Spin-dependent forces of quarks in baryon

Nonperturbative spin-dependent forces of quarks in a baryon are calculated directly from the QCD Lagrangian in the framework of the Field Correlator Method both for heavy and light quarks. Resulting forces contain terms of 5 different structures, only one being known before in asymptotic form. Perturbative terms obtained by the same method are standard and have different signs and structures with respect to the corresponding nonperturbative ones, implying possible cancellations for some baryonic states.