Exotic hadrons associated with $b$-quark

TL;DR

This paper reviews the advantages of studying exotic hadrons with $b$-quarks, highlighting experimental and theoretical progress in understanding multiquark states and strong interaction dynamics.

Contribution

It provides a comprehensive overview of experimental findings and theoretical insights into $b$-quark associated exotic hadrons, emphasizing recent progress from Belle, Belle II, and LHCb experiments.

Findings

Observation of $Z_b$, $X_b$, and $Y_b$ states

Enhanced theoretical understanding due to heavier bottom quark mass

Extensive experimental investigations through $B$ and $ ext{Lambda}_b$ decays

Abstract

Compared to charmonium-like states, exotic hadrons associated with $b$-quark offer distinct advantages for exploring the nature of multiquark phenomena and the dynamics of the strong interaction. Due to the heavier bottom quark mass, theoretical calculations, particularly those based on effective field theories and potential models, tend to be more reliable and under better control in the bottomonium sector. With its clean $e^+e^-$ collision environment and high luminosity, the Belle and Belle II experiments are ideally suited to explore these exotic hadrons associated with $b$-quark, including $Z_b$, $X_b$, and $Y_b$ states, and charmonium-like states in $B$ decays. Utilizing the large proton--proton collision dataset, the LHCb experiment has conducted extensive investigations of heavy-flavor multiquark states through $B$ and $\Lambda_b$ decay channels. The relevant phenomenological interpretations are also reviewed.