Preliminary results from the 2000 run of CERES on low-mass $e^{+}e^{-}$ pair production in Pb - Au collisions at 158 A GeV

CERES has measured low-mass $e^{+}e^{-}$ pairs in Pb- Au collisions at 158 A GeV in the year 2000 Pb run at the SPS with the goal of shedding more light on the origin of the previously observed low-mass pair enhancement. The spectrometer was upgraded with a radial TPC to improve the mass resolution. A very effective rejection of the combinatorial background is achieved using the combined information of the two RICH detectors, the d$E$/dx signal of the doublet of silicon drift chambers, and the TPC track d$E$/dx information. Various steps and the current status of the data analysis are presented. Corrigendum. Table 1 and figures 3 and 4, as originally published, represent an earlier version of the data analysis. The corrected table and figures have been published as a Corrigendum (see below). The Corrigendum has also been appended at the end of the PDF file linked to this page.