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arXiv · 2206.07110

Precision measurement of the Z boson invisible width in pp collisions at $\sqrt{s}$ = 13 TeV

CMS Collaboration
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Abstract

A precise measurement of the invisible width of the Z boson produced in proton-proton collisions at a center-of-mass energy of 13 TeV is presented using data recorded by the CMS experiment at the LHC, corresponding to an integrated luminosity of 36.3 fb$^{-1}$. The result is obtained from a simultaneous fit to kinematic distributions for two data samples of Z boson plus jets: one dominated by Z boson decays to invisible particles and the other by Z boson decays to muon and electron pairs. The invisible width is measured to be 523 $\pm$ 3 (stat) $\pm$ 16 (syst) MeV. This result is the first precise measurement of the invisible width of the Z boson at a hadron collider, and is the single most precise direct measurement to date, competitive with the combined result of the direct measurements from the LEP experiments.

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CMS Collaboration. 2023-06-01. Precision measurement of the Z boson invisible width in pp collisions at $\sqrt{s}$ = 13 TeV. https://doi.org/10.1016/j.physletb.2022.137563

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