COULOMB EFFECTS ON PARTICLE SPECTRA IN RELATIVISTIC NUCLEAR COLLISIONS

Coulomb effects on pi(+/-) and K+/- spectra in relativistic nuclear co llisions are investigated. At collision energies around 1 GeV the rati o of pi(-) to pi(+) is enhanced several times at low transverse moment a but less at ultrarelativistic energies. We describe the ratios at SI S, AGS, and SPS energies with simple analytic models as well as more e laborate numerical models incorporating the expansion dynamics. The Co ulomb effect depends on the properties of the source after the violent collision phase and provides information on source sizes, freeze-out times, and expansion velocities. Comparison with results from HBT anal yses are made. Predictions for pi(+/-) and K+/- at RHIC and LHC energi es are given. [S0556-2813(98)02105-0].