Mesonnucleon

Mesonnucleon refers to systems and interactions between a meson and a nucleon (proton or neutron). It includes elastic scattering, inelastic processes, and the possible formation of bound states or resonances in the meson-nucleon sector. Studying mesonnucleon dynamics helps illuminate the non-perturbative regime of the strong interaction.

The meson-nucleon interaction arises from quantum chromodynamics at low energies and is typically described with effective theories and models. Early approaches used meson-exchange pictures in which forces between hadrons are mediated by exchanging light mesons such as pions, kaons, or etas. Modern treatments employ chiral effective field theory, coupled-channel analyses, and lattice QCD to compute scattering amplitudes, phase shifts, and resonance properties across different isospin and strangeness sectors.

Resonances and bound states in the meson-nucleon sector include candidates such as the Lambda(1405), discussed as a quasi-bound Kbar-n state with strong coupling to the pi-Sigma channel in many models. Other states appear as dynamically generated resonances in meson-nucleon scattering. Experimental studies probe mesonnucleon interactions through pion-nucleon and kaon-nucleon scattering, meson production, and meson-containing exotic atoms, providing data to constrain theory.

The mesonnucleon sector informs the understanding of nuclear forces, hypernuclei, and the behavior of QCD in the non-perturbative regime. It remains an active area of research with ongoing developments in effective field theories, lattice simulations, and experimental measurements. Related topics include the nuclear force, meson exchange, chiral perturbation theory, and lattice QCD.