CDF W mass anomaly with a Stueckelberg-Higgs portal

We propose an explanation to the new W mass measurement recently reported by the CDF collaboration, which is larger than the standard model expectation by about 7 standard deviations. To alleviate the tensions that are imposed on the electroweak sector by the new W mass measurement, we carry out an analysis in the Stueckelberg extended standard model where a new neutral gauge boson appears which mixes with the two neutral gauge bosons in the electroweak sector both via the Stueckelberg mass terms and via the gauge invariant Stueckelberg-Higgs portal interaction and spoils the custodial symmetry at the tree level so that the simple relation between the W boson mass and the Z boson mass does not hold. We find that such an extension increases the W boson mass if the new gauge boson mass is larger than the Z boson mass. We further show that there exists a significant part of the parameter space in the extended model which includes the CDF mass anomaly and is consistent with the various observables at the Z pole and consistent with the ATLAS dilepton limits. The Stueckelberg Z'(St) boson, which resolves the CDF W mass anomaly, should be searchable in future LHC experiments. (C) 2022 The Author(s). Published by Elsevier B.V.

Automated summary

We propose an explanation for the new W mass measurement reported by the CDF collaboration, which deviates from the standard model expectation by about 7 standard deviations. By introducing a new neutral gauge boson in the Stueckelberg extended standard model, we alleviate the tensions in the electroweak sector caused by the new W mass measurement. We find that the extension increases the W boson mass when the mass of the new gauge boson is larger than that of the Z boson. Additionally, we show that there exists parameter space in the extended model consistent with the CDF mass anomaly as well as various observables at the Z pole and ATLAS dilepton limits. The Stueckelberg Z'(St) boson, which resolves the CDF W mass anomaly, can be searched for in future LHC experiments.