Precision measurement of R=σL/σTand F2 in deep inelastic electron scattering on deuterium and iron targets

We report new results on a precision measurement of the ratio R=σL/σT from deuterium, iron and gold targets, on the ratio σFe/σD and on the structure function F2, for deep inelastic electron‐nucleus scattering in the range 0.2≤x≤0.5 and 1≤Q2≤10(GeV/c)2. We find no difference between RFe and Rd. Our results show, for first time, a clear falloff of R with increasing Q2 at SLAC energies. Our R and F2 results are in good agreement with QCD predictions only when corrections for target mass effects are included.