A Preliminary Improved Test of the Flavor Independence of Strong Interactions

We present an improved comparison of the strong couplings of gluons to light (u, d, and s), c, and b quarks, determined from multijet rates in avor-tagged samples of hadronic Z decays recorded with the SLC Large Detector at the SLAC Linear Collider between 1993 and 1995. Flavor separation on the basis of lifetime and decay multiplicity di erences among hadrons containing light, c, and b quarks was made using the SLD precision tracking system, yielding tags with high purity and low bias against 3-jet nal states. We nd: uds s = all s = 0:997 0:011(stat) 0:011(syst) 0:005(theory), c s= all s = 0:984 0:042 0:053 0:022, b s= all s = 1:022 0:019 0:023 0:012. Contributed to the XVIII International Symposium on Lepton Photon Interactions, July 28 August 1 1997, Hamburg, Germany, and to the International Europhysics Conference on High Energy Physics, 19-26 August 1997, Jerusalem, Israel; Ref: 289. Work supported by Department of Energy contract DE{AC03{76SF00515.