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Thermodynamics of O(N) sigma models: 1/N corrections

Jens O. Andersen·Daniel Boer·Harmen J. Warringa
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Abstract

The thermodynamics of the O(N) linear and nonlinear sigma models in 3+1 dimensions is studied. We calculate the pressure to next-to-leading order in the 1/N expansion and show that at this order, temperature-independent renormalization is only possible at the minimum of the effective potential. The 1/N expansion is found to be a good expansion for N as low as 4, which is the case relevant for low-energy QCD phenomenology. We consider the cases with and without explicit symmetry breaking. We show that previous next-to-leading order calculations of the pressure are either breaking down in the temperatures of interest, or based on unjustifiable high-energy approximations.

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Jens O. Andersen, Daniel Boer, Harmen J. Warringa. 2004-08-03. Thermodynamics of O(N) sigma models: 1/N corrections. https://doi.org/10.1103/physrevd.70.116007

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