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arXiv · 0710.3403

On the two-photon decay width of the sigma meson

Francesco Giacosa·Thomas Gutsche·Valery E. Lyubovitskij
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Abstract

We shortly report on the two-photon decay width of the light $σ$-meson interpreted as a quarkonium state. Results are given in dependence on the $σ$-mass and the constituent mass of the light quark. The triangle quark-loop diagram, responsible for the two-photon transition, is carefully evaluated: a term in the transition amplitude, often omitted in literature, results in destructive interference with the leading term. As a result we show that the two-photon decay width of the $σ$ in the quarkonium picture is less than 1 keV for the physical range of parameters.

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Francesco Giacosa, Thomas Gutsche, Valery E. Lyubovitskij. 2008-03-12. On the two-photon decay width of the sigma meson. https://doi.org/10.1103/physrevd.77.034007

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