Large violation of the flavour SU(3) symmetry in $\eta$MAID2018 isobar model

TL;DR

The paper reveals that the etaMAID2018 isobar model explains the neutron anomaly through significant violation of flavour SU(3) symmetry, challenging conventional interpretations and suggesting potential ways to restore symmetry.

Contribution

It uncovers the large SU(3) symmetry violation in etaMAID2018 as the basis for explaining the neutron anomaly without exotic resonances.

Findings

Large SU(3) symmetry violation underpins the neutron anomaly explanation.

Conventional models may rely on symmetry violations rather than new physics.

Discussion on restoring SU(3) symmetry in the model.

Abstract

We demonstrate that the explanation of the neutron anomaly around $W\sim 1685$MeV in $\gamma N\to \eta N$ reactions provided by the $\eta$MAID2018 isobar model is based on large violation of the flavour SU(3) symmetry in hadron interactions. This is yet another example of how conventional explanation (without invoking exotic narrow nucleon resonance) of the neutron anomaly metamorphoses into unconventional physics picture of hadron interactions. A possibility to mend the flavour SU(3) symmetry for some of resonances in $\eta$MAID model is discussed.