We have a number of projects available for prospective students. The descriptions below are intended to be demonstrative of the kinds of research projects we offer. Most of these are appropriate for undergraduate projects, internships, honours, as well as as PhD. So if you are interested in undertaking a research project like the ones listed below at any level of your academic career please get in touch.
Dark matter
Dark Matter and new physics signatures in the sky
Supervisor: Céline Bœhm
Understanding the nature of dark matter is one of the last bastions of cosmology and particle physics. Its very existence highlights the need for new physics and could lead to a conceptual revolution in our understanding of fundamental principles. In this project, we will study the signatures of specific dark matter models in the sky (and new physics in general) in light of forthcoming experiments such as CTA and the SKA. This project is at the frontier of particle physics, cosmology and astronomy. Not much prior knowledge is needed but please do expect to code in python.
Mass modelling in clusters of galaxies and dark matter constraints
Supervisor: Céline Bœhm
Clusters of galaxies are prime targets to study the properties of the invisible matter (the so-called dark matter) that makes up most of the matter in the Universe. In this project, you will model the mass distribution of the dark matter in a distant cluster using HST data (as well as other Astronomy survey data) and constrain dark matter microscopic interactions using their corresponding signatures in the electromagnetic spectrum.
Unravelling the history of the Milky Way’s halo with Gaia
Supervisor: Ciaran O’Hare
The European Space Agency’s revolutionary mission Gaia has mapped almost 2 billion stars in the Milky Way with unprecedented accuracy. This huge dataset is enabling us to deconstruct the components of the Milky Way and determine the major events that took place in its 13 billion year history. One of the most surprising discoveries was a vast structure that is invisible to the naked eye, but has left a unique dynamical imprint on the galaxy This project would involve analysing the Gaia data to determine the extent of this structure and what caused it. It would also be interesting to consider the implications of this structure for searches for the elusive dark matter.
Informing searches for dark matter using galaxy simulations
Supervisor: Ciaran O’Hare
We have extremely strong evidence that our galaxy is embedded in a vast halo made up of an invisible material called dark matter. The quest for the particle identity of this substance has driven the development of some of the most sensitive particle physics experiments ever performed. Nevertheless, dark matter remains undetected. As this has been going on, in the astrophysics community, decades of extensive computational work has resulted in extraordinarily sophisticated numerical simulations needed to understand the complex processes involved in the formation of galaxies. The outputs of these simulations are fake galaxies that look remarkably like our own Milky Way. As well as normal luminous matter, these simulations must also track the dark matter halos of their galaxies. We therefore have a unique opportunity to gain insight into what terrestrial dark matter experiments should be seeing by analysing the dark matter halos surrounding these Milky Way analogues. This project would be a blend of astrophysics and particle physics. The work would involve manipulating data from large hydrodynamic simulations, extracting the dark matter distribution around the “fake” Earth’s location, and using this to predict the particle physics signals for a range of hypothesised dark matter particle candidates.
Current direct detection experiments
Data analysis development for the SABRE South experiment
Supervisor: Theresa Fruth
The SABRE South experiment is the first dark matter search in Australia and the Southern Hemisphere. The experiment is looking for dark matter interactions in a NaI crystal. The resulting scintillation signal would be detected by light detectors attached to either end of the crystal. The signature of a dark matter signal would be an annual variation in interaction rate. To maximise the sensitivity of the experiment, we need efficient data analysis methods to select signal pulses and reject background noise.
The aim of this project is to develop efficient data analysis method using simulation and test-stand data.
Data quality and monitoring sensor analysis for the LZ Dark Matter Experiment
Supervisor: Theresa Fruth
The LZ experiment is on of the most sensitive direct detection searches for dark matter ever performed. Its recently published first science result set world-leading limits for Weakly Interacting Massive Particles (WIMPs). As data taking is continuing, it is cirtical to further our understanding of the detector. As a rare event search it is essential that any period of detector instability is vetoed and removed from the data before the final analysis. A suite of monitoring sensors (electromagnetic, acoustic, temperature) have been installed in the detector for this purpose. The student on this project will work on understanding the signals from these sensors further by analysing data from LZ and additionally performing test measurements in the lab in Sydney. The student will have the opportunity to integrate their analysis in the LZ data quality procedure. There will be opportunity to use machine learning algorithms for this project.
Single photon response analysis for the LZ Dark Matter Experiment
Supervisor: Theresa Fruth
The LZ Experiment is one of the most sensitive direct detection searches for dark matter ever performed. Its recently published first science result set world-leading limits for Weakly Interacting Massive Particles (WIMPs). As data taking is continuing, it is critical to improve its low energy detection efficiency. To do this we need to further improve our modelling of single photon signals and to develop algorithms to extract these small signals from the data stream. The student on this project will have the opportunity to work with data from LZ, as well as work on preparing a setup in the lab in Sydney and take measurements there.
Development of new detectors
DNA as a particle detector
Supervisor: Ciaran O’Hare, Céline Bœhm
We have recently begun theoretical and experimental investigation into a radical new particle detection technology. The detector material is made up of single or double-stranded DNA that could be broken by incoming ionising particles. These particles could include high energy cosmic rays, neutrinos, and even dark matter. By precisely sequencing and arranging the strands of DNA and collecting the severed remains, it should be possible to reconstruct the tracks left by the incoming particles to nanoscale precision. We have some proof-of-concept Monte Carlo simulations already constructed, this project would extend upon this preliminary work to try and optimise the detector further, test its design, and potentially take the concept in new directions.
CYGNUS: a large-scale directional dark matter detector
Supervisor: Ciaran O’Hare
The quest for the mysterious dark matter that makes up most of the mass in the Universe has inspired some of the most sensitive physics experiments ever performed. These giant detectors are often located underground or inside of mountains and are some of the quietest places in the Universe. Nevertheless, dark matter has still not been detected. To assist in the global search for dark matter, the Australian particle physics community has endeavoured to construct the first underground lab in the southern hemisphere, to be located in a working gold mine in Stawell, Victoria. One of the flagship detectors that will be situated at Stawell is one node of a planned network of experiments known as CYGNUS. The experimental principle behind CYGNUS sets it apart from all currently running experiments. CYGNUS aims to detect not just the incoming dark matter particles themselves, but also their directions. This enables far superior background rejection capabilities, as well as the potential to more precisely study the nature of dark matter and its behaviour in our galaxy. This project will be centred around finding the optimal running configurations of CYGNUS to detect and study dark matter. The work will involve a mixture of theoretical particle physics calculations, statistical analyses, as well as detector simulations.
Gravitational detection of dark matter
Supervisor: Ciaran O’Hare, Celine Boehm
We have abundant evidence from across astronomy and cosmology that galaxies are embedded inside vast halos of an invisible material. This so-called dark matter outweighs normal matter by around 5 to 1, however as of yet we have no evidence that dark matter interacts with us via any other way other than gravity. Particle physics experiments have been running for decades trying to detect the interactions of dark matter particles, but they have so far come up empty handed. We must therefore reckon with the possibility that dark matter only interacts gravitationally. Since gravity is such a weak force this idea sounds as though it would doom all hopes of detecting dark matter in the lab. However thanks to recent technological advances in developing ultra-sensitive opto-mechanical accelerometers, there may be an experiment one can construct that would be able to detect the incredibly weak gravitational pull of a dark matter particle as it passed through the laboratory. This project would be theoretical and computational in nature and would focus around figuring out the optimal design of such a detector to detect dark matter using gravity alone.
Neutrinos
Supernova early warning with neutrinos
Supervisor: Ciaran O’Hare
If a massive star explodes in our galaxy, the prompt luminous emission would last only a brief period before decaying away. To understand such a complex event like a supernovae, astronomers would desirably like to catch one in the act. Fortunately, with neutrinos we may have a way to do this. Neutrinos are generated in enormous quantities during supernovae, and carry up to 99% of the total energy generated despite the fact they are almost massless. Unlike photons which get caught up in the surrounding shock wave, neutrinos sail out of the collapsing stellar core unimpeded. This means that neutrinos arrive at Earth several hours before the light reaches us. A “Supernova Early Warning System” of neutrino detectors around the world will therefore be a valuable way to warn of a supernova about to explode. The aim of this project will be to determine the required characteristics of this network, for instance how precisely the direction of the supernova needs to be measured to be useful to astronomers. This will require calculating the neutrino emission from a supernova and the interaction rates of neutrinos inside detectors.
Neutrinos for nuclear security
Supervisor: Ciaran O’Hare
Whenever a nuclear fission reaction takes place, a tiny fraction of the energy released is in the form of neutrinos. It is impossible to prevent the neutrinos from escaping the reactor, so even if a nuclear reaction were being performed in a clandestine manner, the secret would always be given away in the form of neutrinos. Of course this very nature makes them extraordinarily difficult to detect. However we are entering an era in which will have many gigantic liquid-based neutrino detectors around the world with masses in excess of thousands of tons. This project would involve determining the feasibility of detecting neutrinos from nuclear reactors around the world. This would require calculating the the rates of neutrinos emitted during nuclear reactions and construct a global map of the reactor neutrino flux. The aim would be to design the optimum network of detectors with ability to monitor undeclared nuclear reactions, while also dealing with an abundant background of other neutrinos originating from the Sun and nuclear decays inside the Earth.
Astroparticle physics and cosmology
New particles from the Sun
Supervisor: Ciaran O’Hare
One of the best ways to search for the existence of new particles in Nature is to accelerate and smash other particles together inside colliders. We have been able to reach exceedingly high energies in current colliders, which is good for finding very heavy particles. But what if the new particles in nature are lighter but so weakly-coupled that we simply cannot generate them in sufficient quantities to see in colliders? Fortunately we have a giant ball of burning plasma practically on our doorstep in the form of the Sun. Many of our best ideas for new physics introduce new light particles —- such as the axion, dark photons, or chameleons — that would be impossible to see in colliders, but would be generated copiously in the Sun’s core. This theoretical project would involve calculating the production rate of new particles inside the solar plasma, and then trying to understand the kinds of particle physics experiments we should point at the Sun to try and detect them.
Numerical simulations of the early Universe: cosmic strings and dark matter
Supervisor: Ciaran O’Hare
The physics that governs the very early Universe, before the formation of the first atomic nuclei, is a hotly debated topic in the particle physics and cosmology community. One possibility that has been pondered for many decades, but has enjoyed resurgence in interest recently, is the formation of cosmic strings. These are a kind of “topological defect” which can be formed when the Universe undergoes a phase transition; they can be thought of in a similar way to cracks in a sheet of ice. They are extremely thin, but with lengths that can extend across the size of the observable Universe. The resurgence in interest recently is because such cosmic strings are a prediction of a candidate for dark matter that is extremely popular right now: the axion. This project will involve setting up a numerical simulation of the very early Universe to study how cosmic strings form and decay, and make predictions about the resulting dark matter.