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arXiv · 2408.07535

Electroweak $η_{\rm w}$ meson

Abstract

We argue that the Standard Model is accompanied by a new pseudo-scalar degree of freedom, $η_{\rm w}$-meson, which cancels the topological susceptibility of the electroweak vacuum and gets its mass from this effect. The prediction is based on the analyticity properties of the Chern-Simons correlator combined with the basic features of gravity. Depending on the quality level of the $U(1)_{B+L}$-symmetry, $η_{\rm w}$ emerges as a $B+L$ pseudo-Goldstone boson or as a Stückelberg $2$-form of the electroweak gauge redundancy. An intriguing scenario of the first category is the emergence of $η_{\rm w}$ in the form of the phase of a $U(1)_{B+L}$-violating fermion condensate triggered by the instantons, somewhat similar to $η'$-meson in QCD. Regardless of its origin, the presence of $η_{\rm w}$-meson in the theory appears to be a matter of consistency.

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BibTeXRIS

Gia Dvali, Archil Kobakhidze, Otari Sakhelashvili. 2025-06-11. Electroweak $η_{\rm w}$ meson. https://doi.org/10.1103/mxdm-wb1p

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