ИСТИНА

New experimental and theoretical evidences of six-quark (dibaryon) resonances in NN system are presented. Excitation of intermediate dibaryons in the processes of one- and two-pion production in NN collisions is considered. In particular, relative contributions of an intermediate \Delta isobar and isovector dibaryons in the reaction pp -> d\pi^+ are investigated. Inclusion of dibaryon resonances is shown to considerably improve the description of experimental data for this reaction, provided the consistent parameterization of the \pi N \Delta vertex in \pi N and NN scattering is used. Manifestation of the intermediate isoscalar and isovector dibaryon resonances in the two-pion production processes is also studied. The interpretation of the near-threshold enhancement in the reaction pn -> d(\pi\pi)_0 (the so-called ABC-effect) in terms of the sigma-dressed isoscalar dibaryon is given. The possible quark-cluster structure of dibaryons and their role in the short-range nuclear force are discussed.