@article{KaireitSorrentinoRenneetal.2017, author = {Kaireit, Till F. and Sorrentino, Sajoscha A. and Renne, Julius and Schoenfeld, Christian and Voskrebenzev, Andreas and Gutberlet, Marcel and Schulz, Angela and Jakob, Peter M. and Hansen, Gesine and Wacker, Frank and Welte, Tobias and T{\"u}mmler, Burkhard and Vogel-Claussen, Jens}, title = {Functional lung MRI for regional monitoring of patients with cystic fibrosis}, series = {PLoS ONE}, volume = {12}, journal = {PLoS ONE}, number = {12}, doi = {10.1371/journal.pone.0187483}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-172457}, year = {2017}, abstract = {Purpose To test quantitative functional lung MRI techniques in young adults with cystic fibrosis (CF) compared to healthy volunteers and to monitor immediate treatment effects of a single inhalation of hypertonic saline in comparison to clinical routine pulmonary function tests. Materials and methods Sixteen clinically stable CF patients and 12 healthy volunteers prospectively underwent two functional lung MRI scans and pulmonary function tests before and 2h after a single treatment of inhaled hypertonic saline or without any treatment. MRI-derived oxygen enhanced T1 relaxation measurements, fractional ventilation, first-pass perfusion parameters and a morpho-functional CF-MRI score were acquired. Results Compared to healthy controls functional lung MRI detected and quantified significantly increased ventilation heterogeneity in CF patients. Regional functional lung MRI measures of ventilation and perfusion as well as the CF-MRI score and pulmonary function tests could not detect a significant treatment effect two hours after a single treatment with hypertonic saline in young adults with CF (p>0.05). Conclusion This study shows the feasibility of functional lung MRI as a non-invasive, radiation-free tool for monitoring patients with CF.}, language = {en} } @article{OPUS4-22582, title = {Measurement of the exclusive gamma gamma -> mu\(^+\)mu\(^-\) process in proton-proton collisions at root s=13 TeV with the ATLAS detector}, series = {Physics Letters B}, volume = {777}, journal = {Physics Letters B}, organization = {The ATLAS Collaboration}, doi = {10.1016/j.physletb.2017.12.043}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-225825}, pages = {303-323}, year = {2018}, abstract = {The production of exclusive gamma gamma -> mu(+)mu(-) events in proton-proton collisions at a centre-of-mass energy of 13 TeV is measured with the ATLAS detector at the LHC, using data corresponding to an integrated luminosity of 3.2 fb(-1). The measurement is performed for a dimuon invariant mass of 12 GeV < m(mu+mu-) < 70 GeV. The integrated cross-section is determined within a fiducial acceptance region of the ATLAS detector and differential cross-sections are measured as a function of the dimuon invariant mass. The results are compared to theoretical predictions both with and without corrections for absorptive effects. (c) 2017 The Author(s). Published by Elsevier B.V.}, language = {en} } @article{OPUS4-22689, title = {Observation of Light-by-Light Scattering in Ultraperipheral Pb + Pb Collisions with the ATLAS Detector}, series = {Physical Review Letters}, volume = {123}, journal = {Physical Review Letters}, organization = {The ATLAS Collaboration}, doi = {10.1103/PhysRevLett.123.052001}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-226892}, pages = {1-21}, year = {2019}, abstract = {This Letter describes the observation of the light-by-light scattering process, gamma gamma -> gamma gamma, in Pb + Pb collisions at root S-NN = 5.02 TeV. The analysis is conducted using a data sample corresponding to an integrated luminosity of 1.73 nb(-1), collected in November 2018 by the ATLAS experiment at the LHC. Light-by-light scattering candidates are selected in events with two photons produced exclusively, each with transverse energy E-T(gamma) > 3 GeV and pseudorapidity vertical bar eta(gamma)vertical bar < 2.4, diphoton invariant mass above 6 GeV, and small diphoton transverse momentum and acoplanarity. After applying all selection criteria, 59 candidate events are observed for a background expectation of 12 +/- 3 events. The observed excess of events over the expected background has a significance of 8.2 standard deviations. The measured fiducial cross section is 78 +/- 13(stat) +/- 7(syst) +/- 3(lumi) nb.}, language = {en} } @article{OPUS4-22578, title = {Search for diboson resonances with boson-tagged jets in \({pp}\) collisions at root S=13 TeV with the ATLAS detector}, series = {Physics Letters B}, volume = {777}, journal = {Physics Letters B}, organization = {The ATLAS Collaboration}, doi = {10.1016/j.physletb.2017.12.011}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-225782}, pages = {91-113}, year = {2018}, abstract = {Narrow resonances decaying into WW, WZ or ZZ boson pairs are searched for in 36.7 fb(-1) of proton-proton collision data at a centre-of-mass energy of root s = 13 TeV recorded with the ATLAS detector at the Large Hadron Collider in 2015 and 2016. The diboson system is reconstructed using pairs of large-radius jets with high transverse momentum and tagged as compatible with the hadronic decay of high-momentum Wor Zbosons, using jet mass and substructure properties. The search is sensitive to diboson resonances with masses in the range 1.2-5.0 TeV. No significant excess is observed in any signal region. Exclusion limits are set at the 95\% confidence level on the production cross section times branching ratio to dibosons for a range of theories beyond the Standard Model. Model-dependent lower limits on the mass of new gauge bosons are set, with the highest limit set at 3.5 TeV in the context of mass-degenerate resonances that couple predominantly to bosons. (c) 2017 The Author(s). Published by Elsevier B.V.}, language = {en} } @article{OPUS4-22611, title = {Search for flavour-changing neutral current top-quark decays \(t\) -> \({qZ}\) in proton-proton collisions at root s=13 TeV with the ATLAS detector}, series = {Journal of High Energy Physics}, volume = {176}, journal = {Journal of High Energy Physics}, number = {7}, organization = {The ATLAS Collaboration}, doi = {10.1007/JHEP07(2018)176}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-226114}, pages = {1-40}, year = {2018}, abstract = {A search for flavour-changing neutral-current processes in top-quark decays is presented. Data collected with the ATLAS detector from proton-proton collisions at the Large Hadron Collider at a centre-of-mass energy of root s = 13TeV, corresponding to an integrated luminosity of 36.1 fb(-1), are analysed. The search is performed using top-quark pair events, with one top quark decaying through the t -> qZ (q = u, c) flavour-changing neutral-current channel, and the other through the dominant Standard Model mode t -> bW. Only Z boson decays into charged leptons and leptonic W boson decays are considered as signal. Consequently, the final-state topology is characterized by the presence of three isolated charged leptons (electrons or muons), at least two jets, one of the jets originating from a b-quark, and missing transverse momentum from the undetected neutrino. The data are consistent with Standard Model background contributions, and at 95\% confidence level the search sets observed (expected) upper limits of 1.7 x 10(-4) (2.4 x 10(-4)) on the t -> uZ branching ratio and 2.4 x 10(-4) (3.2 x 10(-4)) on the t -> cZ branching ratio, constituting the most stringent limits to date.}, language = {en} } @article{OPUS4-31736, title = {Search for heavy particles decaying into a top-quark pair in the fully hadronic final state in \({pp}\) collisions at root s=13 TeV with the ATLAS detector}, series = {Physical Review D}, volume = {99}, journal = {Physical Review D}, number = {9}, organization = {The ATLAS Collaboration}, doi = {10.1103/PhysRevD.99.092004}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-317362}, pages = {1-38}, year = {2019}, abstract = {A search for new particles decaying into a pair of top quarks is performed using proton-proton collision data recorded with the ATLAS detector at the Large Hadron Collider at a center-of-mass energy of root s = 13 TeV corresponding to an integrated luminosity of 36.1 fb(-1). Events consistent with top-quark pair production and the fully hadronic decay mode of the top quarks are selected by requiring multiple high transverse momentum jets including those containing b-hadrons. Two analysis techniques, exploiting dedicated top-quark pair reconstruction in different kinematic regimes, are used to optimize the search sensitivity to new hypothetical particles over a wide mass range. The invariant mass distribution of the two reconstructed top-quark candidates is examined for resonant production of new particles with various spins and decay widths. No significant deviation from the Standard Model prediction is observed and limits are set on the production cross-section times branching fraction for new hypothetical Z' bosons, dark-matter mediators, Kaluza-Klein gravitons and Kaluza-Klein gluons. By comparing with the predicted production cross sections, the Z' boson in the topcolor-assisted-technicolor model is excluded for masses up to 3.1-3.6 TeV, the dark-matter mediators in a simplified framework are excluded in the mass ranges from 0.8 to 0.9 TeV and from 2.0 to 2.2 TeV, and the Kaluza-Klein gluon is excluded for masses up to 3.4 TeV, depending on the decay widths of the particles.}, language = {en} } @article{OPUS4-22610, title = {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}, series = {European Physical Journal C}, volume = {78}, journal = {European Physical Journal C}, organization = {The ATLAS Collaboration}, doi = {10.1140/epjc/s10052-018-6081-9}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-226109}, pages = {1-38}, year = {2018}, abstract = {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.}, language = {en} } @article{OPUS4-22608, title = {Search for top squarks decaying to tau sleptons in \(pp\) collisions at root \(s\)=13 TeV with the ATLAS detector}, series = {Physical Review D}, volume = {98}, journal = {Physical Review D}, organization = {The ATLAS Collaboration}, doi = {10.1103/PhysRevD.98.032008}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-226080}, pages = {1-33}, year = {2018}, abstract = {A search for direct pair production of top squarks in final states with two tau leptons, b-jets, and missing transverse momentum is presented. The analysis is based on proton-proton collision data at root s = 13 TeV corresponding to an integrated luminosity of 36.1 fb(-1) recorded with the ATLAS detector at the Large Hadron Collider in 2015 and 2016. Two exclusive channels with either two hadronically decaying tau leptons or one hadronically and one leptonically decaying tau lepton are considered. No significant deviation from the Standard Model predictions is observed in the data. The analysis results are interpreted in terms of model-independent limits and used to derive exclusion limits on the masses of the top squark (t) over tilde (1) and the tau slepton (tau) over tilde (1) in a simplified model of supersymmetry with a nearly massless gravitino. In this model, masses up to m((t) over tilde (1)) = 1.16 TeV and m ((tau) over tilde (1)) = 1.00 TeV are excluded at 95\% confidence level.}, language = {en} } @article{OPUS4-22073, title = {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}, series = {Journal of High Energy Physics}, volume = {108}, journal = {Journal of High Energy Physics}, number = {6}, organization = {The ATLAS collaboration}, doi = {10.1007/JHEP06(2018)108}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-220733}, pages = {1-95}, year = {2018}, abstract = {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.}, language = {en} } @article{OPUS4-22598, title = {Search for W ' -> \({tb}\) decays in the hadronic final state using \({pp}\) collisions at root s=13 TeV with the ATLAS detector}, series = {Physics Letters B}, volume = {781}, journal = {Physics Letters B}, organization = {The ATLAS Collaboration}, doi = {10.1016/j.physletb.2018.03.036}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-225987}, pages = {327-348}, year = {2018}, 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. (C) 2018 The Author. Published by Elsevier B.V.}, language = {en} } @article{SchlottmannSchickeKruegeretal.2019, author = {Schlottmann, Elisabeth and Schicke, David and Kr{\"u}ger, Felix and Lingnau, Benjamin and Schneider, Christian and H{\"o}fling, Sven and L{\"u}dge, Kathy and Porte, Xavier and Reitzenstein, Stephan}, title = {Stochastic polarization switching induced by optical injection in bimodal quantum-dot micropillar lasers}, series = {Optics Express}, volume = {27}, journal = {Optics Express}, number = {20}, doi = {10.1364/OE.27.028816}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-228603}, pages = {28816-28831}, year = {2019}, abstract = {Mutual coupling and injection locking of semiconductor lasers is of great interest in non-linear dynamics and its applications for instance in secure data communication and photonic reservoir computing. Despite its importance, it has hardly been studied in microlasers operating at mu W light levels. In this context, vertically emitting quantum dot micropillar lasers are of high interest. Usually, their light emission is bimodal, and the gain competition of the associated linearly polarized fundamental emission modes results in complex switching dynamics. We report on selective optical injection into either one of the two fundamental mode components of a bimodal micropillar laser. Both modes can lock to the master laser and influence the non-injected mode by reducing the available gain. We demonstrate that the switching dynamics can be tailored externally via optical injection in very good agreement with our theory based on semi-classical rate equations. (C) 2019 Optical Society of America under the terms of the OSA Open Access Publishing Agreement}, language = {en} }