DMUK

Thursday 22 Sept 2022, 09:00 → 21:00 Europe/London

Lecture Theatre 2 (Level 1) (Blackett Laboratory, Imperial College London)

Henrique Araujo, Christopher McCabe (King's College London)

This is a one-day meeting for the UK's Dark Matter community to meet up, present research, and discuss the latest progress in the field (see DMUK webpage for more information). The meeting will take place from 10:00 to 17:30 in the Blackett Laboratory, Imperial College London, in Lecture Theatre 2 (Level 1).

We would like this to be an in-person meeting, but a zoom connection will also be made available (below) for those who are not able to travel.

Imperial is easily accessible by public transport (see this link for how to get there); driving is strongly discouraged as there virtually no parking on campus (but please do contact us if you have an accessibility barrier). There is accommodation information below.

Please submit an abstract if you would like to give a talk. We particularly encourage talks from younger members of the community. The deadline for registration is 8th September 2022.

We gratefully acknowledge the financial support provided by the Astroparticle Physics group of the Institute of Physics.

 

09:00 → 10:00 Arrival: Tea & coffee & chat

10:00 → 12:00 Session 1 (morning): Dark matter searches underground

Convener: Henrique Araujo

10:00 Welcome

Speaker: Henrique Araujo

DMUKMeetingImperial_20220922.pdf

10:10 Boulby Underground Laboratory: plans for development of facilities and science

An overview of work underway to develop Boulby Underground Laboratory facilities to host future UK and international underground science project.

Speaker: Sean Paling

DMUK_Boulby_2022.pdf

10:30 Direct Dark Matter searches with the DarkSide-20k experiment

DarkSide-20k is a next-generation direct dark matter search experiment under construction at the Gran Sasso National Laboratory (LNGS) in Italy. The core of the detector is a two-phase liquid argon time projection chamber designed to probe WIMP interactions down to the neutrino floor, with an exposure goal of ~200 tonne-years in expectation of a WIMP-nucleon cross section of 10^-47 cm2 for a WIMP mass of 1TeV/c2 during a 10-year run. In order to ensure zero instrumental backgrounds, low-radioactivity underground argon (depleted in 39Ar) is used as the detector medium. This reduces the internal background, while a 25 cm2 Silicon Photo Multiplier (SiPM) modules capable of resolving single photoelectrons are developed and will be installed in both the active detector volume and the veto system. An overview of the DarkSide experimental program and the DarkSide-20k detector will be presented with a focus on the SiPM construction and testing procedures.

Speakers: Dr Ioannis Manthos (University of Birmingham (GB)), Ioannis Manthos

Manthos_Darkside.pdf

10:50 Update on dark matter searches using NaI from the COSINE-100 experiment

COSINE-100 is a NaI dark matter detection experiment located at the Yangyang Underground Laboratory in South Korea, designed with the main goal of testing the controversial, positive dark matter signal from the DAMA experiments using the same target material. COSINE-100 has been operational for almost six years and in that time has been the first NaI experiment to exclude the DAMA signal in certain dark matter models, as well as publishing multiple annual modulation search results which provide a model-independent check on the DAMA signal. This talk, an overview of the COSINE-100 detector will be given, with particular focus on recent and upcoming results, including newly published three years of annual modulation search data, an investigation of DAMA’s analysis method using COSINE-100 data, and upcoming searches with five years of annual modulation data.

Speaker: Robert Neal (Sheffield University)

DMUK 2022.pdf

11:10 Recent physics results from NEWS-G

The NEWS-G collaboration is searching for light dark matter using spherical proportional counters. Access to the mass range from 50 MeV to 10 GeV is enabled by the combination of low energy threshold, light gaseous targets (H, He, Ne), and highly radio-pure detector construction. The NEWS-G collaboration has constructed a new, 140 cm in diameter, spherical proportional counter at LSM using 4N copper with 500 um electroplated inner layer. Prior to shipping the detector to SNOLAB, a short data-taking campaign was undertaken at LSM using methane. New physics results from this run, leading to world-leading spin-dependent sensitivity will be presented.

Speaker: Patrick Knights (Birmingham University)

dmuk_2022_sep_newsg_knights.pdf

11:30 First Results and Status of the LUX-ZEPLIN (LZ) Experiment

The LUX-ZEPLIN (LZ) direct dark matter detection experiment is currently operating at the Sanford Underground Research Facility (SURF) in Lead, South Dakota. LZ recently set new limits on WIMP-nucleus interactions above 9 GeV/c^2 with its first science run (SR1). This talk will detail these results, the status and outlook of the project.

Speaker: Amy Cottle

DMUK_LZ.pdf

12:00 → 13:00 Break: Lunch

13:00 → 15:00 Session 2 (early pm): Quantum sensors for dark matter

Convener: Dr Christopher McCabe (King's College London)

13:00 An update on Quantum Sensing for the Hidden Sector

I present an update on the work of the Quantum Sensing for the Hidden Sector collaboration, who are designing and building detectors for wave-like dark matter, particularly axions in the first instance, in the UK.

Speaker: Ed Daw

QSHS_dmuk_ed_daw.pdf

13:20 A new search for dark matter axions using quantum technologies

The toolkit of quantum technologies developed in atomic, molecular and optical physics are ideally suited to enhance the search for dark matter axions with masses above ~40 µeV. I will present an overview of a new experimental effort at Imperial College, developing technologies to initially target an axion mass range 120-250 µeV. We will use a large mode area Fabry-Perot cavity to efficiently convert axions into microwave photons. Compared to other geometries, the Fabry-Perot cavity can have a large volume factor, high Q and can be easily tuned. To detect the microwaves, we plan to use an electron in a Penning trap as a single photon counter. Individual microwave absorption events will change the cyclotron state of the electron, causing measurable shifts in the trapped particle’s oscillation frequencies. This versatile device will also open up other possible detection routes for alternative dark matter candidates.

Speaker: Jack Devlin (Imperial College London)

DMUK22Sep2022_JAD.pdf

DMUK22Sep2022_JAD_PDF.pdf

DMUK22Sep2022_JAD.pptx

13:40 QUEST-DMC: Simulation studies for the detection of sub-GeV dark matter with a superfluid 3He calorimeter.

Several independent observations suggest that there is more mass in the Universe than has been directly observed. Dark matter is a hypothetical new form of matter that does not interact with the electromagnetic field and has a very weak interaction with ordinary baryonic matter. WIMPs (weakly interacting massive particles) are a dark matter candidate currently widely investigated in experiments, but most experiments are constrained to spin-independent interactions in the 10–100 GeV/c2 mass range. QUEST-DMC will use superfluid 3He as a dark matter collision target, aiming to reach the world-leading sensitivity to spin-dependent interactions of 0.1-1 GeV/c2 mass dark matter candidates. Here we discuss a simulation of the superfluid 3He bolometer's impact energy sensitivity, and argue that recoil energy of <10 eV can be detected using nanomechanical resonators. We also investigate the sources of radioactive background at and above this region and their relative importance using the Geant4 particle physics simulations toolkit. We aim to report on the development of a dark matter bolometer based on these studies and present the preliminary sensitivity results.

Speaker: Paolo Franchini (RHUL & Lancaster University)

Franchini-DMUK-2022.pdf

14:00 BREAD: Broadband Reflector Experiment for Axion Detection

The BREAD Collaboration proposes a novel dish antenna programme for broadband searches of terahertz axion dark matter. Its hallmark is a cylindrical metal barrel converting axions to photons that are focused by a parabolic reflector onto ultralow-noise quantum sensors. We present the BREAD conceptual design and science program from dark photon pilot planned at Fermilab to large-scale experiment. BREAD is projected to open multiple decades of unexplored coupling sensitivity across meV to eV masses that has long eluded existing resonant-cavity haloscopes. Based on Phys. Rev. Lett. 128 (2022) 131801

Speaker: Jesse Liu (University of Cambridge)

DMUK-BREAD-22-Sep-2022.pdf

14:20 AION: the Atom Interferometer Observatory and Network

I introduce the Atom Interferometer Observatory and Network (AION), an experimental programme which aims to use cold strontium atoms to search for ultra-light dark matter and to explore gravitational waves. I outline the experimental concept of AION, and its place within the landscape of ultra-light dark matter detectors. Finally, I give progress update for the AION project in the UK, which is entering its 2nd year.

Speaker: Richard Hobson

20220922_DMUK_AION_RichardHobson.pdf

14:40 Dark matter searches using levitated optomechanics

Levitated optomechanics provides a novel platform to test fundamental physics. One such application provides a unique directional dark matter direct detection technique to explore alternative parameter space to that being investigated by large scale experiments deployed underground. We detail our experiment, capable of resolving collisions in all three dimensions, utilising nanoparticles (10^-18 kg) for composite dark matter searches in the 10 MeV – 10 GeV mass range. We detail the theoretical calculations, experimental apparatus, data analysis framework and statistical inference that we aim to use to obtain results competitive with world-leading dark matter constraints. We present sensitivity projections for our experiment, informed by an initial characterisation of relevant backgrounds. We also discuss planned future work to explore alternative dark matter models using this experiment and complimentary approaches.

Speaker: Robert S James

DMUK_RJ.pdf

15:00 → 15:30 Break: Tea & coffee

15:30 → 17:40 Session 3 (late pm): Dark matter from particle physics to astrophysics and cosmology

Conveners: Dr Sally Shaw (UCSB), Sally Shaw (Edinburgh University)

15:30 Migdal effect: New insights and updated predictions

Previous calculations of the Migdal effect assumed small values of the nuclear recoil velocity and were limited to the ionisation of single electrons. I will discuss new calculations of the Migdal effect that are robust for any conceivable value of the nuclear recoil velocity and allow for the ionisation of multiple electrons. Our results enable robust predictions of the Migdal effect scattering rate in experiments using neutron sources, and in dark matter direct detection experiments.

Speaker: Dr Christopher McCabe (King's College London)

DMUK_mccabe.pdf

15:50 The MIGDAL experiment at the NILE facility of the Rutherford Appleton Laboratory

I will report on the status of the construction of the experiment and analysis of preliminary data from detector commissioning.

Speaker: Dr Pawel Majewski (STFC/Rutherford Appleton Laboratory)

DMUK Imperial Sept 2022.pdf

16:10 Maximising sensitivity to low mass dark matter with the Migdal effect and exploring non-standard models including isospin violation in liquid noble direct detection experiments

Liquid noble direct dark matter detection experiments aim to detect galactic dark matter scattering off nuclei in highly sensitive detectors in underground laboratories. As positive signals of dark matter in the lab are elusive, it is crucial that current and future experiments broaden the reach and scope of dark matter models which are explored. In this presentation I will report on work exploring sensitivity to low mass dark matter exploiting the Migdal effect: this will include presentation of recently-released DarkSide-50 results, reinterpretation of existing Xenon-1T data, and future sensitivity projections for next generation argon and xenon detectors. I will also present new studies of the sensitivity of existing and future argon- and xenon-based detectors to isospin violating dark matter, demonstrate the complementarity of different target materials in the search for dark matter, and the importance of nuclear form factor models for properly characterising any discovery.

Speaker: Ellen Sandford

ES_DMUK-Sept22-7.pdf

16:30 Constraining Dark Matter Spikes with OJ287

We use the extreme black hole binary system OJ287 to place constraints on dark matter spikes expected outside supermassive black holes as predicted by theory.

Speaker: Prof. Malcolm Fairbairn (Physics, King's College London)

imperial_dmuk_fairbairn.pdf

16:50 Signatures of Non-thermal Dark Matter with Kination and Early Matter Domination: Gravitational Waves versus Laboratory Searches

The non-thermal production of dark matter (DM) usually requires very tiny couplings of the dark sector with the visible sector and therefore is notoriously challenging to hunt in laboratory experiments. Here we propose a novel pathway to test such a production in the context of a non-standard cosmological history, using both gravitational wave (GW) and laboratory searches. We investigate the formation of DM from the decay of a scalar field that we dub as the reheaton, as it also reheats the Universe when it decays. We consider the possibility that the Universe undergoes a phase of kination (w_kin >1/3) before the reheaton dominates the energy density of the Universe and eventually decays into Standard Model and DM particles. We then study how first-order tensor perturbations generated during inflation, the amplitude of which may get amplified during the kination era and lead to detectable signals at the GW detectors such as LISA, ET, u-DECIGO, BBO, etc. Demanding that the reheaton produces the observed DM relic density, we show that the reheaton's lifetime and branching fractions are dictated by the cosmological scenario we show that it is long-lived and can be searched in DUNE, FASER, FASER-II, MATHUSLA, SHiP, etc. experiments and identify the parameter space where one may complement with the detectable GW signals. In particular we find that a kination-like period with an equation-of-state parameter w_kin ~ 0.5 and a reheaton mass O(0.5−5) GeV and a DM mass of O(10-100) keV may lead to sizeable imprints in both kinds of searches satisfying Big Bang Nucleosynthesis (BBN) constraints.

Speaker: Dr Lucien Heurtier (IPPP, Durham, England)

Heurtier2022_Fall.pdf

17:10 Dark Matter reaching out

A brief discussion on outreach in our community.

Speakers: Nicolas Angelides, Nicolas Angelides (Imperial College London)

DMDAY 2022.pdf

17:40 → 17:45 Adjourn

Convener: Henrique Araujo