QCD tests with polarized beams

Abstract

We present three QCD studies performed by the SLD experiment at SLAC, utilizing the highly polarized SLC electron beam. We examined particle production differences in light quark and antiquark hemispheres, and observed more high momentum baryons and K−'s than antibaryons and K+'s in quark hemispheres, consistent with the “leading particle” hypothesis. We performed a search for jet handedness in light q- and q¯-jets. Assuming Standard Model values of quark polarization in Z0 decays, we have set an improved upper limit on the analysing power of the handedness method. We studied the correlation between the Z0 spin and the event-plane orientation in polarized Z0 decays into three jets. The CP-even and T-odd triple product S → Z ⋅ ( k → 1 × k → 2 ) formed from the two fastest jet momenta, k → 1 and k → 2 , and the Z0 polarization vector S → Z , is sensitive to physics beyond the Standard Model.