DMUK Meeting December 2025 - University of Birmingham

Monday 1 Dec 2025, 09:00 → 21:50 GMT

University of Birmingham

A 1-day meeting for the UK's Dark Matter community to meet up, present research, and discuss the latest progress in the field.

Event details: The meeting will take place from 10:00 to 18:00 on Monday 1st of December 2025 on the Edgbaston Campus of the University of Birmingham, in the Arts Building Lecture Room 8 (301).

For those unable to attend in person, a Zoom connection will be available. Please indicate on the registration form if you are planning to attend in-person or online.

Abstract Submission and Registration: Registration for the meeting is now open.

Please submit an abstract in the registration form if you would like to be considered for a talk. We encourage talks from the full breadth of the UK dark matter community and particularly from early career members of the community.

Abstract submission and registration will close on the 19th of November.

Location: The University of Birmingham is located in Edgbaston, Birmingham and is easily accessible by public transport via the "University" train station just by campus (with a direct connection from Birmingham New Street). The postcode for the North East Car Park is B15 2SA, if you are travelling by car. More detailed directions can be found here. A campus map can be found here.

Acknowledgments: Lunch and coffee will be provided. Support for this event is gratefully received from the Astroparticle Physics group of the Institute of Physics.

Zoom Link: 

https://bham-ac-uk.zoom.us/j/6904384136

Arrival Period

Morning Session 1

1 The QSHS axion search

Quantum Sensors for the Hidden Sector is a UK collaboration that is probing axion dark matter. I will motivate axions as a dark matter candidate, discuss the experiement, and present an update on our project.

Speaker: Prof. Ed Daw (The University of Sheffield)

the_qshs_axion_search.pdf

2 A high quality factor dielectric Fabry-Perot cavity for detecting dark matter axions

The axion, as well as being a proposed solution to the strong CP problem, is a well-motivated candidate for dark matter [1]. The Quantum enhanced Particle Astrophysics (QuEPA) project at Imperial College London looks to detect axions with a microwave cavity and trapped electrons. Towards this goal, a dielectric Fabry-Perot cavity has been developed as a dark matter haloscope to convert axions to microwave photons when the cavity is placed in a strong, homogeneous magnetic field [2]. The goal is to explore in the 125-250 µeV (30-60 GHz) mass range. In this talk, I will present the motivations and benefits of using this type of cavity for a dark matter axion search and the latest experimental results in the characterisation of this cavity. [1] D. Marsh, Physics Reports 643 (2016) P1-79 DOI: 10.1016/j.physrep.2016.06.005. [2] I. G. Irastorza and J. Redondo, Progress in Particle and Nuclear Physics 102 P89-159 (2018) DOI:10.1016/j.ppnp.2018.05.003.

Speaker: Jonathan Gosling (Imperial College London)

A high quality factor dielectric Fabry-Perot cavity for axion dark matter detection.pdf

A high quality factor dielectric Fabry-Perot cavity for axion dark matter detection.pptx

3 Quantum limited superconducting resonator amplifiers for high frequency Axion dark matter search

Superconducting Parametric Amplifiers (SPAs) have seen great interest in recent years due to their high gain and quantum limited noise performance. Among these amplifiers, resonant SPAs have been widely developed for experiments where ultra low-noise narrow-band amplification is of interest, such as the search for Axion dark matter in particle physics and the detection of spectroscopic lines in astrophysics, while also finding applications in quantum computing. This work presents an amplifier based on a Complementary Split Ring Resonator (CSRR), patterned on a NbTi coated sapphire substrate embedded within a waveguide, designed to work at a set of four narrow frequency bands throughout Ka band (26-40 GHz) using the kinetic inductance of the superconducting film. The S-parameters measured at 400 mK, using a sorption cooler, show the four resonances between 23.3 and 26.3 GHz at 1 GHz spacing, with a maximum transmission on resonance of -1 dB. Four-wave mixing has been observed with each resonance and a maximum signal gain of 30 dB has been measured, corresponding to 29 dB of insertion gain. The noise performance of the amplifier has been measured, showing an added noise of 1.2 half quanta at 400 mK. These results motivate the implementation of such amplifiers in future high frequency Axion dark matter experiments, where system noise has a direct impact on the parameter space explored within a given time.

Speaker: Dr Valerio Gilles (The University of Manchester)

DMUK_VG.pptx

10:50 Refresher Break

Morning Session 2

4 Ultra-pure electroforming at Boulby deep underground laboratory

Rare-event search experiments, for example those looking for dark matter and neutrinoless double beta decay, require increasingly sensitive detectors. A critical aspect of this, is the reduction of backgrounds from detector materials, especially those in contact with the sensitive volume. High-grade copper is an attractive construction choice, due to its commercial availability and lack of long-lived radioisotopes. Despite this, copper can still represent a dominant background, with impurities from the ore, implanted during manufacture or from cosmogenic activation. Underground additive-free electroforming provides a method to produce ultra-pure copper parts with orders of magnitude reduction in background. In this contribution, the now finished construction of a copper electrodeposition facility at Boulby, the UK’s deep underground laboratory, will be outlined which is key for several future experiments. One such experiment DarkSPHERE, a large diameter spherical proportional counter, will be presented along with the near-term plan to electroform a 30cm spherical proportional counter as the first step towards its construction.

Speaker: Mr Giovanni Rogers (University of Birmingham (GB), STFC Boulby Underground Laboratory)

DM-UK.pdf

DM-UK.pptx

5 Designing ultra-radiopure, high-strength, electroformed CuCr and CuCrTi alloys, for rare event searches

Future detecting systems for direct Dark Matter (DM) detection require ultra radiopure materials. Electroformed copper (EFCu) is the material of choice for large-scale detectors thanks to its favourable radiochemical, thermal, and electrical properties. To fulfil the unique radiopurity requirements, experiments pioneer large-scale, additive-free Cu electroformation in deep underground laboratories. This novel technique leads to extreme radiopurities with contamination below $10^{−14}$ grams of $^{232}$Th (Thorium) and $^{238}$U (Uranium) per Cu gram. However, Cu is highly ductile and of low strength, limiting its use for moving mechanical, high-pressure, and load-bearing parts. Alloying Cu with chromium (Cr) can lead to enhanced mechanical properties due to solid solution and precipitation strengthening. Moreover, small additions of titanium (Ti) can allow for improved mechanical strengthening. We investigate and address materials challenges to develop high radiopure Cu-based alloys with significantly higher strength compared to Cu. This would improve the capability for experiments such as DarkSPHERE, a large-scale fully electroformed underground spherical proportional counter operating under high pressure to probe uncharted territory in the search for DM. It is also vital for other rare event searches, including the next-generation experiment XLZD or searches for neutrinoless double $\beta$-decay.

Speaker: Dr Dimitra Spathara (University of Birmingham)

DMUK-Dec25-DimitraSpathara.pdf

6 Status of the LUX-ZEPLIN experiment

Speaker: Mr Nicholas Fieldhouse (University of Oxford)

LZUpdates-NickF.pdf

7 Complementary discoveries: how to be FAIR?

In the global quest for dark matter, we often think of (and wish for!) a scenario where we will have more than one experiment confirming a discovery. The question we'd like to reflect on in this poster is: how do we make sure that others can also reproduce such a finding, or in other words that the data and tools we are using are Findable, Accessible, Interoperable and Reproducible (FAIR)? We will bring forward a simple case study, the European Strategy / Snowmass summary plots, in their evolution from 2019 to 2025, and show how in this case the ESCAPE Virtual Research Environment (VRE) has helped us make our research tools more FAIR within a project from the Initiative for Dark Matter in Europe and Beyond (iDMEu).

Speaker: Sukanya Sinha (The University of Manchester (GB))

DMUK_FAIR_tools-3.pdf

12:30 Lunch Break

Afternoon Session 1

8 Update on XLZD Status

A brief update on the development of the XLZD Rare Event Observatory and our plans to host it in the UK.

Speaker: Prof. Henrique Araujo (Imperial College London)

DMUK_Dec2025_HenriqueAraujo.pdf

9 Update from Boulby Underground Lab

An update on status and plans at the Boulby Underground Laboratory

Speaker: Prof. Sean Paling (STFC Boulby Underground Lab)

DMUK_Boulby_Nov25_v1.pdf

10 Towards the DarkSPHERE experiment

Speaker: Prof. Konstantinos Nikolopoulos (University of Hamburg/University of Birmingham)

20251201_kn_DMUK.pdf

11 Update on the Migdal Experiment

Speaker: Mr Lex Millins (University of Birmingham & STFC RAL)

DMUK25_MIGDAL.pdf

14:50 Coffee Break

Afternoon Session 2

12 Searching for ultralight dark matter using highly charged ion clocks

Highly charged ions (HCIs) offer exceptional prospects for next-generation optical clocks due to their suppressed sensitivity to external perturbations and their potential to probe physics beyond the Standard Model, which could help lift the veil on the nature of dark matter and dark energy. Among them, californium (Cf) ions host optical transitions with predicted ultra-narrow linewidths and enhanced sensitivity to variations in the fine-structure constant, which can be linked, for example, to virialized dark matter scalar fields, making them promising candidates for probing ultralight dark matter. We present our program toward the realization of a Cf-based HCI clock. We introduce our experimental apparatus, which enables charge breeding of HCIs in an electron beam ion trap and their sympathetic cooling in a cryogenic Paul trap. We report on the current status of our experiment, in which we have implanted Xe HCIs into a Coulomb crystal of Ca⁺ ions and are currently performing ion-trap characterization. Our results outline a pathway to a new class of optical frequency standards, bridging precision metrology and searches for new physics.

Speaker: Ms Mingyao Xu (Univerisity of Birmingham)

DMUKpresentation 2025v2.pdf

DMUKpresentation 2025v2.pptx

13 Searching for Ultralight Dark Matter with MOLeQuTE: a Massive Optically Levitated Quantum Tabletop Experiment

Many well theoretically motivated models of ultralight dark matter are expected to give rise to feeble oscillatory forces on macroscopic objects. Optically trapped sensors have high force sensitivies but have remained relatively unexplored in this context. In this work we propose a new, tunable, optically trapped sensor specifically designed to detect such forces. Our design features a high-mass (~mg) plate whose weight is supported by a vertical beam. We present the first systematic analysis and optimisation of quantum noises in optically trapped systems and show that our setup has the potential to operate at the standard quantum limit with current off-the-shelf technologies. We demonstrate that our sensor could offer unique access to large regions of uncharted parameter space of vector B-L dark matter, with projected sensitivities that could advance existing limits by several orders of magnitude over a broad range of frequencies.

Speaker: Louis Hamaide (MITP - JGU University of Mainz)

15min OM 12-25 LH.pdf

14 Dark Matter live

Dark matter studies and search results published by experimental, collider and cosmological communities are frequently reported using different conventions, units and parameterisations. Limits may appear as bounds on cross-sections, event rates, branching fractions, effective couplings or model-specific parameters (for example kinetic mixing parameters, mediator couplings, or axion-photon couplings), and different communities sometimes adopt different shorthand notation or normalisation choices. This heterogeneity makes direct, side-by-side comparison difficult without careful translation. One of the objectives of Dark Matter live is to renormalise and map incoming results onto a consistent, model-aware parameter space so they can be compared coherently. Where possible we re-express published limits into the standard coupling and mass variables used by the broader community (following widely-adopted conventions such as those used in the Beyond Collider classification of dark-matter scenarios and related literature). The site records the original source, the assumptions made in any translation, and any additional caveats so users can trace how a displayed curve was derived.
The platform further lowers the barrier to contribution by providing a simple, validated data-submission workflow based on CSV and JSON metadata, supported by automated checks to ensure reproducibility and reliability. Researchers can add new exclusion or projection curves via straightforward pull requests, while the public codebase guarantees transparency and longevity. In this way, Dark-Matter-Live aims not only to curate state-of-the-art results but also to enable a more inclusive, collaborative, and coherent approach to mapping the dark-matter landscape.

Speaker: Brij Kishor Jashal (Rutherford appelton laboratory)

DMUK_Brij_01-12-2025.pdf

16:20 Refresher Break

Afternoon Session 3

15 Impact of cavities on the detection of quadratically coupled ultra-light dark matter

Ultra-light scalar fields may explain the nature of the dark matter in our universe. If such scalars couple quadratically to particles of the Standard Model the scalar acquires an effective mass which depends on the local matter energy density. The changing mass causes the field to deviate from its cosmological value in experimental environments. In this work we show that the presence of a local over-density enclosing the experiment, for example a cavity, vacuum chamber, or satellite can strongly suppress the value of the scalar and its gradient in the interior. This makes detection of such scalar dark matter challenging, and significantly relaxes constraints on strongly coupled models. We also discuss the possibility that quadratically coupled ultra-light scalar dark matter could be detected by the differential measurement of the force on two cavities of the same mass but different internal structure.

Speaker: Mr Angus MacDonald (University of Nottingham)

Presentation for DMUK.pdf

16 A new WIMP DM connection to the hierarchy problem

We propose a novel link between the hierarchy problem and Weakly Interacting Massive Particles (WIMPs), suggesting that the small mass of the Higgs boson arises from the universe’s WIMP-induced proximity to the critical boundary of a phase transition. Intriguingly, such a requirement aligns with a split spectrum of new light fermions and heavy bosons expected from naturalness, and overlaps with the so-called “WIMP miracle”: a WIMP with mass around the weak scale not only happens to have the correct thermal relic abundance to be the observed dark matter, it can also naturally destabilise the Higgs potential just above the weak scale. This coincidence may signify a more direct link between WIMP dark matter and Higgs naturalness than anticipated from traditional symmetry-based explanations. Using a higgsino-like singlet–doublet model, we show that our Higgs criticality scenario favours TeV-scale WIMP dark matter. It can be thoroughly probed in direct detection experiments, astrophysical signals and future collider searches, further motivating a comprehensive exploration of the remaining heavy WIMP parameter space.

Speaker: Mr Maximilian Detering (King's College London)

DMUK-2025-Detering.pdf