Source theory discussion of deep inelastic scattering with polarized particles.
A general phenomenological framework is provided for the discussion of the inelastic scattering of polarized electrons (muons) on polarized nucleons, when regarded as the absorption of polarized virtual photons. The relevant cross sections compare parallel and antiparallel orientations of the photon helicity and nucleon spin, and also deal with linear combinations of longitudinal and transverse polarization. The polarization asymmetry for transverse polarization, P, assumes a scaling form in the deep inelastic scattering region, and should go to zero as omega(-1) for large omega. The latter behavior is connected, through the use of the improved scaling variable omega(s), with the high energy real photon situation. A sum rule is exhibited which implies that P must change sign in the deep inelastic region. This sum rule also yields the known Drell-Hearn sum rule for real photon Compton scattering, when combined with another, new, sum rule for the anomalous magnetic moment. The latter is verified in the context of pure electrodynamics to the lowest order in alpha. Finally, it is conjectured that P specifically changes from negative to positive values as omega varies from 1 to infinity.
Schwinger
J
J
University of California, Los Angeles, Calif. 90024.