Dispersive techniques for precision low-energy hadron physics and new physics searches

by Dr Sergi Gonzalez-Solis (ICC Barcelona U.)

Thursday 11 Apr 2024, 12:00 → 13:30 Europe/Madrid

IFAE Seminar Room (Face-to-face Only)

One of the main issues posed by the presence of hadrons in any reaction is their final-state interactions (FSI), which are formally expressed in terms of the unitarity of the amplitude. In two-body scattering, unitarity is usually imposed in the direct channel only, as one is not sensitive to the details of the crossed channels. This is certainly not the case for a three-body decay, where the three possible two-hadron channels are physical, and one ideally wants to impose unitarity in all channels at once. The Khuri-Treiman formalism is a dispersive approach which indeed allows one to do so. In the first part of the talk, I will introduce such formalism and study various important applications in low-energy hadron physics, e.g. $V\to3\pi$ $(V=\omega,\phi,J/\psi)$. In the second part, I will use the treatment of dispersion relations to include the effects of strong FSI in several axio-hadronic $\eta$ and $\eta^{\prime}$ decays, e.g. $\eta/\eta^{\prime}\to\pi\pi a$.