#### Non-perturbative propagators and running coupling in the conformal window of QCD

- Event time: 2:00pm
- Event date: 29th January 2014
- Speaker: Markus Hopfer (Graz)
- Location: Higgs Centre Seminar Room, James Clerk Maxwell Building (JCMB) James Clerk Maxwell Building Peter Guthrie Tait Road Edinburgh EH9 3FD GB

### Event details

Using the Dyson-Schwinger approach we investigate QCD with a relatively large number of quark flavours in the chiral limit. A self-consistent treatment of the corresponding propagator equations enables us to study unquenching effects directly via the quark loop diagram in the gluon equation. Above the critical number of fermion flavours the non-perturbative running coupling develops a plateau over a wide momentum range. Correspondingly, the propagators follow a power law behaviour in this momentum range indicating conformal behaviour. Our value $N_f^{crit}\approx 4.5$ is strongly sensitive to the details of the quark-gluon vertex calling for a more detailed investigation of this object.

The Particle Physics Theory seminar is a weekly series of talks reflecting the diverse interests of the group. Topics include analytic and numerical calculations based on the Standard Model of elementary particle physics, theories exploring new physics, as well as more formal developments in gauge theories and gravity..