Nucleon Effective Mass and theADependence of Structure Functions

The nucleon effective mass was successfully used, as the only free parameter, to adjust the ratio $R\mathrm{}\left(A\right)\mathrm{}$ of structure functions measured in a nucleus of mass number $A$ and in the deuteron, for each $A$ value in the SLAC set of experimental data. The resulting $A$ dependence of the effective mass, being linear in $A^{-\frac{1}{3}}$, is consistent with the behavior expected from nuclear structure considerations. The extrapolated value of the effective mass for nuclear matter agrees with previous estimations.