On the relation between momentum and velocity for elementary systems
We investigate how the quantum mechanical position operator can be defined for elementary systems so that the connection, postulated by the special theory of relatively, between velocity (the time derivative of the position) and momentum remains valid. © 1977.
Publication Source (Journal or Book title)
Physics Letters A
O'Connell, R., & Wigner, E. (1977). On the relation between momentum and velocity for elementary systems. Physics Letters A, 61 (6), 353-354. https://doi.org/10.1016/0375-9601(77)90329-2