Phenomenological analysis of nucleon strangeness and meson-nucleon sigma terms

TL;DR

This paper compares the nucleon strangeness and sigma terms calculated using the chiral quark model and the meson cloud model, highlighting differences and sensitivities crucial for future precision measurements.

Contribution

It provides a phenomenological analysis of nucleon strangeness and sigma terms within two models, revealing significant differences and model sensitivities.

Findings

Y_N from the chiral quark model is larger than from the meson cloud model.

The sigma terms σ_{πN}, σ_{KN}, and σ_{ηN} are sensitive to Y_N and σ_{πN}.

Small differences in σ_{πN} between models despite larger differences in Y_N.

Abstract

We calculate the nucleon strangeness $y_N$ in the chiral quark model and the meson cloud model. With the internal relation between the sigma term of $\pi$$N$ ($\sigma_{\pi N}$) and $y_N$, we present the results of $\sigma_{\pi N}$ in these two models. Our calculations show that $y_N$ from the chiral quark model is significant larger than that from the meson cloud model, whereas the difference of $\sigma_{\pi N}$ between the two models is relatively small. We also present the results of $\sigma_{K N}$ and $\sigma_{\eta N}$, which could be determined by $\sigma_{\pi N}$ and $y_N$ from their definition in the current algebra, and find that these two physical parameters are quite sensitive to $y_N$. The results indicate the necessity to restrict the parameters of the two models from more precision measurements.