We determine the scaling equation of state of the three-dimensional O(4) universality class, which is relevant for the finite-temperature transition of quantum chromodynamics with two light flavors. We first consider the small-field expansion of the effective potential (Helmholtz free energy). Then, we apply a systematic approximation scheme based on polynomial parametric representations that are valid in the whole critical regime, satisfy the correct analytic properties (Griffiths' analyticity), take into account the Goldstone singularities at the coexistence curve, and match the small-field expansion of the effective potential. From the approximate representations of the equation of state, we obtain estimates of several universal amplitude ratios.
|Autori interni:||VICARI, ETTORE|
|Autori:||Parisen Toldin F; Pelissetto A; Vicari E|
|Titolo:||The scaling equation of state of the 3-D O(4) universality class RID G-1270-2010|
|Anno del prodotto:||2003|
|Appare nelle tipologie:||1.1 Articolo in rivista|