Precision tests of the chiral anomaly at the COMPASS experiment

by Andrii Maltsev (TUM)

Thursday Nov 7, 2024, 9:30 AM → 10:30 AM Europe/Berlin

E18/ENE Seminar Room 3268 (TUM PH)

Quantum chromodynamics (QCD) has been extremely successful in describing hadron interactions at high energies. However, it is very difficult to obtain quantitative predictions for low-energy hadron interactions from the first principles of QCD.

 

One can use fundamental symmetries of QCD, namely the chiral symmetry, to build an effective field theory, called Chiral Perturbation Theory (ΧPT), which allows to describe the interactions of light mesons at low energies, where the standard perturbative expansion in the strong coupling constant is no longer possible.
Verification of the predictions of these models is important for understanding the low-energy interactions of hadrons.

 

This talk will give an overview of experimental verifications of the predictions of the low-energy models at the COMPASS experiment will be presented. Special emphasis will be given to the so-called anomalous couplings, such as the πγ → ππ, πγ → πη, Kγ → Kπ processes. The status of the measurement of the πγ → ππ coupling constant, F3π, will be presented and the outlook of the measurement of the πγ → πη coupling constant, Fηππγ will be given.