Onebosonexchange

One-boson-exchange (OBE) models are a class of phenomenological approaches in nuclear physics that describe the nucleon-nucleon (NN) interaction as due to the exchange of virtual mesons between nucleons. In these models, the nuclear force arises from t-channel exchange of mesons such as the pion, which provides the longest-range part of the interaction, and heavier mesons like the rho, omega, and a scalar-isoscalar sigma, which contribute to shorter-range features. Each meson contributes a term to the NN potential with a meson-nucleon coupling and a form factor at the vertices, yielding central, tensor, spin-spin, and spin-orbit components. The potential is typically used in nonrelativistic or relativistic scattering equations to compute phase shifts, bound-state properties (notably the deuteron), and other NN observables.

Historically, OBE models were developed in the 1950s–1980s as a practical framework to understand NN forces and to fit scattering data. Notable examples include Bonn-type potentials, Nijmegen potentials, and Paris-type potentials. The models are constructed to reproduce a wide range of NN data up to certain energies and rely on several adjustable parameters, including coupling constants and form factors.

Limitations and status: OBE is an effective, phenomenological description rather than a fundamental theory derived from quantum chromodynamics. The sigma meson often serves as a stand-in for correlated two-pion exchange, and short-range repulsion is modeled by heavier mesons or strong form factors. Modern developments favor chiral effective field theory, which provides a systematically improvable framework grounded in QCD symmetries. Nonetheless, OBE-inspired potentials remain influential in phenomenology and in intuitive understanding of meson-mediated forces.