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arXiv · 0704.2368

Lightest scalar in the SU_L(2)*SU_R(2) linear σmodel

N. N. Achasov·G. N. Shestakov
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Abstract

We consider the lightest scalar meson in the frame of the $SU_L(2)\times SU_R(2)$ linear $σ$ model, keeping in mind that this model could be the low energy realization of the two-flavour QCD. We show that the $σ$ field is described by its four-quark component at least in the $σ$ resonance energy (virtuality) region and the $σ\toγγ$ decay is the four quark transition. We emphasize that residues of the $σ$ pole in the $ππ\toππ$ and $γγ\toππ$ amplitudes do not give an idea about the $σ$ meson nature, and the progress in studying the $σ$ meson production mechanisms in different processes could essentially further us in understanding its nature.

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N. N. Achasov, G. N. Shestakov. 2007-08-18. Lightest scalar in the SU_L(2)*SU_R(2) linear σmodel. https://doi.org/10.1103/physrevlett.99.072001

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