NNLOPS accurate predictions for $W^{+}{W}^{-}$ production

Abstract

We present novel predictions for the production of $W^{+}{W}^{-}$ pairs in hadron collisions that are next-to-next-to-leading order accurate and consistently matched to a parton shower (NNLOPS). All diagrams that lead to the process $pp\to e^{-}{\bar{\nu }}_e{\mu }^{+}{\nu }_{\mu }+X$ are taken into account, thereby including spin correlations and off-shell effects. For the first time full NNLOPS accuracy is achieved for a $2\to 4$ process. We find good agreement, at the 1$\sigma$ level, with the $W^{+}{W}^{-}$ rates measured by ATLAS and CMS. The importance of NNLOPS predictions is evident from differential distributions sensitive to soft-gluon effects and from the large impact ($10$% and more) of including next-to-next-to-leading order corrections on top of MiNLO. We define a charge asymmetry for the $W$ bosons and the leptons in $W^{+}{W}^{-}$ production at the LHC, which is sensitive to the $W$ polarizations and hence can be used as a probe of new physics.

Comments: 40 pages, 11 figures, 3 tables