Exotic Hadrons with Heavy Flavors -X, Y, Z and Related States-

TL;DR

This review discusses recent experimental and theoretical progress on exotic hadrons with heavy flavors, focusing on specific X, Y, Z states, their interpretations, and underlying QCD symmetries.

Contribution

It provides a comprehensive overview of the experimental discoveries and theoretical models of heavy-flavor exotic hadrons, emphasizing hadronic molecules and symmetries.

Findings

Identification of key exotic states like X(3872), Y(4260), Zc(4430)^+, Zc(3900)^+, Zb(10610)^+, Zb(10650)^+

Discussion of hadronic molecule interpretations governed by chiral and heavy-quark symmetries

Summary of theoretical predictions for yet undiscovered exotic hadrons

Abstract

In the past decade, exotic hadrons with charm and bottom flavors have been extensively studied both in experiments and in theories. In this review, we provide topical discussions by selecting $X,Y,Z$ particles, to which Belle has made important contributions. These are $X(3872)$, $Y(4260)$, $Z_c(4430)^+$, $Z_c(3900)^+$, $Z_{b}(10610)^+$ and $Z_{b}(10650)^+$. Based on the current experimental observations, we discuss those states with emphasis on hadronic molecule whose dynamics is governed by chiral symmetry and heavy-quark symmetry of QCD. We also mention briefly various interpretations and some theoretical predictions for the yet undiscovered exotic hadrons.