Search for top squarks in final states with one isolated lepton, jets, and missing transverse momentum in root s=13 TeV pp collisions with the ATLAS detector

TY - JOUR

T1 - Search for top squarks in final states with one isolated lepton, jets, and missing transverse momentum in root s=13 TeV pp collisions with the ATLAS detector

AU - Aaboud, M.

AU - Aad, G.

AU - Abbott, B.

AU - Abdinov, O.

AU - Abeloos, B

AU - AbouZeid, O.S.

AU - Abraham, NL

AU - Abramowicz, H.

AU - Dam, Mogens

AU - Hansen, Jørn Dines

AU - Hansen, Jørgen Beck

AU - Xella, Stefania

AU - Hansen, Peter Henrik

AU - Petersen, Troels Christian

AU - Thomsen, Lotte Ansgaard

AU - Pingel, Almut Maria

AU - Løvschall-Jensen, Ask Emil

AU - Alonso Diaz, Alejandro

AU - Monk, James William

AU - Pedersen, Lars Egholm

AU - Wiglesworth, Graig

AU - Galster, Gorm Aske Gram Krohn

PY - 2016/9/19

Y1 - 2016/9/19

N2 - The results of a search for the top squark, the supersymmetric partner of the top quark, in final states with one isolated electron or muon, jets, and missing transverse momentum are reported. The search uses the 2015 LHC pp collision data at a center-of-mass energy of s=13 TeV recorded by the ATLAS detector and corresponding to an integrated luminosity of 3.2 fb-1. The analysis targets two types of signal models: gluino-mediated pair production of top squarks with a nearly mass-degenerate top squark and neutralino and direct pair production of top squarks, decaying to the top quark and the lightest neutralino. The experimental signature in both signal scenarios is similar to that of a top quark pair produced in association with large missing transverse momentum. No significant excess over the Standard Model background prediction is observed, and exclusion limits on gluino and top squark masses are set at 95% confidence level. The results extend the LHC run-1 exclusion limit on the gluino mass up to 1460 GeV in the gluino-mediated scenario in the high gluino and low top squark mass region and add an excluded top squark mass region from 745 to 780 GeV for the direct top squark model with a massless lightest neutralino. The results are also reinterpreted to set exclusion limits in a model of vectorlike top quarks.

AB - The results of a search for the top squark, the supersymmetric partner of the top quark, in final states with one isolated electron or muon, jets, and missing transverse momentum are reported. The search uses the 2015 LHC pp collision data at a center-of-mass energy of s=13 TeV recorded by the ATLAS detector and corresponding to an integrated luminosity of 3.2 fb-1. The analysis targets two types of signal models: gluino-mediated pair production of top squarks with a nearly mass-degenerate top squark and neutralino and direct pair production of top squarks, decaying to the top quark and the lightest neutralino. The experimental signature in both signal scenarios is similar to that of a top quark pair produced in association with large missing transverse momentum. No significant excess over the Standard Model background prediction is observed, and exclusion limits on gluino and top squark masses are set at 95% confidence level. The results extend the LHC run-1 exclusion limit on the gluino mass up to 1460 GeV in the gluino-mediated scenario in the high gluino and low top squark mass region and add an excluded top squark mass region from 745 to 780 GeV for the direct top squark model with a massless lightest neutralino. The results are also reinterpreted to set exclusion limits in a model of vectorlike top quarks.

U2 - 10.1103/PhysRevD.94.052009

DO - 10.1103/PhysRevD.94.052009

M3 - Journal article

SN - 2470-0010

VL - 94

JO - Physical Review D

JF - Physical Review D

IS - 5

M1 - 052009

ER -