Anomalous triple gauge couplings in the light of dimension-8 operators in $W^+W^-$

Abstract

We compare the size of dimension-8 effects on $W^+W^-$ production at the LHC arising from the $q\bar q$ and $γγ$ initial states. In particular, we consider bosonic operators, which contribute to the anomalous triple and quadruple gauge couplings. The relevant dimension-6 and dimension-8 operators are matched to the anomalous triple gauge couplings that contribute to the $q\bar q$ channel, allowing for the resummation of large logarithmic contributions arising in the presence of a jet-veto through the program MCFM-RE. For the $γγ$ channel, which receives contributions from both triple and quadruple gauge couplings, such resummation can be performed through the program MadGraph, by simply setting the factorisation scale to the jet-veto scale. We find that, when neglecting fermionic dimension-8 operators, the $γγ$ channel has a dominant bosonic dimension-8 contribution and this channel can be used to understand the range of validity of the Effective Field Theory. With this in mind, and carefully considering theoretical and experimental uncertainties, we provide constraints on higher dimensional operators using current and future data.