TY - JOUR
T1 - Search for direct top squark pair production in events with a Higgs or Z boson, 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 - Abreu, H.
AU - Abreu, R.
AU - Abulaiti, Y.
AU - Acharya, B.S.
AU - Adachi, Shin-ichi
AU - Dam, Mogens
AU - Hansen, Jørn Dines
AU - Hansen, Jørgen Beck
AU - Xella, Stefania
AU - Hansen, Peter Henrik
AU - Petersen, Troels Christian
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
AU - Stark, Simon Holm
AU - Besjes, Geert-Jan
AU - Thiele, Fabian Alexander Jürgen
AU - de Almeida Dias, Flavia
AU - Bajic, Milena
AU - Barr, John
AU - Arnold, H.
AU - Zhu, H.
AU - Zwalinski, L.
PY - 2017/8/1
Y1 - 2017/8/1
N2 - A search for direct top squark pair production resulting in events with either a same-flavour opposite-sign dilepton pair with invariant mass compatible with a Z boson or a pair of jets compatible with a Standard Model (SM) Higgs boson (h) is presented. Requirements on the missing transverse momentum, together with additional selections on leptons, jets, jets identified as originating from b-quarks are imposed to target the other decay products of the top squark pair. The analysis is performed using proton-proton collision data at s=13 TeV collected with the ATLAS detector at the LHC in 2015–2016, corresponding to an integrated luminosity of 36.1 fb−1. No excess is observed in the data with respect to the SM predictions. The results are interpreted in two sets of models. In the first set, direct production of pairs of lighter top squarks (t˜ 1) with long decay chains involving Z or Higgs bosons is considered. The second set includes direct pair production of the heavier top squark pairs (t˜ 2) decaying via t˜ 2→ Zt˜ 1 or t˜ 2→ ht˜ 1. The results exclude at 95% confidence level t˜ 2 and t˜ 1 masses up to about 800 GeV, extending the exclusion region of supersymmetric parameter space covered by previous LHC searches.[Figure not available: see fulltext.].
AB - A search for direct top squark pair production resulting in events with either a same-flavour opposite-sign dilepton pair with invariant mass compatible with a Z boson or a pair of jets compatible with a Standard Model (SM) Higgs boson (h) is presented. Requirements on the missing transverse momentum, together with additional selections on leptons, jets, jets identified as originating from b-quarks are imposed to target the other decay products of the top squark pair. The analysis is performed using proton-proton collision data at s=13 TeV collected with the ATLAS detector at the LHC in 2015–2016, corresponding to an integrated luminosity of 36.1 fb−1. No excess is observed in the data with respect to the SM predictions. The results are interpreted in two sets of models. In the first set, direct production of pairs of lighter top squarks (t˜ 1) with long decay chains involving Z or Higgs bosons is considered. The second set includes direct pair production of the heavier top squark pairs (t˜ 2) decaying via t˜ 2→ Zt˜ 1 or t˜ 2→ ht˜ 1. The results exclude at 95% confidence level t˜ 2 and t˜ 1 masses up to about 800 GeV, extending the exclusion region of supersymmetric parameter space covered by previous LHC searches.[Figure not available: see fulltext.].
U2 - 10.1007/JHEP08(2017)006
DO - 10.1007/JHEP08(2017)006
M3 - Journal article
SN - 1126-6708
VL - 2017
JO - Journal of High Energy Physics
JF - Journal of High Energy Physics
IS - 8
M1 - 006
ER -