Centauro events.

There is some analogy to the physics of spin glasses [@glass]. A spin glass is characterized by a phase space which has a complicated landscape of valleys. As the temperature is reduced, barriers between valleys become significant, and the relaxation times become very long. The system may even get trapped in a single metastable state for the duration of the experiment. One may observe hysteresis in strong magnetic fields that varies with the experimental conditions. Real spin glasses have an anisotropy. In hydrodynamic models of Heisenberg spin glasses one is naturally led to consider a coarse-grained free energy which has similarities to the effective potential given in eq. (20) below.

The paper is organized as follows. In sect. 2 we consider the details of the effective potential, both at zero temperature and at finite temperature, and discuss various possibilities for the symmetry breaking term. In sect. 3 we consider constraints on the parameters of the model arising from the formation of domain walls in the early Universe. In sect. 4 we consider potentially observable effects in high energy collisions, namely, pion production from domain walls. In sect. 5 we present some conclusions.

The Effective Potential
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The sigma 