  High energy reactions may produce a state around the collision point that is
best described by a classical pion field. Such a field might be an isospin
rotated vacuum of the chiral $\sigma$-model or, as discussed in this work, a
solution of the equations of motion resultinng from the coupling of fields of
this model to quarks produced in the collision. In such configurations all
directions in isospin space are allowed leading to a sizable probability of
events with, essentially, only charged particles (Centauros) or all neutral
particles (anti-Centauros). (In more common statistical models of multiparticle
production, the probability of such events is suppressed exponentially by the
total multiplicity.) We find that the isospin violation due to the mass
difference of the up and down quarks has a significant effect on these
distributions and enhances the production of events consisting predominantly of
neutral particles.
