Leptoproduction of Heavy Quarks I-- General Formalism and Kinematics of Charged Current and Neutral Current Production Processes

摘要

Existing calculations of heavy quark production in charged-current andneutral current lepton-hadron scattering are formulated differently because ofthe artificial distinction of ``light'' and ``heavy'' quarks made in thetraditional approach. A proper QCD formalism valid for a wide kinematic rangefrom near threshold to energies much higher then the quark mass should treatthese processes in a uniform way. We formulate a unified approach to both typesof leptoproduction processes based on the conventional factorization theorem.In this paper, we present the general framework with complete kinematicsappropriate for arbitrary masses, emphasizing the simplifications provided bythe helicity formalism. We illustrate this approach with an explicitcalculation of the leading order contribution to the quark structure functionswith general masses. This provides the basis for a complete QCD analysis ofcharged current and neutral current leptoproduction of charm and bottom quarksto be presented in subsequent papers.