Study of exclusive $\eta$ meson production with HADES

by Szymon Trelinski

Friday 21 Nov 2025, 14:30 → 15:15 Europe/Zurich

NB2/158 (RUB)

Abstract:

Proton–proton collisions at a beam kinetic energy of $4.5$ GeV, measured
with the High Acceptance Di-Electron Spectrometer (HADES) at GSI,
provide a unique opportunity to study exclusive $\eta$-meson production. This 
energy lies in an intermediate regime—between near-threshold energies,
where effective Lagrangian models are typically used, and higher
energies ($\sqrt{s}\approx30$ GeV), where Regge phenomenology and Pomeron–Reggeon 
exchanges dominate. Despite its relevance for testing and bridging
theoretical approaches, this region remains experimentally
underexplored, with existing data often limited and affected by large
uncertainties.

In this talk, I will present the $\eta$-reconstruction strategy, outline the 
procedure for determining the total and differential cross sections for
exclusive $\eta$ production at 4.5 GeV, and highlight the next steps for the
$\eta$ analysis.