Foraging mechanisms in excavate flagellates shed light on the functional ecology of early eukaryotes.

The phagotrophic flagellates described as "typical excavates" have been hypothesized to be morphologically similar to the Last Eukaryotic Common Ancestor and understanding the functional ecology of excavates may therefore help shed light on the ecology of these early eukaryotes. Typical excavates are characterized by a posterior flagellum equipped with a vane that beats in a ventral groove. Here, we combined flow visualization and observations of prey capture in representatives of the three clades of excavates with computational fluid dynamic modeling, to understand the functional significance of this cell architecture.

Acoustic tethering of microorganisms.

We show how to construct and apply a setup to acoustically tether and enable behavioral observations of individual microorganisms using simple laboratory equipment and a standard light microscope. We explore the capability of the setup with the freely swimming dinoflagellate Alexandrium minutum as the study organism. The setup allows us to tether cells in focus in the mid-plane of the sample chamber and make observations of individual organisms at high magnification without affecting their flagellar beat frequencies.

Identification and up-regulation of three small heat shock proteins in summer and winter diapause in response to temperature stress in Pieris melete.

Small heat shock proteins (sHSPs) are conserved proteins that play key roles in organismal adaptation to adversity stressors. However, little is known about sHSPs during summer diapause. Three sHSP genes: PmHSP19.

Longitudinal Flow Decorrelations in Xe+Xe Collisions at sqrt[s_{NN}]=5.44 TeV with the ATLAS Detector.

The first measurement of longitudinal decorrelations of harmonic flow amplitudes v_{n} for n=2-4 in Xe+Xe collisions at sqrt[s_{NN}]=5.44  TeV is obtained using 3  μb^{-1} of data with the ATLAS detector at the LHC. The decorrelation signal for v_{3} and v_{4} is found to be nearly independent of collision centrality and transverse momentum (p_{T}) requirements on final-state particles, but for v_{2} a strong centrality and p_{T} dependence is seen.

Measurement of the Lund Jet Plane Using Charged Particles in 13 TeV Proton-Proton Collisions with the ATLAS Detector.

The prevalence of hadronic jets at the LHC requires that a deep understanding of jet formation and structure is achieved in order to reach the highest levels of experimental and theoretical precision. There have been many measurements of jet substructure at the LHC and previous colliders, but the targeted observables mix physical effects from various origins. Based on a recent proposal to factorize physical effects, this Letter presents a double-differential cross-section measurement of the Lund jet plane using 139  fb^{-1} of sqrt[s]=13  TeV proton-proton collision data collected with the ATLAS detector using jets with transverse momentum above 675 GeV.

Measurement of Azimuthal Anisotropy of Muons from Charm and Bottom Hadrons in pp Collisions at sqrt[s]=13 TeV with the ATLAS Detector.

The elliptic flow of muons from the decay of charm and bottom hadrons is measured in pp collisions at sqrt[s]=13  TeV using a data sample with an integrated luminosity of 150  pb^{-1} recorded by the ATLAS detector at the LHC. The muons from heavy-flavor decay are separated from light-hadron decay muons using momentum imbalance between the tracking and muon spectrometers. The heavy-flavor decay muons are further separated into those from charm decay and those from bottom decay using the distance-of-closest-approach to the collision vertex.

Search for Magnetic Monopoles and Stable High-Electric-Charge Objects in 13 Tev Proton-Proton Collisions with the ATLAS Detector.

A search for magnetic monopoles and high-electric-charge objects is presented using 34.4  fb^{-1} of 13 TeV pp collision data collected by the ATLAS detector at the LHC during 2015 and 2016. The considered signature is based upon high ionization in the transition radiation tracker of the inner detector associated with a pencil-shape energy deposit in the electromagnetic calorimeter.

Observation of Electroweak Production of a Same-Sign W Boson Pair in Association with Two Jets in pp Collisions at sqrt[s]=13 TeV with the ATLAS Detector.

This Letter presents the observation and measurement of electroweak production of a same-sign W boson pair in association with two jets using 36.1  fb^{-1} of proton-proton collision data recorded at a center-of-mass energy of sqrt[s]=13  TeV by the ATLAS detector at the Large Hadron Collider. The analysis is performed in the detector fiducial phase-space region, defined by the presence of two same-sign leptons, electron or muon, and at least two jets with a large invariant mass and rapidity difference.

Observation of Light-by-Light Scattering in Ultraperipheral Pb+Pb Collisions with the ATLAS Detector.

This Letter describes the observation of the light-by-light scattering process, γγ→γγ, in Pb+Pb collisions at sqrt[s_{NN}]=5.02  TeV. The analysis is conducted using a data sample corresponding to an integrated luminosity of 1.

Comparison of Fragmentation Functions for Jets Dominated by Light Quarks and Gluons from pp and Pb+Pb Collisions in ATLAS.

Charged-particle fragmentation functions for jets azimuthally balanced by a high-transverse-momentum, prompt, isolated photon are measured in 25  pb^{-1} of pp and 0.49  nb^{-1} of Pb+Pb collision data at 5.02 TeV per nucleon pair recorded with the ATLAS detector at the Large Hadron Collider.

Combination of Searches for Invisible Higgs Boson Decays with the ATLAS Experiment.

Dark matter particles, if sufficiently light, may be produced in decays of the Higgs boson. This Letter presents a statistical combination of searches for H→invisible decays where H is produced according to the standard model via vector boson fusion, Z(ℓℓ)H, and W/Z(had)H, all performed with the ATLAS detector using 36.1  fb^{-1} of pp collisions at a center-of-mass energy of sqrt[s]=13  TeV at the LHC.

Erratum to: Measurement of the boson polarisation in events from collisions at in the lepton + jets channel with ATLAS.

[This corrects the article DOI: 10.1140/epjc/s10052-017-4819-4.].

Search for the Production of a Long-Lived Neutral Particle Decaying within the ATLAS Hadronic Calorimeter in Association with a Z Boson from pp Collisions at sqrt[s]=13 TeV.

This Letter presents a search for the production of a long-lived neutral particle (Z_{d}) decaying within the ATLAS hadronic calorimeter, in association with a standard model (SM) Z boson produced via an intermediate scalar boson, where Z→ℓ^{+}ℓ^{-} (ℓ=e, μ). The data used were collected by the ATLAS detector during 2015 and 2016 pp collisions with a center-of-mass energy of sqrt[s]=13  TeV at the Large Hadron Collider and correspond to an integrated luminosity of 36.1±0.

Search for doubly charged scalar bosons decaying into same-sign boson pairs with the ATLAS detector.

A search for doubly charged scalar bosons decaying into boson pairs is presented. It uses a data sample from proton-proton collisions corresponding to an integrated luminosity of 36.1 fb collected by the ATLAS detector at the LHC at a centre-of-mass energy of 13 TeV in 2015 and 2016.

Combination of the Searches for Pair-Produced Vectorlike Partners of the Third-Generation Quarks at sqrt[s]=13 TeV with the ATLAS Detector.

A combination of the searches for pair-produced vectorlike partners of the top and bottom quarks in various decay channels (T→Zt/Wb/Ht, B→Zb/Wt/Hb) is performed using 36.1  fb^{-1} of pp collision data at sqrt[s]=13  TeV with the ATLAS detector at the Large Hadron Collider. The observed data are found to be in good agreement with the standard model background prediction in all individual searches.

Observation of Centrality-Dependent Acoplanarity for Muon Pairs Produced via Two-Photon Scattering in Pb+Pb Collisions at sqrt[s_{NN}]=5.02 TeV with the ATLAS Detector.

This Letter presents a measurement of γγ→μ^{+}μ^{-} production in Pb+Pb collisions recorded by the ATLAS detector at the Large Hadron Collider at sqrt[s_{NN}]=5.02  TeV with an integrated luminosity of 0.49  nb^{-1}.

Search for Resonant and Nonresonant Higgs Boson Pair Production in the bb[over ¯]τ^{+}τ^{-} Decay Channel in pp Collisions at sqrt[s]=13 TeV with the ATLAS Detector.

A search for resonant and nonresonant pair production of Higgs bosons in the bb[over ¯]τ^{+}τ^{-} final state is presented. The search uses 36.1  fb^{-1} of pp collision data with sqrt[s]=13  TeV recorded by the ATLAS experiment at the LHC in 2015 and 2016.

Search for heavy particles decaying into top-quark pairs using lepton-plus-jets events in proton-proton collisions at with the ATLAS detector.

A search for new heavy particles that decay into top-quark pairs is performed using data collected from proton-proton collisions at a centre-of-mass energy of 13  by the ATLAS detector at the Large Hadron Collider. The integrated luminosity of the data sample is 36.1 fb .

Probing the Quantum Interference between Singly and Doubly Resonant Top-Quark Production in pp Collisions at sqrt[s]=13 TeV with the ATLAS Detector.

This Letter presents a normalized differential cross-section measurement in a fiducial phase-space region where interference effects between top-quark pair production and associated production of a single top quark with a W boson and a b-quark are significant. Events with exactly two leptons (ee, μμ, or eμ) and two b-tagged jets that satisfy a multiparticle invariant mass requirement are selected from 36.1  fb^{-1} of proton-proton collision data taken at sqrt[s]=13  TeV with the ATLAS detector at the LHC in 2015 and 2016.

Measurement of the Soft-Drop Jet Mass in pp Collisions at sqrt[s]=13 TeV with the ATLAS Detector.

Jet substructure observables have significantly extended the search program for physics beyond the standard model at the Large Hadron Collider. The state-of-the-art tools have been motivated by theoretical calculations, but there has never been a direct comparison between data and calculations of jet substructure observables that are accurate beyond leading-logarithm approximation. Such observables are significant not only for probing the collinear regime of QCD that is largely unexplored at a hadron collider, but also for improving the understanding of jet substructure properties that are used in many studies at the Large Hadron Collider.

Search for new phenomena using the invariant mass distribution of same-flavour opposite-sign dilepton pairs in events with missing transverse momentum in collisions with the ATLAS detector.

A search for new phenomena in final states containing an or pair, jets, and large missing transverse momentum is presented. This analysis makes use of proton-proton collision data with an integrated luminosity of , collected during 2015 and 2016 at a centre-of-mass energy 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 or pair and the lightest neutralino ( ) via one of two next-to-lightest neutralino ( ) decay mechanisms: , where the boson decays leptonically leading to a peak in the dilepton invariant mass distribution around the boson mass; and with no intermediate resonance, yielding a kinematic endpoint in the dilepton invariant mass spectrum.

Search for Low-Mass Dijet Resonances Using Trigger-Level Jets with the ATLAS Detector in pp Collisions at sqrt[s]=13 TeV.

Searches for dijet resonances with sub-TeV masses using the ATLAS detector at the Large Hadron Collider can be statistically limited by the bandwidth available to inclusive single-jet triggers, whose data-collection rates at low transverse momentum are much lower than the rate from standard model multijet production. This Letter describes a new search for dijet resonances where this limitation is overcome by recording only the event information calculated by the jet trigger algorithms, thereby allowing much higher event rates with reduced storage needs. The search targets low-mass dijet resonances in the range 450-1800 GeV.

Search for the Decay of the Higgs Boson to Charm Quarks with the ATLAS Experiment.

A direct search for the standard model Higgs boson decaying to a pair of charm quarks is presented. Associated production of the Higgs and Z bosons, in the decay mode ZH→ℓ^{+}ℓ^{-}cc[over ¯] is studied. A data set with an integrated luminosity of 36.