0000000000178881

AUTHOR

Ryan Mueller

Measurements of four-lepton production in pp collisions at s=8 TeV with the ATLAS detector

A search is presented for a high-mass Higgs boson in the , , , and decay modes using the ATLAS detector at the CERN Large Hadron Collider. The search uses proton-proton collision data at a centre-o ...

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Search for high-mass dilepton resonances using 139 fb−1 of pp collision data collected at s=13 TeV with the ATLAS detector

A search for high-mass dielectron and dimuon resonances in the mass range of 250 GeV to 6 TeV is presented. The data were recorded by the ATLAS experiment in proton–proton collisions at a centre-of-mass energy of s=13 TeV during Run 2 of the Large Hadron Collider and correspond to an integrated luminosity of 139 fb −1 . A functional form is fitted to the dilepton invariant-mass distribution to model the contribution from background processes, and a generic signal shape is used to determine the significance of observed deviations from this background estimate. No significant deviation is observed and upper limits are placed at the 95% confidence level on the fiducial cross-section times bran…

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Measurement of jet charge in dijet events froms=8  TeVppcollisions with the ATLAS detector

The momentum-weighted sum of the charges of tracks associated to a jet is sensitive to the charge of the initiating quark or gluon. This paper presents a measurement of the distribution of momentum ...

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Measurement of the differential cross-section of highly boosted top quarks as a function of their transverse momentum ins=8  TeVproton-proton collisions using the ATLAS detector

The differential cross-section for pair production of top quarks with high transverse momentum is measured in 20.3 fb(-1) of proton-proton collisions at a center-of-mass energy of 8 TeV. The measur ...

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Measurement of the Inelastic Proton-Proton Cross Section at s=13  TeV with the ATLAS Detector at the LHC

This Letter presents a measurement of the inelastic proton-proton cross section using 60  μb^{-1} of pp collisions at a center-of-mass energy sqrt[s] of 13 TeV with the ATLAS detector at the LHC. Inelastic interactions are selected using rings of plastic scintillators in the forward region (2.07 10^{-6}, where M_{X} is the larger invariant mass of the two hadronic systems separated by the largest rapidity gap in the event. In this ξ range the scintillators are highly efficient. For diffractive events this corresponds to cases where at least one proton dissociates to a system with M_{X}>13  GeV. The measured cross section is compared with a range of theoretical predictions. When extrapolated…

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Electron and photon performance measurements with the ATLAS detector using the 2015-2017 LHC proton-proton collision data

This paper describes the reconstruction of electrons and photons with the ATLAS detector, employed for measurements and searches exploiting the complete LHC Run 2 dataset. An improved energy clustering algorithm is introduced, and its implications for the measurement and identification of prompt electrons and photons are discussed in detail. Corrections and calibrations that affect performance, including energy calibration, identification and isolation efficiencies, and the measurement of the charge of reconstructed electron candidates are determined using up to 81 fb−1 of proton-proton collision data collected at √s=13 TeV between 2015 and 2017.

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Measurement of the correlation between the polar angles of leptons from top quark decays in the helicity basis ats=7  TeVusing the ATLAS detector

A measurement of the correlations between the polar angles of leptons from the decay of pair-produced t and (t) over bar quarks in the helicity basis is reported, using proton-proton collision data collected by the ATLAS detector at the LHC. The dataset corresponds to an integrated luminosity of 4.6 fb(-1) at a center-of-mass energy of root s = 7 TeV collected during 2011. Candidate events are selected in the dilepton topology with large missing transverse momentum and at least two jets. The angles theta(1) and theta(2) between the charged leptons and the direction of motion of the parent quarks in the t (t) over bar rest frame are sensitive to the spin information, and the distribution of …

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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 √s = 13  TeV at the LHC. In combination with the results at √s = 7 and 8 TeV, an exclusion limit on the H → invisible branching ratio of 0.26(0.17-0.05+0.07) at 95% confidence level is observed (expected).

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Observation of Higgs boson production in association with a top quark pair at the LHC with the ATLAS detector

Physics letters / B 784, 173 - 191 (2018). doi:10.1016/j.physletb.2018.07.035

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