Strangeness in proton and properties of nucleons in nuclear matter revisited

TL;DR

This paper investigates how nucleon properties, including strangeness contributions, change in nuclear matter using a flux tube and diquark model, revealing significant medium effects and their implications.

Contribution

It introduces a flux tube model with strangeness for nucleons and studies medium modifications, providing new insights into nucleon structure in nuclear matter.

Findings

Proton described as a pentaquark with strange quark contribution

Significant modifications in nucleon swelling and mass in medium

Alterations in structure function ratios and sum rules

Abstract

The properties of the nucleons in nuclear medium have been investigated in the context of the flux tube model incorporating strangeness $(s\bar{s})$ contribution to proton structure in conformity with the experimental indication. Proton is described as a pentaquark system with strange quark contribution whereas neutron is described in three quark configuration. The Quasi particle model of diquark is used to describe the structures of the nucleons. Modifications of the properties like swelling, mass, incompressibility, ratio of the structure functions ($\frac{F_{2}^{n}(x)}{F_{2}^{p}(x)}$), Gottfried Sum rule for nucleons in nuclear medium have been studied and significant effects have been observed. It has been suggested that the change of the size degree of freedom of the nucleon in the nuclear medium plays an important role in describing the properties in medium. The results are discussed in detail and compared with existing experimental and theoretical predictions. Some interesting observations are made.