Abstract
The New Muon Collaboration has recently measured the electromagnetic structure functions through deep-inelastic muon scattering from protons and deuterons. Structure functions [] have been measured to very small Bjorken . The results seem to violate the Gottfried sum rule. We discuss various possible reasons for this result, including significant contributions from valence quarks at very small and SU(2)-flavor breaking in the sea. We show that the pionic contribution to the sea-quark distributions gives qualitative agreement with estimates of the SU(2)-flavor-breaking contribution. We discuss various experiments which could give a direct measurement of . We make qualitative estimates of shadowing effects in the deuteron and their impact on the extracted neutron structure functions.
- Received 31 October 1990
DOI:https://doi.org/10.1103/PhysRevD.44.717
©1991 American Physical Society