Asymptotic safety of simple Yukawa systems
We study the triviality and hierarchy problem of a Z2-invariant Yukawa system with massless fermions and a real scalar field, serving as a toy model for the standard-model Higgs sector. Using the functional RG, we look for UV stable fixed points which could render the system asymptotically safe. Whe...
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| Main Authors: | , |
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| Format: | Article (Journal) |
| Language: | English |
| Published: |
23 February 2010
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| In: |
The European physical journal. C, Particles and fields
Year: 2010, Volume: 66, Issue: 3, Pages: 387-402 |
| ISSN: | 1434-6052 |
| DOI: | 10.1140/epjc/s10052-010-1256-z |
| Online Access: | Verlag, lizenzpflichtig, Volltext: https://doi.org/10.1140/epjc/s10052-010-1256-z
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| Author Notes: | Holger Gies, Michael M. Scherer |
| Summary: | We study the triviality and hierarchy problem of a Z2-invariant Yukawa system with massless fermions and a real scalar field, serving as a toy model for the standard-model Higgs sector. Using the functional RG, we look for UV stable fixed points which could render the system asymptotically safe. Whether a balancing of fermionic and bosonic contributions in the RG flow induces such a fixed point depends on the algebraic structure and the degrees of freedom of the system. Within the region of parameter space which can be controlled by a nonperturbative next-to-leading order derivative expansion of the effective action, we find no non-GauĂian fixed point in the case of one or more fermion flavors. The fermion-boson balancing can still be demonstrated within a model system with a small fractional flavor number in the symmetry-broken regime. The UV behavior of this small-Nf system is controlled by a conformal Higgs expectation value. The system has only two physical parameters, implying that the Higgs mass can be predicted. It also naturally explains the heavy mass of the top quark, since there are no RG trajectories connecting the UV fixed point with light top masses. |
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| Item Description: | Gesehen am 14.03.2023 |
| Physical Description: | Online Resource |
| ISSN: | 1434-6052 |
| DOI: | 10.1140/epjc/s10052-010-1256-z |