Conveners
Parallel stream 4: Session 1
- Patrick James Dunne (Imperial College (GB))
- Roger Jones (Lancaster University (GB))
- Patrick James Dunne
- Patrick James Dunne (Imperial College (GB))
Parallel stream 4: Session 2
- Vukasin Milosevic (Imperial College (GB))
- Francesca Di Lodovico (University of London (GB))
Parallel stream 4: Session 3
- Melissa Anne Uchida (Imperial College (GB))
- Nicholas Wardle (Imperial College (GB))
- Edward Thomas Atkin (Imperial College (GB))
We review the recent measurement of the inclusive ttZ cross-section with 36 fb-1 of data at 13 TeV at the ATLAS experiment, using EFT considerations and background modelling for generic SUSY/DM searches as motivation for continuing to improve the precision of this result. We then present plans for a differential ttZ measurement in the 3 and 4 lepton channels with the full 140 fb-1 Run 2...
At low energies, the world around us can be accurately described using the Standard Model. However, this is at best only an ''effective'' description: valid at low energies but destined to break down as experiments probe increasingly higher energies, ultimately requiring a new (UV complete) theory to take over.
In this talk, I will demonstrate that certain constraints must be placed on such...
The author/presenter will outline the status of the search for Supersymmetry (SUSY) in the 3rd generation sector, particularly the SUSY partner of the top quark, using the 140.5 ifb dataset collected from the ATLAS detector from LHC Run 2 (2015-2018).
This analysis is searching in the all-hadronic channel for a reconstructed final state of top-antitop pairs and Missing Energy, looking to...
T2K is a long baseline neutrino oscillation experiment designed to make precise measurements of the parameters governing neutrino oscillations. A muon (anti-)neutrino beam is produced at the Japan Proton Accelerator Research Complex (J-PARC) on the east coast of Japan, and is aimed towards the Super-Kamiokande (SK) detector 295km away near the west coast. In this analysis, Markov Chain Monte...
Understanding neutrino-nucleus interaction cross-sections at the 1-2 percent level will be crucial for the next generation of long baseline neutrino experiments. Due to its low hadron momentum detection threshold, a High Pressure gas Time Projection Chamber (HPTPC) is a strong candidate for achieving a significant reduction in uncertainties on these cross-sections . An HPTPC is part of the...
The measurement of the Unitarity Triangle angle γ is a cornerstone of our understanding of the CKM mechanism of quark interactions.
Due to the tiny theoretical uncertainty in self-tagging B decays to D^()K^() final states, these modes will provide a standard candle in CP-violation physics as we drive towards the ultimate precision in flavour physics.
Results in the simplest final states...
Numerous recent anomalies in the b→sll flavour sector give indication of potential lepton flavour universality (LFU) violation in (axial-)vector couplings.
To probe these anomalies and further assumptions about LFU in other couplings, now more than ever, precise measurements of the SM properties are needed.
This talk presents one arm of these investigations using B+ → K+ee decays, with...
Flavour Changing Neutral Current processes are heavily suppressed in the Standard Model of particle physics and are potentially sensitive to contributions from as yet undiscovered particles. Recent measurements of b→s transitions by the LHCb collaboration show interesting tensions with Standard Model predictions.
The large LHC data set enables measurements of decays involving b→d transitions...
This project aims to explore the effects that changes in a matter density profile could have on neutrino oscillations, and whether these could potentially be seen by the future Hyper-Kamiokande experiment (T2HK). The analysis is extended to include the possibility of having a second detector in Korea (T2HKK).
In the ATLAS HH -> bb̅bb̅ analysis, jets are paired to form Higgs boson candidates by minimizing the perpendicular distance between the pair and the line joining the point (120 GeV, 110 GeV) to the origin in the plane of leading Higgs boson candidate mass -- subleading Higgs boson candidate mass. This strategy is shown to reconstruct background events such that they peak around the point (120...
After the discovery of a Standard Model like Higgs boson, new searches can now change focus towards using it as a tool to probe the Standard Model and new physics. With the largest branching fraction, the bb̅bb̅ final state is one of the leading candidates to observe this process, but the overwhelming backgrounds and the highly boosted topology reached by this process, present a challenge....
Recent observations of B decays hint at discrepancies with predictions of the otherwise overwhelmingly successful Standard Model of Particle Physics. These observations are extremely intriguing, as they can be interpreted in a coherent way in a number of new physics models by introducing a new vector particle such as a Z' or a leptoquark.
This talk will concentrate on one of these...
The angular observables of the B0 -> K*0μμ decay are showing intriguing discrepancies with Standard Model (SM) predictions [1]. The discrepancies indicate a shift of the vector coupling (C9) with a significance of about 3.4 standard deviations. This could be explained by the existence of new heavy vector particles not described by the SM. However, the discrepancies may also be explained by...
With an abundance of cosmological evidence motivating the existence of dark matter, one of the topmost priorities of the High Energy Physics community is understanding its nature and integrating it into our extremely successful (yet incomplete) theory of the Standard Model. Presented here is a collider search for invisible new-physics phenomena using cross-section ratios for pp collisions at a...
The DarkSide-50 experiment at the LNGS underground laboratory is using a dual-phase liquid argon TPC to search for particle dark matter. A recent analysis, based on the use of only the ionization signal from very low energy events, shows the potential of liquid argon to detect low-mass WIMPs (<10 GeV/c^2). The null result of this search is currently the world-leading exclusion limit on...
The DarkSide program for direct dark matter detection is a global collaboration of all the current argon-based dark matter experiments. The Darkside-20k detector will be located in the Laboratori Nazionali del Gran Sasso. It is designed to be experimental-background free and is optimized for sensitivity to high-mass WIMPs. Darkside-20k consists of an inner dual phase liquid argon (LAr) TPC...
The leading upper limit on the Higgs boson to invisible state branching ratio (BR) is 24%, while the Standard Model prediction sits far below at 0.1%. The observed value was measured using pp collision data collected by the CMS experiment between 2011 and 2015. Our analysis targets a better limit by using 13 TeV data from 2016-2018 -- an integrated luminosity of over 130 fb-1 -- in addition to...
To demonstrate whether the particle discovered in 2012 is the Standard Model (SM) Higgs boson, all of its couplings to other SM particles have to be measured. In the SM, the coupling of the Higgs boson to fermions has a strength proportional to the mass of the fermion. Since the b-quark is the heaviest particle that the Higgs can kinematically decay into, it has the largest branching ratio....
Progress on the search for invisibly decaying Higgs bosons at the LHC will be presented. The analysis is being performed using the CMS Run 2 data, taken in 2016-2018. Several key aspects of the analysis will be reviewed including a description of the novel analysis framework, background estimates including NLO QCD and electroweak corrections, and trigger studies. The search results will be...
