  The quantum field theoretical description of coherence in the oscillations of
particles, especially neutrinos, is a standing problem in particle physics. In
this talk, several inconsistencies of the standard approach to particle
oscillations will be explained, and how they are resolved in a
process-independent manner, by a novel approach inspired by the
Bardeen--Cooper--Schrieffer theory of superconductivity and the
Nambu--Jona-Lasinio model. The formalism leads to corrections to the neutrino
oscillation probability originally written by Pontecorvo and Gribov, however
the standard probability is validated in the ultrarelativistic neutrino limit.
The massive neutrino states are interpreted as quasiparticles on a vacuum
condensate of "Cooper pairs" of massless flavour neutrinos. The newly defined
oscillating particle states are for neutrino oscillations what the
Klauder--Sudarshan--Glauber coherent states are for quantum optics.
