University of Minnesota
School of Physics & Astronomy

Nuclear Physics Seminar

Friday, February 3rd 2017
2:00 pm:
Speaker: Jurgen Eser, Frankfurt Institute for Advanced Studies
Subject: The extended linear sigma model within the functional renormalization group approach
Note change in time and location, this week only.

by Jurgen Eser, Florian Divotgey, Dirk H. Rischke

We use the functional renormalization group (FRG) technique to explore the characteristics of the so-called extended linear sigma model (eLSM). This model is an effective description of the strong interaction in terms of quarks and mesonic felds. Besides scalars and pseudoscalars, it also features vector and axial-vector mesons.

The first part focuses on the restoration of chiral symmetry in the context of the transition from hadronic matter to the quark-gluon plasma in the phase diagram of quantum chromodynamics (QCD). Results on the order of the chiral phase transition in the presence of vector and axial-vector mesons will be presented. Vector mesons are of particular interest since modifications related to chiral symmetry restoration affect their in-medium spectral properties, which can be detected via decays into dileptons. Effects of the axial anomaly and the explicit breaking of chiral symmetry due to nonzero quark masses are also studied. The mass degeneracy of chiral partners beyond the phase boundary and the phase diagram as a function of the temperature and the quark-chemical potential will be shown.

The second part sheds light on the low-energy limit of the eLSM. We consider the influence of wave-function renormalization factors and couplings beyond the local potential approximation. The infrared-relevant couplings can be associated with the corresponding low-energy constants of QCD.

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