W-boson mass anomaly as a manifestation of spontaneously broken additional SU(2) global symmetry on a new fundamental scale

TL;DR

This paper proposes that the recent W-boson mass anomaly can be explained by a spontaneously broken additional SU(2) global symmetry, leading to a Goldstone boson mechanism that affects the W-boson mass.

Contribution

It introduces a novel scenario involving an extra SU(2) global symmetry that accounts for the W-boson mass discrepancy through radiative corrections and Goldstone bosons.

Findings

The model reproduces the observed 70 MeV W-boson mass shift.

The relation between the mass shift and electromagnetic coupling is derived.

Charged Higgs masses receive electromagnetic radiative contributions.

Abstract

Recently the CDF Collaboration has announced a new precise measurement of the $W$-boson mass $M_W$ that deviates from the Standard Model (SM) prediction by $7\sigma$. The discrepancy in $M_W$ is about $\Delta_W\simeq70$ MeV and probably caused by a beyond the SM physics. Within a certain scenario of extension of the SM, we obtain the relation $\Delta_W\simeq\frac{3\alpha}{8\pi}M_W\simeq70$ MeV, where $\alpha$ is the electromagnetic fine structure constant. The main conjecture is the appearance of longitudinal components of the $W$-bosons as the Goldstone bosons of a spontaneously broken additional $SU(2)$ global symmetry at distances much smaller than the electroweak symmetry breaking scale. We argue that within this scenario, the masses of charged Higgs scalars can get an electromagnetic radiative contribution which enhances the observed value of $M_{W^\pm}$ with respect to the usual SM prediction. Our relation for $\Delta_W$ follows from the known one-loop result for the corresponding effective Coleman-Weinberg potential in combination with the Weinberg sum rules.