0000000000194924
AUTHOR
Nils A. Tornqvist
Unitarity constraints on resonance mixing and the Okubo-Zweig-Iizuka rule
We discuss unitarity constraints on the (complex) mixing angle (δ) between resonances. In particular, when the mixing is small, as when it is forbidden by the Okubo-Zweig-Iizuka (OZI) rule, or some other mechanism, one can derive useful bounds on δ or determine Arg (δ) from the data of allowed decays of the resonances. In the case of f′−f mixing the unitarity bound |δ|≳0.05±0.015 is barely compatible with the experimental f′←ππ rate (if one assumes that it is dominated by f′←f←ππ transition). Furthermore, experimentally Im δ≈0 which together with unitarity gives Re δ=−0.08±0.03, in clear discrepancy with the observed f′←ππ rate. This suggests that the mixing of f′ with higher f-like recurre…
Review of Particle Properties
This biennial Review summarizes much of Particle Physics. Using data from previous editions, plus 2205 new measurements from 667 papers, we list, evaluate, and average measured properties of gauge bosons, leptons, quarks, mesons, and baryons. We also summarize searches for hypothetical particles such as Higgs bosons, heavy neutrinos, and supersymmetric particles. All the particle properties and search limits are listed in Summary Tables. We also give numerous tables, figures, formulae, and reviews of topics such as the Standard Model, particle detectors, probability, and statistics. This edition features expanded coverage of CP violation in B mesons and of neutrino oscillations. For the fir…