UK-APP and OWAN 25 conferences

2 Jun 2025, 08:00 → 3 Jun 2025, 20:00 GMT

On June 2^nd and 3^rd 2025, King's College London will jointly host two conferences back to back: The semi-annual UK-APP conference and the OWAN 25 conference (see descriptions below). The two events are one day long each and cover different aspects of astroparticle/neutrino physics from both a theoretical and an experimental/observational point of view, which allows for an exceptional opportunity to make the two communities interact.

The two events are free to attend, with a conference dinner offered on the evening of June 2^nd to accepted participants. Although participants are encouraged to attend both events, they are free to register for only one event. Limited travel funding will be available for students and early career researchers on demand upon registration.

 

Location: King's College London, Strand Campus, Macadam Building, Room MB 4.2 (https://www.kcl.ac.uk/visit/macadam-building)

 

Note that the number of speakers and participants for each event is limited. 

 

---------- Description ----------

 

UK-APP: Astroparticle phenomenology plays a crucial role in particle physics, as it allows to connect microscopic theories of nature with cosmological and experimental data, enlarging the scope of many next-generation observatories. Inspired by the success of the DM-UK (dark matter experimental searches), Cosmo UK (cosmology), or UK-QFT (formal quantum field theory) conferences, this series will take place semi-annually across various UK universities, with each event lasting one day. 

Funded by the IoP Astroparticle Physics (APP) group, this conference series provides a platform for early career researchers to gain visibility and for the UK astroparticle physics community–broadly defined (beyond Standard Model and early universe phenomenology, cosmic ray searches, gravitational waves, etc)–to gather regularly, share insights, and foster collaborations. 

 

OWAN 25: Cosmic particles bombarding the Earth’s atmosphere provide a constant source of neutrinos. In the past, the study of these atmospheric neutrinos led to the celebrated discovery of neutrino oscillation; today, it allows us to understand their fundamental properties and their impact as a background for rare-event searches better than ever. Atmospheric neutrino observations in future flagship observatories like IceCube, KM3NeT, JUNO, Hyper-Kamiokande, DUNE, ANITA/PUEO, P-ONE, and SNO+ offer incredible opportunities to explore physics beyond the Standard Model of particle physics. 

Thanks to a Joint Research Award funded by King's College London and Université Paris Cité, this one-day event aims to review the status of present-day atmospheric neutrino measurements and to identify possible unexplored opportunities in future experiments. 

 

Monday 2 June

09:00 → 09:30 Registration and Breakfast

09:30 → 10:30 UK-APP: Opening Session

09:30 Beyond-standard-model constraints with CMB and large-scale-structure measurements

The cosmic microwave background (CMB) provides us with an extremely well-calibrated and well-understood photon source: it is incredibly uniform (to within 0.001%), and follows an almost perfect black-body spectrum. As it shines through the entire evolving Universe, it passes through a range of diverse environments and interacts with various structures, picking up new signals. CMB observations can thus be used to constrain beyond-standard-model physics happening in such environments. In particular, around galaxies there are diffuse clouds of ionised electron gas, which scatters the CMB; and also magnetic fields, with which the photons can also interact. I will talk about using CMB observations to constrain well-motivated BSM interactions that can occur in such environments, in particular showing constraints on dark-photon and light-axion extensions to the Standard Model, and discuss how current constraints can be extended to a wider range of parameter space.

Speaker: Fiona McCarthy

10:00 Into the Elusive Universe -- Probing Dark Matter with Precision Space Missions and Quantum Sensors

Dark matter, neutrinos, and gravity interact feebly with the rest of the Standard Model particles, yet govern how the Universe evolves and operates. Together, they are the elusive parts of the Universe that have profound implications for particle physics, astrophysics, and cosmology. In this talk, I will use the planetary-defense mission, OSIRIS-REx, and the precision tracking data of the dangerous (potentially hazardous) asteroid Bennu, to establish new constraints on the gravitational interaction of dark matter in the solar system [1]. I will also utilize the ultra-precision astrometric data to set world-leading constraints on cosmic neutrino over density and hidden fifth forces.

Furthermore, I propose a space mission concept with quantum clocks (inspired by the NASA Deep Space Atomic Clock, DSAC) onboard a future solar probe (inspired by the Parker Solar Probe) to search for ultralight dark matter bound to the Sun [2]. Such a mission would allow us to probe theoretically motivated wave-like/fuzzy dark matter models with distinctive cosmic evolutions and particle-physics consequences. These works are in close collaboration with NASA JPL, ESA, and NIST, aiming to shed new light on the deepest questions of the Elusive Universe.

Speaker: Dr Yu-Dai Tsai (Cornell University)

10:30 → 11:00 Coffee Break

11:00 → 12:00 UK-APP: Gravitational Waves & Early Universe

11:00 Cosmological gravitational particle production: Starobinsky vs Bogolyubov, uncertainties, and issues

Gravitational particle production provides an ever-present background in non-thermal dark matter studies. I discuss the correspondence between the Starobinsky and Bogolyubov approaches to the problem of inflationary particle production, and derive strong constraints on frameworks with scalar dark relics.

Speaker: Duarte Miguel da Silva Feiteira (University of Helsinki)

11:30 Observable Primordial Gravitational Waves from Modified Gravity

This talk will discuss my work on primordial GWs from modified gravity (arXiv:2502.03573). We probe the spectrum of primordial gravitational waves (GWs) produced during the eras of hyperkination, kination, and reheating in a non-minimally coupled, L ∝ (1 + ξχ/MPl)^t(R + αR2), modified gravity model using the Palatini formulation under a runaway inflaton potential. The coupling order t is varied to examine a large class of theories up to χ2R2. For models with t > 0, reheating is not
achieved naturally; hence, we supplement such theories with a reheating mechanism based on the interaction of inflaton and radiation produced at the end of inflation due to cosmological expansion, which gives successful radiation domination with Treh ∼ 10^8 GeV. We demonstrate that the energy density of the GWs is enhanced as a function of the coupling during kination for all considered theories, and a short-lived phase of hyperkination, a result of R2 in Palatini, truncates the boost and avoids the over-production of GWs. Our work provides another strong hint towards the inclusion of R2 terms. The spectrum remains flat for the period of hyperkination and reheating. We find that as we decrease the order of the coupling, the spectra shift towards a more observable regime of future GW experiments. We also highlight the observability of GWs from the minimal Starobinsky model and the availability of wide parameter space. The observation of the plateau during reheating will
constrain the H and Ωend values, while the spectral shape of the boost obtained during kination will confirm the nature of the theory. The bounds from hyperkination lie in the kHz-GHz frequency range. If observed, it will confirm an important prediction of inflation and the existence of a modi- fied theory of gravity. In this talk, I will focus on GW production during the very early universe and its observational signatures today.

Speaker: Hardik Jitendra Kuralkar (Indian Institute of Science Education and Research Bhopal)

12:30 → 13:30 Lunch

13:30 → 15:00 UK-APP: Dark Matter & Phenomenology

13:30 Primordial Black Hole Hot Spots and Nucleosynthesis

Upon their evaporation via Hawking radiation, primordial black holes (PBHs) may deposit energy in the ambient plasma on scales smaller than the typical distance between two black holes, leading to the formation of hot spots around them. My talk will be based on arXiv:2501.05531, where we investigate how the corresponding rise of the local temperature during the evaporation may act as a shield against the release of low-energy photons, affecting PBH’s capacity to dissociate light nuclei after Big-Bang Nucleosynthesis through photodissociation. We study the different ways PBH hot spots affect the flux of low-energy photons expected from PBH evaporation, and we find that such effects can be particularly relevant to the physics of photo-dissociation during Big-Bang Nucleosynthesis for PBHs with masses between 10^11 g and 3×10^12g. We emphasize that the magnitude of this effect is highly dependent on the specific shape of the temperature profile around PBHs and its time evolution. This underscores the necessity for a comprehensive study of PBH hot spots and their dynamics in the future.

Speaker: Clelia Altomonte (King's College London)

14:00 Massive graviton dark matter searches with atom interferometers

Atom interferometers offer exceptional sensitivity to ultra-light dark matter (ULDM) through their precise measurement of phenomena acting on atoms. Previous work has established their capability to detect scalar and vector ULDM, but their potential for detecting spin-2 ULDM has until recently remained unexplored. In this talk I will introduce the sensitivity of atom interferometers to spin-2 ULDM by considering several frameworks for massive gravity: a Lorentz-invariant Fierz-Pauli case and two Lorentz-violating scenarios. Coherent oscillations of the spin-2 ULDM field induce a measurable phase shift through three distinct channels: coupling of the scalar mode to atomic energy levels, and vector and tensor effects that modify the propagation of atoms and light. Atom interferometers uniquely probe all of these effects, while providing sensitivity to a different mass range from laser interferometers. These results demonstrate an exciting new theory target for atom interferometers and other quantum sensors to explore. Based on arXiv: 2412.14282; work in collaboration with Diego Blas and Christopher McCabe.

Speaker: John Carlton

14:30 Non-abelian Embeddings of the Standard Model Group and charge quantisation

In this talk, I will show a novel minimal non-abelian gauge group to embed the G_{SM}/Z1 quotient with fractionally charged beyond the standard model matter fields and show how we can define a new quantum number n_6 that is written in terms of the generators of G_{SM}. We also comment on interesting aspects of this new number, like how the degree of compositeness can shift n_6. This new quantum number we suggest can give a full spectrum of allowed electric and magnetic charges and has an important connection to the topology of the standard model gauge group. I will also present results from ultra high energy cosmic ray simulations for magnetic monopoles of different magnetic charges as predicted by each quotient group of the SM.

Speaker: Yunji Ha (IPPP, Durham)

15:00 → 15:30 Coffee Break

15:30 → 17:00 UK-APP: Instruments & Observational Prospects

15:30 The Cherenkov Telescope Array Observatory (CTAO)

The Cherenkov Telescope Array Observatory (CTAO) is the next-generation observatory for ground- based gamma-ray astrophysics. CTAO will achieve unprecedented sensitivity and angular resolution at energies from 20 GeV to 300 TeV across both the northern and southern hemisphere skies. Con- struction and early operations are underway at the two sites of La Palma in the Canary islands, and in the Paranal desert in Chile. The science cases with CTAO include understanding cosmic particle acceleration, probing extreme environments, and the nature of dark matter. The main UK contribu- tions to CTAO instrumentation are the cameras for the Small-Sized Telescopes.

Speaker: Jeffrey Grube (King's College London)

17:00 → 18:30 Reception

18:30 → 20:30 Conference Dinner

Tuesday 3 June

09:00 → 09:50 Registration and Breakfast

09:50 → 11:00 OWAN 25

09:50 welcome

Speaker: Teppei Katori

10:00 IceCube-Upgrade

Speaker: Teppei Katori

10:30 KM3NeT-ORCA

Speaker: Joao Coelho

11:00 → 11:30 Coffee Break

11:30 → 12:30 OWAN 25

11:30 JUNO

Speaker: Amina Khatun

12:00 DUNE

Speaker: Dan Barrow

12:30 → 13:30 Lunch

13:30 → 15:00 OWAN 25

13:30 Atmospheric neutrino flux prediction

Speaker: Yiwen Yang

14:00 Earth tomography

Speaker: Isabel Goos

14:30 Super-Kamiokande

Speaker: Rory Ramsden

15:00 → 15:30 Coffee Break

15:30 → 17:00 OWAN 25

15:30 Discussion

16:00 Super-Kamiokande, crosssection analysis

Speaker: Nahid Bhuiyan

16:20 SNO+ spallation neutron

Speaker: Katharine Dixon

16:40 ORCA, earthtomography analysis

Speaker: Yael Deniz

17:00 → 18:00 Reception