$t\bar{t}$ cross section near the production threshold in NNLO of NRQCD

Abstract

The cross section near the $t\bar{t}$ production threshold in $e^{+}{e}^{-}$ annihilation and $\gamma \gamma$ collisions is discussed. The NNLO results within NRQCD are briefly overviewed.

Comments: 17 pages, latex, 1 figure. Talk presented at Quarks-2000 Seminar, Pushkin, Russia, May 13-21, 2000