# On the $\eta$ and $\eta'$ Photoproduction Beam Asymmetry at High Energies

## TL;DR

This paper investigates how beam asymmetries in eta and eta' photoproduction at high energies can reveal hidden strangeness components, focusing on the contribution of the phi Regge pole and its implications for upcoming experiments.

## Contribution

It provides the first estimate of the phi Regge pole's contribution to beam asymmetries in eta and eta' photoproduction, highlighting their sensitivity to hidden strangeness.

## Key findings

- The ratio of asymmetries in eta' and eta production is close to unity at high energies.
- The phi Regge pole significantly influences the beam asymmetries in the Regge limit.
- Predictions are relevant for upcoming Jefferson Lab measurements.

## Abstract

We show that, in the Regge limit, beam asymmetries in $\eta$ and $\eta'$ photoproduction are sensitive to hidden strangeness components. Under reasonable assumptions about the couplings we estimate the contribution of the $\phi$ Regge pole, which is expected to be the dominant hidden strangeness contribution. The ratio of the asymmetries in $\eta'$ and $\eta$ production is estimated to be close to unity in the forward region $0 < -t/\text{GeV}^2 \leq 1$ at the photon energy $E_\text{lab} = 9$~GeV, relevant for the upcoming measurements at Jefferson Lab.