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What can we learn from a second phi meson peak in ultrarelativistic nuclear collisions?

Che Ming Ko·David Seibert
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Abstract

The decay width of a phi meson is reduced from its vacuum value as its mass decreases in hot hadronic matter as a result of the partial restoration of chiral symmetry. This reduction is, however, cancelled by collisional broadening through the reactions $ϕπ\to KK^*$, $ϕK\toϕK$, $ϕρ\to KK$, and $ϕϕ\to KK$. The resulting phi meson width in hot hadronic matter is found to be less than about 10 MeV for temperatures below 200 MeV. If hadronic matter has a strong first-order phase transition, this narrow phi meson with reduced mass will appear as a second peak in the dilepton spectrum in ultrarelativistic heavy ion collisions. We discuss use of this second phi peak to determine the transition temperature and the lifetime of the two-phase coexistence region in the case of a strong first-order phase transition. We also discuss using the peak to determine the range of temperatures over which the transition occurs in the case of a smooth but fast change in the entropy density.

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Che Ming Ko, David Seibert. 1993-12-15. What can we learn from a second phi meson peak in ultrarelativistic nuclear collisions?. https://doi.org/10.1103/physrevc.49.2198

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