Violation of custodial symmetry from W-boson mass measurements

The new measurement of the W-boson mass from the CDF Collaboration shows a significant tension with the Standard Model prediction. We quantify this discrepancy within a state-of-the-art analysis of electroweak precision data and scrutinize the leading deformations of the Standard Model effective field theory arising at dimension six. We find evidence for a nonzero value of the T parameter, i.e., for a novel source of violation of custodial symmetry, pointing to physics beyond the Standard Model at the 4.5s level. We contextualize the implications of our findings in light of other present anomalies in particle physics.

Automated summary

The new measurement of the W-boson mass from the CDF Collaboration shows a significant discrepancy with the Standard Model prediction, indicating possible physics beyond the Standard Model.