e4) hadronic contribution to lepton magnetic moments and to calculate αQED(MZ2). A simpler model of constituent quarks with momentum independent masses gives less favourable results.