Quantum Chromodynamics, the theory of quarks and gluons, whose interactions can be
described by a local SU (3) gauge symmetry with charges called “color quantum numbers” …

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 …

Multiquark resonances are undoubtedly experimentally observed. The number of states and
the amount of details on their properties have been growing over the years. It is very recent …

This review presents an overview of the remarkable progress in the field of heavy-quark
exotic hadrons over the past 15 years. It seeks to be pedagogical rather than exhaustive …

For many decades after the invention of the quark model in 1964 there was no evidence that
hadrons are formed from anything other than the simplest pairings of quarks and antiquarks …

Quantum chromodynamics (QCD), the generally accepted theory for strong interactions,
describes the interactions between quarks and gluons. The strongly interacting particles that …

An analytic method of smearing link variables in lattice QCD is proposed and tested. The
differentiability of the smearing scheme with respect to the link variables permits the use of …

Glueballs, hybrids and multiquark states are predicted as bound states in models guided by
quantum chromo dynamics (QCD), by QCD sum rules or QCD on a lattice. Estimates for the …

We review how lattice QCD can contribute to the prediction and the comprehension of
tetraquarks, pentaquarks and related exotic hadrons such as hybrids, with at least one …

A review of the theoretical and experimental status of hybrid hadrons is presented. The
states π 1 (1400), π 1 (1600), and π 1 (2015) are thoroughly reviewed, along with …