The transverse spin asymmetry of a quark in a baryon and the linear polarization of a gluon in a vector meson are studied from the t-channel point of view. Using the Altarelli-Parisi approach, they are shown to obey independent evolution equations and to decrease with increasing Q 2 • We investigate the possibility to measure them at leading twist, to leading order in et. and et.8 and without analyzing the final polarizations. This requires simultaneous polarization of the beam and the target; the observable effect is in the azimuthal distribution of the high PT particle or jet. Assuming a simple (quark + scalar diquark) model for the baryon, a large asymmetry is expected in pp Drell-Yan collisions, a smaller one in high Pr pp collisions, from the interference term in the scattering of two identical quarks.

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