  The leading-order parton processes that produce a dilepton with large
transverse momentum predict that the transverse polarization should increase
with the transverse momentum for almost any choice of the quantization axis for
the spin of the virtual photon. The rate of approach to complete transverse
polarization depends on the choice of spin quantization axis. We propose axes
that optimize that rate of approach. They are determined by the momentum of the
dilepton and the direction of the jet that provides most of the balancing
transverse momentum.
