Probing the gluon self-interaction in light mesons

Area of Science:

• * Quantum Chromodynamics (QCD) and Hadron Physics.
• * Theoretical Nuclear and Particle Physics.

Background:

• * Understanding light meson properties is crucial for testing fundamental theories of strong interactions.
• * Previous models often simplify the complex interactions within mesons, particularly the role of gluon self-interactions.

Purpose of the Study:

• * To investigate the masses and decay constants of light mesons.
• * To explicitly include non-Abelian contributions from gluon self-interaction to the quark-gluon vertex.
• * To assess the impact of gluon self-interaction on meson properties beyond the rainbow-ladder approximation.

Main Methods:

• * Coupled system of Dyson-Schwinger and Bethe-Salpeter equations.
• * Construction of a Bethe-Salpeter kernel satisfying the axial-vector Ward-Takahashi identity.
• * Numerical solution of all equations in the complex plane, including full momentum dependencies.

Main Results:

• * Calculated masses and decay constants for light mesons.
• * Observed indications of a nonperturbative cancellation between gluon self-interaction and pion cloud effects in the rho meson mass.
• * Demonstrated the influence of gluon self-interaction on meson properties.

Conclusions:

• * The study provides a more comprehensive theoretical framework for light meson properties.
• * The cancellation effect in the rho meson mass highlights the importance of nonperturbative dynamics.
• * Results pave the way for further investigations into QCD phenomena.