Perturbative QCD analysis is presented of the cumulative out-of-plane
momentum distribution in the near-to-planar e+e- annihilation events, K_out <<
Q. In this kinematical region multiple gluon radiation effects become
essential. They are resummed with the single-logarithmic accuracy, which
programme includes the 2-loop treatment of the basic radiation and matching
with the exact O(alpha_s^2) result.
Dedicated experimental analyses of 3-jet event characteristics are of special
interest for the study of the non-perturbative confinement effects.Comment: 32 pages, 1 figure, JHEP class include