Gauge invariance of the Landau nonlinear damping decrement of Bose excitations in a quark–gluon plasma: Part II

The physical mechanisms determining the nonlinear scattering of plasmons on particles of a quark–gluon plasma are analyzed. The connection between the Landau nonlinear damping decrement of longitudinal oscillations and the damping decrement derived from the hard-temperature loop approximation is investigated. The part of the decrement that depends on the gauge parameter on the mass shell is shown to be equal to zero.