CUBES 2026

24 Apr 2026, 09:00 → 26 Apr 2026, 16:10 Asia/Seoul

Cheonwangbong Hall (The-K Jirisan Family Hotel, Sandong, Gurye)

The 8th Mini-Workshop on

Chirality in the Universe Beyond the Electroweak Scale

April 24–26, 2026
The-K Jirisan Family Hotel, Gurye, Korea

Overview

CUBES 2026 was the 8th installment in our CUBES workshop series on fundamental aspects of particle physics. Since its inception, CUBES has focused on the role of chirality in understanding particle flavor and symmetry in high energy physics. Over the years, the workshop has naturally evolved into a forum that brings together researchers across high energy physics, cosmology, and astrophysics, exploring how fundamental symmetries and interactions are realized across energy and cosmic scales. CUBES remains discussion-oriented, providing an informal environment where established researchers and early-career scientists can exchange ideas, present new perspectives, and reflect on future directions in the field.

Program

View the full timetable

Plenary Speakers

• Jae Hyeok Chang (Seoul National University)
• Kang-Sin Choi (Ewha Womans University)
• Chang Hyon Ha (Chung-Ang University)
• Sang Hui Im (IBS CTPU-PTC)
• Boris Ivanov (IBS DMAG)
• Kwang Sik Jeong (Pusan National University)
• Yu Seon Jeong (Sungkyunkwan University)
• Choong Sun Kim (Yonsei University)
• Hang Bae Kim (Hanyang University)
• Hongjoo Kim (Kyungpook National University)
• Hyung Do Kim (Seoul National University)
• Jeong Han Kim (Chungbuk National University)
• Ji-hoon Kim (Seoul National University)
• Jongkuk Kim (Kangwon National University)
• Jae Sik Lee (Chonnam National University)
• Hyunbae Park (IBS CTPU-CGA)
• Seong Chan Park (Yonsei University)
• Chang Sub Shin (Chungnam National University)
• Seodong Shin (Jeonbuk National University)
• Masahide Yamaguchi (IBS CTPU-CGA)
• Jeong Yeol Yang (IBS CUP)
• Jaeok Yi (KAIST)

Young Researchers Session

• Haebarg Gang (Jeonbuk National University)
• Junghoon Joh (Sungkyunkwan University)
• Wonkyung Kim (IBS CUP)
• Junseung Pi (Chungbuk National University)
• Bijaya Sharma (IBS CUP) 

Organizers

• Won Sang Cho (IBS CTPU-PTC)
• Kiwoon Choi (IBS CTPU-PTC)
• Eung Jin Chun (KIAS)
• Dong-Won Jung (IBS CTPU-CGA)
• Yeongduk Kim (IBS CUP)
• Yoomin Oh (IBS CUP)
• SungWoo Youn (IBS DMAG)

Poster

Hosted by

 

 

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Friday 24 April

16:30 → 18:30 Registration & Discussion with Refreshments (16:30-)

18:30 → 20:00 Reception

Saturday 25 April

07:30 → 09:00 Breakfast

09:00 → 10:15 Session 1

Convener: Kiwoon Choi (IBS CTPU-PTC)

09:00 Cosmic Neutrino Background as a New Tool of Particle Physics and Cosmology

Speaker: Masahide Yamaguchi (IBS CTPU-CGA)

09:25 The SM is Good

Speaker: Seongchan Park (Yonsei University)

09:50 Cosmic Mystery of Super-early, Super-massive Black Holes: Perspectives from the Hydrodynamics+N-body Hybrid Simulations

Speaker: Ji-hoon Kim (Seoul National University)

CUBES_Gurye_042526_short.pdf

10:15 → 10:35 Coffee Break

10:35 → 12:15 Session 2

Convener: Yoomin Oh (Center for Underground Physics, Institute for Basic Science)

10:35 Search for Invisible Particles at GRANDE

Speaker: Hong Joo Kim (Kyungpook National University)

CUBES2026_hjkim.pdf

11:00 Neutrino Physics in IceCube

Speaker: Chang Hyon Ha (Chung-Ang University)

CUBES2026_ChangHyonHa.pdf

11:25 Haloscope Axion Search Experiments at Dark Matter Axion Group

Axion haloscopes are among the most promising approaches for detecting dark matter, requiring coverage over a broad frequency range from hundreds of MHz to hundreds of GHz. The detection principle proposed by Sikivie employs high-quality microwave resonators immersed in a strong magnetic field, with sensitivity significantly enhanced by cryogenic low-noise amplification.
The Dark Matter Axion Group (DMAG) at the Institute for Basic Science (IBS) operates several state-of-the-art haloscope experiments based on 8 T and 12 T superconducting magnets, including large-bore cavity systems. These experiments target the frequency range of 1–6 GHz using copper-based microwave cavities combined with high-temperature superconducting (HTS) structures.
The readout chain is based on Josephson parametric amplifiers (JPAs), achieving noise performance close to the standard quantum limit and enabling high scanning rates. A multi-JPA configuration extends the amplification bandwidth approximately linearly with the number of devices, without significant noise degradation.
We present the design and operational principles of the readout systems, along with recent developments in cavity technology leading to enhanced quality factors. Preliminary results from recent scans are discussed, and corresponding exclusion limits on the axion–photon coupling are reported.

Speaker: Boris Ivanov (IBS DMAG)

2026_QUBES.pptx

11:50 Constraints on Generalized Neutrino Interactions in the keV Region of the Tritium β-Decay Spectrum

The effective Lagrangian for tritium β decay in the Standard Model can be extended by introducing additional Lorentz-invariant coupling terms analogous to those of the electroweak interaction. This framework, known as Generalized Neutrino Interactions (GNIs), incorporates interactions involving light and heavy neutrinos as well as right- and left-handed neutrino currents coupled to quarks and leptons. We measure the tritium β-decay spectrum using a LiF crystal coupled to a cryogenic metallic magnetic calorimeter (MMC) over a four-month data-taking period. This presentation reports the analysis results constraining the GNI coupling constants based on a 10-day subset of the full four-month data set.

Speaker: Jeong Yeol Yang (IBS CUP)

CUBES2026_constraints on Generalized Neutrino Interactions in the keV.pdf

12:15 → 13:30 Lunch

13:30 → 14:45 Session 3

Convener: Eung Jin Chun (KIAS)

13:30 Electroweak Phase Transition Triggered by Hidden QCD

Speaker: Kwang Sik Jeong (Pusan National University)

13:55 Primordial Black Holes as Dark Sector Factories

Speaker: Jae Hyeok Chang (Seoul National University)

Slides_Chang.pdf

14:20 Kinetic Isocurvature Perturbation

Speaker: Chang Sub Shin (Chungnam National University)

KIP_CUBES 2026_CSSHIN.pdf

14:45 → 15:05 Photo Session w/ Refereshments

15:05 → 16:45 Session 4

Convener: Won Sang Cho (IBS CTPU-PTC)

15:05 Quantum Entanglement and Bell Nonlocality in Top-Quark Pair Production at a Photon Linear Collider

Speaker: Jae Sik Lee (Chonnam National University)

JSL.pdf

15:30 Fermion Effect on Gauge Tachyons and Cosmological Relaxation of the Weak scale

Speaker: Sang Hui Im (IBS CTPU-PTC)

15:55 Higgs Mass is Natural

Speaker: Kang-Sin Choi (Ewha Womans University)

kschoi.pdf

16:20 Neural Networks from the Perspective of Physics

In this talk, we approach deep neural networks from the perspective of physics, introducing the bulk–boundary decomposition as a novel framework for analyzing their training dynamics. By treating the learning process as a physical system, we demonstrate that the stochastic gradient descent formulation yields a Lagrangian that can be cleanly separated into a data-independent bulk action and a data-dependent boundary action. The bulk governs the intrinsic dynamics dictated by the network's architecture, whereas the boundary encapsulates the stochastic interactions driven by training data. This decomposition reveals the fundamentally local and homogeneous structure underlying deep networks. Building on this insight, we construct a field-theoretic formulation of neural dynamics, offering a new physical paradigm for interpreting modern artificial intelligence.

Speaker: Jaeok Yi (KAIST)

Synaptic Field Theory.pdf

16:45 → 17:05 Break

17:05 → 18:20 Young Researchers Session

Convener: Ki-Young Choi (Sungkyunkwan University)

17:05 Localized Overdensities from Inflationary Particle Production and Their Signatures in Cosmic Structure Formation

Speaker: Junseung Pi (Chungbuk National University)

CUBES 2026_JunseungPi.pptx

17:20 Pioneering Sub-GeV Dark Matter Limits with COSINE-100

We report new constraints on the spin-dependent (SD) WIMP-proton cross section using the COSINE-100 experiment at the Yangyang Underground Laboratory. This analysis achieves a pioneering detection threshold of 3 and 4 pulse clusters corresponding to the measured photoelectrons. This allows us to access the unstudied few-photoelectron regime, significantly below the previous 8-photoelectron threshold. Using four years of stable data, we find no statistically significant evidence of annual modulation. Furthermore, we establish the world's most stringent SD WIMP-proton constraints for NaI(Tl) in the $1.75–2.25$ GeV/$c^2$ mass range. By incorporating the Migdal effect, we further extend our sensitivity into the $15–58$ MeV/$c^2$regime, setting new world-leading limits. These results demonstrate the unique capability of NaI(Tl) targets to probe previously unexplored regions of the dark matter parameter space.

Speaker: Wonkyung Kim (IBS CUP / UST)

2026CUBES_wkk.pdf

17:35 Probing Neutrinoless Double Electron Capture in Calcium-40 with AMoRE

The search for neutrinoless double electron capture (0ν2EC) is a powerful probe for lepton-number violation and the Majorana nature of neutrinos. We report on a search for the 0ν2EC decay of ⁴⁰Ca using the AMoRE-I cryogenic detector array, which utilizes metallic magnetic calorimeters (MMCs) and ^48depl.Ca¹⁰⁰MoO₄ crystals. Analyzing a total exposure of 7.32 kg·yr (1.39 kg·yr of ⁴⁰Ca), we find no evidence of a signal and set a lower half-life limit of T^0ν_1/2 > 1.7 × 10²² yr at 90% C.L. Furthermore, we project a sensitivity of 9.1 × 10²² yr for the upcoming AMoRE-II phase. These results highlight the versatility of the AMoRE detector technology in investigating rare decay processes beyond its primary 0νββ search program.

Speaker: Bijaya Sharma (IBS CUP)

Bijaya_0v2EC_study.pdf

17:50 Galactic Center Excess from the 17.5 Years of Fermi-LAT Data

Speaker: Haebarg Kang (Jeonbuk National University)

Galactic_Center_Excess_with_17_5yr_Fermi-LAT_data.pptx

18:05 Photon Axion Enhancement around PBH

Dark matter (DM) can be gravitationally captured around a massive compact object, forming a dense halo. If primordial black holes (PBHs) exist, surrounding dark matter particles can be accreted through gravitational attraction, leading to the formation of a DM halo with a steep spike profile near the PBH.

If the dark matter consists of axions or axion-like particles (ALPs), the high number density in the spike region can significantly enhance photon production via stimulated decay. When the axion number density exceeds a critical threshold, photon enhancement becomes efficient, potentially generating a strong electromagnetic signal.

Photons emitted from the dense DM halo surrounding a PBH may propagate to Earth and could be detected in the radio frequency range, providing a possible observational signature of axion dark matter and primordial black holes.

Speaker: Junghoon Joh (Sungkyunkwan University)

PBH_CUBES_Junghoon Joh.pdf

18:20 → 20:00 Banquet

Sunday 26 April

07:30 → 09:00 Breakfast

09:00 → 10:40 Session 5

Convener: SungWoo Youn (Institute for Basic Science / Dark Matter Axion Group)

09:00 Cepheids as a Dark Matter Detector

Speaker: Hyung Do Kim (Seoul National University)

CUBES2026HDKim.pdf

09:25 Constraining Dark Matter with Early-Universe 21-cm Signals

The 21-cm line of hydrogen is emerging as a promising probe of the first 0.1 billion years of cosmic history. We conduct a suite of hydrodynamical simulations to precisely model the impact of sub-Mpc structure formation on 21-cm emission during these early epochs. We find that this small-scale matter clumping turns highly nonlinear at z≲30, leading to ~10% changes in the sky-averaged 21-cm intensity and ~50% changes in the 21-cm power spectrum in the standard cold dark matter scenario, relative to previous theoretical predictions. These nonlinear clumping effects are highly sensitive to non-standard dark matter scenarios, such as warm or fuzzy dark matter, opening a new avenue for constraining dark matter properties with upcoming lunar and ground-based 21-cm surveys. Our results provide a theoretical framework for interpreting data from these future experiments.

Speaker: Hyunbae Park (IBS CTPU-CGA)

CUBES_HyunbaePark.pptx

09:50 Gravitational Waves as Probes of Dark Matter Around Binary Black Holes

Speaker: Jeong Han Kim (Chungbuk National University)

CUBE_2026_Jeong_Han_Kim.pdf

10:15 The Puzzles of UHECR: Anisotropy Studies

Speaker: Hang Bae Kim (Hanyang University)

The puzzles of UHECR (20260426, CUBES2026).pdf

10:40 → 11:00 Coffee Break

11:00 → 12:40 Session 6

Convener: Dong-Won Jung (IBS CTPU-CGA)

11:00 Two-Neutrino Beta Decay (2νβ+β−)

Speaker: Choong Sun Kim (Yonsei University)

11:25 Nucleon Structure Functions at Low Momentum Transfer for Neutrino Cross Sections

Speaker: Yu Seon Jeong (Sungkyunkwan University)

11:50 B→K+νν Excess and Dark Matter Semi-Annihilation

In 2023, Belle II collaboration announced the observarion of the B→K+νν decay channel for the first time. This decay channel provides a clean signal with high precision in theoretical calculation. However, we encounter 2.8σ deviation from the Standard Model prediction. To resolve this excess, we study scalar dark matter model with local discrete Z 3 Z 3 ​ symmetry. Considering dark Higgs mass is 2GeV, we can explain the recent Br(B→K νν) excess reported from Belle II collaboration and relic abundance at the same time.

Speaker: Jongkuk Kim (Kangwon National University)

CUBES_JKK.pdf

12:15 Solar Neutrino Precession

Speaker: Seodong Shin (Jeonbuk National University)

12:40 → 14:00 Conclusion & Lunch