Effects Of Quark-gluon Interactions Induced By Nontrivial Topological Structures In The QCD Vacuum

QCD has very complicated vacuum structure,filled with non-abelian interac-tions and fluctuations.In most perturbative theories,people expand fields in the neighbour of one specific vacuum,such procedure usually causes a loss of informa-tion,such as certain global symmetry will be no longer manifest,thus is blind to certain global propertities of the field theory.The tunneling effects are of key im-portance in order to reproduce the lost infomation and restore the spontaneously broken symmetries.Such tunnel effects can be described useing so-called instanton,a non-trivial field structure emerged in Euclidean space-time,tunneling between different vacua.They are solutions of equation of motion in Euclidean space.In this dissertation we first introduc instanton in quantum mechanics and QCD in details,then discuss their application in various strong processes.A new mech-anism for the pion production in high energy reactions is suggested.It is related to a possibility for the direct production of the pions induced by instantons.This mechanism does not require any fragmentation functions for the production of pseu-doscalar mesons in high energy reactions with hadrons.We calculate the contribu-tion from the new mechanism to the inclusive ?0-meson production in high energy proton-proton collisions.It is shown that it gives the dominant contribution to the inclusive cross-sections in the few GeV region for the transverse momentum of the final pion with large rapidity.We discuss the possible applications of the new mech-anism to the phenomenon of large spin effects observed in numerous high energy reactions and to particle productions in the relativistic heavy ion collisions.We also calculate the unpolarized and polarized gluon distributions in the con-stituent quark and in the nucleon.First we calculate the gluon distributions inside the constituent quark generated by the perturbative quark-gluon interaction,the non-perturbative quark-gluon interaction,and the non-perturbative quark-gluon-pion anomalous chromomagnetic interaction.The method is the same as that used in deriving Altarelli-Parisi equation.Then,since nuleon can be regarded as comprised of constituent quarks,we can use convolution method to get gluon distribution in nu-cleon from that in constituent quark.The calculation shows that quark-gluon-pion interaction plays an important role in producing the unpolarized and the polarized gluon distributions.In the end we calculate the electromagnetic Pauli form factor of quark induced by instantons.Such efforts have been done by others before,but the results are usually divergent at Q2?0,while our result is not,hence our result can give the contribution at vanishing Q2,i.e.the magnetic moment.This result can be used to calculate the single spin asymmetry(SSA)in hadron collision process in the future.