Three-body forces in Bethe-Salpeter and light-front equations

Tuesday 17 Jun 2008, 14:00 → 15:00 Europe/Paris

Salle 149 (LPSC)

Séminaire de V.A. Karmanov Abstract: Bethe-Salpeter and light-front bound state equations for three scalar particles interacting by scalar exchange-bosons are solved, for the first time, in ladder truncation. In contrast to two-body systems, the three-body binding energies obtained in these two approaches differ significantly from each other: the ladder kernel in light-front dynamics underbinds by approximately a factor of two compared to the ladder Bethe-Salpeter equation. By taking into account three-body forces in the light-front approach, generated by two exchange-bosons in flight, we find that most of this difference disappears; for small exchange masses, the obtained binding energies coincide with each other. This means that in few-body systems, the three-body forces should be taken into account on the equal ground with other relativistic corrections.