Baryonic contributions to e+e− yields in a hydrodynamic model of Pb+Au collisions at the SPS Original Research Article

We analyze e+e− yields from matter containing baryons in addition to mesons using a hydrodynamic approach to describe Pb+Au collisions at 158 A GeV/c. We use two distinctly different e+e− production rates to provide contrast. Although the presence of baryons leads to significant enhancement of e+e− emission relative to that from mesons-only matter, the calculated results fall below the data in the range 400 < Me+e−/MeV < 600. The calculated results are, however, only 1.3–1.5 standard deviations below the data, which may not be statistically significant.