학술논문
Search for Z′ bosons decaying to pairs of heavy Majorana neutrinos in proton-proton collisions at s = 13 TeV
Document Type
Original Paper
Author
Source
Journal of High Energy Physics. 2023(11)
Subject
Language
English
ISSN
1029-8479
Abstract
Abstract: A search for the production of pairs of heavy Majorana neutrinos (Nℓ ) from the decays of Z′ bosons is performed using the CMS detector at the LHC. The data were collected in proton-proton collisions at a center-of-mass energy of smNℓmZ′mZ′mNℓmZ′mNℓmZ′mZ′ = 13 TeV, with an integrated luminosity of 138 fb−1 . The signature for the search is an excess in the invariant mass distribution of the final-state objects, two same-flavor leptons (e or μ) and at least two jets. No significant excess of events beyond the expected background is observed. Upper limits at 95% confidence level are set on the product of the Z′ production cross section and its branching fraction to a pair of Nℓ , as functions of Nℓ and Z′ boson masses (smNℓmZ′mZ′mNℓmZ′mNℓmZ′mZ′ and smNℓmZ′mZ′mNℓmZ′mNℓmZ′mZ′, respectively) for smNℓmZ′mZ′mNℓmZ′mNℓmZ′mZ′ from 0.4 to 4.6 TeV and smNℓmZ′mZ′mNℓmZ′mNℓmZ′mZ′ from 0.1 TeV to smNℓmZ′mZ′mNℓmZ′mNℓmZ′mZ′/2. In the theoretical framework of a left-right symmetric model, exclusion bounds in the smNℓmZ′mZ′mNℓmZ′mNℓmZ′mZ′-smNℓmZ′mZ′mNℓmZ′mNℓmZ′mZ′ plane are presented in both the electron and muon channels. The observed upper limit on smNℓmZ′mZ′mNℓmZ′mNℓmZ′mZ′ reaches up to 4.42 TeV. These are the most restrictive limits to date on the mass of Nℓ as a function of the Z′ boson mass.