Observation of Electroweak Production of Pairs of; <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline">; <mml:mi>Z</mml:mi>; </mml:math>; Bosons in Proton-Proton Collisions at 13 TeV | CU Experts

; The first evidence of electroweak (EW) production of pairs of; ; Z; ; bosons in association with two jets (jj) in the final state; ; ; Z; Z; jj; →; ℓ; ℓ; ν; ν; jj; ; ; , where; ; ℓ; =; e; ; ,; ; ; μ; ; ; , is reported by the CMS experiment. The analysis is based on a data sample of proton-proton (; ; p; p; ; ) collisions at; ; ; s; ; =; 13; ; ; TeV; ; , corresponding to an integrated luminosity of; ; 138; ; ; ; fb; ; −; 1; ; ; ; . Events are selected by requiring exactly two leptons of same flavor and opposite charge, large missing transverse momentum, and two jets with a large rapidity separation and large invariant mass. The EW production cross section in a fiducial volume is; ; ; ; ; σ; ; ; EW; ; ; (; p; p; →; Z; Z; jj; →; ℓ; ℓ; ν; ν; jj; ); =; ; 0.3; ; ; 7; ; ; −; 0.12; ; ; +; 0.14; ; ; ; ; (; stat; ); ; ; −; 0.06; ; ; +; 0.06; ; ; ; (; syst; ); ; ; ; fb; ; ; , in agreement with the standard model prediction of; ; 0.39; ±; 0.06; ; ; fb; ; . The observed (expected) significance of the signal is 3.1 (2.8) standard deviations. Limits on anomalous quartic gauge couplings are derived in terms of dimension-8 effective field theory operators. A combination with the previously reported result from the; ; Z; Z; ; decay channel with four charged leptons yields an observed (expected) significance of 5.0 (4.5) standard deviations for the EW production of; ; Z; ; boson pairs.;

Gevorgyan A; Hayrapetyan A; Makarenko V; Tumasyan A; Adam W; Benato L; Bergauer T; Dragicevic M; Gundacker S; Guven AK

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