multimeson

Multimeson is a term used in particle and nuclear physics to denote systems that involve more than one meson. It can refer to final states produced in high-energy collisions, or to bound or resonant configurations in which several mesons interact with each other through the strong force. In hadron spectroscopy, multimeson states are studied to understand meson–meson interactions and the possible formation of hadronic molecules or multi-channel resonances.

Theoretical descriptions rely on effective field theories rooted in QCD. At low energies, chiral perturbation theory and related models are used, often combined with unitarization techniques to describe resonant behavior and multi-meson couplings. Lattice QCD provides first-principles calculations of multi-meson systems in finite volumes, from which scattering information can be inferred with methods such as the Luscher approach or its generalizations. Other approaches include coupled-channel analyses and phenomenological models of meson-meson interactions.

Experimentally, multimeson final states arise in decays of heavier hadrons and in direct production in collider and fixed-target experiments. Identifying genuine multi-meson bound states or resonances requires amplitude analyses and careful control of backgrounds, as signals can be broad or overlapping with single-meson resonances.

Research on multimeson systems helps illuminate non-perturbative QCD, the spectrum of light mesons, and the possible existence of hadronic molecules, contributing to broader questions about confinement and the composition of matter under strong interaction.