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Bound-state effects in μ^+ e^- \to γγand \bar{B}^{0}_s \to γγdecays

J. O. Eeg·K. Kumericki·I. Picek
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Abstract

We demonstrate that in the double-radiative decays of heavy-light QED and QCD atoms, μ^{+} e^{-} \to γγand \bar{B}^{0}_{s} \to γγ, there is a contribution coming from operators that vanish on the free-quark mass shell. This off-shell effect is suppressed with respect to the effect of the well known flavour-changing magnetic-moment operator by the bound-state binding factor. Accordingly, the negligible off-shellness of the weakly bound QED atoms becomes important for strongly bound QCD atoms. We present this effect in two different model-approaches to QCD, one of them enabling us to keep close contact to the related effect in QED.

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J. O. Eeg, K. Kumericki, I. Picek. 2000-07-17. Bound-state effects in μ^+ e^- \to γγand \bar{B}^{0}_s \to γγdecays. https://doi.org/10.1007/s100520000471

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