### Abstract

We study the strange quark mass dependence of the tricritical point of the U(3)_{L}×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}×U(3)_{R} symmetric model, going through the U(2)_{L}×U(2)_{R} symmetric one, at the SU(2)_{L}×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}×SU(2)_{R} linear sigma model. By investigating the thermodynamics of this latter model we identified the tricritical surface of the U(3)_{L}×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, and then the μqTCP(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.

Original language | English |
---|---|

Article number | 125038 |

Journal | Physical Review D - Particles, Fields, Gravitation and Cosmology |

Volume | 82 |

Issue number | 12 |

DOIs | |

Publication status | Published - Dec 1 2010 |

### Fingerprint

### ASJC Scopus subject areas

- Nuclear and High Energy Physics
- Physics and Astronomy (miscellaneous)