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arXiv · 1709.08595

Theoretical analysis of the $\gamma\gamma \to \pi^0 \eta$ process

Igor Danilkin·Oleksandra Deineka·Marc Vanderhaeghen
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Abstract

We present a theoretical study of the $\gamma\gamma \to \pi\eta$ process from the threshold up to 1.4 GeV in the $\pi\eta$ invariant mass. For the s-wave $a_0(980)$ resonance state we adopt a dispersive formalism using a coupled-channel Omn\`es representation, while the d-wave $a_2(1320)$ state is described as a Breit-Wigner resonance. An analytic continuation to the $a_0(980)$ pole position allows us to extract its two-photon decay width as $\Gamma_{a_0\to\gamma\gamma}=0.27(4)$ keV.

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Igor Danilkin, Oleksandra Deineka, Marc Vanderhaeghen. 2017-09-25. Theoretical analysis of the $\gamma\gamma \to \pi^0 \eta$ process. https://doi.org/10.1103/physrevd.96.114018

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