Perturbative QCD Application In Quark Potential Models

In this thesis, we first discuss the origin of the non-Galilean invariance term in the usual effective one gluon exchange q-q interaction and point out that the Galilean-invariance is not a proper requirement for two-particle interactions, then we take a new approach to derive the off shell interaction potential V_q-qqq and make the Hermitian conjugation property of V_q-qqq restored. To understand the supression of spin orbit forces in bafyons, we derive the fourth-order quark-quark interaction in perturbative QCD with emphasis on a rigorous investigation of the spin orbit interaction terms and we propose a new way which can use Feynman diagram technic to calculate the time-ordered diagram. In order to derive the qq(q|-)-qq(q|-) interaction, we generalize the Fierz transformation from SU(N)(N ≤4) scalar and pseudo scalar to SU(N) tensor and point out that the qq(q|-) — qq(q|-) interaction may be useful in an extended quark potential model calculation. In addition, we make a perturbative QED correction to the effective one gluon exchange process and expect that this QED and QCD interference effect will give us a good guide for understanding the charge symmetry breaking(CSB).