A Crucial Test for Color-Octet Production Mechanism in Z^0 Decays

Abstract

The direct production rates of $D$-wave charmonia in the decays of $Z^0$ is evaluated. The color-octet production processes $Z^0{\to }^3{D}_J(c\bar{c})q\bar{q}$ are shown to have distinctively large branching ratios, the same order of magnitude as that of $J/\psi$ prodution, as compared with other $D$-wave charmonium production mechanisms. This may suggest a crucial channel to test the color-octet mechanism as well as to observe the $D$-wave charmonium states in $Z^0$ decays. In addition, a signal for the ${}^3{D}_J$ charmonium as strong as $J/\psi$ or ${\psi }^{\prime }$ with large transverse momentum at the Tevatron should also be observed.

Comments: 14 pages in LaTex (3 figures in PS-file)