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arXiv · 1507.03769

Moments of $ϕ$ meson spectral functions in vacuum and nuclear matter

Philipp Gubler·Wolfram Weise
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Abstract

Moments of the $ϕ$ meson spectral function in vacuum and in nuclear matter are analyzed, combining a model based on chiral SU(3) effective field theory (with kaonic degrees of freedom) and finite-energy QCD sum rules. For the vacuum we show that the spectral density is strongly constrained by a recent accurate measurement of the $e^+ e^- \to K^+ K^-$ cross section. In nuclear matter the $ϕ$ spectrum is modified by interactions of the decay kaons with the surrounding nuclear medium, leading to a significant broadening and an asymmetric deformation of the $ϕ$ meson peak. We demonstrate that both in vacuum and nuclear matter, the first two moments of the spectral function are compatible with finite-energy QCD sum rules. A brief discussion of the next-higher spectral moment involving strange four-quark condensates is also presented.

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Philipp Gubler, Wolfram Weise. 2015-11-12. Moments of $ϕ$ meson spectral functions in vacuum and nuclear matter. https://doi.org/10.1016/j.physletb.2015.10.068

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