Speaker
Gregorio Herdoiza
(KPH Mainz and IFT Madrid)
Description
The QCD contributions to the vacuum polarisation function are
responsible for a large fraction of the theoretical uncertainty in the
running of the QED coupling and therefore limit its impact on
electroweak precision tests. We use lattice simulations with N_f=2
O(a) improved Wilson fermions to determine the Adler function in a
broad range of momentum transfer Q^2. The running of the QED coupling,
including valence contributions from u, d, s and c quarks, is compared
to phenomenological results at intermediate Q^2 values. In the large
Q^2 regime, the lattice determination of the Adler function is fitted
to perturbation theory in order to explore the feasibility of a
determination of the strong coupling constant.
Primary author
Gregorio Herdoiza
(KPH Mainz and IFT Madrid)
Co-authors
Anthony Francis
(KPH Mainz)
Benjamin Jäger
(Swansea U.)
Hanno Horch
(KPH Mainz)
Hartmut Wittig
(KPH Mainz)
Harvey Meyer
(KPH Mainz)
