Two-photon decay of pseudoscalar quarkonia

Abstract

We report on our recent evaluation of the two-photon width of the pseudoscalar quarkonia, eta_c(nS) and eta_b(nS) in an approach based on Heavy-Quark Spin Symmetry (HQSS). To what concerns the 1S state eta_c, our parameter-free computation agrees with experiments, as well as most of other theoretical works. On the other hand, our computation for the 2S-state looks 2S like a confirmation that there may exist an anomaly related to the decay of eta_c(2S), especially in the light of the new preliminary result of the Belle collaboration. We also point out that the essentially model-independent ratio of eta_b two-photon width to the Upsilon leptonic width and the eta_b two-photon width could be used to extract the strong coupling constant alpha_s.

Presented by T.N. Pham at the Joint Meeting Heidelberg-Liege-Paris-Wroclaw (HLPW08), Spa, Belgium, 6-8 March 2008, 9 pages, 2 figures, LaTeX, uses aip-6s.clo, aipproc.cls and aipxfm.sty (included)

References in corpus (9)

• J/psi, psi' and Upsilon Production at Hadron Colliders: a review
• Observation of the eta_c(2S) in exclusive B-->K KsK-pi+ decays
• Two-Photon Decays of Mesons in a Relativistic Quark Model
• Dynamic Properties of Charmonium
• Annihilation Rate of Heavy $0^{-+}$ Quarkonium in Relativistic Salpeter Method
• Two-photon width of eta_c and eta'_c from Heavy-Quark Spin Symmetry
• Two-photon width of eta_b, eta'_b and eta''_b from Heavy-Quark Spin Symmetry
• etab Decay into Two Photons
• On the relations between two-photon and leptonic widths of low-lying S-wave states of charmonium

Cited by in corpus (5)

• Partonic structure of neutral pseudoscalars via two photon transition form factors
• Effective Lagrangian for Two-photon and Two-gluon Decays of $P$-wave Heavy Quarkonium ${\chi }_{c0,2}$ and ${\chi }_{b0,2}$ states
• Two-Photon, Two-gluon and Radiative Decays of Heavy Flavoured Mesons
• Photo-production of ${\eta }_{c,b}$ near Threshold
• Measurement of eta_c(1S), eta_c(2S) and non-resonant eta' pi+ pi- production via two-photon collisions