Babar Ali

Search for resonances in diphoton events at √s=13 TeV with the ATLAS detector

A bstractSearches for new resonances decaying into two photons in the ATLAS experiment at the CERN Large Hadron Collider are described. The analysis is based on proton-proton collision data corresponding to an integrated luminosity of 3.2 fb−1 at s=13

Study of hard double-parton scattering in four-jet events in pp collisions at √s=7 TeV with the ATLAS experiment

\sqrt{s}=13

Search for new phenomena in a lepton plus high jet multiplicity final state with the ATLAS experiment using √s=13 TeV proton-proton collision data

TeV recorded in 2015. Two searches are performed, one targeted at a spin-2 particle of mass larger than 500 GeV, using Randall-Sundrum graviton states as a benchmark model, and one optimized for a spin-0 particle of mass larger than 200 GeV. Varying both the mass and the decay width, the most significant deviation from the background-only hypothesis is observed at a diphoton invariant mass around 750 GeV with local significances of 3.8 and 3.9 standard deviations in the searches optimized for a spin-2 and spin-0 particle, respectively. The global significances are estimated to be 2.1 standard deviations for both analyses. The consistency between the data collected at 13 TeV and 8 TeV is also evaluated. Limits on the production cross section times branching ratio to two photons for the two resonance types are reported.

MPX Detectors as LHC Luminosity Monitor

A search for the supersymmetric partners of quarks and gluons (squarks and gluinos) in final states containing hadronic jets and missing transverse momentum, but no electrons or muons, is presented. The data used in this search were recorded in 2015 and 2016 by the ATLAS experiment in

Measurement of top quark pair differential cross sections in the dilepton channel in pp collisions at √s =7 and 8 TeV

\sqrt{s}

Measurements of top-quark pair differential cross-sections in the lepton+jets channel in pp collisions at √s=13 TeV using the ATLAS detector

=13 TeV proton--proton collisions at the Large Hadron Collider, corresponding to an integrated luminosity of 36.1 fb

Precision Luminosity of LHC Proton–Proton Collisions at 13 TeV Using Hit Counting With TPX Pixel Devices

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Measurements of ψ(2S) and X(3872) → J/ψπ + π − production in pp collisions at √s=8 TeV with the ATLAS detector

. The results are interpreted in the context of various models where squarks and gluinos are pair-produced and the neutralino is the lightest supersymmetric particle. An exclusion limit at the 95\% confidence level on the mass of the gluino is set at 2.03 TeV for a simplified model incorporating only a gluino and the lightest neutralino, assuming the lightest neutralino is massless. For a simplified model involving the strong production of mass-degenerate first- and second-generation squarks, squark masses below 1.55 TeV are excluded if the lightest neutralino is massless. These limits substantially extend the region of supersymmetric parameter space previously excluded by searches with the ATLAS detector.