Evidence for longitudinally polarized $W$ bosons in the electroweak production of same-sign $W$ boson pairs in association with two jets in pp collisions at $\sqrt{s}=13$ TeV with the ATLAS detector

Abstract

This Letter reports the first evidence of production of same-sign $W$ boson pairs where at least one of the $W$ bosons is longitudinally polarized and the most stringent constraint to date for the production of two longitudinally polarized same-sign $W$ bosons. The data set used corresponds to an integrated luminosity of 140 fb${}^{-1}$ of proton-proton collisions at a center-of-mass energy of 13 TeV, collected with the ATLAS detector during Run 2 of the Large Hadron Collider. The study is performed in final states including two same-sign leptons (electrons or muons), missing transverse momentum, and at least two jets with a large invariant mass and a large rapidity difference. Two independent fits are performed targeting the production of same-sign $W$ bosons with at least one, or two longitudinally polarized $W$ bosons. The observed (expected) significance of the production with at least one longitudinally polarized $W$ boson is 3.3 (4.0) standard deviations. An observed (expected) 95% confidence level upper limit of 0.45 (0.70) fb is reported on the fiducial production cross section of two longitudinally polarized same-sign $W$ bosons.

38 pages in total, author list starting page 21, 4 figures, 5 tables, published Phys. Rev. Lett. All figures including auxiliary figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/STDM-2019-29/

References in corpus (10)

• Observation of a new particle in the search for the Standard Model Higgs boson with the ATLAS detector at the LHC
• Observation of a new boson at a mass of 125 GeV with the CMS experiment at the LHC
• A parton shower algorithm based on Catani-Seymour dipole factorisation
• A portrait of the Higgs boson by the CMS experiment ten years after the discovery
• A detailed map of Higgs boson interactions by the ATLAS experiment ten years after the discovery
• Luminosity determination in $pp$ collisions at $\sqrt{s}=13$ TeV using the ATLAS detector at the LHC
• Measurements of production cross sections of WZ and same-sign WW boson pairs in association with two jets in proton-proton collisions at $\sqrt{s}=$ 13 TeV
• Software and computing for Run 3 of the ATLAS experiment at the LHC
• Measurement and interpretation of same-sign $W$ boson pair production in association with two jets in $pp$ collisions at $\sqrt{s}=13$ TeV with the ATLAS detector
• The performance of missing transverse momentum reconstruction and its significance with the ATLAS detector using 140 fb${}^{-1}$ of $\sqrt{s}=13$ TeV $pp$ collisions

Cited by in corpus (3)

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