e+ e- pairs from pi- A reactions

Abstract

We calculate dilepton production for the reactions ${\pi }^{-}$C and ${\pi }^{-}$Pb at 1.3 GeV within a semi-classical BUU transport model and compare our results to a previously published calculation. We show that a modified treatment of the $\rho$-meson production and propagation gives substantially different results. We, furthermore, discuss uncertainties related to the electromagnetic decay of the $\rho$-meson and the elementary ${\pi }^{-}N\to e^{+}{e}^{-}X$ channels.

Comments: 12 pages, including 4 postscript figures