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Angerami, A.

Publications and source records attributed to Angerami, A..

At least 271 records · Page 15
All sourcesNASA NTRSDOE OSTI
DOE OSTI2019

Searches for scalar leptoquarks and differential cross-section measurements in dilepton–dijet events in proton–proton collisions at a centre-of-mass energy of $\sqrt{s}$ = 13 TeV with the ATLAS experiment

Searches for scalar leptoquarks pair-produced in proton–proton collisions at $\sqrt{s}$ =13 TeV at the Large Hadron Collider are performed by the ATLAS experiment. A data set corresponding to an integrated luminosity of 36.1 fb -1 is used. Final states containing two electrons or two muons and two or more jets are studied, as are states with one electron or muon, missing transverse momentum and two or more jets. No statistically significant excess above the Standard Model expectation is observed. The observed and expected lower limits on the leptoquark mass at 95% confidence level extend up to 1.29 TeV and 1.23 TeV for first- and second-generation leptoquarks, respectively, as postulated in the minimal Buchmüller–Rückl–Wyler model, assuming a branching ratio into a charged lepton and a quark of 50%. In addition, measurements of particle-level fiducial and differential cross sections are presented for the Z→ ee, Z→ μμ and $ t\bar{t} $ processes in several regions related to the search control regions. Predictions from a range of generators are compared with the measurements, and good agreement is seen for many of the observables. However, the predictions for the Z→ ℓℓ measurements in observables sensitive to jet energies disagree with the data.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2019

Erratum to: Search for supersymmetry in final states with two same-sign or three leptons and jets using 36 fb -1 of $ \sqrt{s} $ = 13 TeV pp collision data with the ATLAS detector

One correction is made to the figure 4e of the paper. The reported cross-sections, both the experimental upper limits and the theoretical prediction, corresponded only to a fiducial region of the phase space with at least two prompt same-sign electrons or muons before detector simulation (p T > 10 GeV, |η| < 2.8). The updated figure 4e instead presents the results without this requirement, i.e. in the full phase space as it should, given the y-axis label of the plot. The reported sensitivity of the analysis, i.e. the ability to exclude top squark masses below 700 GeV in this scenario, is however unchanged since the same requirements were applied to the analysis and to the theory predictions.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2019

Modelling radiation damage to pixel sensors in the ATLAS detector

Silicon pixel detectors are at the core of the current and planned upgrade of the ATLAS experiment at the LHC. Given their close proximity to the interaction point, these detectors will be exposed to an unprecedented amount of radiation over their lifetime. The current pixel detector will receive damage from non-ionizing radiation in excess of 10 15 1 MeV n eq /cm 2 , while the pixel detector designed for the high-luminosity LHC must cope with an order of magnitude larger fluence. We present a digitization model incorporating effects of radiation damage to the pixel sensors. The model is described in detail and predictions for the charge collection efficiency and Lorentz angle are compared with collision data collected between 2015 and 2017 (≤ 10 15 1 MeV n eq /cm 2 ).

43 PARTICLE ACCELERATORS↗