Single-event upset was investigated in high-density flash memories from two dfferent manufacturers. Many types of functional abnormalities can be introduced in these devices by heavy-ions because of their complex internal architecture. Changes in the stored memory contents sometimes occurred, even when devices were irradiated in a read mode with the internal charge pump inactive. For one device technology, unusually high currents were observed during post-irradiation cycling that were high enough to cause catastrophic failure.

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This paper presents direct searches for lepton flavour violation in Higgs boson decays, H → eτ and H → μτ, performed using data collected with the ATLAS detector at the LHC. The searches are based on a data sample of proton-proton collisions at a centre-of-mass energy $$ \sqrt{s} $$ s = 13 TeV, corresponding to an integrated luminosity of 138 fb−1. Leptonic (τ → ℓνℓντ) and hadronic (τ → hadrons ντ) decays of the τ-lepton are considered. Two background estimation techniques are employed: the MC-template method, based on data-corrected simulation samples, and the Symmetry method, based on exploiting the symmetry between electrons and muons in the Standard Model backgrounds. No significant excess of events is observed and the results are interpreted as upper limits on lepton-flavour-violating branching ratios of the Higgs boson. The observed (expected) upper limits set on the branching ratios at 95% confidence level, $$ \mathcal{B} $$ B (H → eτ) < 0.20% (0.12%) and $$ \mathcal{B} $$ B (H → μτ ) < 0.18% (0.09%), are obtained with the MC-template method from a simultaneous measurement of potential H → eτ and H → μτ signals. The best-fit branching ratio difference, $$ \mathcal{B} $$ B (H → μτ) → $$ \mathcal{B} $$ B (H → eτ), measured with the Symmetry method in the channel where the τ-lepton decays to leptons, is (0.25 ± 0.10)%, compatible with a value of zero within 2.5σ.

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Differential and double-differential distributions of kinematic variables of leptons from decays of top-quark pairs ($$ t\overline{t} $$ t t ¯ ) are measured using the full LHC Run 2 data sample collected with the ATLAS detector. The data were collected at a pp collision energy of $$ \sqrt{s} $$ s = 13 TeV and correspond to an integrated luminosity of 140 fb−1. The measurements use events containing an oppositely charged eμ pair and b-tagged jets. The results are compared with predictions from several Monte Carlo generators. While no prediction is found to be consistent with all distributions, a better agreement with measurements of the lepton pT distributions is obtained by reweighting the $$ t\overline{t} $$ t t ¯ sample so as to reproduce the top-quark pT distribution from an NNLO calculation. The inclusive top-quark pair production cross-section is measured as well, both in a fiducial region and in the full phase-space. The total inclusive cross-section is found to be$$ {\sigma}_{t\overline{t}}=829\pm 1\ \left(\textrm{stat}\right)\pm 13\ \left(\textrm{syst}\right)\pm 8\ \left(\textrm{lumi}\right)\pm 2\ \left(\textrm{beam}\right)\ \textrm{pb}, $$ σ t t ¯ = 829 ± 1 stat ± 13 syst ± 8 lumi ± 2 beam pb , where the uncertainties are due to statistics, systematic effects, the integrated luminosity and the beam energy. This is in excellent agreement with the theoretical expectation.