Time-energy uncertainty relation and Lorentz covariance

The uncertainty relations applicable to space and time separations between the quarks in a hadron are discussed. It is pointed out that the time-energy uncertainty relation between the time and energy separations is the same as the relationship between the widths and lifetimes of unstable states. It is then shown that this relation can be combined with Heisenberg’s position-momentum uncertainty relation to give the uncertainty principle in a covariant form. It is pointed out that this effect manifests itself in Feynman’s parton picture.