Experimental study of color degree of freedom of gluons ine+e−annihilation at √saround 60 GeV

We have studied four-jet angular distributions using data collected with the VENUS detector at the KEK ${\mathit{e}}^{+}$ ${\mathit{e}}^{\mathrm{-}}$ collider at TRISTAN at c.m. energies between 54 and 64 GeV. The obseved angular distributions are consistent with QCD, but are inconsistent with the Abelian gluon model at the 5% significance level. We have further obtained 95%-confidence experimental bounds on the fundamental parameters of the SU(${\mathit{N}}_{\mathit{c}}$) local color symmetry.