CHARGE ASYMMETRY OF PARTON DISTRIBUTIONS

We calculate the valence distribution of down quarks in the proton and up quarks in the neutron (the ‘minority’ quark distributions), taking into consideration the major sources of charge symmetry violation, including the effect of the mass difference of the u and d quarks on the bag wave function, and the masses of the intermediate diquark states. The relative difference of the distributions can be as large as 10% for intermediate values of Bjorken x.