Transverse momentum resummation effects in W^+W^- measurements

Abstract

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.

21 pages, 9 figures, v2: minor changes/refs updated

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Cited by in corpus (17)

• Understanding the large-distance behavior of transverse-momentum-dependent parton densities and the Collins-Soper evolution kernel
• Automated NNLL+NLO Resummation for Jet-Veto Cross Sections
• NLO QCD+NLO EW corrections to diboson production matched to parton shower
• Measurements of the Higgs boson production cross section and couplings in the W boson pair decay channel in proton-proton collisions at $\sqrt{s}$ = 13 TeV
• Precision measurement of the W boson decay branching fractions in proton-proton collisions at $\sqrt{s}=$ 13 TeV
• Measurement of $W^{+}{W}^{-}$ production in association with one jet in proton--proton collisions at $\sqrt{s}=8$ TeV with the ATLAS detector
• Constraints on anomalous Higgs boson couplings from its production and decay using the WW channel in proton-proton collisions at $\sqrt{s}$ = 13 TeV
• Transverse momentum resummation at N3LL+NNLO for diboson processes
• Distinctive Heavy Higgs Decays
• $k_t$-factorization vs collinear factorization in $W^{+}{W}^{-}$ pair production at the LHC
• A New Observable for Identifying Dijet Resonances
• Diphoton production at hadron colliders: transverse-momentum resummation at next-to-next-to-leading logarithmic accuracy
• Theory Summary and Prospects
• Search for dark matter particles in W${}^{+}$W${}^{-}$ events with transverse momentum imbalance in proton-proton collisions at $\sqrt{s}$ = 13 TeV
• Measurements of $W^{+}{W}^{-}$ production cross-sections in $pp$ collisions at $\sqrt{s}=13$ TeV with the ATLAS detector
• Threshold resummation for $W$-boson pair production at NNLO+NNLL
• Using Random Forests to Classify W+W- and ttbar Events