NEW PERSPECTIVES FOR QCD: NEAR-CONFORMAL QCD AND THE NOVEL EFFECTS OF FINAL-STATE INTERACTIONS

摘要

The effective QCD charge extracted from face="symbol">t decay isremarkably constant at small momenta, implying the near-conformal behavior of hadronicinteractions at small momentum transfer. The correspondence of large N_Csupergravity theory in higher-dimensional anti-de Sitter spaces with gauge theory inphysical space-time also has interesting implications for hadron phenomenology in theconformal limit, such as constituent counting rules for hard exclusive processes. Theutility of light-front quantization and light-front Fock wavefunctions for analyzing suchphenomena and representing the dynamics of QCD bound states is reviewed. The novel effectsof initial- and final-state interactions in hard QCD inclusive processes, includingBjorken-scaling single-spin asymmetries and the leading-twist diffractive and shadowingcontributions to deep inelastic lepton-proton scattering are also discussed.