Low-mass lepton pairs from hadron and neutrino beams

A simple model based on meson annihilation is proposed to explain low-mass production of lepton pairs for both hadron and neutrino beams. Resonances, such as the $\rho$ and $\omega$, are naturally taken into account and are shown to give rise to a large but unexpected contribution at very low pair masses. Numerical results are given together with comparisons to data. For the most part, the normalizations are taken from other experimental data.