Exclusive dilepton and Upsilon production with CMS: a feasibility study

Exclusive production of dileptons with no significant additional activity in the CMS detector occurs with high cross section in gamma-mediated processes at the LHC. A feasibility study based on a full CMS simulation concludes that selecting events with a single pair of back-to-back $\mu^{+}\mu^{-}$ or $e^{+}e^{-}$ provides a high-statistics calibration sample, e.g. for luminosity measurement and alignment of forward proton detectors. Photoproduction of Upsilon mesons, another copious source of exclusive dileptons, is also presented.