%0 Journal Article
%T Search for a scalar partner of the top quark in the all-hadronic t(t)over-bar plus missing transverse momentum final state 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 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 Madaffari, D.
%A Mamuzic, J.
%A Marti-Garcia, S.
%A Martinez Agullo, P.
%A Mitsou, V. A.
%A Moreno Llacer, M.
%A Poveda, J.
%A Rodriguez Bosca, S.
%A Ruiz-Martinez, A.
%A Salt, J.
%A Santra, A.
%A Sayago Galvan, I.
%A Soldevila, U.
%A Sanchez, J.
%A Valero, A.
%A Valls Ferrer, J. A.
%A Vos, M.
%J European Physical Journal C
%D 2020
%V 80
%N 8
%I Springer
%@ 1434-6044
%G English
%F ATLASCollaborationAad_etal2020
%O WOS:000615182800002
%O exported from refbase (https://references.ific.uv.es/refbase/show.php?record=4705), last updated on Tue, 23 Feb 2021 08:54:46 +0000
%X A search for direct pair production of scalar partners of the top quark (top squarks or scalar third-generation up-type leptoquarks) in the all-hadronic t (t) over bar plus missing transverse momentum final state is presented. The analysis of 139 fb(-1) of root s = 13 TeV proton-proton collision data collected using the ATLAS detector at the LHC yields no significant excess over the Standard Model background expectation. To interpret the results, a supersymmetric model is used where the top squark decays via (t) over tilde -> t(*) (chi) over tilde (0)(1), with t(*) denoting an on-shell (off-shell) top quark and (chi) over tilde (0)(1) the lightest neutralino. Three specific event selections are optimised for the following scenarios. In the scenario where m((t) over tilde) > m(t) + m((chi) over tilde 10), top squark masses are excluded in the range 400-1250 GeV for (chi) over tilde (0)(1) masses below 200 GeV at 95% confidence level. In the situation where m((t) over tilde) similar to m(t) + m((chi) over tilde 10), top squarkmasses in the range 300-630 GeV are excluded, while in the case where m((t) over tilde) < m(W) + m(b) + m(<(chi)over tilde>10) (with m((t) over tilde) – m((chi) over tilde 10) >= 5 GeV), considered for the first time in an ATLAS all-hadronic search, top squark masses in the range 300-660 GeV are excluded. Limits are also set for scalar third-generation up-type leptoquarks, excluding leptoquarks with masses below 1240 GeV when considering only leptoquark decays into a top quark and a neutrino.
%R 10.1140/epjc/s10052-020-8102-8
%U https://arxiv.org/abs/2004.14060
%U https://doi.org/10.1140/epjc/s10052-020-8102-8
%P 737 - 44pp