Center of mass velocity from Mass Polariton solution to Abraham-Minkowski controversy

A one-hundred-year old controversy, the Abraham-Minkowski controversy, concerns two widely disparate predictions for the momentum of light in glass. In the Abraham case the photon momentum is inversely proportional to the index of refraction while the photon momentum predicted by Minkowski formulation is proportional to the index of refraction. In spite of significant theoretical and experimental effort neither formulation could convincingly be shown to be correct. A new model, called the Mass Polariton model, MP, was recently introduced that resolves the contradictions in the Abraham and Minkowski formulations and experimental results. Both the MP and Minkowski model predict the same momentum change for a photon entering glass from a vacuum, yet the Minkowski model allows violation of the center of mass theorem. This paper shows that the MP model, in spite of predicting the same momentum change as the Minkowski model, obeys the center of mass theorem.