Search for lepton-flavor-violating decays of the Z boson into a r lepton and a light lepton with the ATLAS detector



Aaboud, M, Aad, G, Abbott, B, Abdinov, O, Abeloos, B, Abhayasinghe, DK, Abidi, SH, AbouZeid, OS, Abraham, NL, Abramowicz, H
et al (show 2900 more authors) (2018) Search for lepton-flavor-violating decays of the Z boson into a r lepton and a light lepton with the ATLAS detector. PHYSICAL REVIEW D, 98 (9). 092010-.

Access the full-text of this item by clicking on the Open Access link.
[img] Text
1804.09568v1.pdf - Submitted version

Download (1MB)

Abstract

Direct searches for lepton flavor violation in decays of the $Z$ boson with the ATLAS detector at the LHC are presented. Decays of the $Z$ boson into an electron or a muon and a hadronically decaying $\tau$ lepton are considered. The searches are based on a data sample of proton-proton collisions collected by the ATLAS detector in 2015 and 2016, corresponding to an integrated luminosity of 36.1 fb$^{-1}$ at a center-of-mass energy of $\sqrt{s} = 13$ TeV. No significant excess of events above the expected background is observed, and upper limits on the branching ratios of lepton-flavor-violating decays are set at the 95% confidence level: $\mathcal{B} (Z\to e\tau) < 5.8 \times 10^{-5}$ and $\mathcal{B} (Z\to \mu\tau) < 2.4 \times 10^{-5}$. This is the first limit on $\mathcal{B} (Z\to e\tau)$ with ATLAS data. The upper limit on $\mathcal{B} (Z\to \mu\tau)$ is combined with a previous ATLAS result based on 20.3 fb$^{-1}$ of proton-proton collision data at a center-of-mass energy of $\sqrt{s} = 8$ TeV and the combined upper limit at 95% confidence level is $\mathcal{B} (Z\to \mu\tau) < 1.3 \times 10^{-5}$.

Item Type: Article
Additional Information: 43 pages in total, author list starting page 27, 8 figures, 6 tables, published in Phys. Rev. D. All figures including auxiliary figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/EXOT-2016-36/
Uncontrolled Keywords: hep-ex, hep-ex
Depositing User: Symplectic Admin
Date Deposited: 19 Sep 2018 09:26
Last Modified: 26 Apr 2023 22:36
DOI: 10.1103/PhysRevD.98.092010
Open Access URL: https://journals.aps.org/prd/abstract/10.1103/Phys...
Related URLs:
URI: https://livrepository.liverpool.ac.uk/id/eprint/3026487