ATLAS Collaboration(Aad, G. et al), Alvarez Piqueras, D., Cabrera Urban, S., Castillo Gimenez, V., Costa, M. J., Fernandez Martinez, P., et al. (2015). Search for a new resonance decaying to a W or Z boson and a Higgs boson in the ll/lv/vv plus b(b)over-bar final states with the ATLAS detectorv. Eur. Phys. J. C, 75(6), 263–21pp.
Abstract: A search for a new resonance decaying to a W or Z boson and a Higgs boson in the ll/lv/vv + b (b) over bar final states is performed using 20.3 fb(-1) of pp collision data recorded at root s = 8 TeV with the ATLAS detector at the Large Hadron Collider. The search is conducted by examining the WH/ZH invariant mass distribution for a localized excess. No significant deviation from the Standard Model background prediction is observed. The results are interpreted in terms of constraints on the Minimal Walking Technicolor model and on a simplified approach based on a phenomenological Lagrangian of Heavy Vector Triplets.
|
ATLAS Collaboration(Aad, G. et al), Amos, K. R., Aparisi Pozo, J. A., Bailey, A. J., Cabrera Urban, S., Cantero, J., et al. (2023). Search for resonant WZ production in the fully leptonic final state in proton-proton collisions at √s=13 TeV with the ATLAS detector. Eur. Phys. J. C, 83(7), 633–34pp.
Abstract: A search for a WZ resonance, in the fully leptonic final state (electrons or muons), is performed using 139 fb(-1) of data collected at a centre-of-mass energy of 13 TeV by the ATLAS detector at the Large Hadron Collider. The results are interpreted in terms of a singly charged Higgs boson of the Georgi-Machacek model, produced by WZ fusion, and of a Heavy Vector Triplet, with the resonance produced by WZ fusion or the Drell-Yan process. No significant excess over the Standard Model prediction is observed and limits are set on the production cross-section times branching ratio as a function of the resonance mass for these processes.
|
ATLAS Collaboration(Aad, G. et al), Aparisi Pozo, J. A., Bailey, A. J., Cabrera Urban, S., Cardillo, F., Castillo Gimenez, V., et al. (2021). Search for chargino-neutralino pair production in final states with three leptons and missing transverse momentum in root s=13 TeV pp collisions with the ATLAS detector. Eur. Phys. J. C, 81(12), 1118–55pp.
Abstract: A search for chargino-neutralino pair production in three-lepton final states with missing transverse momentum is presented. The study is based on a dataset of root s = 13 TeV pp collisions recorded with the ATLAS detector at the LHC, corresponding to an integrated luminosity of 139 fb(-1). No significant excess relative to the Standard Model predictions is found in data. The results are interpreted in simplified models of supersymmetry, and statistically combined with results from a previous ATLAS search for compressed spectra in two-lepton final states. Various scenarios for the production and decay of charginos ((chi) over tilde (+/-)(1)) and neutralinos ((chi) over tilde (0)(2)) are considered. For pure higgsino (chi) over tilde (+/-)(1)(chi) over tilde (0)(2) pair-production scenarios, exclusion limits at 95% confidence level are set on (chi) over tilde (0)(2) masses up to 210 GeV. Limits are also set for pure wino (chi) over tilde (+/-)(1)(chi) over tilde (0)(2) pair production, on (chi) over tilde (0)(2) masses up to 640 GeV for decays via on-shell W and Z bosons, up to 300 GeV for decays via off-shell W and Z bosons, and up to 190 GeV for decays via W and Standard Model Higgs bosons.
|
ATLAS Collaboration(Aad, G. et al), Aparisi Pozo, J. A., Bailey, A. J., Cabrera Urban, S., Castillo, F. L., Castillo Gimenez, V., et al. (2020). 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. Eur. Phys. J. C, 80(8), 737–44pp.
Abstract: 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.
|
ATLAS Collaboration(Aad, G. et al), Alvarez Piqueras, D., Cabrera Urban, S., Castillo Gimenez, V., Costa, M. J., Fernandez Martinez, P., et al. (2016). Search for direct top squark pair production in final states with two tau leptons in pp collisions at root s=8 TeV with the ATLAS detector. Eur. Phys. J. C, 76(2), 81–30pp.
Abstract: A search for direct pair production of the supersymmetric partner of the top quark, decaying via a scalar tau to a nearly massless gravitino, has been performed using 20 fb(-1) of proton-proton collision data at root s = 8 TeV. The data were collected by the ATLAS experiment at the LHC in 2012. Top squark candidates are searched for in events with either two hadronically decaying tau leptons, one hadronically decaying tau and one light lepton, or two light leptons. No significant excess over the Standard Model expectation is found. Exclusion limits at 95 % confidence level are set as a function of the top squark and scalar tau masses. Depending on the scalar tau mass, ranging from the 87 GeV LEP limit to the top squark mass, lower limits between 490 and 650 GeV are placed on the top squark mass within the model considered.
|
