Meson $m_T$-scaling in heavy-ion collisions at SIS energies

Abstract

We perform systematical studies on transverse-mass spectra of ${\pi }^0$, $\eta$, $\omega$, $\varphi$, $K^{+}$ and $K^{-}$ mesons for C + C, Ni + Ni, Au + Au collisions at SIS energies within the HSD transport approach. We find that the $m_T$-spectra sensitively reflect the in-medium properties of the mesons. The 'bare mass' scenario leads to a general scaling behaviour for the meson $m_T$-spectra when including a mass shift due to the associate strangeness production threshold for kaons and antikaons whereas a 'dropping' mass scheme violates this $m_T$-scaling. The relative slope parameters, however, provide valuable information about the average meson potentials in the nuclear medium.

Comments: 15 pages, LaTeX, including 4 postscript figures, UGI-97-29, submitted to Phys. Lett. B