The interaction between two bags due to fluctuating colour fields

The van der Waals force between two hadronic spherical bags is calculated, assuming that the surrounding colour ‘medium’ obeys the condition εμ = 1, ε being the colour permittivity and μ (⪢ 1) the colour permeability. The quark-gluon coupling is neglected, so that use can be made or prior electrodynamic calculations by Mitchell and Ninham (J. Chem. Phys. 56 (1972) 1117), Brevik and Skurdal (Physica A 199 (1993) 412) and others. It turns out that in the case of nucleons, at distances R ∼ 5 fm, the van der Waals force comes out in remarkably good numerical agreement with the spin-isospin-independent nucleonic force. The van der Waals interaction thus seems to be of considerable importance in the hadronic world.