A systematic large-mass expansion of the quark-antiquark effective Hamiltonian due to instantons is developed. The O(m-2) spin-spin and spin-orbit contributions are evaluated in the dilute-gas approximation. These can be expressed in terms of differential operators acting on the spin-independent potential. The three-quark effective Hamiltonian (in a color-singlet state) is shown to be a sum of quark-antiquark Hamiltonians. The structure and numerical value of the effective Hamiltonian is discussed.
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)