THE DYNAMICAL RETARDATION EFFECT FOR THE MASS SPECTRUM OF BOUND Q(Q)OVER-BAR SYSTEMS

摘要

The Logunov-Tavkhelidze quasipotential approach is used in order to evaluate the first-order corrections to the bound-q (q) over bar-system masses due to the dynamical retardation effect. The confining q (q) over bar kernel is taken to be a 4-dimensional oscillator in the momentum space, being the covariantized version of the static 3-dimensional oscillator potential. The parameters arising in the kernel are determined via the comparison of the quasipotential to the static 3-dimensional kernel in the nonrelativistic limit p/m --> 0. It turned out that the first-order perturbative corrections due to the retardation are of a relatively small size and do not exceed 30% in the light-quark sector. The ambiguities arising in the transition from the 3-dimensional to the 4-dimensional description of the q (q) over bar system under study are discussed. [References: 22]