2018/09/30 by I. D. Bobovnikov, P. Osland, A. A. Pankov · 3 citations
Physics and Astronomy · #hep-ph
paper · pdf · doi:10.1103/physrevd.98.095029
published as Phys. Rev. D 98, 095029 (2018) · 16 pages, some figures. arXiv admin note: text overlap with arXiv:1707.02717, arXiv:1406.6776. v2: version to appear in PRD
arxiv created 2018/11/23 · arxiv updated 2018/12/05
New neutral vector bosons Z' decaying to charged gauge boson pairs W+W- are predicted in many scenarios of new physics, including models with an extended gauge sector such as E6, left-right symmetric Z^′\rm LRS and the sequential standard model Z'\rm SSM. For these benchmark models we calculate and present theoretical expectations for different values of the Z^′ mass M2 and mixing parameter ξ. Our results are based on the narrow width approximation which allows to make a convenient comparison of experiment to theoretical benchmark models. The diboson production allows to place stringent constraints on the Z-Z' mixing angle and the Z' mass, which we determine by using data from pp collisions at √(s)=13 TeV recorded by the ATLAS detector at the CERN LHC, with integrated luminosity of ∼ 36 fb-1. By comparing the experimental limits to the theoretical predictions for the total cross section of Z' resonant production and its subsequent decay into W+W- pairs, we show that the derived constraints on the mixing angle for the benchmark models are of the order of a few × 10-4, i.e., greatly improved with respect to those derived from the global analysis of electroweak data. We combine the limits derived from diboson production data with those obtained from the Drell--Yan process in order to significantly extend the exclusion region in the M2-ξ parameter plane. Also, we demonstrate that further improvement on the constraining of this mixing can be achieved through analysis of the full set of Run~II data.