It has been recently shown that a chiral molecule accelerates linearly along a
spatially uniform magnetic field, as a result of the parity-time symmetry breaking induced
in its QED self-interaction. In this work we extend that result to fundamental particles
which present EW self-interaction, in which case parity is violated by the EW interaction
itself. In particular, we demonstrate that, in a spatially uniform and adiabatically timevarying magnetic field, an unpolarized proton coupled to the leptonic vacuum acquires
a kinetic momentum antiparallel to the magnetic field, whereas virtual leptons gain an
equivalent Casimir momentum in the opposite direction. That momentum is proportional
to the magnetic field and to the square of Fermi’s constant. We prove that the kinetic
energy of the proton is a magnetic energy which constitutes a Doppler-shift correction to
its EW self-energy.
