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arXiv · hep-ph/0304173

How to parameterize a light and broad resonance (the $σ$ meson)

Hanqing Zheng
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Abstract

We point out that a commonly used parameterization form to describe the $σ$ resonance is problematic by introducing a spurious singularity below two particle threshold, on the second sheet. The spurious singularity violates chiral symmetry and leads to sizable contribution when the resonance is light and broad -- as what happens to the $σ$ resonance, hence must be removed.

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Hanqing Zheng. 2003-08-06. How to parameterize a light and broad resonance (the $σ$ meson). https://arxiv.org/abs/hep-ph/0304173

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