nLab eta-meson

Idea

A meson:

The Lorentz pseudoscalar and isospin scalar, bound from up/down-quarks in the first generation of fundamental particles and a strange quark in the second generation of fundamental particles. Hence a heavy meson with respect to 2-flavor chiral perturbation theory.

flavors of fundamental fermions in the standard model of particle physics:
generation of fermions	1st generation	2nd generation	3d generation
quarks ($q$)
up-type	up quark ($u$)	charm quark ($c$)	top quark ($t$)
down-type	down quark ($d$)	strange quark ($s$)	bottom quark ($b$)
leptons
charged	electron	muon	tauon
neutral	electron neutrino	muon neutrino	tau neutrino
bound states:
mesons	light mesons: pion ($u d$) ρ-meson ($u d$) ω-meson ($u d$) f1-meson a1-meson	strange-mesons: ϕ-meson ($s \bar s$), kaon, K*-meson ($u s$, $d s$) eta-meson ($u u + d d + s s$) charmed heavy mesons: D-meson ($u c$, $d c$, $s c$) J/ψ-meson ($c \bar c$)	bottom heavy mesons: B-meson ($q b$) ϒ-meson ($b \bar b$)
baryons	nucleons: proton $(u u d)$ neutron $(u d d)$

References

General

See also:

• Wikipedia, Eta meson

Decays

• B. M. K. Nefkens, J. W. Price, The Neutral Decay Modes of the Eta-Meson, Phys. Scripta T99:114-122, 2002 (arXiv:nucl-ex/0202008)

• Andrzej Kupsc, What is interesting in $\eta$ and $\eta'$ Meson Decays?, AIPConf. Proc. 950:165-179, 2007 (arXiv:0709.0603)

• Florian Jonas, Measurement of $\omega$ and $\eta$ mesons via their three pion decay with ALICE in pp collisions at $\sqrt{s} = t TeV$, 2018 (cds:2653176)

On the Dalitz decay of the $\eta$-meson:

• Sergi González-Solís, Single and double Dalitz decays of $\pi^0$, $\eta$ and $\eta'$ mesons, Nuclear and Particle Physics Proceedings Volumes 258–259, January–February 2015, Pages 94-97 (doi:10.1016/j.nuclphysbps.2015.01.021)