Symmetric and Nonsymmetric Tricritical Points in Liquid Sulfur Solutions

The dilute $n\to 0$ vector model, recently used to model the phase equilibria in sulfur solutions and living polymers, possesses a nonsymmetrical tricritical point of the sort found in three- and more-component solutions at a small nonzero value of the magnetic field as well as the symmetric tricritical point at zero field. This has interesting consequences for the phase diagrams of sulfur solutions and suggests a resolution of a number of discrepancies between the earlier (zero-field) theory of Scott and experiments on sulfur solutions.