Nuclear effects in deuteron and the Gottfried sum rule

Recent NMC data on the ratio of the deep inelastic structure functions F2 per nucleon for deuterium relative to hydrogen are analysed in the context of the Gottfried sum rule. It is shown that the discrepancy between the Gottfried sum rule prediction and NMC data analysis may be interpreted as a nuclear effect in deuterium as it is suggested by several models. This fact, applied to nuclear-deuterium measured ratios, modifies the standard picture of nuclear effects. (orig.)