Improved test of the flavor independence of strong interactions

We present an improved comparison of the strong coupling of the gluon to light (q(l) = u + d + s), c, and b quarks, determined from multijet rates in flavor-tagged samples of hadronic Z(0) decays recorded with the SLC Large Detector at the SLAC Linear Collider between 1993 and 1995. Flavor separation among primary q(l)(q) over bar(l), c (c) over bar, and b (b) over bar final states was made on the basis of the reconstructed mass of long-lived heavy-hadron decay vertices, yielding tags with high purity and low bias against greater than or equal to 3-jet final states. We find: alpha(s)(c)/alpha(s)(uds) = 1.036 +/- 0.043(stat)(-0.045)(+0.041)(syst)(-0.018)(+0.020)(theory) and alpha(s)(b)/alpha(s)(uds) = 1.004 +/- 0.018(stat)(-0.031)(+0.026)(syst)(-0.029)(+0.018)(theory).