Strong decays of $N^{*}(1535)$ in an extended chiral quark model

TL;DR

This paper investigates the strong decay processes of the $N^{*}(1535)$ resonance using an extended chiral quark model that includes five-quark components, improving the understanding of decay ratios.

Contribution

It introduces the inclusion of low-lying five-quark components into the chiral quark model to better explain the decay behaviors of $N^{*}(1535)$.

Findings

Five-quark components significantly affect decay rates.

Both lowest and next-to-lowest energy five-quark states contribute to $N\, ext{eta}$ decay.

The model better explains the large $N\, ext{eta}$ to $N\, ext{pi}$ decay ratio.

Abstract

The strong decays of the $N^{*}(1535)$ resonance are investigated in an extended chiral quark model by including the low-lying $qqqq\bar{q}$ components in addition to the $qqq$ component. The results show that these five-quark components in $N^{*}(1535)$ contribute significantly to the $N^{*}(1535)\to N\pi$ and $N^{*}(1535)\to N\eta$ decays. The contributions to the $N\eta$ decay come from both the lowest energy and the next-to-lowest energy five-quarks components, while the contributions to the $N\pi$ decay come from only the latter one. Taking these contributions into account, the description for the strong decays of $N^{*}(1535)$ is improved, especially, for the puzzling large ratio of the decays to $N\eta$ and $N\pi$.