$ZZ$ production at the LHC: NNLO predictions for $2\ell 2\nu$ and $4\ell$ signatures

Abstract

We consider QCD radiative corrections to $ZZ$ production for all experimentally relevant leptonic processes. We report on a novel computation of next-to-next-to-leading-order (NNLO) corrections to the diboson signature with two charged leptons and missing transverse energy ($\ell \ell$+$E_T^{\mathrm{miss}}$). All relevant final states are considered: $\ell \ell {\nu }_{\ell }{\nu }_{\ell }$, $\ell \ell {\nu }_{{\ell }^{\prime }}{\nu }_{{\ell }^{\prime }}$ and $\ell {\nu }_{\ell }{\ell }^{\prime }{\nu }_{{\ell }^{\prime }}$. We also study processes with four charged leptons: $\ell \ell \ell \ell$ and $\ell \ell {\ell }^{\prime }{\ell }^{\prime }$. For the first time NNLO accuracy is achieved for a process mixing two double-resonant diboson topologies ($ZZ/W^{+}{W}^{-}\to \ell \ell {\nu }_{\ell }{\nu }_{\ell }$). We find good agreement with ATLAS data at 8 TeV. NNLO corrections are large (5-20% and more), and interference effects between $ZZ$ and $W^{+}{W}^{-}$ resonances turn out to be negligible in most cases.

Comments: 14 pages, 6 figures, 2 tables