Ruling out light axions: The writing is on the wall

Beyer, Konstantin A.; Sarkar, Subir

doi:10.21468/SciPostPhys.15.1.003

SciPost Physics

Ruling out light axions: The writing is on the wall

Konstantin A. Beyer, Subir Sarkar

SciPost Phys. 15, 003 (2023) · published 10 July 2023

doi: 10.21468/SciPostPhys.15.1.003
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Abstract

We revisit the domain wall problem for QCD axion models with more than one quark charged under the Peccei-Quinn symmetry. Symmetry breaking during or after inflation results in the formation of a domain wall network which would cause cosmic catastrophe if it comes to dominate the Universe. The network may be made unstable by invoking a "tilt" in the axion potential due to Planck scale suppressed non-renormalisable operators. Alternatively the random walk of the axion field during inflation can generate a "bias" favouring one of the degenerate vacua, but we find that this mechanism is in practice irrelevant. Consideration of the axion abundance generated by the decay of the wall network then requires the Peccei-Quinn scale to be rather low - thus e.g. ruling out the DFSZ axion with mass below $\sim$ 11 meV, where most experimental searches are in fact focused.

TY  - JOUR
PB  - SciPost Foundation
DO  - 10.21468/SciPostPhys.15.1.003
TI  - Ruling out light axions: The writing is on the wall
PY  - 2023/07/10
UR  - https://scipost.org/SciPostPhys.15.1.003
JF  - SciPost Physics
JA  - SciPost Phys.
VL  - 15
IS  - 1
SP  - 003
A1  - Beyer, Konstantin A.
AU  - Sarkar, Subir
AB  - We revisit the domain wall problem for QCD axion models with more than one quark charged under the Peccei-Quinn symmetry. Symmetry breaking during or after inflation results in the formation of a domain wall network which would cause cosmic catastrophe if it comes to dominate the Universe. The network may be made unstable by invoking a "tilt" in the axion potential due to Planck scale suppressed non-renormalisable operators. Alternatively the random walk of the axion field during inflation can generate a "bias" favouring one of the degenerate vacua, but we find that this mechanism is in practice irrelevant. Consideration of the axion abundance generated by the decay of the wall network then requires the Peccei-Quinn scale to be rather low - thus e.g. ruling out the DFSZ axion with mass below $\sim$ 11 meV, where most experimental searches are in fact focused.
ER  -

@Article{10.21468/SciPostPhys.15.1.003,
	title={{Ruling out light axions: The writing is on the wall}},
	author={Konstantin A. Beyer and Subir Sarkar},
	journal={SciPost Phys.},
	volume={15},
	pages={003},
	year={2023},
	publisher={SciPost},
	doi={10.21468/SciPostPhys.15.1.003},
	url={https://scipost.org/10.21468/SciPostPhys.15.1.003},
}

Cited by 9

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¹ Konstantin A. Beyer,
¹ Subir Sarkar

¹ Rudolf Peierls Centre for Theoretical Physics, University of Oxford

Funder for the research work leading to this publication

Science and Technology Facilities Council [STFC]