arXiv subjects
Publications and source records attributed to Dominic Stafford.
A first search is presented for BSM resonances in four top quark production in the 2 lepton channel, using $138\mathrm{fb}^{-1}$ $pp$ data collected at $\sqrt{s}=13$ TeV, and $35\mathrm{fb}^{-1}$ $\sqrt{s}=13.6$ TeV $pp$ data. No significant excess is observed; limits are set on vector Z', scalar, pseudoscalar and ALP mediators. Z' mediators with 50% width are excluded up to 850 GeV (1000 GeV expected).
Recent searches for dark matter (DM) produced in association with top quarks from the ATLAS and CMS experiments using data collected between 2015 and 2018 are presented. These comprise searches from both experiments for DM in association with a single top quark; an improved ATLAS search for DM in single lepton $t\bar{t}$ final states; an ATLAS search stop squarks decaying to a top quark, a charm quark and neutralinos, and a CMS search for DM produced in association with a pair of top quarks or a single top. These analyses feature novel machine learning and advanced background estimation techniques. No statistically significant excess is observed in any of these searches.
We present a novel simulation of a strongly interacting dark sector also known as the Hidden Valley scenarios using angular ordered showers and the cluster hadronisation model in Herwig 7. We discuss the basics of this implementation and the scale hierarchies underpinning the simulation. With the help of a few benchmarks, we show the effect of variation of dark sector parameters on thrust and angularities within the dark sector, and study correlation functions, which can be helpful for understanding the angular structure of these events. Finally we comment on the uncertainties introduced due to lack of knowledge of hadronisation parameters within the dark sectors.