Quark Model and multiquark system

TL;DR

This paper reviews the historical development of the Quark Model, its extensions, and recent observations of exotic multiquark states like tetraquarks and pentaquarks, highlighting ongoing research in hadron structure.

Contribution

It provides a comprehensive review of the Quark Model's evolution and discusses recent experimental discoveries of exotic multiquark states.

Findings

Confirmation of quark model predictions through particle discoveries

Observation of exotic multiquark states such as tetraquarks and pentaquarks

Enhanced understanding of quark confinement mechanisms

Abstract

The discovery of many particles, especially in the 50's, when the firsts accelerators appeared, caused the searching for a model that would describe in a simple form the whole of known particles. The Quark Model, based in the mathematical structures of group theory, provided in the beginning of the 60's a simplified description of hadronic matter already known, proposing that three particles, called quarks, would originate all the observed hadrons. This model was able to preview the existence of particles that were later detected, confirming its consistency. Extensions of the Quark Model were made in the beginning of the 70's, focusing in describing observed particles that were excited states of the fundamental particles and others that presented new quantum numbers (flavors). Recently, exotic states as tetraquarks and pentaquarks types, also called multiquarks systems, previewed by the model, were observed, what renewed the interest in the way as quarks are confined inside the hadrons. In this article we present a review of the Quark Model and a discussion on the new exotic states.