Small instantons and the strong CP problem in composite Higgs models

Gupta, R. S.; Khoze, V. V.; Spannowsky, M.

doi:10.1103/physrevd.104.075011

Small instantons and the strong CP problem in composite Higgs models

Gupta, R. S.; Khoze, V. V.; Spannowsky, M.

Authors

R. S. Gupta

Professor Valentin Khoze valya.khoze@durham.ac.uk
Professor

Professor Michael Spannowsky michael.spannowsky@durham.ac.uk
Director

Abstract

We show that QCD instantons can generate large effects at small length scales in the ultraviolet in standard composite Higgs models that utilize partial compositeness. This has important implications for possible solutions of the strong CP problem in these models. First we show that in the simplest known UV completions of composite Higgs models, if an axion is also present, it can have a mass much larger than the usual QCD axion. Even more remarkable is the case where there are no axions, but the strong CP problem can be solved by generating the up quark mass entirely from the contribution of instantons thus reviving the massless up-quark solution for these models. In both cases no additional field content is required apart from what is required to realize partial compositeness.

Citation

Gupta, R., Khoze, V., & Spannowsky, M. (2021). Small instantons and the strong CP problem in composite Higgs models. Physical Review D, 104(7), Article 075011. https://doi.org/10.1103/physrevd.104.075011

Journal Article Type	Article
Acceptance Date	Sep 9, 2021
Online Publication Date	Oct 7, 2021
Publication Date	Oct 1, 2021
Deposit Date	Jan 19, 2022
Publicly Available Date	Jan 20, 2022
Journal	Physical Review D
Print ISSN	2470-0010
Electronic ISSN	2470-0029
Publisher	American Physical Society
Peer Reviewed	Peer Reviewed
Volume	104
Issue	7
Article Number	075011
DOI	https://doi.org/10.1103/physrevd.104.075011

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