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arXiv · 2507.01277

The electromagnetic form factors of $\Sigma$ and $\Sigma^0 \to \Lambda$ transition in the timelike region

Cheng Chen·Bing Yan·Bing-Wei Long·Ju-Jun Xie
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Abstract

We investigate the $e^+e^-\to \Sigma\bar{\Sigma}$ and $e^+e^-\to \Lambda\bar{\Sigma}^0$ reactions within the extended vector meson dominance model. In addition to the ground state mesons $\rho$ and $\omega$, we consider the contributions of the excited states $\rho(3D)$, $\omega(3D)$, $\phi(3D)$, and $\rho(6D)$. It is found that the current experimental data on the $\Sigma$ electromagnetic form factors in timelike region can be well reproduced. And the $\phi(3D)$ resonance is essential to the near threshold enhancement of the cross section for the $e^+e^-\to \Sigma\bar{\Sigma}$ reaction. Furthermore, in the $e^+e^-\to \Lambda\bar{\Sigma}^0$ reaction, the $\rho(3D)$ is important to get a good fit for the experimental results.

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Cheng Chen, Bing Yan, Bing-Wei Long, Ju-Jun Xie. 2025-07-02. The electromagnetic form factors of $\Sigma$ and $\Sigma^0 \to \Lambda$ transition in the timelike region. https://arxiv.org/abs/2507.01277

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