22.05.2017 16:15

Electromagnetic decay of the neutral pion investigated using the Dyson-Schwinger framework

Esther Weil (Gießen)

In this talk I will summarize our recent calculation of the transition form factor of the neutral pion to two virtual photons (π0 → γ(∗)γ(∗)).  This form factor is described by a QCD matrix element, so that a non-perturbative approach is required.  Our method is to numerically solve truncated versions of the Dyson-Schwinger and Bethe-Salpeter equations.  Using this technique we have calculated the form factor in different kinematic regimes.  In the first half of my talk I will discuss the case of one on-shell and one highly virtual photon.  In this regime our approach predicts a sizable correction to the expected Brodsky-Lepage scaling prediction.  In the second half I will discuss the rare decay π0 → e+e.  I will focus on a rediscovered numerical method, expected to have applications to other systems, in which the integration contour is routed along a complicated path in the complex plane.


The talk is based on our recent publications arXiv:1704.06046 and arXiv:1704.05774.


(Seminarraum II, HISKP)

Kategorie: Feldtheorie, Kernphysik