# Is there a narrow $N(1685)$?

## TL;DR

This study reanalyzes recent experimental data on eta photoproduction and finds that a full partial wave analysis can explain the results without invoking a narrow $N(1685)$ resonance, challenging previous claims.

## Contribution

The paper demonstrates that the data can be explained without a narrow resonance, questioning prior interpretations of the $N(1685)$ as a narrow state.

## Key findings

- Full partial wave analysis fits the data well without a narrow resonance.
- Introducing a narrow $N(1685)$ resonance worsens the fit quality.
- No compelling evidence for the existence of a narrow $N(1685)$ resonance.

## Abstract

The helicity-dependent observable $E$ for the reaction $\gamma d\to \eta n (p)$ with a spectator proton was recently measured by the A2 Collaboration at MAMI in Mainz. The data were interpreted as further evidence for a narrow resonance with spin and parity $J^P=1/2^+$ ($P_{11}$ wave). However, a full partial wave analysis without any narrow resonance leads to an excellent description of the data, imposing a narrow resonance with the properties suggested by the A2 Collaboration leads to a significant deterioration of the fit quality: there is no need for a narrow resonance.