%0 Journal Article %T Search for new phenomena in events with two opposite-charge leptons, jets and missing transverse momentum in pp collisions at root s=13 TeV with the ATLAS detector %A ATLAS Collaboration (Aad, G. et al %A Aparisi Pozo, J. A. %A Bailey, A. J. %A Cabrera Urban, S. %A Cardillo, F. %A Castillo, F. L. %A Castillo Gimenez, V. %A Costa, M. J. %A Escobar, C. %A Estrada Pastor, O. %A Ferrer, A. %A Fiorini, L. %A Fullana Torregrosa, E. %A Fuster, J. %A Garcia, C. %A Garcia Navarro, J. E. %A Gonzalez de la Hoz, S. %A Gonzalvo Rodriguez, G. R. %A Guerrero Rojas, J. G. R. %A Higon-Rodriguez, E. %A Lacasta, C. %A Lozano Bahilo, J. J. %A Mamuzic, J. %A Marti-Garcia, S. %A Martinez Agullo, P. %A Mitsou, V. A. %A Moreno Llacer, M. %A Poveda, J. %A Prades IbaƱez, A. %A Rodriguez Bosca, S. %A Ruiz-Martinez, A. %A Sabatini, P. %A Salt, J. %A Santra, A. %A Sayago Galvan, I. %A Soldevila, U. %A Sanchez, J. %A Torro Pastor, E. %A Valero, A. %A Valls Ferrer, J. A. %A Villaplana Perez, M. %A Vos, M. %J Journal of High Energy Physics %D 2021 %V 04 %N 4 %I Springer %@ 1029-8479 %G English %F ATLASCollaborationAad_etal2021 %O WOS:000642153100001 %O exported from refbase (https://references.ific.uv.es/refbase/show.php?record=4795), last updated on Mon, 10 May 2021 14:42:06 +0000 %X The results of a search for direct pair production of top squarks and for dark matter in events with two opposite-charge leptons (electrons or muons), jets and missing transverse momentum are reported, using 139 fb(-1) of integrated luminosity from proton-proton collisions at root s = 13 TeV, collected by the ATLAS detector at the Large Hadron Collider during Run 2 (2015-2018). This search considers the pair production of top squarks and is sensitive across a wide range of mass differences between the top squark and the lightest neutralino. Additionally, spin-0 mediator dark-matter models are considered, in which the mediator is produced in association with a pair of top quarks. The mediator subsequently decays to a pair of dark-matter particles. No significant excess of events is observed above the Standard Model background, and limits are set at 95% confidence level. The results exclude top squark masses up to about 1 TeV, and masses of the lightest neutralino up to about 500 GeV. Limits on dark-matter production are set for scalar (pseudoscalar) mediator masses up to about 250 (300) GeV. %K Hadron-Hadron scattering (experiments) %R 10.1007/JHEP04(2021)165 %U https://arxiv.org/abs/2102.01444 %U https://doi.org/10.1007/JHEP04(2021)165 %P 165-62pp