Revisit of Coulomb effects on pi^{-}/pi^{+} ratio in heavy-ion collisions

Abstract

It is shown that the large $\pi^{-}/\pi^{+}$ ratio at low pion energies recently observed in the reaction of Au+Au at $E_{beam}/A=1.0$ GeV at SIS/GSI is due to the strong Coulomb field of the reaction system.