Etaprime and Eta Mesons with Connection to Anomalous Glue

Abstract

We review the present understanding of etaprime and eta meson physics and these mesons as a probe of gluon dynamics in low-energy QCD. Recent highlights include the production mechanism of eta and etaprime mesons in proton-nucleon collisions from threshold to high-energy, the etaprime effective mass shift in the nuclear medium, searches for possible eta and etaprime bound states in nuclei as well as precision measurements of eta decays as a probe of light-quark masses. We discuss recent experimental data, theoretical interpretation of the different measurements and the open questions and challenges for future investigation.

arXiv commentReview, 25 pages, 11 figures, to appear in Reviews of Modern Physics

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• Invariant mass distributions for the pp to p p eta reaction at Q=10 MeV
• Total and differential cross sections of $\eta$-production in proton-deuteron fusion for excess energies between $Q_{\eta }=13\text{MeV}$ and $Q_{\eta }=81\text{MeV}$
• The mass of the two lightest quarks
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• Hadronic interaction of eta and eta-prime mesons with nucleons
• eta-prime Meson Production in Nucleon-Nucleon Collisions Near The Threshold
• On Quasibound N* Nuclei
• Search for $C$ violation in the decay $\eta \to {\pi }^0+e^{+}+e^{-}$ with WASA-at-COSY
• Study of the N N eta' production with COSY-11
• Upper limit of the total cross section for the pn --> pn eta' reaction
• The Two Pomerons
• The quest to find an electric dipole moment of the neutron
• $\eta$ and ${\eta }^{\prime }$ masses and decay constants
• Spin dependence of η meson production in proton-proton collisions close to threshold
• Study of semi-inclusive production of eta' mesons in B decays

Cited by in corpus (36)

• An updated review of the new hadron states
• Precision tests of fundamental physics with $\eta$ and ${\eta }^{\prime }$ mesons
• Study of the axial U(1) anomaly at high temperature with lattice chiral fermions
• Light meson spectroscopy from Dalitz plot analyses of ${\eta }_c$ decays to ${\eta }^{\prime }{K}^{+}{K}^{-}$, ${\eta }^{\prime }{\pi }^{+}{\pi }^{-}$, and $\eta {\pi }^{+}{\pi }^{-}$ produced in two-photon interactions
• $S$- and $P$-wave fully-strange tetraquark states from QCD sum rules
• QCD axial anomaly enhances the $\eta {\eta }^{\prime }$ decay of the hybrid candidate ${\eta }_1(1855)$
• The chiral phase transition and the axial anomaly
• Witten-Veneziano mechanism and pseudoscalar glueball-meson mixing in holographic QCD
• Decay behaviors of the fully-bottom and fully-charm tetraquark states
• Comprehensive study of mass modifications of light mesons in nuclear matter in the three-flavor extended Linear Sigma Model
• Photo- and electro-production of narrow exotic states: from light quarks to charm and up to bottom
• Resonance-like structure near the $\eta d$ threshold in the $\gamma d${$\to$}${\pi }^0\eta d$ reaction
• $\eta$-glueball mixing from $N_f=2$ lattice QCD
• ${\pi }^{-}p\to {\eta }^{(\prime )}{\pi }^{-}p$ in the double-Regge region
• $\eta$ and ${\eta }^{\prime }$ mesons in nuclear matter and nuclei
• Search for the $\eta$ mesic ${}^3$He in the $pd\to dp{\pi }^0$ reaction with the WASA-at-COSY facility
• Search for eta mesic 3He with the WASA-at-COSY facility in the pd-> 3He 2gamma and pd-> 3He 6gamma reactions
• Hadronic molecular states with the quark contents $bc\bar{s}\bar{q}$, $b\bar{c}s\bar{q}$, and $b\bar{c}\bar{s}q$
• Gamow-Teller transitions and the spin EMC effect: the Bjorken sum-rule in medium
• Eta-nucleon and eta-prime-nucleon coupling constants in QCD and the role of gluons
• Molecular pentaquark states with open charm and bottom flavors
• Emergent Gauge Symmetries and Particle Physics
• Light Hadron Masses from a Matrix Model for QCD
• Coherent photoproduction of the neutral pion and eta meson on the deuteron at incident energies below 1.15 GeV
• Spectral function of the ${\eta }^{\prime }$ meson in nuclear medium based on phenomenological models
• Measurement of the absolute branching fractions of Jpsi to gamma eta and eta decay modes
• Two-gluon production of $\varphi$ and ${\eta }^{\prime }$ mesons in proton-proton collisions at high energies
• Status of the search for $\eta$-mesic nuclei with particular focus on $\eta$-Helium bound states
• Pion-induced production of $\Lambda (1520)$ hyperons on nuclei near threshold
• Exotic properties of N^*(1895) and its impact on photoproduction of light hyperons
• The ${\eta }^{\prime }N$ interaction from the ${\eta }^{\prime }p$ correlation function
• Revisiting ${\eta }^{\prime }(958)$ nuclear states
• Near-threshold ${\eta }^{\prime }$ meson production in ${\pi }^{-}A$ reactions
• Nature of $X(2370)$
• Different scenarios of dynamical chiral symmetry breaking in the interacting instanton liquid model via flavor symmetry breaking
• Feasibility of the observation of ${\eta }^{\prime }$ mesic nuclei in the semi-exclusive ${}^{12}$C($p,dp$) reaction