Darmstadt 2016 – scientific programme

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HK: Fachverband Physik der Hadronen und Kerne

HK 39: Hadron Structure and Spectroscopy VII

HK 39.2: Talk

Wednesday, March 16, 2016, 17:00–17:15, S1/01 A5

The Low-Energy Constants of the extended Linear Sigma Model — •Florian Divotgey, Francesco Giacosa, Peter Kovacs, and Dirk H. Rischke — Institut für Theoretische Physik, Goethe-Universität Frankfurt am Main

The low-energy dynamics of Quantum Chromodynamics (QCD) is fully determined by the interactions of the (pseudo-) Nambu-Goldstone bosons of spontaneous chiral symmetry breaking, i.e., for two quark flavors, the pions. Pion dynamics is described by the low-energy effective theory of QCD, chiral perturbation theory (ChPT), which is based on the nonlinear realization of chiral symmetry [1]. An alternative description is provided by the Linear Sigma Model, where chiral symmetry is linearly realized. An extended version of this model, the so-called extended Linear Sigma Model (eLSM) was recently developed [2,3] which incorporates all J^P=0^±, 1^± qq mesons up to 2 GeV in mass. A fit of the coupling constants of this model to experimentally measured masses and decay widths has a surprisingly good quality [3]. In this talk, it is demonstrated that the low-energy limit of the eLSM, obtained by integrating out all fields which are heavier than the pions, assumes the same form as ChPT. Moreover, the low-energy constants (LECs) of the eLSM agree with those of ChPT.

[1] J. Gasser and H. Leutwyler, Annals Phys. 158, 142 (1984).

[2] D. Parganlija, F. Giacosa and D. H. Rischke, Phys. Rev. D 82, 054024 (2010).

[3] D. Parganlija, P. Kovacs, G. Wolf, F. Giacosa and D. H. Rischke, Phys. Rev. D 87, no. 1, 014011 (2013).