The historical missing meson problem

Víctor Enguita will present a mash-up of two papers:

- The U(1) problem (Steven Weinberg, Phys. Rev. D 11, 3583) (https://journals.aps.org/prd/abstract/10.1103/PhysRevD.11.3583)

- Symmetry Breaking through Bell-Jackiw Anomalies (Gerardus 't Hooft, Phys. Rev. Lett. 37, 8) (https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.37.8)

The historical missing meson problem refers to the seeming presence of an approximate U(1) axial symmetry in QCD, which leads to the prediction of an extra light particle that is absent in the hadronic spectrum. We will discuss the solution to this problem and how it connects to the strong CP problem.

Please, this meeting is 'senior free'. Only predocs and postdocs.