Classical glueballs in non-Abelian Born-Infeld theory.

It is shown that the Born-Infeld-type modification of the quadratic Yang-Mills action gives rise to classical particlelike solutions prohibited in the standard Yang-Mills theory. This becomes possible due to breaking of the scale invariance by the Born-Infeld nonlinearity. New classical glueballs, which are of a sphaleronic nature, exhibit a striking similarity to the Bartnik-McKinnon solutions to the Yang-Mills theory coupled to gravity.