Vacuum, confinement, and QCD strings in the vacuum correlator method
Russian Federation State Scientific Center ‘A.I. Alikhanov Institute of Theoretical and Experimental Physics’, ul. Bolshaya Cheremushkinskaya 25, Moscow, 117259, Russian Federation
QCD vacuum properties and the structure of color fields in hadrons are reviewed using the complete set of gauge-invariant gluon field correlators. QCD confinement is produced by correlators with a certain Lorentz structure, which violate the Abelian Bianchi identities and are therefore absent in QED. These correlators are used to define an effective colorless field satisfying the Maxwell equations with a nonzero effective magnetic current. In the language of correlators and the effective field, it is shown that non-Abelian interaction of gluon gauge fields leads to quark confinement due to effective circular magnetic currents that squeeze gluon fields into a string in accordance with the ’dual Meissner effect’. Distributions of effective gluon fields in mesons, baryons, and glueballs with static sources are plotted.