A polarized proton beam in a $\mathrm{PP}$ or a $P\overline{P}$ collider permits a normalization-independent determination of the quark polarization inside a hadron via the forward-backward asymmetry in $W^{\pm }$ decay. For an unpolarized beam one still obtains useful information about antiquark distributions.

• Received 4 February 1986

DOI:https://doi.org/10.1103/PhysRevLett.56.1542