Structure functions in the polarized Drell-Yan processes with spin-1/2 andspin-1 hadrons. II. Parton model - art. no. 054018

We analyze the polarized Drell-Yan processes with spin-1/2 and spin-1 hadro ns in a parton model. Quark and antiquark correlation functions are express ed in terms of possible combinations of Lorentz vectors and pseudovectors w ith the constrains of Hermiticity, parity conservation, and time-reversal i nvariance. Then, we find tenser-polarized distributions for a spin-1 hadron . The naive parton model predicts that there exist 19 structure functions. However, there are only four or five nonvanishing structure functions, depe nding on whether the cross section is integrated over the virtual-photon tr ansverse momentum (Q) over right arrow(T), or the limit Q(T)-->0 is taken. One of the finite structure functions is related to the tenser-polarized di stribution b(1), and it does not exist in the proton-proton reactions. The vanishing structure functions should be associated with higher-twist physic s. The tensor distributions can be measured by the quadrupole polarization measurements. The Drell-Yan process has an advantage over the lepton reacti on in the sense that the antiquark tensor polarization could be extracted r ather easily. [S0556-2821(99)05815-4].