Light-front Qcd and Heavy Quark Systems ? 1 Hadronic Phenomenology in the Lf Formulation 1.1 an Overview

In this series of lectures, I shall begin with the current investigations on phenomenology of hadron dynamics to demonstrate the importance of solving hadronic bound states within the framework of light-front (LF) QCD. Then, I will describe the basic procedure how to formulate the canonical theory of LFQCD, including light-front quantization of QCD, light-front gauge singularity, and light-front two-component formalism. I will also present a complete one-loop QCD calculation in terms of the light-front time-ordering perturbation theory, in comparison with the usual covariant perturbative QCD calculation. Following thereby I will discuss the development of heavy-quark eeective theory and the manifestation of heavy quark symmetry on the light-front. Finally, by applying recently developed similarity renormalization group approach to light-front heavy quark eeective theory, I will show a rigorous derivation of quark connnement interaction from LFQCD and its application to solve heavy hadron bound states. Simply speaking, the main task in the investigation of hadronic physics is how to provide a QCD description of hadronic structure. More speciically, how can we compute directly from QCD the fruitful hadronic properties, such as the hadronic structure functions in lepton-nucleon deep inelastic scatterings, the partonic fragmentation functions in high energy hadron-hadron or e + e ? collisions, and many hadronic form factors in various hadronic decay processes. However, although QCD has been accepted as a fundamental theory of the strong interaction that governs the underlying dynamics of hadronic constituents, a complete QCD description to hadronic structure is still lacking. In this series of lectures, I will attempt to show you that the light-front formulation of eld theory may provide a natural and systematic QCD description to all the processes mentioned above Zhang (1994)]. Historically, light-front dynamics played a very important role in every step of the development of the strong interaction theory. The most important application of light-front dynamics to hadronic physics is perhaps the parton phenomena in the lepton-nucleon deep inelastic scatterings (DIS). As it is well-known,