2025 CDM Annual Workshop

6:30-9:00

Breakfast (for those staying at the Rex, this is included with the room, for others it will be paid for separately)

Rex Brasserie 

8:30-9:00

30

Registration (for those not registered on previous days)

Arrival Tea & Coffee

Ballroom Foyer

9:00-9:15

15

Welcome to Country

Paul Girrawah House or Dr Matilda House

Session 1

Session Chair - Lindsey Bignell

(Mic/AV - Victoria Bashu)

9:15-9:30

15

Welcome from Director and housekeeping

Elisabetta Barberio / Anita Vecchies

9:30-10:15

45

Keynote - Dark matter from an astronomical perspective

Kenneth Freeman

The discovery of dark matter in the universe led to a  change in our understanding of the universe and how the structures in the visible universe formed and evolved.  I will give an overview of the steps and mis-steps, and a few of the most important papers that led up to this paradigm shift.  

We now know that most of the mass of galaxies is in the form of dark matter.   I will also discuss how the properties of halos for the dark halos of individual galaxies change systematically with galactic mass, over about 5 decades in mass, as we go from the  giant spirals to  the dwarf spheroidal galaxies.

10:15-10:30

15

ECR Committee update

ECR Committee members

The ECR Committee will give a short overview of the workshop held on Monday and Tuesday.

10:30-11:00

30

Morning Tea and Contact Officer meet and greet

Session 2

Session Chair - Michaela Froehlich

(Mic/AV - Amrita Banerjee)

11:00-12:00

60

Mentoring session

Building your Profile & Getting Noticed on LinkedIn

Michaela Froehlich

Fleur Morrison / Sharry

12:00-12:15

15

Recent progress on the ORGAN Experiment

Aaron Quiskamp

We have begun commissioning a squeezed-state receiver for the ORGAN-Q experiment using two travelling-wave parametric amplifiers (TWPAs) to reduce the effective system noise and push beyond the standard quantum limit. This upgrade will push ORGAN’s sensitivity closer to the QCD-axion model bands. Additionally, we rapidly responded to the TASEH dark-photon detection claim by commissioning a dedicated ORGAN search and, via an independent analysis, we have excluded the reported line at the 99% confidence level.

12:15-12:30

15

Characterisation and Simulation of Photomultiplier Tube (PMT) Response in the SABRE South Experiment

Sharry

Photomultiplier Tubes (PMTs) are central to the SABRE South experiment’s ability to detect rare, low-energy events, such as potential dark matter interactions in ultra-pure NaI(Tl) crystals. To correctly interpret what the detector sees, we need simulations that faithfully reproduce how our PMTs respond to real signals. This work presents the comparison of the simulated PMT waveforms from our custom simulation framework with actual SABRE South PMT data.
Key properties such as gain, dark rate, timing response, and afterpulsing are studied in PMT tests to build a clear picture of how the PMTs behave under real experimental conditions. Alongside this, we develop and refine simulated PMT waveforms that aim to capture the key physical and electronic effects shaping the signal. By comparing these simulations directly with data, discrepancies are identified and used to refine the simulation framework. This iterative process helps to improve the accuracy of the detector response simulation, which is crucial for reliable event reconstruction and background rejection.
The major output from this work will be a realistic PMT response simulation framework tailored to SABRE South, built on detailed characterisation of PMT performance from calibration and background runs. Our goal is to bridge the gap between simulation and data, so we can confidently interpret the signals
SABRE South observes.

12:30-13:30

60

Lunch

(and Executive Committee meeting)

Ballroom foyer

(Executive Committee in Room 6)

Session 3

Session Chair - Ben McAllister

(Mic/AV - Max Fleming)

13:30-14:00

30

Outreach and Education update

Update on Partner Schools research project

Jackie Bondell

Victoria Millar

Jackie will present an overview of the outreach and education activities of the Centre as well as opportunities for Centre members to get invovled.

Victoria will provide an update on the research being undertaken at the Centre’s partner schools assessing the impact of outreach activities.

14:00-14:15

15

Tidal adaptive softening and artificial fragmentation in cosmological simulations

Robert Mostoghiu Paun

N-body cosmological simulations often suffer from artificial fragmentation that creates a "beads-on-a-string" effect, an issue especially visible in warm dark matter models. This work tests a spatially adaptive softening technique, which adjusts gravitational force resolution based on the tidal field, as a potential solution to this problem. While the method improves force accuracy in idealized tests, it does not substantially reduce spurious haloes in full cosmological simulations, although it does alter their formation times. This work concludes by noting how initial conditions affect halo formation regions and proposes strategies for mitigating these numerical artefacts within existing N-body frameworks.

14:15-14:30

15

Untangling the local Cosmic Web with Caustic Skeleton theory

Amelie Read

Caustic Skeleton (CS) theory offers a promising new approach to classifying present-day observed large-scale structures according to their origins and formation history. However, the CS framework is relatively new and has thus far remained abstract and in the mathematical world, despite the fact that it has proven very effective at classifying structure in simulations. Hence, we are pulling CS theory into reality by applying it to the Manticore simulations, which provide a cutting-edge reconstruction of the 2M++ galaxy survey of the local Universe. By generating a detailed map of caustics in the local Universe, we can investigate the connection between the properties of galaxies in the large-scale structures of the constructed caustic skeleton and thereby implications for our Universe's underlying cosmology.

14:30-14:45

15

Dark sector searches at Belle and Belle II

Daniel Marcantonio

Recent results from Belle II provide new sensitivity to dark sector particles produced either directly in electron-positron collisions or in rare meson decays. Searches such as B --> KX can probe scenarios with feebly-interacting or invisible particles, while other analyses target dark photon or dark Higgs production. With its growing dataset and constantly improving reconstruction techniques, Belle II will continue to push into new regions of parameter space in the coming years.

14;45-15:00

15

Using new computational methods to characterise model phenomenology

Riya Raizada

Upcoming Stage IV surveys are anticipated to create a large abundance of high resolution data of astronomical data. As such, there is a pressing need for accurate and wide-spread Dark Matter model predictions of observable phenomena in the universe. While simulations can assist in addressing this issue, they have a steep trade off between computational expense and accuracy that must be overcome in order to match the resolution of Stage IV surveys. The integration of Machine Learning and Emulation techniques can assist in overcoming such issues.

15:00-15:30

30

Afternoon Tea

Session 4

Session Chair - Aaron Quiskamp

(Mic/AV - Michael Bradley)

15:30-15:45

15

Towards a Machine Learning ParticleFlow Algorithm at the ATLAS Experiment

Matthew Green

The ATLAS ParticleFlow algorithm combines the measurements from the tracker and the calorimeter in such a way to not double count any energy contributions. However, with the High Luminosity experimental program about to commence at the LHC, there has been immense effort to improve ParticleFlow in the harsh pileup conditions. A majority of this work has been investigating state-of-the-art machine learning methods to replace either individual steps of the algorithm (modular), or the entire algorithm (end-to-end). This talk will focus on using a Graph Neural Network (GNN) as a tool for calibration within some Machine Learning ParticleFlow algorithm.

15:45-16:00

15

Structure and evolution of axion miniclusters

Ananthu Krishnan Anikumar

If QCD axion is dark matter, it can have structure on galactic scales in the event of post-inflationary symmetry breaking. These miniclusters/minihalos will result in clumping of the dark matter, affecting the local density, which needs to be taken into consideration for haloscope experiments. In our work, we observed the detailed structure of these minicluster (halos) using N-body simulations. It was observed that the high-density miniclusters formed before matter-radiation equality are well-preserved within the larger minicluster halos formed later through hierarchical structure formation.

16:00-17:00

60

Innovation and Translation update

Christine Thong / Robert Mostoghiu Paun

I will provide an update on innovation/translation activities in the Centre as well as a more detailed report on the IdeaSquare activities at CERN. I will also run an activity around translation.

18:30-22:00

Workshop dinner and talent show

Grand Ballroom

• 18:30 Start

• 18:45 Entree

• 19:30 Main

  • Talent Show

• 20:30 Dessert

Dress code: There is no formal dress code for the dinner. Whilst smart casual is the general expectation, you are welcome to wear any clothing representing your cultural heritage or to express your personality or identity.

9:00-17:00

Breakout room

Room 6

6:30-9:00

Breakfast (for those staying at the Rex, this is included with the room, for others it will be paid for separately)

Rex Brasserie 

9:00-9:15

15

Registration (for those not registered on previous days)

Ballroom foyer

Session 1

Session Chair - Giorgio Busoni

(Mic/AV - Raj Aryan Singh)

9:15-9:45

30

Keynote - Directions in Dark Matter Model Building

Raymond Volkas

I’ll present a whiteboard talk reviewing some of the directions being pursued in dark matter model building. I will try to narrate as much of a synthesis as I can manage, limited by the knowledge that the spectrum of dark matter candidates is notoriously very broad. My focus will be on models and concepts, touching on phenomenology only glancingly.

9:45-10:30

45

Keynote - Dark matter experiments

Phillip Urquijo

Building dark matter direct detection experiments involves 5-15 year timescales that create significant personnel and management challenges beyond the technical difficulties. Drawing from experience across Belle, Belle II, ATLAS, LHCb, SABRE, and Hyper-Kamiokande, this talk examines the complete experimental lifecycle including FTE management, the career-span mismatch problem, common failure modes, and risk mitigation strategies. I will discuss practical lessons on what enables experiments to succeed despite fragmented effort, funding uncertainty, and the unique demands of underground physics.

10:30-11:00

30

Morning Tea and EDI Committee meet and greet (TBC)

Session 2

Session Chair - Zuzana Slavkovska

(Mic/AV - Danish Khan)

11:00-11:25

25

SABRE South update

Leonie Einfalt

SABRE is an international collaboration operating paired dark-matter detectors in the Northern (SABRE North) and Southern Hemispheres (SABRE South). This dual-site strategy is designed to distinguish true dark-matter signals from seasonal or environmental backgrounds, a capability uniquely enabled by the presence of a Southern Hemisphere experiment. SABRE South is located at SUPL in regional Victoria. SUPL sits 1024 m underground  within the Stawell Gold Mine.

Substantial progress has been achieved in the procurement, testing, and preparation of equipment for installation. The SABRE South muon-veto detector and data-acquisition systems are already operational at SUPL and are currently recording data. Full commissioning of the complete SABRE South detector is planned for 2026.

This presentation will summarise the construction progress, expected detector performance, and the projected physics reach of SABRE South.

11:25-11:40

15

SUPL update

Kim Mintern-Lane

Over the past 12 months, the Stawell Underground Physics Laboratory (SUPL) has continued to mature as Australia’s only deep underground research facility. This presentation will highlight key milestones achieved across operations, infrastructure development, and scientific collaboration — including progress on the SABRE South dark matter experiment, commissioning of new research infrastructure, and enhancements to the laboratory’s environmental and safety systems. Looking ahead, the talk will outline forward priorities for 2026 and beyond, including radon mitigation initiatives, expanded research partnerships, and preparations for future low-background and quantum sensing programs.

11:40-11:55

15

Environmental entanglement and the wave packet approach to neutrino oscillations

Eden Isaac

We consider the implications of quantum mechanical entanglement on the coherence of neutrino oscillations. Using a toy example of the double slit experiment, we investigate the effect of environmental entanglement in suppressing coherence and introduce density matrix formalism. This formalism is then applied to neutrino oscillations to quantify decoherence due to the separation of neutrino mass eigenstate wave packets.

11:55-12:00

5

Group photo

Exit via the double glass doors in the ballroom foyer and assemble outside.

Listen to instructions at the end of this session. It’s likely we will assemble just outside the front of the building for a group photo.

12:00-13:00

60

Lunch

Session 3

Session Chairs - Theresa Fruth / Jade McKenzie