Two-photon width of etab, eta'b and eta''b from Heavy-Quark Spin Symmetry
Abstract
We predict the two-photon width of the pseudoscalar bottomonia, Gamma(etab -> gamma gamma), Gamma(eta'b -> gamma gamma) and Gamma(eta''b -> gamma gamma) within a Heavy-Quark Spin-Symmetry setting following the same line as our recent work for the corresponding decays for charmonia. Binding-energy effects are included for excited states and are shown to shift up the eta'b and eta''b widths by 10 %. We point out that the essentially model independent ratio Gamma(etab -> gamma gamma)/Gamma(Upsilon -> ll) and the branching ratio BR(etab -> gamma gamma) obtained could be used to extract the coupling constant alphas.
Turn this paper into a full lesson
ArcXiv compiles a staged curriculum from this paper: 8-12 lessons across beginner → advanced, synthesised section guides, visuals, flashcards, a quiz, exercises, and on-demand deep dives per section. Grounded in the abstract, never invented.