Abstract
A secluded U(1) sector with weak admixture to photons, , and the scale of the breaking below 1 GeV represents a natural yet poorly constrained extension of the standard model. We analyze of muons and electrons together with other precision QED data, as well as radiative decays of strange particles to constrain the mass-mixing angle () parameter space. We point out that and can be consistent with the hypothesis of the HyperCP Collaboration, which seeks to explain the anomalous energy distribution of muon pairs in the process by a resonance, without direct contradiction to the existing data on radiative kaon decays. The same parameters lead to an upward correction to the anomalous magnetic moment of the muon, possibly relaxing some tension between the experimental value and theoretical determinations of . The ultrafine energy resolution scan of the cross section and dedicated analysis of lepton spectra from decays should be able to provide a conclusive test of this hypothesis and improve the constraints on the model.
- Received 13 July 2009
DOI:https://doi.org/10.1103/PhysRevD.80.095002
©2009 American Physical Society