Differential cross-section measurements for the electroweak production of dijets in association with a $Z$ boson in proton-proton collisions at ATLAS

ArXiv 2006.15458 (2020)

Search for dijet resonances in events with an isolated charged lepton using s = 13 TeV proton-proton collision data collected by the ATLAS detector

Journal of High Energy Physics Springer 2020:6 (2020) 151

Authors:

G Aad, B Abbott, DC Abbott, A Abed Abud, K Abeling, DK Abhayasinghe, SH Abidi, OS AbouZeid, NL Abraham, H Abramowicz, H Abreu, Y Abulaiti, BS Acharya, B Achkar, S Adachi, L Adam, C Adam Bourdarios, L Adamczyk, L Adamek, J Adelman, M Adersberger, A Adiguzel, S Adorni, T Adye

Abstract:

A search for dijet resonances in events with at least one isolated charged lepon is performed using 139 fb−1 of s = 13 TeV proton-proton collision data recorded by the ATLAS detector at the LHC. The dijet invariant-mass (mjj) distribution constructed from events with at least one isolated electron or muon is searched in the region 0.22 < mjj< 6.3 TeV for excesses above a smoothly falling background from Standard Model processes. Triggering based on the presence of a lepton in the event reduces limitations imposed by minimum transverse momentum thresholds for triggering on jets. This approach allows smaller dijet invariant masses to be probed than in inclusive dijet searches, targeting a variety of new-physics models, for example ones in which a new state is produced in association with a leptonically decaying W or Z boson. No statistically significant deviation from the Standard Model background hypothesis is found. Limits on contributions from generic Gaussian signals with widths ranging from that determined by the detector resolution up to 15% of the resonance mass are obtained for dijet invariant masses ranging from 0.25 TeV to 6 TeV. Limits are set also in the context of several scenarios beyond the Standard Model, such as the Sequential Standard Model, a technicolor model, a charged Higgs boson model and a simplified Dark Matter model.

Measurement of the $t\bar{t}$ production cross-section in the lepton+jets channel at $\sqrt{s}=13\;$TeV with the ATLAS experiment

ArXiv 2006.13076 (2020)

Search for new non-resonant phenomena in high-mass dilepton final states with the ATLAS detector

ArXiv 2006.12946 (2020)

Realising a species-selective double well with multiple-radiofrequency-dressed potentials

Journal of Physics B: Atomic, Molecular and Optical Physics IOP Publishing 53:15 (2020) 155001

Authors:

Aj Barker, S Sunami, D Garrick, A Beregi, K Luksch, E Bentine, Cj Foot

Abstract:

Techniques to manipulate the individual constituents of an ultracold mixture are key to investigating impurity physics. In this work, we confine a mixture of hyperfine ground states of 87Rb atoms in a double-well potential. The potential is produced by dressing the atoms with multiple radiofrequencies. The amplitude and phase of each frequency component of the dressing field are controlled to independently manipulate each species. Furthermore, we verify that our mixture of hyperfine states is collisionally stable, with no observable inelastic loss.