English

Electroweak hierarchy from conformal and custodial symmetry -- "Custodial Naturalness"

High Energy Physics - Phenomenology 2025-05-14 v1

Abstract

I introduce the idea of "Custodial Naturalness" to explain the origin of the electroweak (EW) scale hierarchy. Custodial Naturalness is based on classical scale invariance as well as an extension of the Standard Model (SM) scalar sector custodial symmetry. In a minimal realization, this requires a single new complex scalar field charged under a new U(1) gauge symmetry, which partially overlaps with BLB-L. Classical scale invariance and the high-scale scalar sector SO(6) custodial symmetry are radiatively broken by quantum effects that generate a new intermediate scale by dimensional transmutation. The little hierarchy problem is solved because the Higgs boson arises as pseudo-Nambu-Goldstone boson (pNGB) of the spontaneously broken SO(6) custodial symmetry. The minimal realization of Custodial Naturalness has the same number of parameters as the SM and predicts testable new physics in the form of a heavy ZZ' as well as a light but close-to invisible dilaton.

Keywords

Cite

@article{arxiv.2505.08776,
  title  = {Electroweak hierarchy from conformal and custodial symmetry -- "Custodial Naturalness"},
  author = {Andreas Trautner},
  journal= {arXiv preprint arXiv:2505.08776},
  year   = {2025}
}

Comments

Contribution to the 2025 Electroweak session of the 59th Rencontres de Moriond, La Thuile, Italy, March 23-30, 2025; 6 pages, based on 2407.15920, 2502.09699