2023 CDM Annual Workshop

7:00-9:00

Breakfast (for those staying the night before)

Promenade Restaurant

8:30-9:00

30

Registration (for those not registered on previous days)

Function foyer (outside Ballrooms)

9:00-9:10

10

Welcome to Country

Uncle Rod

9:10-9:30

20

Welcome from Director and housekeeping

Elisabetta Barberio / Anita Vecchies

Session 1

Session Chair - Tony Williams

Ballrooms 1 + 2

9:30-10:00

30

Keynote presentation - Status and prospects of underground Direct Detection experiments

Marc Schumann

The direct detection of dark matter particles scattering off a laboratory target is a way to probe the dark matter around us. I will briefly review the current status of the field and what is required to cover the entire accessible parameter space before irreducible neutrino backgrounds limit the detection sensitivity.

10:00-10:30

30

Keynote presentation - LHC summary talk

Paul Jackson

The ATLAS experiment at the Large Hadron Collider (LHC) is one of the most powerful tools in the search for dark matter. Dark matter is a mysterious substance that makes up about 85% of the matter in the universe, but it cannot be directly observed because it does not interact with light or other forms of electromagnetic radiation. However, dark matter does interact with ordinary matter through gravity, and this interaction can be indirectly detected by the ATLAS experiment.

One way that ATLAS searches for dark matter is by looking for events with large missing transverse momentum. Missing transverse momentum is a measure of the amount of momentum that is missing from an event. If dark matter particles are produced in a collision at the LHC, they will escape the detector without interacting with it, leaving behind a signature of missing transverse momentum. ATLAS has also conducted searches for dark matter by looking for decays of the Higgs boson into invisible particles and other invisible signatures. If the Higgs boson can decay into dark matter particles, it would provide a direct link between dark matter and the Standard Model of particle physics. To date, ATLAS has not found any definitive evidence for dark matter. However, the experiment has placed important constraints on the properties of dark matter particles. These constraints have helped to guide the development of new theories of dark matter, and they will continue to be important as the search for dark matter continues.

This talk will cover the contributions to searches being made by Centre researchers and discuss our efforts in work to upgrade the detector for future higher energy and intensity collisions at the LHC.

10:30-11:00

30

Icebreaker activity

Anita Vecchies

This will be a group activity on each table. We will ask the room a simple question and give each table a few minutes to discuss their answers. Then half the table (every second person) gets up and swaps to another table where you will answer the next question. And repeat until we have run out of time. The questions will be light (eg. What’s your favourite beverage?) and some with a bit of a physics focus (eg. what’s your favourite equation) it’s not mandatory for everyone on the table to answer every question.

11:00-11:30

30 min

Morning Tea

Function foyer (outside Ballrooms)

Session 2

Session Chair - Irene Bolognino

Ballrooms 1 + 2

11:30-12:00

30

Keynote presentation - Theory summary talk - Astroparticle

Celine Boehm

12:00-13:00

60

EDI training session - Part 1 - Neurodiversity presentation - Supporting a neurodiverse workforce

Ash Vance and Chris Ferguson from Untapped Talent

13:00-14:00

60 min

Lunch

Function foyer (outside Ballrooms)

Session 3

Session Chair - Celine Boehm

Ballrooms 1 + 2

14:00-15:00

60

EDI training session - Part 2 - Neurodiversity workshop

Facilitated by Ash Vance and Chris Ferguson from Untapped Talent

15:00-15:15

15

Impact of nuclear structure on nuclear responses to WIMP elastic scattering

Raghda Abdel Khaleq

We build on previous work by investigating the sensitivity of nuclear response functions to nuclear structure for WIMP-nucleus elastic scattering, employing nuclear shell model interactions which differ from those used in previous literature to facilitate comparison between different nuclear structure results. This is performed for isotopes relevant to direct detection experiments:19F , 23Na, 28−30Si, 40Ar, 127I, 70,72−74,76Ge and 128−132,134,136Xe. Our integrated nuclear response values sometimes exhibit large (up to orders-of-magnitude) factor differences compared to those in previous works for certain WIMP-nucleus interaction channels and their associated isotopes. We highlight potential nuclear modelling uncertainties in WIMP-nucleus scattering amplitudes, and deduce the effect of these uncertainties on the scattering cross-sections associated with the XENON100 and LUX direct detection experiments for natXe isotopes.

15:15-15:30

15

Probing dark matter with gravitational waves

Giovanni Tomaselli

Future gravitational wave detectors will enable precision studies of black hole environments. Possible scenarios include: accretion disks, dark matter overdensities, or superradiant clouds of ultralight bosons. I will show how these environments alter the gravitational waveform, and how their characteristic imprint can allow us to identify them. I will then focus on the case of a cloud of ultralight bosons, discussing its properties, as well as its extremely peculiar gravitational wave signatures.

15:30-16:00

30 min

Afternoon Tea

Function foyer (outside Ballrooms)

Session 4

Session Chair - Theresa Fruth

Ballrooms 1 + 2

16:00-16:15

15

Dark Galaxies in the WALLABY survey

Jeremy Mould

WALLABY is a survey of the southern hemisphere in neutral hydrogen with the Australian Square Kilometre Array Pathfinder. In the pilot survey we are finding that 1% of the detected galaxies have no optical counterpart. Dark matter inferred from the velocity field of the gas is the main component of these galaxies.

16:15-16:30

15

Improving ATLAS Hadronic Object Performance with ML/AI Algorithms

Albert Kong

Experimental uncertainties related to hadronic object reconstruction can limit the precision of physics analyses at the LHC, and so improvements in performance have the potential to broadly increase the impact of results. Hadronic object reconstruction is also one of the most promising settings for cutting-edge machine learning and artificial intelligence algorithms at the LHC. Recent refinements to reconstruction and calibration procedures for ATLAS jets and MET result in reduced uncertainties, improved pileup stability and other performance gains. In this contribution, selected highlights of these developments will be presented.

16:30-16:45

15

First science run results of XENONnT

Yajing Xing

The XENONnT experiment, situated at the Laboratori Nazionali del Gran Sasso in Italy, is a leading experiment in the search for Dark Matter (DM). With its 5.9-tonne liquid xenon time projection chamber, this experiment seeks to detect weakly-interacting massive particles (WIMPs) as the primary objective. Having achieved unprecedented purity and background level, it opens the door to exploring various other rare signals, such as solar axions, axion-like particles, bosonic dark matter, and even solar neutrinos. This talk will provide an overview of the XENONnT detector, its performance, and the key findings from its first science run.

16:45-17:00

15

Exploring light dark matter with the Migdal effect in hydrogen-doped liquid xenon

Alexander Ritter

An ongoing challenge in dark matter direct detection is to improve the sensitivity to light dark matter in the MeV-GeV mass range. One proposal is to dope a liquid noble-element direct detection experiment with a lighter element such as hydrogen, while another avenue is to exploit the Migdal effect, where a nuclear recoil leads to electronic ionisation or excitation. Combining these ideas we find that current and future liquid-xenon detectors doped with hydrogen could have sensitivity to dark matter masses as low as 5 MeV. Notably, this technique substantially enhances the sensitivity of direct detection to spin-dependent proton scattering, well beyond the reach of any current experiments.

17:00-17:10

10

Group photo

Assemble on lawn outside the Stamford Grand

17:10-1830

80 min

Poster Session - platters provided

There will be a cash bar at the session where people can purchase their own drinks

Ballroom 3

Full details here: 2023 CDM Annual Workshop Poster Session - (Public) ARC CoE for Dark Matter Particle Physics - Confluence (atlassian.net)

During the poster session, there will be a photographer in Ballroom 5 set up to take profile photos of any Centre members that would like them. These will be provided to you after the workshop for you to use on the Centre website or LinkedIn etc.

There will also be a short opportunity to take some smaller group photos.

7:00-9:00

Breakfast (for those staying the night before)

Promenade Restaurant

8:30-9:00am

30

Registration (for those not registered on previous days)

Function foyer (outside Ballrooms)

Session 1

Session Chair - Sara Diglio

Ballrooms 1 + 2

9:00-9:30

30

Keynote presentation - Theory summary talk

Peter Cox

9:30-10:00

30

Keynote presentation - Metrology summary talk

Michaela Froehlich

Nuclear recoils induced by dark matter interactions typically have energies in a region heavily affected by environmental radioactive and cosmic background. Thus, metrology activities are largely focused on how to measure radioactivity in detector materials and the associated laboratory environment. This talk will focus on the most important radioactive species likely to impact detector capability, namely K-40, I-129 and Pb-210.

10:00-10;30

30

Keynote presentation - WISP/Axion summary talk

Michael Tobar

The axion is a putative particle that should exist to solve the strong CP problem in QCD, and if it exists can be calculated to be created in the early Universe and can account for all the perceived dark matter. The axion is predicted to interact with standard model particles allowing various avenues for detection. If axions interact with photons, Maxwell’s equations of electrodynamics are modified through the chiral anomaly g_{aγγ}, and solving these equations in various situations has allowed the determination of a variety of experimental techniques to search for axion dark matter. We will review how electrodynamics is modified, and show how to calculate the sensitivity of a variety of experiments over a variety of mass ranges.

More recently interactions between putative axions and magnetic monopoles have been revisited, in this case the axion-photon coupling parameter space is expanded from one parameter to three (g_{aγγ}, g_{aEM}, g_{aMM}), allowing new ways to search for axions and a possible indirect way to determine if magnetically charged matter exists. We propose to undertake new experiments during the life time of this Centre, giving a new opportunity for significant alternative searches for dark matter.

10:30-11:00

30

SABRE South update

Phillip Urquijo

The SABRE (Sodium iodide with Active Background REjection) experiment aims to detect an annual rate modulation from dark matter interactions in ultra-high purity NaI(Tl) crystals in order to provide a model independent test of the signal observed by DAMA/LIBRA. It is made up of two separate detectors; SABRE South located at the Stawell Underground Physics Laboratory (SUPL), in regional Victoria, Australia, and SABRE North at the Laboratori Nazionali del Gran Sasso (LNGS).

SABRE South is designed to disentangle seasonal or site-related effects from the dark matter-like modulated signal by using an active veto and muon detection system.  Ultra-high purity NaI(Tl) crystals are immersed in a linear alkyl benzene (LAB) based liquid scintillator veto, further surrounded by passive steel and polyethylene shielding and a plastic scintillator muon veto. Significant work has been undertaken to understand and mitigate the background processes, that take into account radiation from the detector materials, from both intrinsic and cosmogenic activated processes, and to understand the performance of both the crystal and veto systems. SABRE South will be assembled and commissioned in 2024/2025.

This talk will report the general status of SABRE South.

https://darkmatteraustralia.atlassian.net/wiki/download/attachments/1662681103/SABRE Annual Meeting.pdf?api=v2

11:00-11:30

30 min

Morning Tea

Function foyer (outside Ballrooms)

Session 2

Session Chair - Gary Hill

Ballrooms 1 + 2

11:30-12:00

30

DSTG priorities, projects, job opportunities and tips

Damian Marinaro

Damian will present a brief introduction to the Defence Science and Technology Group and provide insights on working with and for DSTG. Some of the research areas of interest to Defence will be outlined, intended as a primer to stimulate further discussion during and following the Workshop.