AW Thomas | Searcharxiv

arXiv2007

Progress in Understanding the Nuclear Equation of State at the Quark Level

At the present time there is a lively debate within the nuclear community concerning the relevance of quark degrees of freedom in understanding nuclear structure. We outline the key issues and review the impressive progress made recently within the framework of the quark-meson coupling model. In particular, we explain in quite general terms how the modification of the internal structure of hadrons in-medium leads naturally to three- and four-body forces, or equivalently, to density dependent effective interactions.

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arXiv1998

Sigma and omega meson propagation in a dense nuclear medium

The propagation of the scalar ($σ$) and vector ($ω$) mesons in nuclear matter is studied in detail using the Walecka model over a wide range of densities and including the effects of a finite $σ$ width through the inclusion of a two-pion loop. We calculate the dispersion relation and spectral functions of the $σ$ and (transverse and longitudinal) $ω$ mesons, including the effect of $σ$-$ω$ mixing in matter. It is shown that the mixing effect is quite important in the propagation of the (longitudinal) $ω$ and $σ$ mesons above normal nuclear matter density. We find that there is a two-peak structure in the spectral function of the $σ$ channel, caused by $σ$-$ω$ mixing.

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