# Compton scattering off proton in the third resonance region

## TL;DR

This paper presents the first comprehensive analysis of Compton scattering off protons in the third resonance region, utilizing a coupled-channel model to identify key resonances and determine their properties.

## Contribution

It introduces a full coupled-channel analysis of Compton scattering in the third resonance region, identifying crucial resonances and constraining their helicity couplings using recent experimental data.

## Key findings

- Identification of $D_{33}(1700)$ and $F_{35}(1930)$ resonances as essential in 1.6-1.8 GeV range.
- Determination of helicity couplings for these resonances.
- Discussion of possible spin and parity of new narrow resonances.

## Abstract

Compton scattering off the proton in the third resonance region is analyzed for the first time, owing to the full combined analysis of pion- and photo-induced reactions in a coupled-channel effective Lagrangian model with K-matrix approximation. Two isospin $I=3/2$ resonances $D_{33}(1700)$ and $F_{35}(1930)$ are found to be essential in the range of 1.6 - 1.8 GeV. The recent beam asymmetry data of Compton scattering from the GRAAL facility are used to determine the helicity couplings of these resonances, and strong constraints are coming also from $\pi N$ and $K\Sigma$ photoproduction data. The possible spin and parity of new narrow resonances is discussed.