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Nambu-Jona-Lasinio Models Beyond the Mean Field Approximation

P. Domitrovich·D. Bückers·H. Müther
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Abstract

Inspired by the model of Nambu and Jona-Lasinio, various Lagrangians are considered for a system of interacting quarks. Employing standard techniques of many-body theory, the scalar part of the quark self-energy is calculated including terms up to second-order in the interaction. Results obtained for the single-particle Green's function are compared with those which only account for the mean-field or Hartree-Fock term in the self-energy. Depending on the explicit form of the Lagrangian, the second-order contributions range between 4 and 90 percent of the leading Hartree-Fock term. This leads to a considerable momentum dependence of the self-energy and the effective mass of the quarks.

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P. Domitrovich, D. Bückers, H. Müther. 1993-04-01. Nambu-Jona-Lasinio Models Beyond the Mean Field Approximation. https://doi.org/10.1103/physrevc.48.413

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