The $\eta$ - $\eta\prime$ mixing angle revisited

The η-η′ mixing angle revisited

The value of the η-η′ mixing angle θP is phenomenologically deduced from a rather exhaustive and up-to-date analysis of data including strong decays of tensor and higher-spin mesons, electromagnetic decays of vector and pseudoscalar mesons, J/ψ decays into a vector and a pseudoscalar meson, and other transitions. A value of θP between −17◦ and −13◦ is consistent with the present experimental ev...

Photoproduction of Eta and Etaprime Mesons on the Nucleon

The isobar models η-MAID and η-MAID have been used to analyze new data on quasifree η photoproduction on the deuteron from Bonn and recent η data on the proton from Jlab. In η photoproduction on the neutron a bump around W = 1700 MeV was observed which could possibly arise from a narrow P11 state that is discussed as a nonstrange member of the Θ antidecuplett. In η photoproduction on the proton...

Third Mixing Angle

We show that the Hidden Local Symmetry Model, supplemented with well-known procedures for breaking flavor SU(3) and nonet symmetry, provides all the information contained in the standard Chiral Perturbation Theory (ChPT) Lagrangian L (0) + L (1). This allows to rely on radiative decays of light mesons (V P γ and P γγ) in order to extract some numerical information of relevance to ChPT: a value ...

Effect of Merging Angle on Turbulent Mixing Layers

The Weak Mixing Angle at Low Energies

We determine the weak mixing angle in the MS-scheme, sin θ̂W (μ), at energy scales μ relevant for present and future low energy electroweak measurements. We relate the renormalization group evolution of sin θ̂W (μ) to the corresponding evolution of α̂(μ) and include higher-order terms in αs and α that had not been treated in previous analyses. We also up-date the analysis of non-perturbative, hadr...