Lepton Pair Production in Hadronic Collisions

Abstract

This is a review of the experimental status of production of massive (m ⩾ 1 GeV) lepton pairs in hadronic collisions.¹ The catch-all diagrams (Fig. 1) illustrate the principal motivations for this ever-expanding activity:

$$ pp \to {\ell ^ + }{\ell ^ - } + \,\,hadrons.{\,^2}$$

(1a)

It provides a third reaction to the probe of hadronic substructure via virtual photons; the other two being

$$ep \to e\,\, + \,\,hadrons\,;$$

(1b)

$${e^ + }{e^ - }\, \to \,hadrons\,\,.$$

(1c)

The relevant energy variable for (1b) is Q², the momentum transfer. This is limited by the energy of lepton beams ∿ 200 GeV at FNAL and SPS implies a Q_max ² ∿ 400 GeV².