Strange mass dependence of the tricritical point in the U(3)_L x U(3)_R chiral sigma model

Abstract

We study the strange quark mass dependence of the tricritical point of the U(3)_L x U(3)_R linear sigma model in the chiral limit. Assuming that the tricritical point is at a large strange mass value, the strange sector as well as the η-a_0 sector decouples from the light degrees of freedom which determines the thermodynamics. By tracing this decoupling we arrive from the original U(3)_L x U(3)_R symmetric model, going through the U(2)_L x U(2)_R symmetric one, at the SU(2)_L x SU(2)_R linear sigma model. One-loop level beta functions for the running of the parameters in each of these models and tree-level matching of the coupling of these models performed at intermediate scales are used to determine the influence of the heavy sector on the parameters of the SU(2)_L x SU(2)_R linear sigma model. By investigating the thermodynamics of this latter model we identified the tricritical surface of the U(3)_L x U(3)_R linear sigma model in the chiral limit. To apply the results for QCD we used different scenarios for the m_s and μ_q dependence of the effective model parameters, then the μ_q^TCP(m_s) function can be determined. Depending on the details, a curve bending upwards or downwards near μ_q=0 can be obtained, while with explicit chemical potential dependence of the parameters the direction of the curve can change with m_s, too.

17 pages, 6 figures, uses revtex4-1

References in corpus (7)

• QCD at finite chemical potential with six time slices
• The chiral critical point of Nf=3 QCD at finite density to the order (mu/T)^4
• The critical surface of the SU(3)_L x SU(3)_R chiral quark model at non-zero baryon density
• Influence of the isospin and hypercharge chemical potentials on the location of the CEP in the mu_B-T phase diagram of the SU(3)_L x SU(3)_R chiral quark model
• U_A(1) Anomaly in Hot and Dense QCD and the Critical Surface
• Resummed one-loop determination of the phase boundary of the SU(3)_R x SU(3)_L linear sigma model in the m_pi-m_K-plane
• Phases and properties of quark matter

Cited by in corpus (2)

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• On-shell versus curvature mass parameter fixing schemes in the quark-meson model and its phase diagrams