Nuclear shadowing in the structure function F3(x)

Nuclear modification of the structure function F3 is investigated. Although it could be estimated in the medium and large x regions from the nuclear structure function F2A, it is essentially unknown at small x. The nuclear structure function F3A at small x is investigated in two different theoretical models: a parton-recombination model with Q2 rescaling and an aligned-jet model. We find these models predict completely different behavior at small x: antishadowing in the first parton model and shadowing in the aligned-jet model. Therefore, studies of the ratio F3AF3D at small x could be useful in discriminating among different models, whith produce similar shadowing behavior in the structure function F2. We also estimate currently acceptable nuclear modification of F3 at small x by using F2AF2D experimental data and baryon-number conservation.