Inequality for Backward Electron- and Muon-Nucleon Scattering at High Momentum Transfer

From a sum rule for backward ν-p scattering, valid only in the limit of large four-momentum transfer q², we obtain an inequality for backward e-p inelastic scattering which depends upon the commutator of space components of isospin currents. Given chiral U(6)×U(6) current algebra, the total backward scattering at fixed large q² is predicted to be at least as great as that from a point Dirac particle with charge ±1/2e.