Search for new non-resonant phenomena in high-mass dilepton final states with the ATLAS detector
Date
2020
Authors
Aad, G.
Abbott, B.
Abbott, D.C.
Abed Abud, A.
Abeling, K.
Abhayasinghe, D.K.
Abidi, S.H.
AbouZeid, O.S.
Abraham, N.L.
Abramowicz, H.
Journal Title
Journal ISSN
Volume Title
Publisher
Journal of High Energy Physics
Abstract
A search for new physics with non-resonant signals in dielectron and dimuon final states in the mass range above 2 TeV is presented. This is the first search for non-resonant signals in dilepton final states at the LHC to use a background estimate from the data. The data, corresponding to an integrated luminosity of 139 fb−1, were recorded by the ATLAS experiment in proton-proton collisions at a center-of-mass energy of s√ = 13 TeV during Run 2 of the Large Hadron Collider. The benchmark signal signature is a two-quark and two-lepton contact interaction, which would enhance the dilepton event rate at the TeV mass scale. To model the contribution from background processes a functional form is fit to the dilepton invariant-mass spectra in data in a mass region below the region of interest. It is then extrapolated to a high-mass signal region to obtain the expected background there. No significant deviation from the expected background is observed in the data. Upper limits at 95% CL on the number of events and the visible cross-section times branching fraction for processes involving new physics are provided. Observed (expected) 95% CL lower limits on the contact interaction energy scale reach 35.8 (37.6) TeV.
Description
We thank CERN for the very successful operation of the LHC, as well as the support staff
from our institutions without whom ATLAS could not be operated efficiently. The crucial computing support from all WLCG partners is acknowledged gratefully,
in particular from CERN, the ATLAS Tier-1 facilities at TRIUMF (Canada), NDGF
(Denmark, Norway, Sweden), CC-IN2P3 (France), KIT/GridKA (Germany), INFN-CNAF
(Italy), NL-T1 (Netherlands), PIC (Spain), ASGC (Taiwan), RAL (UK) and BNL (USA),
the Tier-2 facilities worldwide and large non-WLCG resource providers. Major contributors
of computing resources are listed in ref. [52].
Keywords
Hadron-Hadron scattering (experiments)
Citation
Aad, G., Abbott, B., Abbott, D. C., Abed Abud, A., Abeling, K., Abhayasinghe, D. K., … Zwalinkski, L. (2020). Search for new non-resonant phenomena in high-mass dilepton final states with the ATLAS detector. Journal of High Energy Physics, 2020(5). https://doi.org/10.1007/JHEP11(2020)005