In the case of multiple collision vertices from pileup interactions, the candidate vertex with the largest value of summed physics-object $\pt^2$ is taken to be the primary $\Pp\Pp$ interaction vertex. The physics objects are the jets, clustered using the jet finding algorithm [@Cacciari:2008gp; @Cacciari:2011ma] with the tracks assigned to candidate vertices as inputs, and the associated missing transverse momentum, taken as the negative vector sum of the of those jets. Events affected by reconstruction failures, detector malfunctions, or noncollision backgrounds, are identified and rejected by dedicated filters [@Sirunyan:2019kia].

Electrons are reconstructed by combining information from the tracker and energy deposits in the ECAL [@Khachatryan:2015hwa]. Muons are reconstructed by combining information from the tracker and the muon system [@Sirunyan:2018]. Only tracks originating from the PV can be associated with the electrons or muons, and quality criteria [@Khachatryan:2015hwa; @Sirunyan:2018] are further imposed that obtain more pure identification without substantial loss of efficiency. To suppress leptons stemming from  and  decays, while retaining leptons from  decays, isolation is required from jet activity within a cone of radius $\Delta R = \sqrt{\smash[b]{(\Delta\eta)^2+(\Delta\phi)^2}} = 0.3$. The isolation is defined as the scalar  sum of the PF candidates within the cone divided by the lepton . The 