Welcome address by the Dean of Science, Prof Muronga and Prof Andre Venter, Head of the Department of Physics followed by overview of workshop by Profs. Bruce Mellado and Alan Cornell.
Existence of dark matter has been inferred from its large scale gravitational interactions at various astrophysical and cosmological scales. There is no evidence as yet of non-gravitational interaction of dark matter with the SM particles. The nature of dark matter particles remains unknown. Search strategies to unravel its properties will be reviewed. The search strategies involve looking for...
We have implemented spherical harmonics for intrinsically deformed nuclei collisions (U+U) at RHIC and (Xe+Xe) at LHC, in HIJING and AMPT models and calculated various physical observables. The study of intrinsic deformation in nucleus is important because it may cause asymmetry in the initial configuration of interacting particles and thus affect the final observables. It is also important to...
We highlight how Rule-based Integration (Rubi) is an enhanced method of symbolic integration which allows for the integration of many difficult integrals not accomplished by other computer algebra systems. Using Rubi, many integration techniques become tractable. Integrals are approached using step-wise simplification, hence distilling an integral (if the solution is unknown) into composite...
Infinite derivative gravity is a theory which extends on general relativity by modifying the Einstein-Hilbert action. Where the hope is that we are able to remove the pathologies found in the UV region of general relativity. In this talk I will present various linearised metrics in the theory of infinite derivative gravity and will show that we indeed are able to remove the singularities that...
In a novel investigation into the physics of a strongly coupled quark gluon plasma, we compute for the first time the suppression of $\Upsilon$(1S) in a strongly coupled QGP and compare the results to those from a weakly coupled QGP. The complex binding energies which inform the thermal width and hence the $R_{AA}$ of the bottomonia in $\sqrt{s}_{NN}=2.76$ TeV Pb+Pb collisions are determined...
Heavy flavours (charm and beauty) quarks are produced in the early stages of ultra-relativistic collisions via hard scatterings and are an important tool for studying different aspects of Quantum Chromodynamics (QCD) in hadronic collisions. Charged-particle multiplicity gives information on the global characteristics of the event and can be exploited to investigate the possible influence of...
The measurements of heavy-flavour production via leptonic decays in proton-
proton (pp) collisions with ALICE at Large Hadron Collider (LHC) energies are
described. Heavy flavour (charm and beauty) are produced at an early stage of
the collision via hard scatterings. In ALICE, heavy-flavour measurements are
measured in the central barrel (|η|<0.9) via the semi-electronic decay channel
and at...
In heavy ion collisions, strangeness enhancement had been proposed as a
signature of the QGP formation. Surprisingly, more recent observations have
shown an enhanced production of (multi-)strange hadrons in high-multiplicity pp
and p-Pb collisions at the LHC. The multiplicity dependence of strangeness
production measured with the ALICE experiment will be discussed in pp, p-Pb,
Xe-Xe and Pb-Pb...
Based on a number of features from proton-proton collisions with Run 1 data a boson with a mass around the EW scale was postulated such that a significant fraction of its decays would entail the Standard Model (SM) Higgs boson and an additional scalar, $S$. One of the phenomenological implications of a simplified model, where $S$ is treated a SM Higgs boson, is the the anomalous production of...
In this talk we discuss a model consisting of Two-Higgs Doublet Model (2HDM) along with a CP even scalar singlet with different global ${\mathbb Z}_2$ symmetry. Let us call this new model "2HDM+S". We discuss the constraints on its parameters emanating from our phenomenological studies. We use it further to explain the possibility of producing new scalars in the electron-proton collider...
The muon anomalous magnetic moment (muon $𝑔−2$) is among the most precisely measured quantities in particle physics. The latest measurement is discrepant from the predictions of the Standard Model – the difference between the experimental and theoretical values is in the range of three to four standard deviations. One possible explanation for this is the interaction of the muon with particles...
A search for boson that lies beyond the standard model is conducted where the progenitor 125 Gev Higgs Boson decays ultimately to four leptons (electrons or muons). The Higgs boson provides a portal into the hidden sector which contains dark particles. The processes under consideration include H → ZX→ 4l and H → XX → 4l where X is the dark vector boson Zd or the pseudoscalar boson a, which are...
The search for W$^\prime \to tb $ decays in the hadronic final states using the full run 2 data, which was collected by the ATLAS detector at the Large Hadron Collider (LHC), is on going. Reconstruction of the top-quark is one of the crucial steps in this search. To conduct the study of improving the top-quark reconstruction, two signal samples, which had 2 and 3.5 TeV W$^\prime$ masses were...
Improvement in the modelling of color reconnection (CR) is critical for precise measurements in $t\bar{t}$ events at the Large Hadron Collider. Modelling of CR is one of the main sources of uncertainty in top quark measurements. Different experimental observables have been studied, but due to lack of sensitivity they don't provide convenient input to constrain the modelling of CR. In this...
Several ongoing projects, involving data analysis using jet substructure and machine learning method will be summarised. ATLAS boosted heavy neutrino search and the measurement of several substructure observables in different topologies will be mentioned. The former is a precursor of several other planned searched in unusual topologies. Jet tagging using modern machine learning methods is...
Most of the interesting physics signatures at the LHC require the identification of prompt non-fake leptons or photons. Non-fake leptons are usually isolated and have no activity around them hence it is important to define an “isolation energy” around leptons to reduce any contamination from non-prompt and fake objects. In this proceeding, reoptimization studies have been performed to...
A search for a new resonance motivated by strong deviations in the production of multiple leptons at the EW scale is conducted. The analysis is part and parcel of the Madala hypothesis whereby a heavy-scalar `H' decays to two photons, which is necessary to study a resonance diphoton mass peak of this scale. The analysis final state is therefore characterized by two photons and...
This proceeding presents the top-quark background estimation for the $H\rightarrow Sh$ search.$~$The final state for this search is characterized by two leptons (electron and muon) and at least two jets. The top-quark is the dominant background contribution for this analysis. The analysis strategy defines the Signal, Control and Validation Regions which are in the phase space of 0 $b$-jet,1...
The W+Jets(s) fake background estimation for $H\rightarrow Sh \rightarrow 2\ell$ + jets final state is presented. This paper focuses on the $W$+Jet(s) background estimation for the for the BSM search $H\rightarrow Sh \rightarrow 2\ell$ + >= 2 jets analysis with the ATLAS detector. Background processes that produce the same leptonic plus missing transverse energy signature in the detector,...
The Madala hypothesis extends the Standard Model by introducing two additional scalar bosons: the Madala particle $H$ and the Higgs-like boson $S$. In this scenario physics beyond the Standard Model in the Higgs sector can be explored through the decay of the Madala particle into the $S$ and Higgs bosons. Several of the dominant decay channels of the $S$ and Higgs may produce a pair of...
As pointed out in a number of works, the LHC is displaying a number of anomalies in the production of multiple leptons in proton-proton collisions. A simplified model where a scalar, $H$, with a mass around the EW scale that decays predominantly to $Sh$, where $S$ is a EW singlet and $h$ is the Higgs boson in the Standard Model (SM), seems to do a reasonable job in capturing these anomalies....
This project concerns the development of the Common Readout Unit (CRU) user logic for the Muon Identifier (MID) of the ALICE detector. In light of the upgrades to the Large Hadron Collider (LHC) resulting in increased data throughput the ALICE MID requires an upgrade of its Data Acquisition chain, most notably a move from the legacy triggered readout method to a continuous readout method. The...
The low-voltage power supply system upgrade project primarily focuses on the requirements of the new Front-end Electronics (FEE) along with vital power distribution considerations to achieve a robust and effective low-voltage power supply system for the new FEE. The new FEE (DualSAMPA and SOLAR) are designed to have a much higher power consumption compared to the present FEE. For this purpose,...
A series of Test-Beam setup campaigns took place since 2015 until 2018 where the LHC has been shut down for the next 2 years (LHC Long Shut down). During the Test-Beam campaigns the phase-II upgrade electronic prototypes have been evaluated and to help with estimate provisions for future commissioning efforts. The primary objective of the Test-Beam campaigns for ATLAS Tile Calorimeter...
This proceeding presents the design and production of the testing stations to examine the reliability and quality of the Tile Calorimeter LVPS (Low Voltage Power Supplies), which will power the next generation of upgraded hardware in the TileCal (Tile Calorimeter) system of ATLAS at CERN. A LVPS brick is subjected to a stressed environment where the load and temperature are both elevated. In...
In this study, a wireless radio-frequency mesh network was set up in an indoor environment, namely, the School of Physics building. The purpose of the wireless mesh network (WMN) was to enable data to be communicated between the routers or nodes located within the coverage area. Data comprising of latency, outlier ratios, number of hops and packet delivery ratios was collected and analyzed...
The search for new physics beyond the standard model is vital for ATLAS experiments to answer fundamental questions concerning laws of interactions and forces. This study searches for heavy resonances decaying to $Z\gamma$ in association with missing energy using data of the LHC proton-proton collisions at a centre of mass of 13 TeV collected by the ATLAS experiment. Using the multivariate...
Motivated by strong deviations in the production of multiple leptons at the Electroweak (EW) scale we attempt a search for a resonance, which could provide a direct evidence for new physics Beyond the Standard Model (BSM). Here we attempt a search for a resonance in the Z and photon system in association with jets and missing transverse energy. For BSM studies missing transverse energy is a...
This project studies the use of random forest algorithm in discriminating jets initiated by quark or gluons. Jets are collimated flow of hadrons from quarks and gluons produced in collisions clustered using dedicated algorithm. The random forest which is an ensemble decision tree is discussed in detail on why it is suitable to this kind of data. Monte Carlo generated dataset is used to train...
High-energy particle physics experiments usually involve retrieving useful and interesting event data out of extremely large data sets where in most cases there is less signal and more background. To produce the best possible experimental results it is desirable to optimally discriminate between signal and background. The Toolkit for Multivariate Analysis (TMVA) within ROOT provides many...
A search for the Dark Matter (DM) in association with the Standard Model like Higgs boson was performed during the 2015 and 2016 data. In this analysis we use Multivariate Analysis (MVA) methods to suppress the fake missing transverse energy, using the Boosted Decision Tree (BDT) we are able to enhance the regression performance of typically weak MVA methods for the DM search. We scan the...
The discovery of the Higgs boson in 2012 completed the Standard Model and plays a crucial role in studies of theories beyond the Standard Model (BSM). The Madala Hypothesis is one example of BSM model and puts forward a new Heavy scalar (H) to explain anomalies observed in Run 1 and Run 2 data of the LHC. The Heavy scalar H can decay to a Higgs boson in association with jets, leptons and...
