23–28 Jun 2014
Columbia University
US/Eastern timezone

Study of the couplings of QED and QCD from the Adler function

27 Jun 2014, 15:15
20m
301 Pupin

301 Pupin

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)

Presentation materials