UCLA

From the studies of rates and distributions of heavy quark (c, b) mesons we have developed additional evidence that hadron formation, at least in the simplest environment of e+e- collisions, is dominantly controlled by a space-time area law ("STAL"), an approach suggested by both non-perturbative QCD and relativistic string models. From the dynamics of heavy quarks whose classical space-time world-lines deviate significantly from the light-cone, we report the exact calculation of the relevant space-time area and the derivation of a Lorentz invariant variable, z_eff, which reduces to the light-cone momentum fraction z for low mass quarks. Using z_eff in the exponent of our fragmentation function in place of z, we find persuasive agreement with L=0,1 charmed and bottom meson data as well as for u, d, s L=0 states. Presuming STAL to be a valid first-order description for all these meson data, we find the scale of other possible second-order effects to be limited to ~ 20% or less of the observed rates. The model favors a b-quark mass of ~ 4.5 GeV.