Accurate Measurement of F2d/F2p and Rd-Rp.

Abstract Results are presented for F 2 d / F 2 p and R d − R p from simultaneous measurements of deep inelastic muon scattering on hydrogen and deuterium targets, at 90, 120, 200 and 280 GeV. The difference R d − R p , determined in the range 0.002 x Q 2 of 5 GeV 2 , is compatible with zero. The x and Q 2 dependence of F 2 d / F 2 p was measured in the kinematic range 0.001 x Q 2 2 with small statistical and systematic errors. For x > 0.1 the ratio decreases with Q 2 .