Logarithmic corrections to the equation of state in the SU(2) ⊗ SU(2) Nambu-Jona-Lasinio model Original Research Article

We present results from a Monte Carlo simulation of the Nambu-Jona-Lasinio model, with continuous SU(2) ⊗ SU(2) chiral symmetry, in four Euclidean dimensions. Different model equations of state, corresponding to different theoretical scenarios, are tested against the order parameter data. The results are sensitive to necessary assumptions about the shape and extent of the scaling region. Our best fits favour a trivial scenario in which the logarithmic corrections are qualitatively similar to those predicted by the large Nf approximation. This is supported by a separate analysis of finite volume corrections for data taken directly in the chiral limit.