Exclusive dilepton production in ultraperipheral $PbPb$ collisions at the LHC.

In this paper we perform a systematic study of the exclusive dilepton production by $\gamma \gamma$ interactions in $PbPb$ collisions at the LHC Run 2 energies considering different levels of precision for the treatment of the absorptive corrections and for the nuclear form factor. The rapidity and invariant mass distributions are estimated taking into account the experimental cutoffs and a comparison with the recent ALICE and ATLAS data for the $e^+ e^-$ and $\mu^+ \mu^-$ production is presented.