TY  - JOUR
A1  - Camargo-Molina, J. E.
A1  - Garbrecht, B.
A1  - O'Leary, B.
A1  - Porod, W.
A1  - Staub, F.
T1  - Constraining the Natural MSSM through tunneling to color-breaking vacua at zero and non-zero temperature
JF  - Physics Letters B
N2  - We re-evaluate the constraints on the parameter space of the minimal supersymmetric standard model from tunneling to charge- and/or color-breaking minima, taking into account thermal corrections. We pay particular attention to the region known as the Natural MSSM, where the masses of the scalar partners of the top quarks are within an order of magnitude or so of the electroweak scale. These constraints arise from the interaction between these scalar tops and the Higgs fields, which allows the possibility of parameter points having deep charge- and color-breaking true vacua. In addition to requiring that our electroweak-symmetry-breaking, yet QCD- and electromagnetism-preserving vacuum has a sufficiently long lifetime at zero temperature, also demanding stability against thermal tunneling further restricts the allowed parameter space.
KW  - Supersymmetry
KW  - Vacuum stability
Y1  - 2014
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-118458
VL  - 737
ER  - 
TY  - JOUR
T1  - Search for supersymmetry in final states with two same-sign or three leptons and jets using 36 fb\(^{−1}\) of \(\sqrt{s}=13\) TeV \(pp\) collision data with the ATLAS detector
JF  - Journal of High Energy Physics
N2  - A search for strongly produced supersymmetric particles using signatures involving multiple energetic jets and either two isolated same-sign leptons (\(e\) or \(µ\)), or at least three isolated leptons, is presented. The analysis relies on the identification of \(b\)-jets and high missing transverse momentum to achieve good sensitivity. A data sample of proton-proton collisions at \(\sqrt{s} = 13\) TeV recorded with the ATLAS detector at the Large Hadron Collider in 2015 and 2016, corresponding to a total integrated luminosity of 36.1 fb\(^{−1}\), is used for the search. No significant excess over the Standard Model prediction is observed. The results are interpreted in several simplified supersymmetric models featuring \(R\)-parity conservation or \(R\)-parity violation, extending the exclusion limits from previous searches. In models considering gluino pair production, gluino masses are excluded up to 1.87 TeV at 95% confidence level. When bottom squarks are pair-produced and decay to a chargino and a top quark, models with bottom squark masses below 700 GeV and light neutralinos are excluded at 95% confidence level. In addition, model-independent limits are set on a possible contribution of new phenomena to the signal region yields.
KW  - High energy physics
KW  - Hadron-Hadron scattering (experiments)
KW  - Supersymmetry
Y1  - 2017
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-172787
VL  - 2017
IS  - 09
ER  - 
TY  - JOUR
T1  - Search for new phenomena with large jet multiplicities and missing transverse momentum using large-radius jets and flavour-tagging at ATLAS in 13 TeV \(pp\) collisions
JF  - Journal of High Energy Physics
N2  - A search is presented for particles that decay producing a large jet multiplicity and invisible particles. The event selection applies a veto on the presence of isolated electrons or muons and additional requirements on the number of \(b\)-tagged jets and the scalar sum of masses of large-radius jets. Having explored the full ATLAS 2015-2016 dataset of LHC proton-proton collisions at \(\sqrt{s}\) = 13 TeV, which corresponds to 36.1 fb\(^{−1}\) of integrated luminosity, no evidence is found for physics beyond the Standard Model. The results are interpreted in the context of simplified models inspired by R-parity-conserving and R-parity-violating supersymmetry, where gluinos are pair-produced. More generic models within the phenomenological minimal supersymmetric Standard Model are also considered.
KW  - High energy physics
KW  - Beyond Standard Model
KW  - Hadron-Hadron scattering (experiments)
KW  - Supersymmetry
Y1  - 2017
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-172302
VL  - 34
ER  - 
TY  - JOUR
T1  - Search for top-squark pair production in final states with one lepton, jets, and missing transverse momentum using 36 fb\(^{-1}\) of root s=13 TeV \({pp}\) collision data with the ATLAS detector
JF  - Journal of High Energy Physics
N2  - The results of a search for the direct pair production of top squarks, the supersymmetric partner of the top quark, in final states with one isolated electron or muon, several energetic jets, and missing transverse momentum are reported. The analysis also targets spin-0 mediator models, where the mediator decays into a pair of dark-matter particles and is produced in association with a pair of top quarks. The search uses data from proton-proton collisions delivered by the Large Hadron Collider in 2015 and 2016 at a centre-of-mass energy of root s = 13TeV and recorded by the ATLAS detector, corresponding to an integrated luminosity of 36 fb(-1). A wide range of signal scenarios with different mass-splittings between the top squark, the lightest neutralino and possible intermediate supersymmetric particles are considered, including cases where the W bosons or the top quarks produced in the decay chain are off-shell. No significant excess over the Standard Model prediction is observed. The null results are used to set exclusion limits at 95% confidence level in several supersymmetry benchmark models. For pair-produced top-squarks decaying into top quarks, top-squark masses up to 940 GeV are excluded. Stringent exclusion limits are also derived for all other considered top-squark decay scenarios. For the spin-0 mediator models, upper limits are set on the visible cross-section.
KW  - Hadron-Hadron scattering (experiments)
KW  - Dark-matter production
KW  - Symmetry-breaking
KW  - Plus plus
KW  - Model
KW  - Supersymmetry
KW  - Program
KW  - LHS
KW  - Mass
KW  - Extension
KW  - Physics
Y1  - 2018
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-220733
VL  - 108
IS  - 6
ER  - 
TY  - JOUR
T1  - Search for new phenomena using the invariant mass distribution of same-flavour opposite-sign dilepton pairs in events with missing transverse momentum in root \(s\)=13 TeV \(pp\) collisions with the ATLAS detector
JF  - European Physical Journal C
N2  - A search for new phenomena in final states containing an e(+)e(-) or m(+)m(-) pair, jets, and large missing transverse momentum is presented. This analysis makes use of proton-proton collision data with an integrated luminosity of 36.1 fb(-1), collected during 2015 and 2016 at a centre of-mass energy Os = 13 TeV with the ATLAS detector at the Large Hadron Collider. The search targets the pair production of supersymmetric coloured particles (squarks or gluinos) and their decays into final states containing an e(+)e(-) or m(+)m(-) pair and the lightest neutralino ((c) over tilde (0)(1)) via one of two next-to-lightest neutralino ((c) over tilde (0)(2)) decay mechanisms: (c) over tilde (0)(2) Z (c) over tilde (0)(1), where the Z boson decays leptonically leading to a peak in the dilepton invariant mass distribution around the Z boson mass; and (c) over tilde (0)(2) l(+)1(-) (c) over tilde (0)(1) with no intermediate l(+)l(-) resonance, yielding a kinematic endpoint in the dilepton invariant mass spectrum. The data are found to be consistent with the Standard Model expectation. Results are interpreted using simplified models, and exclude gluinos and squarks with masses as large as 1.85 and 1.3 TeV at 95% confidence level, respectively.
KW  - Parton Distributions
KW  - Gluino Production
KW  - ++
KW  - Extension
KW  - Energy
KW  - Squark
KW  - Supersymmetry
KW  - Physics
KW  - Decay
Y1  - 2018
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-226109
VL  - 78
ER  - 
TY  - JOUR
T1  - A search for pair-produced resonances in four-jet final states at root s=13 TeV with the ATLAS detector
JF  - The European Physical Journal C
N2  - A search for massive coloured resonances which are pair-produced and decay into two jets is presented. The analysis uses 36.7 fb(-1) of root s = 13 TeV pp collision data recorded by the ATLAS experiment at the LHC in 2015 and 2016. No significant deviation from the background prediction is observed. Results are interpreted in a SUSY simplified model where the lightest supersymmetric particle is the top squark, (t) over tilde, which decays promptly into two quarks through R-parity-violating couplings. Top squarks with masses in the range 100 GeV < m((T) over tilde) < 410 GeV are excluded at 95% confidence level. If the decay is into a b-quark and a light quark, a dedicated selection requiring two b-tags is used to exclude masses in the ranges 100 GeV < m((t) over tilde) < 470 GeV and 480 GeV < m(<(t)over tilde>) < 610 GeV. Additional limits are set on the pair-production of massive colour-octet resonances.
KW  - Patron Distributions
KW  - Collicions
KW  - Extension
KW  - Squark
KW  - Supersymmetry
KW  - Color
KW  - Decay
Y1  - 2018
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-225465
VL  - 78
IS  - 250
ER  - 
TY  - JOUR
T1  - Search for pair production of Higgsinos in final states with at least three \(b\)-tagged jets in root \(s\)=13 TeV \(pp\) collisions using the ATLAS detector
JF  - Physical Review D
N2  - A search for pair production of the supersymmetric partners of the Higgs boson (higgsinos (H) over tilde) in gaugemediated scenarios is reported. Each higgsino is assumed to decay to a Higgs boson and a gravitino. Two complementary analyses, targeting high- and low-mass signals, are performed to maximize sensitivity. The two analyses utilize LHC pp collision data at a center-of-mass energy root s = 13 TeV, the former with an integrated luminosity of 36.1 fb(-1) and the latter with 24.3 fb(-1), collected with the ATLAS detector in 2015 and 2016. The search is performed in events containing missing transverse momentum and several energetic jets, at least three of which must be identified as b-quark jets. No significant excess is found above the predicted background. Limits on the cross section are set as a function of the mass of the <(Hover tilde> in simplified models assuming production via mass-degenerate higgsinos decaying to a Higgs boson and a gravitino. Higgsinos with masses between 130 and 230 GeV and between 290 and 880 GeV are excluded at the 95% confidence level. Interpretations of the limits in terms of the branching ratio of the higgsino to a Z boson or a Higgs boson are also presented, and a 45% branching ratio to a Higgs boson is excluded for m(<(Hover tilde>) approximate to 400 GeV.
KW  - Gluino Production
KW  - Supersymmetry
KW  - Extension
KW  - Squark
KW  - Predictions
KW  - Supersymmetric models
KW  - Hierarchy problem
KW  - Extensions of Higgs sector
Y1  - 2018
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-226010
VL  - 98
ER  - 
TY  - JOUR
T1  - Search for squarks and gluinos in final states with same-sign leptons and jets using 139 fb\(^{-1}\) of data collected with the ATLAS detector
JF  - Journal of High Energy Physics
N2  - A search for supersymmetric partners of gluons and quarks is presented, involving signatures with jets and either two isolated leptons (electrons or muons) with the same electric charge, or at least three isolated leptons. A data sample of proton-proton collisions at root s = 13 TeV recorded with the ATLAS detector at the Large Hadron Collider between 2015 and 2018, corresponding to a total integrated luminosity of 139 fb(-1), is used for the search. No significant excess over the Standard Model expectation is observed. The results are interpreted in simplified supersymmetric models featuring both R-parity conservation and R-parity violation, raising the exclusion limits beyond those of previous ATLAS searches to 1600 GeV for gluino masses and 750 GeV for bottom and top squark masses in these scenarios.
KW  - Hadron-Hadron scattering (experiments)
KW  - Supersymmetry
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-277538
IS  - 6
ER  -