Decoherence of Quark Colour States in QCD Vacuum

Strong interactions which lead to quark confinement are analyzed from the point of view of quantum information theory. It is shown how states with nontrivial colour charge can be transformed into white mixed states described by density matrices and how the information about colour states of quarks is lost due to interactions with non-Abelian quantum gauge fields. For mixed state of a single quark the entropy growth rate is found to be proportional to the tension of QCD string. (author)