TY - JOUR
T1 - Search for a scalar partner of the top quark in the all-hadronic tt¯ plus missing transverse momentum final state at √s=13 TeV with the ATLAS detector
AU - Aad, G
AU - Åkesson, Torsten
AU - Bocchetta, Simona
AU - Corrigan, Eric Edward
AU - Doglioni, Caterina
AU - Geisen, Jannik
AU - Gregersen, Kristian
AU - Brottmann Hansen, Eva
AU - Hedberg, Vincent
AU - Jarlskog, Göran
AU - Kellermann, Edgar
AU - Konya, Balazs
AU - Lytken, Else
AU - Mankinen, Katja
AU - Marcon, Caterina
AU - Mjörnmark, Ulf
AU - Mullier, Geoffrey André Adrien
AU - Pöttgen, Ruth
AU - Poulsen, Trine
AU - Skorda, Eleni
AU - Smirnova, Oxana
AU - Zwalinski, L.
AU - ATLAS Collaboration
PY - 2020
Y1 - 2020
N2 - 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 tt¯ plus missing transverse momentum final state is presented. The analysis of 139 fb - 1 of 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~→t(∗)χ~10, with t(∗) denoting an on-shell (off-shell) top quark and χ~10 the lightest neutralino. Three specific event selections are optimised for the following scenarios. In the scenario where mt~>mt+mχ~10, top squark masses are excluded in the range 400–1250 GeV for χ~10 masses below 200 GeV at 95% confidence level. In the situation where mt~∼mt+mχ~10, top squark masses in the range 300–630 GeV are excluded, while in the case where mt~<mW+mb+mχ~10 (with mt~-mχ~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. © 2020, CERN for the benefit of the ATLAS collaboration.
AB - 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 tt¯ plus missing transverse momentum final state is presented. The analysis of 139 fb - 1 of 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~→t(∗)χ~10, with t(∗) denoting an on-shell (off-shell) top quark and χ~10 the lightest neutralino. Three specific event selections are optimised for the following scenarios. In the scenario where mt~>mt+mχ~10, top squark masses are excluded in the range 400–1250 GeV for χ~10 masses below 200 GeV at 95% confidence level. In the situation where mt~∼mt+mχ~10, top squark masses in the range 300–630 GeV are excluded, while in the case where mt~<mW+mb+mχ~10 (with mt~-mχ~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. © 2020, CERN for the benefit of the ATLAS collaboration.
U2 - 10.1140/epjc/s10052-020-8102-8
DO - 10.1140/epjc/s10052-020-8102-8
M3 - Article
SN - 1434-6044
VL - 80
JO - European Physical Journal C
JF - European Physical Journal C
IS - 8
M1 - 737
ER -