2022/04/09 by Mattias Blennow, Blennow, Mattias, Pilar Coloma +5
Physics and Astronomy · #Dark Matter and Cosmic Phenomena #FOS: Physical sciences #High Energy Physics - Phenomenology (hep-ph) #Neutrino Physics Research #Particle physics theoretical and experimental studies
paper · pdf · doi:10.48550/arxiv.2204.04559
openalex publication_date 2022/04/09 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We point out that right-handed neutrinos can resolve the tension between the latest CDF II measurement of the W-boson mass, MW, and the standard model. Integrating out the new states yields a single d=6 operator, which induces a deviation from unitarity in the PMNS matrix. This alters the extraction of the Fermi constant from muon decay and increases the prediction for MW, in line with the CDF II result. Non-unitarity of the PMNS matrix would also affect beta, meson, and tau decays. We find that the CDF II value for MW can be explained without conflicting with lepton flavour universality constraints or the invisible decay width of the Z. However, the so-called Cabibbo angle anomaly is worsened if right-handed neutrinos are the origin of the d=6 operator. The situation improves if the operator coefficient is left unconstrained, implying additional sources of new physics, but a common explanation of both anomalies is in tension with universality bounds.