Μανουήλ Γεδεών - Ευγένιος Ιερεύς: Η ζωοδόχος πηγή [1886]: Η λόγος περί του βιβλίου

The decay η ′ c → η

The decay η ′ c → η c π π. Abstract It is pointed out that the decay of the recently observed charmonium η ′ c resonance, η ′ c → η c π π is simply related to the well studied decay ψ ′ → J/ψ π π and can thus be used for absolute normalization of other decay modes of the η ′ c. The total rate of the discussed decay should be approximately three to four times the corresponding rate for the ψ ′ r...

Hadronic η and η ′ decays

The hadronic decays η, η′ → 3π and η′ → ηππ are investigated within the framework of U(3) chiral effective field theory in combination with a relativistic coupled-channels approach. Final state interactions are included by deriving sand p-wave interaction kernels for meson-meson scattering from the chiral effective Lagrangian and iterating them in a Bethe-Salpeter equation. Very good overall ag...

Temperature Dependence of η and η ′ Masses

We investigate the temperature dependence of η and η′ masses due to scatterings from thermal pions in a heat bath using the non-linear sigma model. We show that mass shifts of η and η′ and the shift in the mixing angle are negligible.

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...

The η and η ′ mesons in QCD