Influence of the U(1)_A Anomaly on the QCD Phase Transition

Abstract

The SU(3)_{r} \times SU(3)_{\ell} linear sigma model is used to study the chiral symmetry restoring phase transition of QCD at nonzero temperature. The line of second order phase transitions separating the first order and smooth crossover regions is located in the plane of the strange and nonstrange quark masses. It is found that if the U(1)_{A} symmetry is explicitly broken by the U(1)_{A} anomaly then there is a smooth crossover to the chirally symmetric phase for physical values of the quark masses. If the U(1)_{A} anomaly is absent, then there is a phase transition provided that the σmeson mass is at least 600 MeV. In both cases, the region of first order phase transitions in the quark mass plane is enlarged as the mass of the σmeson is increased.

5 pages, 3 figures, Revtex, discussion extended and references added. To appear in PRD

References in corpus (5)

• Insight into the Scalar Mesons from a Lattice Calculation
• Chiral Symmetry Restoration at Nonzero Temperature in the SU(3) \times SU(3) Linear Sigma Model
• Topological susceptibility in full QCD at zero and finite temperature
• Effective Restoration of the U_A(1) symmetry in the SU(3) linear sigma model
• Large N_c, chiral approach to M_eta' at finite temperature

Cited by in corpus (17)

• QCD at finite temperature and chemical potential from Dyson-Schwinger equations
• The chiral critical line of N_f=2+1 QCD at zero and non-zero baryon density
• Critical Points in the Linear Sigma Model with Quarks
• The three-flavor chiral phase structure in hot and dense QCD matter
• Anomalous chirality fluctuations in the initial stage of heavy ion collisions and parity odd bubbles
• Chiral symmetry restoration in linear sigma models with different numbers of quark flavors
• Phase diagram and thermodynamics of the Polyakov linear sigma model with three quark flavors
• Fluctuations and the axial anomaly with three quark flavors
• First-Order Chiral Phase Transition in High-Energy Collisions: Can Nucleation Prevent Spinodal Decomposition?
• The critical surface of the SU(3)_L x SU(3)_R chiral quark model at non-zero baryon density
• Mass sensitivity of the three-flavor chiral phase transition
• Mapping the boundary of the first order finite temperature restoration of chiral symmetry in the m_pi-m_K--plane with a linear sigma model
• QCD phase transitions in the light quark chiral limit
• Effects of the anomaly on the two-flavor QCD chiral phase transition
• Localized rainbows in the QCD phase diagram
• Finite temperature symmetry restoration in the U_L(3)xU_R(3) linear sigma model from a large-n approximation
• The boundary of the first order chiral phase transition in the m_pi-m_K--plane with a linear sigma model