Indeed. In the CFL-phase of color superconductors the photon mixes with the diagonal gluon. One specific combination remains massless while the orthogonal com

Indeed. In the CFL-phase of color superconductors the photon mixes with the diagonal gluon. One specific combination remains massless while the orthogonal combination gets a mass. My colleagues and I jokingly called them the phuon and the gluton when talking privately.