Unitarity with quarks despite confinement: Connection between deep inelastic scattering and deep inelastic annihilation processes in the scaling limit

Abstract

We prove that in a parton model which incorporates confinement there exists a subtle connection between analyticity of the virtual Compton amplitude and unitarity with quarks. Then we show that the experimental data on\(\nu \bar W_2 \) for pions and νW2 for nucleons indicatein our model an exactly zero free mass of at least one of the u or d quarks. This turns out, also, to be essential to understand the accepted behaviour of the pion electromagnetic form factor.