RELATIVISTIC TRANSFORMATION OF MAGNETIC DIPOLE MOMENT

We consider three difierent deflnitions of magnetic dipole moment for electrically neutral compact bunches of charged particles and show that, in general, they are not equivalent to each other with respect to their relativistic transformation. In particular, we prove that the \conflgurational" deflnition of magnetic dipole moment mc = 1 R V (r £ j)dV (in the common designations) and its deflnition through generated electromagnetic fleld (\source" deflnition ms) or experienced force (\force" deflnition mf) lead to difierent relativistic transformations of mc and ms (mf). The results obtained shed light on the available disagreements with respect to relativistic transformation of a magnetic dipole moment, and they can be used in covariant formulation of classical electrodynamics in material media.