TY - JOUR T1 - A search for resonances decaying into a Higgs boson and a new particle \(X\) in the \({XH}\) -> \({qqbb}\) final state with the ATLAS detector JF - Physics letters B N2 - A search for heavy resonances decaying into a Higgs boson (H) and a new particle (X) is reported, utilizing 36.1 fb(-1) of proton-proton collision data at root s = 13 TeV collected during 2015 and 2016 with the ATLAS detector at the CERN Large Hadron Collider. The particle Xis assumed to decay to a pair of light quarks, and the fully hadronic final state XH -> q (q) over bar 'b (b) over bar is analysed. The search considers the regime of high XH resonance masses, where the X and H bosons are both highly Lorentz-boosted and are each reconstructed using a single jet with large radius parameter. A two-dimensional phase space of XH mass versus X mass is scanned for evidence of a signal, over a range of XH resonance mass values between 1 TeV and 4 TeV, and for X particles with masses from 50 GeV to 1000 GeV. All search results are consistent with the expectations for the background due to Standard Model processes, and 95% CL upper limits are set, as a function of XH and X masses, on the production cross-section of the XH -> q (q) over bar 'b (b) over bar resonance. (c) 2018 The Author(s). Published by Elsevier B.V. KW - Proton-Proton Collisions KW - Root-S=13 TEV KW - MASS Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-225435 VL - 779 ER - TY - JOUR A1 - Rogowski-Lehmann, Natalie A1 - Geroula, Aikaterini A1 - Prejbisz, Aleksander A1 - Timmers, Henri J. L. M. A1 - Megerle, Felix A1 - Robledo, Mercedes A1 - Fassnacht, Martin A1 - Fliedner, Stephanie M. J. A1 - Reincke, Martin A1 - Stell, Anthony A1 - Januszewicz, Andrzej A1 - Lenders, Jacques W. M. A1 - Eisenhofer, Graeme A1 - Beuschlein, Felix T1 - Missed clinical clues in patients with pheochromocytoma/paraganglioma discovered by imaging JF - Endocrine Connections N2 - Background: Pheochromocytomas and paragangliomas (PPGLs) are rare but potentially harmful tumors that can vary in their clinical presentation. Tumors may be found due to signs and symptoms, as part of a hereditary syndrome or following an imaging procedure. Objective: To investigate potential differences in clinical presentation between PPGLs discovered by imaging (iPPGLs), symptomatic cases (sPPGLs) and those diagnosed during follow-up because of earlier disease/known hereditary mutations (fPPGL). Design: Prospective study protocol, which has enrolled patients from six European centers with confirmed PPGLs. Data were analyzed from 235 patients (37 iPPGLs, 36 sPPGLs, 27% fPPGLs) and compared for tumor volume, biochemical profile, mutation status, presence of metastases and self-reported symptoms. iPPGL patients were diagnosed at a significantly higher age than fPPGLs (P<0.001), found to have larger tumors (P=0.003) and higher metanephrine and normetanephrine levels at diagnosis (P=0.021). Significantly lower than in sPPGL, there was a relevant number of self-reported symptoms in iPPGL (2.9 vs 4.3 symptoms, P< 0.001). In 16.2% of iPPGL, mutations in susceptibility genes were detected, although this proportion was lower than that in fPPGL (60.9%) and sPPGL (21.5%). Patients with PPGLs detected by imaging were older, have higher tumor volume and more excessive hormonal secretion in comparison to those found as part of a surveillance program. Presence of typical symptoms indicates that in a relevant proportion of those patients, the PPGL diagnosis had been delayed. Precis: Pheochromocytoma/paraganglioma discovered by imaging are often symptomatic and carry a significant proportion of germline mutations in susceptibility genes. KW - pheochromocytoma KW - paraganglioma KW - imaging KW - signs and symptoms KW - prospective KW - Biochemical-Diagnosis KW - Plasma KW - MASS KW - Normetanephrine KW - Metanephrine KW - Paraganglioma KW - Society KW - Utility Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-226481 VL - 7 IS - 11 ER - TY - JOUR T1 - Search for a heavy Higgs boson decaying into a \(Z\) boson and another heavy Higgs boson in the \({llbb}\) final state in \({pp}\) collisions at root \(s\)=13 TeV with the ATLAS detector JF - Physics Letters B N2 - A search for a heavy neutral Higgs boson, A, decaying into a Z boson and another heavy Higgs boson, H, is performed using a data sample corresponding to an integrated luminosity of 36.1 fb(-1) from proton-proton collisions at root s = 13 TeV recorded in 2015 and 2016 by the ATLAS detector at the Large Hadron Collider. The search considers the Z boson decaying to electrons or muons and the H boson into a pair of b-quarks. No evidence for the production of an A boson is found. Considering each production process separately, the 95% confidence-level upper limits on the pp -> A -> ZH production cross-section times the branching ratio H -> bb are in the range of 14-830 fb for the gluon-gluon fusion process and 26-570 fb for the b-associated process for the mass ranges 130-700 GeV of the H boson and 230-800 GeV of the A boson. The results are interpreted in the context of two-Higgs-doublet models. (C) 2018 Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/). Funded by SCOAP(3). KW - Hadron Colliders KW - Parton Distributions KW - MASS Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-226098 VL - 783 ER - TY - JOUR T1 - Search for the standard model Higgs boson produced in association with top quarks and decaying into a b(b)overbar pair in \(pp\) collisions at root \(s\)=13 TeV with the ATLAS detector JF - Physical Review D N2 - A search for the standard model Higgs boson produced in association with a top-quark pair, t(t)overbarH, is presented. The analysis uses 36.1 fb(-1) of pp collision data at root s = 13 TeV collected with the ATLAS detector at the Large Hadron Collider in 2015 and 2016. The search targets the H -> b(b)overbar decay mode. The selected events contain either one or two electrons or muons from the top-quark decays, and are then categorized according to the number of jets and how likely these are to contain b-hadrons. Multivariate techniques are used to discriminate between signal and background events, the latter being dominated by ft + jets production. For a Higgs boson mass of 125 GeV, the ratio of the measured t(t)overbarH signal cross-section to the standard model expectation is found to be mu = 0.84(-0.61)(+0.64). A value of mu greater than 2.0 is excluded at 95% confidence level (C.L.) while the expected upper limit is mu < 1.2 in the absence of a t(t)overbarH signal. KW - ++ KW - Symmetries KW - program KW - MASS KW - spontaneous symmetry breaking KW - Higgs bosons KW - Top quark Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-226545 VL - 97 IS - 7 ER - TY - JOUR T1 - Search for a Structure in the B-s(0) π\(^{±}\) Invariant Mass Spectrum with the ATLAS Experiment JF - Physical Review Letters N2 - 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. KW - Mass Spectrum KW - Parton Distributions KW - Decay sequence KW - Analysis KW - MASS KW - Hadron colliders KW - Exotic mesons Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-226539 VL - 120 ER - TY - JOUR T1 - Identification of boosted Higgs bosons decaying into \(b\)-quark pairs with the ATLAS detector at 13 TeV JF - European Physical Journal C N2 - This paper describes a study of techniques for identifying Higgs bosons at high transverse momenta decaying into bottom-quark pairs, H -> b (b) over bar, for proton-proton collision data collected by the ATLAS detector at the Large Hadron Collider at a centre-of-mass energy root s = 13 TeV. These decays are reconstructed from calorimeter jets found with the anti-k(t) R = 1.0 jet algorithm. To tag Higgs bosons, a combination of requirements is used: b-tagging of R = 0.2 track-jets matched to the large-R calorimeter jet, and requirements on the jet mass and other jet substructure variables. The Higgs boson tagging efficiency and corresponding multijet and hadronic top-quark background rejections are evaluated using Monte Carlo simulation. Several benchmark tagging selections are defined for different signal efficiency targets. The modelling of the relevant input distributions used to tag Higgs bosons is studied in 36 fb(-1) of data collected in 2015 and 2016 using g -> b (b) over bar and Z(-> b (b) over bar)gamma event selections in data. Both processes are found to be well modelled within the statistical and systematic uncertainties. KW - Parton distributions KW - PP collisions KW - search KW - MASS Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-226812 VL - 79 IS - 836 ER -