Entropy, Quantum Decoherence and Pointer States in Scalar ``Parton'' Fields

Entropy arises in strong interactions by a dynamical separation of ``partons'' from unobservable ``environment'' modes due to confinement. For interacting scalar fields we calculate the statistical entropy of the observable subsystem. Diagonalizing its functional density matrix yields field pointer states and their probabilities in terms of Wightman functions. It also indicates how to calculate a finite geometric entropy proportional to a surface area.