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 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.

Search for heavy neutrinos and right-handed bosons in events with two leptons and jets in collisions at [Formula: see text] with the ATLAS detector.

This letter reports on a search for hypothetical heavy neutrinos, , and right-handed gauge bosons, , in events with high transverse momentum objects which include two reconstructed leptons and at least one hadronic jet. The results were obtained from data corresponding to an integrated luminosity of 2.1 fb collected in proton-proton collisions at [Formula: see text] with the ATLAS detector at the CERN Large Hadron Collider.

Measurement of the top quark mass with the template method in the [Formula: see text] channel using ATLAS data.

The top quark mass has been measured using the template method in the [Formula: see text] channel based on data recorded in 2011 with the ATLAS detector at the LHC. The data were taken at a proton-proton centre-of-mass energy of [Formula: see text] and correspond to an integrated luminosity of 1.04 fb.

Measurement of [Formula: see text] production with a veto on additional central jet activity in collisions at [Formula: see text] TeV using the ATLAS detector.

A measurement of the jet activity in [Formula: see text] events produced in proton-proton collisions at a centre-of-mass energy of 7 TeV is presented, using 2.05 fb of integrated luminosity collected by the ATLAS detector at the Large Hadron Collider. The [Formula: see text] events are selected in the dilepton decay channel with two identified -jets from the top quark decays.

Measurement of the charge asymmetry in top quark pair production in collisions at [Formula: see text] using the ATLAS detector.

A measurement of the top-antitop production charge asymmetry is presented using data corresponding to an integrated luminosity of 1.04 fb of collisions at [Formula: see text] TeV collected by the ATLAS detector at the LHC. Events are selected with a single lepton (electron or muon), missing transverse momentum and at least four jets of which at least one jet is identified as coming from a -quark.