|
|
ATLAS Collaboration(Aaboud, M. et al), Alvarez Piqueras, D., Barranco Navarro, L., Cabrera Urban, S., Castillo Gimenez, V., Cerda Alberich, L., et al. (2018). Search for photonic signatures of gauge-mediated supersymmetry in 13 TeV pp collisions with the ATLAS detector. Phys. Rev. D, 97(9), 092006–32pp.
Abstract: A search is presented for photonic signatures, motivated by generalized models of gauge-mediated supersymmetry breaking. This search makes use of proton-proton collision data at root s = 13 TeV corresponding to an integrated luminosity of 36.1 fb(-1) recorded by the ATLAS detector at the LHC, and it explores models dominated by both strong and electroweak production of supersymmetric partner states. Experimental signatures incorporating an isolated photon and significant missing transverse momentum are explored. These signatures include events with an additional photon or additional jet activity not associated with any specific underlying quark flavor. No significant excess of events is observed above the Standard Model prediction, and 95% confidence-level upper limits of between 0.083 and 0.32 fb are set on the visible cross section of contributions from physics beyond the Standard Model. These results are interpreted in terms of lower limits on the masses of gluinos, squarks, and gauginos in the context of generalized models of gauge-mediated supersymmetry, which reach as high as 2.3 TeV for strongly produced and 1.3 TeV for weakly produced supersymmetric partner pairs.
|
|
|
|
ATLAS Collaboration(Aaboud, M. et al), Alvarez Piqueras, D., Barranco Navarro, L., Cabrera Urban, S., Castillo Gimenez, V., Cerda Alberich, L., et al. (2018). Search for a Structure in the B-s(0) pi(+/-) Invariant Mass Spectrum with the ATLAS Experiment. Phys. Rev. Lett., 120(20), 202007–19pp.
Abstract: A search for the narrow structure, X(5568), reported by the DO Collaboration in the decay sequence X -> B-s(0) pi +/-, B-s(0) -> J/psi phi, is presented. The analysis is based on a data sample recorded with the ATLAS detector at the LHC corresponding to 4.9 fb(-1) of pp collisions at 7 TeV and 19.5 fb(-1)at 8 TeV. No significant signal was found. Upper limits on the number of signal events, with properties corresponding to those reported by DO, and on the A production rate relative to B-s(0) mesons, rho x, were determined at 95% confidence level. The results are N(X) < 382 and rho x <0.015 for B-s(0) mesons with transverse momenta above 10 GeV and N(X) < 356 and rho(x) < 0.016 for transverse momenta above 15 GeV. Limits are also set for potential B-s(0) pi(+) resonances in the mass range 5550 to 5700 MeV.
|
|
|
|
ATLAS Collaboration(Aaboud, M. et al), Alvarez Piqueras, D., Barranco Navarro, L., Cabrera Urban, S., Castillo Gimenez, V., Cerda Alberich, L., et al. (2019). Search for light resonances decaying to boosted quark pairs and produced in association with a photon or a jet in proton-proton collisions at root s=13 TeV with the ATLAS detector. Phys. Lett. B, 788, 316–335.
Abstract: This Letter presents a search for new light resonances decaying to pairs of quarks and produced in association with a high-p(T) photon or jet. The dataset consists of proton-proton collisions with an integrated luminosity of 36.1 fb(-1) at a centre-of-mass energy of root s = 13 TeV recorded by the ATLAS detector at the Large Hadron Collider. Resonance candidates are identified as massive large-radius jets with substructure consistent with a particle decaying into a quark pair. The mass spectrum of the candidates is examined for local excesses above background. No evidence of a new resonance is observed in the data, which are used to exclude the production of a lepto-phobic axial-vector Z' boson. (C) 2018 The Author(s). Published by Elsevier B.V.
|
|
|
|
ATLAS Collaboration(Aaboud, M. et al), Alvarez Piqueras, D., Bailey, A. J., Barranco Navarro, L., Cabrera Urban, S., Castillo Gimenez, V., et al. (2018). Search for W ' -> tb decays in the hadronic final state using pp collisions at root s=13 TeV with the ATLAS detector. Phys. Lett. B, 781, 327–348.
Abstract: A search for W'-boson production in the W' -> t (b) over bar -> q (q) over bar 'b (b) over bar decay channel is presented using 36.1 fb(-1) of 13 TeV proton-proton collision data collected by the ATLAS detector at the Large Hadron Collider in 2015 and 2016. The search is interpreted in terms of both a left-handed and a right-handed chiral W' boson within the mass range 1-5 TeV. Identification of the hadronically decaying top quark is performed using jet substructure tagging techniques based on a shower deconstruction algorithm. No significant deviation from the Standard Model prediction is observed and the results are expressed as upper limits on the W' -> t (b) over bar production cross-section times branching ratio as a function of the W'-boson mass. These limits exclude W' bosons with right-handed couplings with masses below 3.0 TeV and W' bosons with left-handed couplings with masses below 2.9 TeV, at the 95% confidence level.
|
|
|
|
ATLAS Collaboration(Aaboud, M. et al), Alvarez Piqueras, D., Barranco Navarro, L., Cabrera Urban, S., Castillo Gimenez, V., Cerda Alberich, L., et al. (2018). Search for High-Mass Resonances Decaying to tau nu in pp Collisions at root s=13 TeV with the ATLAS Detector. Phys. Rev. Lett., 120(16), 161802–20pp.
Abstract: A search for high-mass resonances decaying to tau nu using proton-proton collisions at root s = 13 TeV produced by the Large Hadron Collider is presented. Only tau-lepton decays with hadrons in the final state are considered. The data were recorded with the ATLAS detector and correspond to an integrated luminosity of 36.1 fb(-1). No statistically significant excess above the standard model expectation is observed; model-independent upper limits are set on the visible tau nu production cross section. Heavy W' bosons with masses less than 3.7 TeV in the sequential standard model and masses less than 2.2-3.8 TeV depending on the coupling in the nonuniversal Go(221) model are excluded at the 95% credibility level.
|
|
