On the phenomenological analyses of $s$-${\bar s}$ asymmetry in the nucleon sea

TL;DR

This paper compares two phenomenological models predicting opposite shapes for the strange-antistrange asymmetry in the nucleon sea, emphasizing the importance of experimental data to distinguish between them.

Contribution

It provides a detailed re-analysis of two models with opposite predictions, highlighting the parameter independence of the shape of the asymmetry and the reasons for their differences.

Findings

Predictions for the shape of $s(x)-\bar{s}(x)$ are parameter independent and opposite in the two models.

The models' differences stem from their distinct fluctuation functions and parametrizations.

Experimental data can potentially distinguish between the two models.

Abstract

Two phenomenological models which give opposite predictions for the $s$-${\bar s}$ asymmetry in the nucleon sea are re-analyzed carefully. It is pointed out that although the quantitative results in both models depend dramatically on the parameters, the predictions for the shape of $s(x)-{\bar s}(x)$ in the two models are parameter independent and opposite. Thereby the coming experiments are likely to be able to distinguish the two models. We find that the reason for the two models giving opposite predictions is that the fluctuation functions and parametrizations for the strange (anti-strange) quark distribution in the baryon (meson) in the two models are quite different. To further investigate these models, we use the same parametrizations for the strange (anti-strange) distributions of the baryon (meson) in the two models. We find that one of the models depends strongly on the parameter which controls the behavior of the meson-baryon fluctuation function. Also the two models agree on the shape and size of $s$-${\bar s}$ for some values of the model parameters, but can disagree strongly for others.