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arXiv · 1611.05960

Two Photon Transition Form Factor of $\bar{c}c $ Quarkonia

Jing Chen·Minghui Ding·Lei Chang·Yu-xin Liu
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Abstract

The two photon transition of $\bar{c}c$ quarkonia are studied within a covariant approach based on the consistent truncation scheme of the quantum chromodynamics Dyson-Schwinger equation for the quark propagator and the Bethe--Salpeter equation for the mesons. We find the decay widths of $\eta_{c}^{} \to \gamma\gamma$ and $\chi_{c0,2}^{} \to \gamma\gamma$ in good agreement with experimental data. The obtained transition form factor of $\eta_{c}^{} \to \gamma\gamma^{\ast}$ for a wide range of space-like photon momentum transfer squared is also in agreement with the experimental findings of the BABAR experiment. As a by-product, the decay widths of $\eta_{b}^{},\chi_{b0,2}^{} \to \gamma\gamma$ and the transition form factor of $\eta_{b}^{}, \chi_{c0,b0}^{} \to\gamma\gamma^{\ast}$ are predicted, which await for experimental test.

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Jing Chen, Minghui Ding, Lei Chang, Yu-xin Liu. 2016-11-18. Two Photon Transition Form Factor of $\bar{c}c $ Quarkonia. https://doi.org/10.1103/physrevd.95.016010

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