Improved luminosity determination in collisions at [Formula: see text] using the ATLAS detector at the LHC.

The luminosity calibration for the ATLAS detector at the LHC during collisions at [Formula: see text] in 2010 and 2011 is presented. Evaluation of the luminosity scale is performed using several luminosity-sensitive detectors, and comparisons are made of the long-term stability and accuracy of this calibration applied to the collisions at [Formula: see text]. A luminosity uncertainty of [Formula: see text] is obtained for the 47 pb of data delivered to ATLAS in 2010, and an uncertainty of [Formula: see text] is obtained for the 5.

Search for a light charged Higgs boson in the decay channel [Formula: see text] in [Formula: see text] events using collisions at [Formula: see text] with the ATLAS detector.

A search for a charged Higgs boson () in [Formula: see text] decays is presented, where one of the top quarks decays via →, followed by → two jets ([Formula: see text]). The other top quark decays to , where the  boson then decays into a lepton (/) and a neutrino. The data were recorded in collisions at [Formula: see text] by the ATLAS detector at the LHC in 2011, and correspond to an integrated luminosity of 4.

Measurement of splitting scales in → events at [Formula: see text] with the ATLAS detector.

A measurement of splitting scales, as defined by the clustering algorithm, is presented for final states containing a boson produced in proton-proton collisions at a centre-of-mass energy of 7 TeV. The measurement is based on the full 2010 data sample corresponding to an integrated luminosity of 36 pb which was collected using the ATLAS detector at the CERN Large Hadron Collider. Cluster splitting scales are measured in events containing bosons decaying to electrons or muons.

Multi-channel search for squarks and gluinos in [Formula: see text] collisions with the ATLAS detector at the LHC.

A search for supersymmetric particles in final states with zero, one, and two leptons, with and without jets identified as originating from -quarks, in 4.7 fb of [Formula: see text] collisions produced by the Large Hadron Collider and recorded by the ATLAS detector is presented. The search uses a set of variables carrying information on the event kinematics transverse and parallel to the beam line that are sensitive to several topologies expected in supersymmetry.

Measurement of the [Formula: see text] production cross section in the tau + jets channel using the ATLAS detector.

A measurement of the top quark pair production cross section in the final state with a hadronically decaying tau lepton and jets is presented. The analysis is based on proton-proton collision data recorded by the ATLAS experiment at the LHC, with a centre-of-mass energy of 7 TeV. The data sample corresponds to an integrated luminosity of 1.

Jet energy resolution in proton-proton collisions at [Formula: see text] recorded in 2010 with the ATLAS detector.

The measurement of the jet energy resolution is presented using data recorded with the ATLAS detector in proton-proton collisions at [Formula: see text]. The sample corresponds to an integrated luminosity of 35 pb. Jets are reconstructed from energy deposits measured by the calorimeters and calibrated using different jet calibration schemes.

Measurement of jet shapes in top-quark pair events at [Formula: see text] using the ATLAS detector.

A measurement of jet shapes in top-quark pair events using 1.8 fb of [Formula: see text] collision data recorded by the ATLAS detector at the LHC is presented. Samples of top-quark pair events are selected in both the single-lepton and dilepton final states.

Dense arrays of micro-needles for recording and electrical stimulation of neural activity in acute brain slices.

Objective: This paper describes the design, microfabrication, electrical characterization and biological evaluation of a high-density micro-needle array. The array records from and electrically stimulates individual neurons simultaneously in acute slices of brain tissue.

Approach: Acute slices, arguably the closest in-vitro model of the brain, have a damaged surface layer.

Search for direct top squark pair production in final states with one isolated lepton, jets, and missing transverse momentum in sqrt[s] = 7 TeV pp collisions using 4.7 fb(-10 of ATLAS data.

A search is presented for direct top squark pair production in final states with one isolated electron or muon, jets, and missing transverse momentum in proton-proton collisions at sqrt[s] = 7 TeV. The measurement is based on 4.7 fb(-1) of data collected with the ATLAS detector at the LHC.

Search for a supersymmetric partner to the top quark in final states with jets and missing transverse momentum at sqrt[s] = 7 TeV with the ATLAS detector.

A search for direct pair production of supersymmetric top squarks (t(1)) is presented, assuming the t(1) decays into a top quark and the lightest supersymmetric particle, χ(1)(0), and that both top quarks decay to purely hadronic final states. A total of 16 (4) events are observed compared to a predicted standard model background of 13.5(-3.

Properties and application of a multichannel integrated circuit for low-artifact, patterned electrical stimulation of neural tissue.

Objective: Modern multielectrode array (MEA) systems can record the neuronal activity from thousands of electrodes, but their ability to provide spatio-temporal patterns of electrical stimulation is very limited. Furthermore, the stimulus-related artifacts significantly limit the ability to record the neuronal responses to the stimulation. To address these issues, we designed a multichannel integrated circuit for a patterned MEA-based electrical stimulation and evaluated its performance in experiments with isolated mouse and rat retina.

Efficient coding of spatial information in the primate retina.

Sensory neurons have been hypothesized to efficiently encode signals from the natural environment subject to resource constraints. The predictions of this efficient coding hypothesis regarding the spatial filtering properties of the visual system have been found consistent with human perception, but they have not been compared directly with neural responses. Here, we analyze the information that retinal ganglion cells transmit to the brain about the spatial information in natural images subject to three resource constraints: the number of retinal ganglion cells, their total response variances, and their total synaptic strengths.

Determination of the strange-quark density of the proton from ATLAS measurements of the W→ℓν and Z→ℓℓ cross sections.

A QCD analysis is reported of ATLAS data on inclusive W(±) and Z boson production in pp collisions at the LHC, jointly with ep deep-inelastic scattering data from HERA. The ATLAS data exhibit sensitivity to the light quark sea composition and magnitude at Bjorken x∼0.01.

Search for pair production of a new b' quark that decays into a Z boson and a bottom quark with the ATLAS detector.

A search is reported for the pair production of a new quark b' with at least one b' decaying to a Z boson and a bottom quark. The data, corresponding to 2.0 fb(-1) of integrated luminosity, were collected from pp collisions at √s = 7 TeV with the ATLAS detector at the CERN Large Hadron Collider.

Search for supersymmetry in events with three leptons and missing transverse momentum in √[s]=7 TeV pp collisions with the ATLAS detector.

A search for the weak production of charginos and neutralinos decaying to a final state with three leptons (electrons or muons) and missing transverse momentum is presented. The analysis uses 2.06 fb(-1) of √[s]=7 TeV proton-proton collision data delivered by the Large Hadron Collider and recorded with the ATLAS detector.

Search for pair production of a heavy up-type quark decaying to a W boson and a b quark in the lepton + jets channel with the ATLAS detector.

A search is presented for production of a heavy up-type quark (t') together with its antiparticle, assuming subsequent decay to a W boson and a b quark, t't[over ¯]'→W(+)bW(-)b[over ¯]. The search is based on 1.04 fb(-1) of proton-proton collisions at √[s]=7 TeV collected by the ATLAS detector at the CERN Large Hadron Collider.

Search for a light Higgs boson decaying to long-lived weakly interacting particles in proton-proton collisions at sqrt[s] = 7 TeV with the ATLAS detector.

A search for the decay of a light Higgs boson (120-140 GeV) to a pair of weakly interacting, long-lived particles in 1.94 fb(-1) of proton-proton collisions at sqrt[s] = 7 TeV recorded in 2011 by the ATLAS detector is presented. The search strategy requires that both long-lived particles decay inside the muon spectrometer.

Search for gluinos in events with two same-sign leptons, jets, and missing transverse momentum with the ATLAS detector in pp collisions at sqrt[s]=7 TeV.

A search is presented for gluinos decaying via the supersymmetric partner of the top quark using events with two same-sign leptons, jets, and missing transverse momentum. The analysis is performed with 2.05  fb(-1) of integrated luminosity from pp collisions at sqrt[s]=7  TeV collected by the ATLAS detector at the LHC.

Observation of spin correlation in tt¯ events from pp collisions at √s=7 TeV using the ATLAS detector.

A measurement of spin correlation in tt[over ¯] production is reported using data collected with the ATLAS detector at the LHC, corresponding to an integrated luminosity of 2.1 fb(-1). Candidate events are selected in the dilepton topology with large missing transverse energy and at least two jets.

Search for production of resonant states in the photon-jet mass distribution using pp collisions at √s=7 TeV collected by the ATLAS detector.

This Letter describes a model-independent search for the production of new resonant states in photon+jet events in 2.11 fb(-1) of proton-proton collisions at √s=7 TeV. We compare the photon+jet mass distribution to a background model derived from data and find consistency with the background-only hypothesis.

Search for tb resonances in proton-proton collisions at √s=7 TeV with the ATLAS detector.

This Letter presents a search for tb resonances in 1.04 fb(-1) of LHC proton-proton collision data collected by the ATLAS detector at a center-of-mass energy of 7 TeV. Events with a lepton, missing transverse momentum, and two jets are selected and the invariant mass of the corresponding final state is reconstructed.

Search for down-type fourth generation quarks with the ATLAS detector in events with one lepton and hadronically decaying W bosons.

This Letter presents a search for pair production of heavy down-type quarks decaying via b' → Wt in the lepton + jets channel, as b'b' → W- tW+ t → bbW+ W- W+ W- → l± νbbqqqqqq. In addition to requiring exactly one lepton, large missing transverse momentum, and at least six jets, the invariant mass of nearby jet pairs is used to identify high transverse momentum W bosons. In data corresponding to an integrated luminosity of 1.

Search for scalar bottom quark pair production with the ATLAS detector in pp collisions at sqrt[s]=7 TeV.

The results of a search for pair production of the scalar partners of bottom quarks in 2.05  fb(-1) of pp collisions at sqrt[s]=7  TeV using the ATLAS experiment are reported. Scalar bottom quarks are searched for in events with large missing transverse momentum and two jets in the final state, where both jets are identified as originating from a bottom quark.

Observation of a new χ(b) state in radiative transitions to Υ(1S) and Υ(2S) at ATLAS.

The χ(b)(nP) quarkonium states are produced in proton-proton collisions at the Large Hadron Collider at sqrt[s] = 7  TeV and recorded by the ATLAS detector. Using a data sample corresponding to an integrated luminosity of 4.4  fb(-1), these states are reconstructed through their radiative decays to Υ(1S,2S) with Υ → μ+ μ-.

Search for the standard model Higgs boson in the diphoton decay channel with 4.9 fb(-1) of pp collision data at √s=7 TeV with ATLAS.

A search for the standard model Higgs boson is performed in the diphoton decay channel. The data used correspond to an integrated luminosity of 4.9 fb(-1) collected with the ATLAS detector at the Large Hadron Collider in proton-proton collisions at a center-of-mass energy of √s=7 TeV.