Conveners
Parallel stream 3: Session 1
- Mark Scott (Imperial College London)
Parallel stream 3: Session 2
- Justin Evans (University College London)
- Patrick James Dunne
- Justin Evans (University of Oxford)
- Justin Evans (University of Manchester (UK))
- Patrick James Dunne (Imperial College (GB))
- Patrick James Dunne (Imperial College (GB))
- Abbey Waldron (Oxford/T2K)
Parallel stream 3: Session 3
- Abbey Waldron (Oxford/T2K)
- Samuel Webb (Imperial College (GB))
- Chamkaur Ghag (University College London)
A measurement of the top-antitop charge asymmetry is underway at the ATLAS experiment at the LHC. This is being being performed at 13 TeV with 80 fb-1 of proton-proton collision data, with the eventual aim to use the full 140 fb-1 Run 2 dataset. The method of Fully Bayesian Unfolding (FBU) is employed to determine the parton-level charge asymmetry. This technique generates a posterior...
I will be presenting an overview of the ATLAS analysis of the single dissociative diffraction cross-section in p-p collisions at 13 TeV. I am the main analyser for this measurement and it will be the topic of my PhD thesis.
Single dissociative diffraction (pp->pX) occurs when there is a t-channel exchange with the quantum numbers of the vacuum with one proton remaining intact and the other...
The LHCb experiment provides unique detector coverage, 2 < η < 5, of high energy proton-proton interactions produced at the Large Hadron Collider. Designed to study b- & c-hadron physics, LHCb is fully instrumented in the forward region with excellent tracking and vertex resolution.
The top quark is the heaviest fundamental particle and is expected to play a special role in new physics...
Measurements of CP violation in B decays are entering a high precision era, and with the increasing precision comes a need for an equally precise understanding of limiting uncertainties. I will present a recent, world-leading precision measurement of the CP-violating CKM phase gamma, using data from the LHCb experiment. The measurement used B -> DK decays, where the D meson decays to a neutral...
Various theories beyond the Standard Model propose baryon number violating processes in order to explain the matter-antimatter asymmetry in the universe, many of which result in some form of nucleon decay. Some modes of nucleon decay are invisible, in the sense that the final state particles remain undetected. Following the disappearance of one or two nucleons in such a nucleus, the subsequent...
TORCH (Time Of Internally Reflected CHerenkov light) is a novel concept of a Ring Imaging Cherenkov time-of-flight detector, which is being developed with a possible application in an upgrade of the LHCb experiment in 2030. Currently it is still in the Research and Development (R&D) phase. It utilises Cherenkov radiation to identify particles at low momenta. It would be located at 10m from the...
TORCH is a time-of-flight detector designed to provide particle identification over the 2-10 GeV/c momentum range. Consisting of 18 large quartz plates, TORCH measures the time of arrival of charged particles through prompt Cherenkov light which is trapped by total-internal reflection. At the top of the plate the light is focused onto a row of micro-channel plate (MCP) detectors which measure...
The direct production of chargino-neutralino, pp→χ̃±1χ̃02, followed by their decays via intermediate WH states (χ̃±1χ̃02→W±Hχ̃01χ̃01), where H is the 125-GeV Standard Model Higgs boson, is a very important channel for the search for electroweak supersymmetry at the Large Hadron Collider. Amongst others, the search can be performed in the channel where both the W and the H decay fully...
This talk presents a search for pairs of light Higgs bosons produced in NMSSM decay cascades using the CMS detector. The analysis uses data sets corresponding to the 2016 and 2017 proton-proton collisions at a centre-of-mass energy of 13 TeV. The final state targeted is that where both Higgs bosons decay into bbbar pairs.
The signal model is of interest because, under certain mass...
We examine scenarios in the Next-to-Minimal Supersymmetric Standard Model (NMSSM) whereby two Standard Model-like Higgs bosons are produced via squark and gluino decay cascades along with two light, low-momentum neutrino Lightest Supersymmetric Particles (LSPs), resulting in very little Missing Transverse Energy (MET). Firstly, by recasting a general-purpose Jets+MET αT-based analysis we...
CP violation in the charm sector is predicted to be very small by the Standard Model and so precise measurements represent a low background environment for new physics searches. A sensitive probe is the parameter AΓ which measures time-dependent CP violation and has previously been measured with the LHCb detector in two-body D0 meson decays. D0 neutral mesons are the only ones where...
CP violation has been established in kaon and B-meson systems, but has yet to be observed in baryonic decays. However, sizeable CP asymmetries of up to 20% are expected in certain beauty baryon decays in the Standard Model. A family of 4-body charmless baryonic decays offer a good theoretical motivation for the observation of CP violation. In this analysis a single decay channel of Lb->p3pi is...
Motivated by possible theoretical extensions to the standard model, hidden photons (HP) are a suitable candidate for cold dark matter. Their possible masses cover a broad region, from 10-12 to 106 eV [1]. Large scale direct detection experiments such as LUX-ZEPLIN (LZ), built primarily to detect WIMPs, could also be sensitive to HP dark matter via the so called hidden photoelectric effect in...
Neutrinoless double beta decay (NDBD) is a hypothesised nuclear decay process that, if observed, shows that neutrinos are Majorana particles, signals the existence of lepton number violation and places constraints on the neutrino mass hierarchy. However, with T1/2 > 10^25 years, searching for NDBD requires low backgrounds from intrinsic radiation and excellent energy resolution. In this talk,...
Progress on the development of an analytic signal model for measuring the mass of the Higgs Boson employing the H→ZZ→4l (l=e,mu) channel is presented. The model consists of a double-sided Crystal ball function, which is a function with a Gaussian core and power-law tails. The model is fitted to the four-lepton invariant mass distribution of H→ZZ→4l signal Monte Carlo samples. Results from...
A search is presented for decays of the Higgs boson to a Z boson and a hadronically decaying light resonance, h->ZX->ll+hadrons, using the Run 2 dataset of the ATLAS detector at the LHC. Due to its low mass and high boost, the resonance is reconstructed as a single jet of hadrons. A boosted decision tree is used to suppress the large multijet background. Beyond its potential for new physics,...
