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 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 …

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 …

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 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 …

We use our latest dispersive analysis of π π scattering data and the very recent K ℓ 4
experimental results to obtain the mass, width, and couplings of the two lightest scalar …

We study scalar, pseudoscalar, vector, and axial-vector mesons with nonstrange and
strange quantum numbers in the framework of a linear sigma model with global chiral U (N f) …

By using unitarized two-loop chiral perturbation theory partial waves to describe pion-pion
scattering we find that the dominant component of the lightest scalar meson does not follow …

We discuss the existence of the light scalar meson K* 0 (800)(also called κ) in a rigorous
way, by showing the presence of a pole in the πK→ πK amplitude on the second Riemann …