  The problem of the passage of the neutral massless particle with anomalous
magnetic moment through the external electromagnetic field is considered both
in pseudoclassical and quantum mechanics. The quantum description uses the
hamiltonian in the Foldy--Wouthuysen representation, obtained from the
pseudoclassical hamiltonian of the massive charged particle with anomalous
magnetic moment in interaction with the external electromagnetic field using
Weyl quantization scheme.
