  The W^+W^- cross section has remained one of the most consistently discrepant
channels compared to SM predictions at the LHC, measured by both ATLAS and CMS
at 7 and 8 TeV. Developing a better modeling of this channel is crucial to
understanding properties of the Higgs and potential new physics. In this paper
we investigate the effects of NNLL transverse momentum resummation in measuring
the W^+W^- cross section. In the formalism we employ, transverse momentum
resummation does not change the total inclusive cross section, but gives a more
accurate prediction for the p_T distribution of the diboson system. By
re-weighting the p_T distribution of events produced by Monte Carlo generators,
we find a systematic shift that decreases the experimental discrepancy with the
SM prediction by approximately 3-7% depending on the MC generator and parton
shower used. The primary effect comes from the jet veto cut used by both
experiments. We comment on the connections to jet veto resummation, and other
methods the experiments can use to test this effect. We also discuss the
correlation of resummation effects in this channel with other diboson channels.
Ultimately p_T resummation improves the agreement between the SM and
experimental measurements for most generators, but does not account for the
measured ~20% difference with the SM and further investigations into this
channel are needed.
