Measuring transverse spin correlations by 4-particle correlations in $e^+ e^-\to 2 \ {\rm jets}$

The azimuthal distribution of pairs of particles in a jet is sensitive to the transverse polarization of the quark initiating the jet, but with a sensitivity that involves a nonperturbative analyzing power. We show in detail how to measure the analyzing power from 4-hadron correlations in $e^+ e^- \to 2 \ {\rm jets}$. We explain the combinations of particle flavor that are likely to give the biggest effect.