The quark model was formulated in 1964 to classify mesons as bound states made of a
quark–antiquark pair, and baryons as bound states made of three quarks. For a long time all …

A large number of experimental discoveries especially in the heavy quarkonium sector that
did not meet the expectations of the until then very successful quark model led to a …

In the past decade many charmonium-like states were observed experimentally. Especially
those charged charmonium-like Z c states and bottomonium-like Z b states cannot be …

In the past two decades, a plethora of hadronic states beyond the conventional quark model
of qq ̄ mesons and qqq baryons have been observed experimentally, which motivated …

We discuss the possible existence of the fully-heavy tetraquarks. We calculate the ground-
state energy of the bb ̄ b ̄ b bbb¯ b¯ bound state, where b stands for the bottom quark, in …

A bstract In two recent papers, we used the hadro-quarkonium model to study the properties
of hidden-charm and bottom tetraquarks and pentaquarks. Here, we extend the previous …

We discuss selected and important features of hadronic molecules as one of several
promising forms of exotic hadrons near thresholds. Using examples of $ D {\bar {D}}^{*} …

In the past decade, more and more charmoniumlike and bottomoniumlike states have been
reported in experiments, which have led us to extensive discussions on the underlying …

The P_c(4380)^+ and P_c(4450)^+ states recently discovered at LHCb have masses close
to several relevant thresholds, which suggests they can be described in terms of meson …

We discuss the nature of the χ b (3 P) and X (3872) mesons. Are the χ b (3 P)'s standard bb¯
mesons or bb¯ states with a significative continuum component? Is the X (3872) acc¯ state …