The non-topological Z^′ string in the 331 model and its classical stability

2026/04/08 by Zhengyang Bian, Ning Chen, Mian Guo +4
Physics and Astronomy · #hep-ph #hep-th

paper · pdf · doi:10.1140/epjc/s10052-026-16027-x

Abstract

We study the classical stability of a non-topological Z^′ string in the minimal 331 model, which arises from the maximal symmetry breaking pattern of an \rm SU(6) toy model. Two Higgs triplets are introduced according to the emergent global symmetries in the fermionic sector of the \rm SU(6) toy model, which will achieve the sequential symmetry breaking of \rm SU(3)_c⊗ \rm SU(3)_W ⊗ \rm U(1)_X→ \rm SU(3)_c⊗ \rm SU(2)_W ⊗ \rm U(1)_Y. By analyzing small perturbations around the string background and solving the coupled Helmholtz equations numerically, we find that the string is stable only near the semilocal limit of ϑ_S ≈ \fracπ2, even when Higgs self-couplings are tuned to minimize instabilities. This suggests that such non-topological strings are unlikely to exist in unified theories based on \rm SU(N>5) Lie algebras.

Citations

• Observation of a new particle in the search for the Standard Model Higgs boson with the ATLAS detector at the LHC

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