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$η$-meson in nuclear matter

X. H. Zhong·G. X. Peng·Lei Li·P. Z. Ning
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Abstract

The $η$-nucleon ($η$N) interactions are deduced from the heavy baryon chiral perturbation theory up to the next-to-leading-order terms. Combining the relativistic mean-field theory for nucleon system, we have studied the in-medium properties of $η$-meson. We find that all the elastic scattering $η$N interactions come from the next-to-leading-order terms. The $η$N sigma term is found to be about 280$\pm$130 MeV. The off-shell terms are also important to the in-medium properties of $η$-meson. On application of the latest determination of the $η$N scattering length, the ratio of $η$-meson effective mass to its vacuum value is near $0.84\pm0.015$, while the optical potential is about $-(83\pm5)$ MeV, at the normal nuclear density.

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X. H. Zhong, G. X. Peng, Lei Li, P. Z. Ning. 2005-11-27. $η$-meson in nuclear matter. https://doi.org/10.1103/physrevc.73.015205

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