In-Medium Effects on K0 Mesons in Relativistic Heavy-Ion Collisions

TL;DR

This study measures K0 meson spectra in heavy-ion collisions to investigate in-medium effects, revealing a strong repulsive potential of about 40 MeV, which enhances understanding of kaon behavior in nuclear matter.

Contribution

First experimental measurement of K0 spectra in Ar+KCl collisions at 1.756 A GeV, providing evidence for a significant in-medium kaon potential.

Findings

K0 spectra indicate a strong repulsive in-medium potential (~40 MeV)

Low transverse momentum K0 are effective probes of in-medium effects

Experimental data align with IQMD model predictions

Abstract

We present the transverse momentum spectra and rapidity distributions of $\pi^{-}$ and K$^0_S$ in Ar+KCl reactions at a beam kinetic energy of 1.756 A GeV measured with the spectrometer HADES. The reconstructed K$^0_S$ sample is characterized by good event statistics for a wide range in momentum and rapidity. We compare the experimental $\pi^{-}$ and K$^0_S$ distributions to predictions by the IQMD model. The model calculations show that K$^0_S$ at low tranverse momenta constitute a particularly well suited tool to investigate the kaon in-medium potential. Our K$^0_S$ data suggest a strong repulsive in-medium K$^0$ potential of about 40 MeV strength.