International Workshop on e⁺e⁻ collisions from Phi to Psi 2017

Quark mass dependence in photon pion scattering

27 Jun 2017, 18:30

1h 30m

Helmholtz-Institut Mainz

Board: 18

Poster Poster Session

Speaker

Mr Malwin Niehus (Helmholtz Institut für Strahlen- und Kernphysik, Universität Bonn and Bonn-Cologne Graduate School of Physics and Astronomy)

Description

Usually the simulation of scattering processes in lattice QCD is carried out at unphysical high values of the quark masses [1]. Hence, a method to extrapolate data obtained in lattice calculations to physical masses is needed to allow for comparison between theory and experiment. To obtain a sound extrapolation, dispersion relations and chiral perturbation theory (ChPT) can be invoked. While a simple combined approach known as the inverse amplitude method (IAM) allows for a successful extrapolation of $\pi \pi \to \pi \pi$ data [2], a more complicated framework is needed for inelastic processes such as $\gamma \pi \to \pi \pi$. By extending the dispersive description derived in Ref. [3], the extrapolation can be performed for $\gamma \pi \to \pi \pi$. This particular process is interesting due to both its contribution to the anomalous magnetic moment of the muon and its connection to the axial anomaly. References: - [1] Briceno et al.: https://arxiv.org/abs/1507.06622 - [2] Bolton, Briceno, Wilson: https://arxiv.org/abs/1507.07928 - [3] Hoferichter, Kubis, Sakkas: https://arxiv.org/abs/1210.6793v2

Summary

We investigate the quark mass dependence of the process $\gamma \pi \to \pi \pi$ using dispersion relations and chiral perturbation theory.

Presentation materials

Poster

poster_malwin_niehus.pdf