Generalized vector-dominance model of dilepton production

Abstract

We construct a model for dilepton production in hadron-hadron interactions based on the idea of generalized vector dominance. We argue that in the high-mass region the generalized vector-dominance model and the Drell-Yan parton model are alternative descriptions of the same underlying physics. In the low-mass regions the models differ; the vector-dominance approach predicts a greater production of dileptons. We compare the model to the limited dilepton data that are presently available and also integrate over one of the leptons to study the contributions to the single-lepton yield. We find that the high-mass vector mesons which are the hallmark of the generalized vector-dominance model make little contribution to the large yield of leptons observed in the transverse-momentum range $1<{p}_{\ensuremath{\perp}}<6$ GeV. We illustrate with a simple model, however, the extreme sensitivity of the large-${p}_{\ensuremath{\perp}}$ lepton yield to the large-transverse-momentum tail of vector-meson production.