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” …

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 this review, we present the current state of the art of our understanding of the spectrum of
excited strongly interacting particles and discuss methods that allow for a systematic and …

The existence and properties of the sigma meson have been controversial for almost six
decades, despite playing a central role in the spontaneous chiral symmetry of QCD or in the …

This biennial Review summarizes much of particle physics. Using data from previous
editions, plus 2158 new measurements from 551 papers, we list, evaluate, and average …

We improve our description of π π scattering data by imposing additional requirements on
our previous fits, in the form of once-subtracted Roy-like equations, while extending our …

The Λ (1405) baryon resonance plays an outstanding role in various aspects in hadron and
nuclear physics. It has been considered that the Λ (1405) resonance is generated by the …

We survey contemporary studies of hadrons and strongly interacting quarks using QCD's
Dyson—Schwinger equations, addressing the following aspects: confinement and …

We review the theoretical developments and conceptual advances that stemmed from the
generalization of QCD to the limit of a large number of color charges, originally proposed by't …

The vast majority of hadrons observed in nature are not stable under the strong interaction;
rather they are resonances whose existence is deduced from enhancements in the energy …