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Enhanced Global Symmetry Constraints on epsilon Terms

Z. Duan·P. S. Rodrigues da Silva·F. Sannino
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Abstract

Recently it has been proposed that the physical spectrum of a vector-like gauge field theory may exhibit an enhanced global symmetry near a chiral/conformal phase transition. The new symmetry is related to the possibility, supported by various investigations, that a parity-doubled spectrum develops as the number of fermions Nf is increased to a critical value above which it is expected that the symmetric phase is restored. We show that parity-doubling together with the associated enhanced global symmetry severely constrains the epsilon terms of the effective Lagrangian involving Goldstone bosons as well as massive spin-1 particles. We extend our analysis to underlying fermions in pseudo-real representations of the gauge group.

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Z. Duan, P. S. Rodrigues da Silva, F. Sannino. 2000-09-16. Enhanced Global Symmetry Constraints on epsilon Terms. https://doi.org/10.1016/s0550-3213(00)00550-2

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