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12th Workshop on Flavor Symmetries and Consequences in Accelerators and Cosmology (FLASY 2026)
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Asia/Seoul
Commodore Hotel
Commodore Hotel
Gyeongju
Description
The "12th Workshop on Flavor Symmetries and Consequences in Accelerators and Cosmology - FLASY 2026" will be held in Gyeongju, the thousand-year ancient capital of the Silla Dynasty, Korea, on August 17 - 22, 2026. The workshop will bring together researchers in the field of flavor symmetries, CP violation, Higgs physics, neutrino physics, dark matter, accelerator physics and cosmology to present new results and stimulate discussion and new collaborations.
The workshop venue is Commodore Hotel where your check-in would be possible from Aug 17 (Mon).
Important dates: abstract submission & registration by July 20.
FLASY 2026 will be followed by another workshop in Yeongdo, Busan, about an hour drive distance from Gyeongju or 30 minute by KTX, the 5th workshop of Symmetry and Structure of the Universe (SSU 2026 Busan) on Aug 23 - 27, 2026.
Plenary Speakers
Gautam Bhattacharyya (Ashoka University)
Jae Hyeok Chang (Seoul National University)
Mu-Chun Chen (University of California, Irvine)
Kingman Cheung (National Tsing Hua University)
Kiwoon Choi (IBS-CTPU-PTC)
Ki Young Choi (Sungkyunkwan University)
Patrick Foldenauer (IFT-Madrid)
Andre De Gouvea (Northwestern University)
Sang Hui Im (IBS-CTPU-PTC)
Doojin Kim (University of South Dakota)
Hyung Do Kim (Seoul National University)
Pyungwon Ko (KIAS)
Tatsuo Kobayashi (Hokkaido University)
Youngjoon Kwon (Yonsei University)
Hyunsu Lee (IBS-CUP)
Miguel Levy (University of Basel)
Jia Liu (Peking University)
Enrico Lunghi (Indiana University)
Ernest Ma (University of California, Riverside)
Myriam Mondragon (UNAM, Mexico)
Takuya Morozumi (Hiroshima University)
Takaaki Nomura (Sichuan University)
Hiroshi Okada (Henan Normal University)
Seong Chan Park (Yonsei University)
Michael Ratz (University of California, Irvine)
Narendra Sahu (IIT Hyderabad)
Morimitsu Tanimoto (Niigata University)
Jose W.F. Valle (IFIC/CSIC-Universidad de València)
Zhi-zong Xing (Institute of High Energy Physics, Beijing)
Masahide Yamaguchi (IBS-CTPU-CGA)
Byeongsu Yang (Chonnam National University)
Seokhoon Yun (Kyungpook National University)
Yue Zhao (Hong Kong University of Science and Technology)
Ye-Ling Zhou (Hangzhou Institute for Advanced Study)
Local Organizing Committee
Eung Jin Chun (KIAS, chair)
Sin Kyu Kang (Seoul Tech., co-chair)
Kyu Jung Bae (Kyungpook National University)
Kiwoon Choi (IBS CTPU-PTC)
Kwang Sik Jeong (Pusan National University)
Hye-Sung Lee (KAIST)
Hyun Min Lee (Chung-Ang University)
Jong-Chul Park (Chungnam National University)
Seong Chan Park (Yonsei University)
Seodong Shin (Jeonbuk National University / KIAS)
Participants
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Registration for FLASY 2026 Imhaejeon
Imhaejeon
Commodore Hotel
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Reception 1h
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Welcoming remarks Imhaejeon
Imhaejeon
Commodore Hotel
Convener: Eung Jin Chun (KIAS) -
09:00
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10:30
Neutrino 1Convener: Eung Jin Chun (KIAS)
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09:30
An Overview of Current Neutrino Experiments and Their Prospects 30m
This talk provides an overview of the current status and future prospects of major neutrino experiments from an experimental perspective. Focusing on representative reactor, accelerator, atmospheric, solar, and astrophysical neutrino experiments, it will introduce their scientific objectives and recent progress.
The talk will also review recent experimental developments related to key topics in neutrino physics, including neutrino oscillations, the neutrino mass ordering, leptonic CP violation, and the absolute neutrino mass scale, together with the prospects for future measurements.
Speaker: Byeongsu Yang (Chonnam National University) -
10:00
Majorana versus Dirac, Beyond Neutrinoless Double-Beta Decay 30m
One of the central questions in particle physics is the nature of neutrinos: Are they Majorana or Dirac fermions? I will quickly review the leading experimental campaign to address this question - the search for neutrinoless double-beta decay - and will then discuss other logical possibilities that do not directly involve looking for the violation of lepton number.
Speaker: Andre de Gouvea (Northwestern University)
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10:30
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11:00
Coffee & Discussion 30m
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11:00
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Flavor 1Convener: Hyung Do Kim (Seoul National University)
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11:00
Flavor Alignment and Mass Hierarchy 30m
Flavor alignment and mass hierarchy in quarks are shown to be achievable in a renormalizable theory using the dark sector, while keeping only the one Higgs doublet of the standard model.
Speaker: Ernest Ma (UC Riverside) -
11:30
Anomalies in semileptonic rare B decays 30m
Over the past decade, the LHCb and CMS experiments have reported persistent tensions in several branching fractions and angular observables of exclusive rare semileptonic $b$-hadron decays ($b \to s \mu^+\mu^-$). Taken together, these discrepancies exceed the five-standard-deviation level. However, their interpretation remains the subject of active debate, particularly regarding the size and treatment of nonperturbative QCD effects. In this talk, I review the current experimental and theoretical status of these anomalies and discuss the prospects for resolving their origin with upcoming measurements and improved theoretical calculations.
Speaker: Enrico Lunghi (Indiana University) -
12:00
Experimental landscape of quark flavor physics 30m
In the Standard Model (SM) of particle physics, fermions exhibit a peculiar hierarchical pattern, most notably in their masses, quark flavor mixing, and charged-current weak interactions. The origin of this flavor structure remains unknown within the SM. Hence, testing these flavor phenomena experimentally provides a vital probe for new physics beyond the SM (BSM) and deeper underlying principles.
In this talk, we present recent experimental highlights in quark flavor physics, focusing on results from Belle II, LHCb, BESIII, and other experiments. Covered topics include updates on tests of lepton flavor universality (such as $R(D^{(*)})$), measurements of time-dependent CP violation in $B^0 \to \pi^0 \pi^0$ utilizing quantum entanglement, and recent results on $B$ decays with missing energy in the final state.
Speaker: Youngjoon Kwon (Yonsei University)
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Lunch 1h 30m
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Neutrino 2Convener: Yue Zhao (HKUST)
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14:00
Lepton number densities of Majorana neutrinos at the low energies and implications on neutrino properties 30m
We study the space-time evolution of the lepton number densities of Majorana neutrinos at low energies. We study it for three neutrinos
cases preparing the initial state with momentum distribution amplitude
localized at the space-time origin. The case that the lightest neutrino is massless and the other case with three massive neutrinos are studied.
These two cases can be distinguished by the lepton number densities.
Another related topic which I plan to talk is the implication of the rank two effective Majorana mass matrix at low energies. I will talk about how the present neutrino data constrain the mass matrix and how the information constrain the type I seesaw model with two right-handed neutrinos.Speaker: Morozumi -
14:30
Application of a non-holomorphic modular symmetry for neutrino mass models 30m
In this talk we discuss neutrino mass models with a non-holomorphic modular symmetry in which we can construct a model with simpler field contents compared with holomorphic framework. After reviewing the framework, in particular, a radiative neutrino mass model with Leptoquarks is discussed where lepton and quark sectors are naturally connected. Focusing on neutrino mass matrix, results of numerical analysis of the model are shown where we obtain some predictions about neutrino observables.
Speaker: Takaaki Nomura (Sichuan University) -
15:00
Invariance of the Friedberg-Lee translation as a partial flavor symmetry 30m
A neutrino would be the Goldstone-like (massless) fermion if its field had a translational symmetry, as first pointed out by D.V.Volkov and V.P. Akulov in their pioneering paper about supersymmetry in 1973. But it was R. Friedberg and T.D. Lee who first applied such a working symmetry to constraining the pattern of lepton flavor mixing in 2006. My talk is intended to explain why the Friedberg-Lee translation may serve as a partial flavor symmetry for massive neutrinos in the diagonal charged-lepton basis, and especially why it is analogous to a broken mu-tau reflection symmetry in the neutrino sector which can be compatible with current neutrino oscillation data.
Speaker: Zhi-zhong Xing (Institute of High Energy Physics, Chinese Academy of Sciences)
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Coffee & Discussion 30m
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Tuesday afternoonConvener: Prof. Seodong Shin (Jeonbuk National University)
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16:00
RG Running of Multiple Neutrino Mixing Parameters at Oscillation Experiments 20m
If the new physics scale is within the energy scale of neutrino oscillation experiments, it may lead to a renormalization group (RG) running effect between the production and detection processes as well as between different experiments. It is then possible to use multiple neutrino oscillation experiments to disentangle the multiple RG running parameters. We investigate this effect in a general model-independent sense for a variety of flavor structures in the context of upcoming experiments DUNE-ND, JUNO-TAO, and FASER$\nu$2 that span a large range in neutrino energies and many different flavor combinations. We find strong sensitivity to the running effects of new physics with combination of these experiments, especially the possibility of addressing the non-trivial degeneracies.
Speaker: Chui-Fan Kong (IBS-CTPU-PTC) -
16:20
Structure functions at low momentum transfer and neutrino cross sections (tentative) 20m
Neutrino interaction cross sections below 100 GeV are important for current and next-generation neutrino oscillation experiments. Future accelerator-based experiments such as SHiP and the planned Forward Physics Facility will be able to probe neutrino interactions in this energy regime. Reliable theoretical predictions of neutrino cross sections are essential. In this region, deep inelastic scattering (DIS) cross sections are influenced by nucleon structure functions at low momentum transfer ($Q^2$). For $Q^2$ < 1 GeV^2, in particular, structure functions derived from perturbative QCD based parton distribution functions are not applicable, which requires alternative approaches.
We present data-driven low $Q^2$ structure functions obtained using machine learning method with theoretical constraints. We employ a neural network and train on charged lepton and neutrino scattering data. To describe physical behavior in the low x and low Q^2 limits, we incorporate theoretical guidance from Regge theory and from the PCAC (partially conserved axial-vector current). We also present neutrino cross sections evaluated using the resulting structure functions.Speaker: Yu Seon Jeong (Sungkyunkwan University) -
16:40
Dirac Neutrino Masses from the Scoto-Seesaw Mechanism 20m
In this talk, I will discuss a simple Dirac scoto-seesaw framework based on the anomaly-free $U(1)_{B-L}$ charge assignment $(-4,-4,5)$ for $\nu_R$. This chiral charge assignment naturally accounts for the observed neutrino mass-squared differences, with $\Delta m^2_{\rm atm}$ generated at tree level and $\Delta m^2_{\rm sol}$ arising radiatively. After the spontaneous breaking of gauged $U(1)_{B-L}$, a residual $Z_6$ symmetry stabilizes the dark matter candidate. We investigate two minimal realizations of the framework, finding that both normal and inverted orderings are viable in one case, whereas only normal ordering survives in the other, with distinctive features for neutrino observables. Moreover, the chiral nature of the $U(1)_{B-L}$ charges suppresses the dilepton branching fraction of $Z'$, resulting in weaker ATLAS mass bounds than in the conventional vector $B-L$ scenario, thereby easing constraints on the dark sector.
In this work, we presented the dark matter phenomenology of the singlet scalar and fermionic dark matter candidates. While singlet scalar DM is often severely constrained, the presence of the $Z'$ portal together with annihilation and co-annihilation channels substantially broadens the allowed parameter space. Thus, the framework offers a predictive scenario for neutrino and dark matter phenomenology that can be probed in future experiments.
Speaker: Ranjeet Kumar (Seoul National University of Science and Technology) -
17:00
The Goldstone Portal to Charged Lepton Flavour Violation 20m
Neutrino mass models usually involve the breaking of a custodial symmetry related to the masslessness of neutrinos in the Standard Model. Focusing on low-scale seesaws, we will show how, in contrast with scenarios where the symmetry is explicitly broken, the case of spontaneous symmetry breaking introduces crucial distinct directions, mainly through the associated Nambu-Goldstone Boson ($G$). In this talk, we will explore how the NGB associated with the spontaneous breaking of a global $B-L$ symmetry (giving rise to the Majoron or the Diracon) is the key to testing and falsifying these models. In particular, we will discuss how flavour-violating processes such as $\mu \to e G$ become more relevant and experimentally accessible than the typical loop-induced cLFV signal $\mu \to e \gamma$, offering a sharp, distinct signature in both laboratory searches and cosmological bounds.
Speaker: Antonio Herrero Brocal -
17:20
Quark hierarchies and CP violation from Siegel modular forms 20m
We consider a flavour framework in which quark mass hierarchies naturally arise from a small departure of the modulus VEV from special stabilised regions of genus 2. By extending the modular group to this genus, the same VEV can also account for the spontaneous breaking of the assumed CP symmetry. We present a modular quark model which is able to fit both the mass hierarchies and the CKM matrix through a single mechanism, where the quark mass ratios vanish in the residual symmetry (and CP conserving) limit.
Speaker: Matteo Parriciatu (INFN Sezione Roma Tre) -
17:40
Stringy Constraints on Modular Flavor Models 20m
We investigate stringy constraints on moduli spaces in modular flavor models by analyzing moduli-dependent threshold corrections in heterotic string vacua. While moduli play a crucial role in determining the flavor structure of fermions predicted by modular flavor models, the parameter space in which their vacuum expectation values are allowed has not been fully explored. In this work, within the framework of perturbative heterotic string theory on toroidal orbifolds, we derive constraints on the moduli space and study their systematic behavior. We characterize the stringy constraints in terms of the dilaton, the beta-function coefficients, and the ratio between a complex-structure modulus and a Kähler modulus. It is found that the large value of the modulus controlling the flavor structure, i.e., τ ≃ i∞, is inconsistent within perturbative string theory, and the self-dual point τ = i is also disfavored in the large volume regime of toroidal backgrounds. In addition, we discuss the phenomenological implications of these stringy constraints.
This talk is based on arXiv:2508.12392 [hep-ph].Speaker: Takafumi Kai (Kyushu University)
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Flavor 2Convener: Enrico Lunghi (Indiana University)
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Modular Flavor Symmetries and Fermion Mass Hierarchy 30m
I will discuss recent progress based on modular flavor symmetries to solve the flavor puzzle. In particular, I will describe how modular flavor symmetries can give rise to fermion mass hierarchy and mixing. I will also show that such predictions are stable under renormalization group corrections.
Speaker: Prof. Mu-Chun Chen (University of California, Irvine) -
09:30
Modular Zeros 30m
Modular symmetries have been used to address the flavor puzzle. We will discuss how the properties of modular forms allow us to resolve long-standing puzzles in string and flavor model building.
Speaker: Michael Ratz (University of California, Irvine) -
10:00
Gravity tidings from domain walls: Flavour hierarchies are making waves 30m
Explaining the observed charged fermion mass hierarchies points to flavour symmetries inducing a suppression of the lighter species’ masses. When the symmetries are global, it is expected that such symmetries are broken by gravity via Planck scale suppressed effective operators. The potential of the spontaneous symmetry-breaking “flavon” field, if the symmetry is discrete, then possesses several minima, with the vacuum-degeneracy lifted by the gravity effects. In such scenarios, domain walls might be generated in the process of symmetry breaking. Due to the bias, however, they potentially annihilate sufficiently before Big Bang nucleosynthesis, avoiding conflict with observations and generating a characteristic contribution to the stochastic gravitational wave background. We discuss whether and how minimalistic supersymmetric and non-supersymmetric realisations of such theories can give rise to observable gravitational waves.
Speaker: Miguel Levy (University of Basel)
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10:35
Conference photo
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Coffee & Discussion 25m
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BSM 1Convener: Ki-Young Choi (Sungkyunkwan University)
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11:00
Beyond the Beam-Dump Ceiling: Probing Light Dark Photons at the LHC 30m
Beam-dump experiments provide powerful probes of light and feebly interacting particles, but their sensitivity to visibly decaying mediators is ultimately limited by the requirement that the new particle survive the shielding or baseline before reaching the detector. This geometric requirement produces a characteristic “beam-dump ceiling” in the coupling–mass parameter space, beyond which the mediator decays too promptly to be observed. In this talk, we discuss how the LHC can access part of the parameter space above this ceiling by exploiting its high collision energy, broad detector coverage, and short source-to-detector distances. Focusing on visibly decaying dark photons, we will present ongoing work on two complementary production mechanisms: dark-photon bremsstrahlung from energetic hadrons interacting in the calorimeters, and direct production in association with a hard jet. These channels lead respectively to displaced dimuon and dielectron signatures, allowing the LHC detector to operate, in different ways, as both the source and detector of light dark-sector states. We will discuss realistic trigger and reconstruction requirements, the use of displaced-lepton and parking data sets, preliminary background estimates, and the resulting sensitivity to previously unexplored regions of dark-photon parameter space.
Speaker: Dr Doojin Kim (Texas A&M University) -
11:30
Cepheids as a dark matter detector 30m
Dark photon dark matter with a mass at around meV can be nicely probed by cepheids. Characteristic relationship between period and luminosity is affected by the presence of dark matter. Cooling and heating of Cepheids by dark matter is discussed in detail.
Speaker: Prof. Hyung Do Kim (Seoul National University) -
12:00
Probing Higgs self-coupling using Higgs-pair production at multi-TeV Muon Colliders 30m
One of the ultimate goals of future high-energy colliders is to uncover
the nature of electroweak symmetry breaking (EWSB). In particular, a
precise determination of the Higgs trilinear self-coupling,
$\kappa_3$, would provide crucial insight into the structure of the
Higgs potential and the mechanism of EWSB. We investigate the
sensitivity of multi-TeV muon colliders to $\kappa_3$ through
Higgs-pair production via the vector boson fusion (VBF) channel. We
consider the fully hadronic decay mode of the Higgs pair, $HH \to 4b$,
and analyze both the resolved and boosted kinematic regimes. A suite
of machine-learning techniques is employed to enhance the
signal-to-background discrimination and improve the statistical
significance. We find a substantial improvement in the sensitivity to
$\kappa_3$. By combining the resolved and boosted analyses, we obtain
the 68% confidence intervals $0.80 < \kappa_3 < 1.29$ at a 3-TeV muon
collider and $0.96 < \kappa_3 < 1.05$ at a 10-TeV muon collider.Speaker: Kingman Cheung (National Tsing Hua Univ / Konkuk Univ) -
12:30
Collider Spin Tomography with Missing Neutrinos 30m
Missing neutrinos need not destroy collider spin tomography. We formulate the visible measurement under kinematic ambiguities arising from invisible particles as a coarse-grained positive-operator-valued measure on the production spin density matrix. We show that information loss is governed by the null space of the resulting visible-data map, not by the number of kinematic solutions. In e+e−→τ+τ−→π+π−+νν¯, the twofold ambiguity leaves only the antisymmetric spin-correlation combination Cnr−Crn unidentifiable, while the differential production rate and the remaining fourteen spin coefficients are identifiable. For practical reconstruction under kinematic ambiguities, we develop a self-consistent fixed-point unfolding method using only visible data, without assuming a theoretical production template. Closure tests in Standard Model and anomalous tau-dipole benchmarks show that the method reproduces the truth-level differential production rate and all identifiable spin coefficients, whereas the usual flat average over kinematic folds gives significantly biased reconstructions. When a nontrivial null space is present, the reconstructed identifiable subspace together with positivity yields controlled ranges for concurrence and the CHSH parameter.
Speaker: Jia Liu (Peking University)
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Lunch 1h 30m
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Wednesday afternoon 1Convener: Jong-Chul Park (Chungnam National University)
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14:30
Flavor and precision study of a minimally extended scotogenic model 20m
We investigate the phenomenology of a minimally extended scotogenic model motivated by the observed active neutrino masses, viable dark matter (DM) candidates, and the high-energy behavior of the Standard Model (SM) quartic coupling constant. The neutrino mass generation mechanism is briefly reviewed, covering both normal and inverted mass hierarchies, along with a concise discussion of DM candidates and the associated experimental constraints. Since the model incorporates an extended SM scalar potential, we examine the bounded-from-below conditions, vacuum stability, and renormalization group (RG)-driven perturbativity bounds arising from the extended scalar sector. We further analyze a comprehensive set of flavor observables, including the anomalous magnetic moment of the muon in light of the recent experimental tension of $\Delta a_{\mu}$, the radiative decays $\ell_{\alpha} \rightarrow \ell_{\beta} \gamma$ and $\ell_{\alpha} \rightarrow 3\ell_{\beta}$, the $\mu \rightarrow e$ conversion rate, and electroweak (EW) precision observables, including the oblique parameters and the leptonic decays of the $Z$ and $H$. A numerical scan reveals three notable features: first, the viable fermionic DM candidate mass lies in the range $120-300 \operatorname{GeV}$, while the CP-odd scalar mass is constrained to $300-600 \operatorname{GeV}$; second, the oblique parameters are projected to be within the reach of future precision measurements; and third, the $Z \rightarrow \operatorname{Invisible}$ decay can provide a probe of the Majorana nature of the light active neutrinos.
Speaker: Huchan Lee (Seoul National University of Science and Technology) -
14:50
Reviving the Low-Mass Right Handed Neutrino Regime in Minimal Scotogenic Leptogenesis using Majoron Velocity 20m
In this talk, we will present a possibility of realising successful cogenesis of baryon asymmetry of the Universe, dark matter and neutrino masses within the minimal scotogenic model with low-mass right handed neutrinos (RHN). In the conventional thermal scotogenic leptogenesis setup, there exists a viable parameter space with smaller masses for RHNs as compared to Type-I seesaw case, because the Yukawa couplings for RHNs can be stronger for the same neutrino masses. However, the thermal leptogenesis in the minimal case with two hierarchical RHNs is limited due to the interplay between CP asymmetry generation and washout effects, which typically leads to relatively heavy RHNs. We will show that the presence of a time-dependent Majoron background originating from a global symmetry breaking through its associated Majoron velocity, provides an effective chemical potential that significantly alters the leptogenesis dynamics. This mechanism revives a previously inaccessible low-mass RHN regime while remaining consistent with radiative neutrino mass generation and weakly interacting dark matter. We will discuss the parameter space that successfully reproduces both the observed baryon asymmetry of the Universe and the dark matter relic abundance, highlighting the prospects for low-scale leptogenesis in the minimal scotogenic framework.
Speaker: Arghyajit Datta (Chung-Ang University) -
15:10
Lepton number violation at hadron colliders via pseudo-Dirac heavy neutral leptons 20m
Symmetry-protected low-scale seesaw models can account for the observed neutrino flavour oscillations without fine-tuning, while yielding collider-accessible signatures through pseudo-Dirac heavy neutral leptons (HNLs). Seesaw frameworks generically predict lepton number (LN) violation, which provides a powerful discovery channel. In symmetry-protected realisations, however, the amplitudes for LN violation are strongly suppressed by destructive interference between the contributions of the two quasi-degenerate HNLs within the usual QFT plane-wave treatment. We demonstrate that damped heavy neutrino-antineutrino oscillations significantly alleviate this suppression. We compare the sensitivities to pseudo-Dirac HNLs in both LN-blind and LN-violating channels at the LHC and future hadron colliders such as the FCC-$hh$ and the S$pp$C. We find that, although searches for LN violation outperform their LN-blind counterparts, small mass splittings in the pseudo-Dirac HNL pair can drastically reduce the sensitivities in these channels. We further show that combining LN-blind and LN-violating searches can distinguish a pseudo-Dirac HNL pair from the double-Majorana limit in the intermediate regime where LN violation is observable but not yet saturated.
Speaker: Mr Bruno M. S. Oliveira (Centro de Física Teórica de Partículas (CFTP), Instituto Superior Técnico (IST), Universidade de Lisboa (UL)) -
15:30
Beyond $SU(N)$: $U(3) \times U(2)$ as the true gauge group of the strong and electroweak interactions 20m
The gauge principle is a cornerstone of model building, yet most constructions gauge only the $SU(N)$ factors while leaving the associated $U(1)$ phase redundancies global. I take the gauge principle to its logical extreme and promote all $SU(N)$ groups to $U(N)$, proposing that the underlying symmetry of the strong and electroweak interactions is not $SU(3)_c \times SU(2)_L \times U(1)_Y$ but $U(3) \times U(2)$. Since $U(N) \cong \left[ SU(N) \times U(1) \right] / \mathbb{Z}_N$, the global structure of the group restricts the allowed representations and, combined with anomaly cancellation, turns several ad hoc features of the Standard Model into predictions: charge quantization and the observed hypercharge assignments. Consistency also requires right-handed neutrinos and an extra gauged $U(1)$, which can be identified with $B-L$, so that neutrino masses arise naturally. I will also comment on the associated $Z'$, dark matter from residual discrete symmetries, and the extension to grand unification, where flipped $SU(5)$ is recovered as $U(5)$. I will also argue that fully embracing the gauge principle opens novel avenues for model building, in particular in the flavor sector, where family symmetries are routinely introduced at the algebra level and the global structure of the group is systematically overlooked.
Speaker: Avelino Vicente (IFIC, CSIC-UV)
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Coffee & Discussion 30m
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Wednesday afternoon 2Convener: Kyu Jung Bae
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16:20
Large CP Violation in the Complex Two-Higgs-Doublet Model: From Electron EDM to Hidden CPV 20m
We perform a comprehensive global analysis of the Complex Two-Higgs-Doublet
Model with softly broken Z₂ symmetry, identifying the intrinsic structure
of parameter regions supporting large CP violation under all current
constraints, including the JILA electron EDM bound. Type-I and Type-II
follow qualitatively distinct pathways: Type-I predicts $|d_e| ≳ 10⁻³¹$ e·cm,
fully testable by next-generation EDM experiments, while Type-II permits
nearly maximal Yukawa-sector CP mixing in the heavy Higgs sector.
We further uncover "hidden CP violation" in the Higgs alignment limit,
probeable through CP-violating heavy-scalar Yukawa couplings and the
robust $[H₂,H₃,Z]$ vertex at future colliders.Speaker: Soojin Lee (National Tsing Hua University) -
16:40
On the Low Energy Behavior of Dynamical Gauge Couplings 20m
We study the low-energy behavior of gauge couplings in the presence of dynamical scalar backgrounds. In weakly coupled, renormalizable four-dimensional theories, gauge invariance prevents tree-level modifications of the gauge kinetic term, so the dependence on scalar background is logarithmic, reflecting renormalization group structure. Large variations thus require large field excursions or many generations of charged states. Beyond one loop, other couplings, such as Yukawa or scalar couplings, which may couple directly to charged matter, can enter the gauge beta function, providing a mechanism for large variations. Extra-dimensional scenarios can evade the logarithmic limitation entirely, yielding power-law dependence while maintaining perturbative control. We discuss phenomenological implications for dynamical Standard Model gauge couplings.
Speaker: Michael Shamma (Korea Institute for Advanced Study) -
17:00
Uncovering Hidden Leptonic Correlations with Flow Matching and Autoencoders 20m
In this study, we analyze the latent features of physical observables in the lepton sector using an autoencoder. To obtain the dataset of physical observables, we employ flow matching to globally sample the Yukawa matrices and Majorana mass parameters within the framework of the type-I seesaw mechanism, reproducing the experimentally observed values. The learned latent representation reveals previously unknown correlations among physical observables. These findings may provide new insights into the origin of the neutrino mass hierarchy and the lepton mixing pattern.
Speaker: Haruto Kitagawa (Kyushu University) -
17:20
Two-Pion HBT Signatures of Inhomogeneous Phases in Finite-Density QCD 20m
Spatially inhomogeneous phases may arise transiently in hot and baryon-rich QCD matter and may leave characteristic imprints on two-pion Hanbury Brown–Twiss (HBT) correlations. We investigate such signatures in Au+Au collisions in the RHIC Beam Energy Scan region using the JAM2 transport model. A controlled one-dimensional spatial modulation is imposed on pion emission distributions generated by JAM2, and the resulting finite-relative-momentum correlation structures are studied through an energy scan over $\sqrt{s_{NN}}$ = 7.7–11.5 GeV. We compare calculations with and without the JAM2 first-order phase-transition equation-of-state option. Preliminary results show systematic beam-energy and equation-of-state dependences of the correlation features. We characterize the modulation-related signal using both the correlation function and its ratio to the corresponding unmodulated reference, including the peak position, amplitude, width, and statistical uncertainty. Complementary collective-flow observables will also be examined to relate the HBT response to equation-of-state-dependent expansion dynamics. This study provides a transport-based framework for assessing HBT sensitivity to possible inhomogeneous phases in finite-density QCD.
Speaker: Yongtae Heo (Hiroshima University, WPI-SKCM²) -
17:40
"Heavy-Quark Expansion Meets Experiment: Heavy-Hadron Lifetimes" 20m
In this talk, I review recent progress in the theoretical description of heavy-hadron lifetimes across different flavor systems, ranging from heavy–light mesons and baryons to doubly heavy hadrons. I discuss how spectator effects, weak annihilation, and Pauli interference contribute to lifetime differences among hadrons with the same heavy quark, and how these effects can be quantified using nonperturbative inputs such as NRQCD and lattice QCD. Particular emphasis will be placed on recent calculations of higher-order corrections and their impact on precision predictions.
I will compare theoretical predictions with available experimental measurements and highlight the remaining theoretical uncertainties. These studies provide a coherent picture of heavy-hadron lifetimes across flavor systems and offer important benchmarks for testing our understanding of weak decays and nonperturbative QCD.The presentation will be based on my recent papers:
J. Gratrex, B. Melić, I. Nišandžić: Lifetimes of singly charmed baryons, JHEP 07 (2022) 058;
J. Gratrex, A. Lenz, B. Melić, I. Nišandžić, M.L. Piscopo: Quark-hadron duality at work: lifetimes of bottom baryons, JHEP 04 (2023)034;
L. Dulibić, J. Gratrex, B. Melić, I. Nišandžić: Revisiting lifetimes of doubly charmed baryons, JHEP 07 (2023)061;
L. Dulibić, B. Melić, I. Nišandžić:New Predictions for the Lifetimes of Doubly Heavy Baryons and the Bc Meson e-Print: 2605.04967 [hep-ph]Speaker: Blazenka Melic (Rudjer Boskovic Institute Zagreb)
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Banquet 2h
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Cosmology 1Convener: Seong Chan Park (Yonsei University)
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09:00
Extra-Dimensional Axions: Axion quality and Phenomenology 30mSpeaker: kiwoon choi (ibs)
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09:30
Why is Lambda the zero? 30m
I will discuss why Lambda is the zero.
Speaker: MASAHIDE YAMAGUCHI (Institute for Basic Science) -
10:00
Dark age 21cm signal and low reheating temperature 30m
We introduce an idea to probe the early Universe scenario with low reheating temperature using the observation of cosmological 21cm from dark age in the Universe.
Speaker: Prof. Ki-Young Choi (Sungkyunkwan University)
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09:00
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Thursday morningConvener: Doojin Kim (University of South Dakota)
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10:30
Boiling down Neutrinos: Cosmological First-Order Phase Transitions in Radiative Mass Models 20m
Symmetries are the daily bread of modern particle physicists. In a variety of scenarios their breaking is associated with the formation and expansion of bubbles of true vacuum in what is called a first order phase transition. In this context, Electroweak Baryogenesis, a mechanism proposed over 40 years ago, takes advantage of Electroweak symmetry breaking and offers a way to address the baryon asymmetry of the universe, as all three Sakharov conditions can be realised on the walls of said bubbles. Additionally, the dynamics of bubble collisions could provide interesting gravitational waves signals that could be detected in the years to come.
Although the Standard Model contains all required ingredients, it has long been established that the electroweak phase transition does not proceed via nucleation of bubbles, rather it is a smooth crossover. Additionally, the smallness of the CP violation in SM is insufficient to account for the observed baryon asymmetry.
Extending the SM scalar sector can, however, drastically modify the dynamics of symmetry breaking and provide a richer vacuum structure. In this talk, I will analyse one such extension, the Zee model, first proposed to generating neutrino masses at loop level via the introduction of additional scalar degrees of freedom. We shall show how in this framework the electroweak phase transition actually proceeds via bubble nucleation, and how it could be strong enough to generate the observed baryon asymmetry of the universe.
Speaker: Francesco Paolo Di Meglio (IFIC (UV-CSIC)) -
10:50
Primordial Black Hole Hotspots Beyond Flat Spacetime 20m
Evaporating primordial black holes heat the surrounding plasma via Hawking radiation, forming localized hotspots whose temperature may far exceed that of the cosmological background. Previous studies of hotspot formation and cooling have treated the subsequent energy transport in flat spacetime, thereby neglecting the expansion of the Universe. We formulate the diffusion equation governing the hotspot evolution in an expanding universe, and clarify the regime in which the formalism is valid. We find that hotspot formation is robust against cosmological expansion, and the critical distance scale where Hubble expansion overtakes diffusion coincides with the decoupling radius introduced in earlier work. However, the cooling stage is substantially modified: the plateau temperature decreases more steeply than in the flat-spacetime treatment, and this scaling cannot be obtained by simply redshifting the flat-spacetime solution because expansion also suppresses diffusive transport. As a consequence, all hotspots disappear within a finite time, as opposed to the flat-spacetime prediction of everlasting hotspots in part of the parameter space.
Speaker: Jong-Hyun Yoon (Chungnam National University) -
11:10
Impact of first-order phase transition on dark matter relic 20m
We propose a simple yet testable framework for light fermion dark matter (DM) with mass in the MeV--GeV range, charged under a dark $U(1)_D$ gauge symmetry. Before symmetry breaking, DM annihilates excessively into massless dark gauge bosons, resulting in an under-abundant relic and hence creating severe tension with cosmic microwave background (CMB) and indirect detection constraints. This is naturally remedied by a strongly first-order phase transition (FOPT) in the dark sector, triggered by a scalar field $\Phi$, which gives rise masses to the dark gauge boson ($X_D$) and the physical scalar ($\phi$). To achieve the correct relic abundance while evading indirect detection constraints, the $s$-wave annihilation channel $\chi\bar{\chi} \rightarrow X_D \phi$ is strictly maintained in the kinematically forbidden regime. Crucially, due to the $U(1)_D$ gauge structure, the usual $\chi\bar{\chi} \rightarrow \phi\phi$ annihilation is strictly absent at tree level and only arises at the one-loop level. Within this framework, we explore two distinct possibilities. When the loop-induced $\chi\bar{\chi} \rightarrow \phi\phi$ channel is also kinematically forbidden, it predominantly determines the relic density. Conversely, when the $\chi\bar{\chi} \rightarrow\phi\phi$ channel is kinematically allowed, a rich interplay emerges between the tree-level forbidden $\chi\bar{\chi} \rightarrow X_D \phi$ process and the loop-level allowed $\chi\bar{\chi} \rightarrow\phi\phi$ process, with the dominant contribution being dictated sensitively by the DM mass and gauge coupling. The late-time annihilations are highly suppressed in both of these channels, either by the energetic threshold of the forbidden channel or the $p$-wave velocity suppression of the loop-induced $\chi\bar{\chi} \rightarrow\phi\phi$ final state process, rendering the scenario entirely safe from CMB and indirect search bounds. Moreover, the same symmetry-breaking phase transition is strongly first-order, producing a stochastic gravitational wave background that could be probed by upcoming space-based interferometers and pulsar timing arrays. We demonstrate that achieving the observed DM abundance tightly correlates the DM mass with the nucleation temperature of the phase transition. Thus, this setup links the DM relic abundance, dark-sector dynamics, and gravitational wave signals, offering complementary paths for discovery in both terrestrial and cosmological observations.
Speaker: Partha Kumar Paul (Indian Institute of Technology Hyderabad)
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Excursion 6h 30m
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Dark Matter 1Convener: Pyungwon Ko (KIAS)
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09:00
The Experimental Landscape of Dark Matter Direct Detection 30m
The nature of dark matter remains one of the most compelling open problems connecting particle physics, astrophysics, and cosmology. While theoretical models—from WIMPs to sub-GeV and feebly interacting candidates—offer a rich space of possibilities, the direct detection program that tests them through dark matter scattering on terrestrial targets has advanced dramatically over the past decade. In this talk I present an experimentalist's review of the global direct detection effort. I summarize the current status of the leading liquid-noble (xenon and argon) detectors now approaching the neutrino fog, cryogenic bolometers extending sensitivity into the low-mass region, and the worldwide network of NaI(Tl)-based experiments addressing the long-standing DAMA/LIBRA annual-modulation claim. In this context I review recent results from the COSINE-100 experiment at the Yangyang and Yemilab underground laboratories. I conclude with the prospects for next-generation detectors and the role of Korean underground physics in the coming decade.
Speaker: Dr Hyunsu Lee (IBS) -
09:30
Superheavy Dark Matter 30m
The window of dark matter is widely open in the superheavy domain. However, significant model building is requested to make the theory actually work. In this talk, I will discuss some working examples of superheavy dark matter and their potential signals to test the models.
Speaker: Seong Chan Park (Yonsei University) -
10:00
Primordial Black Holes as Dark Sector Factories 30m
The Hawking radiation of photons from primordial black holes can be detected in future gamma-ray telescopes if PBHs constitute even a small fraction of dark matter. PBHs can likewise radiate new particles, which is particularly interesting when these particles are largely secluded from the Standard Model sector and would otherwise be difficult to access. In this talk, I will describe how such dark sector particles can be probed through the spectrum of Hawking radiation.
Speaker: Jae Hyeok Chang (Seoul National University)
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Conference photo
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Coffee & Discussion 25m
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BSM 2Convener: Kwang Sik Jeong (Pusan National University)
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11:00
Domain walls from discrete flavour symmetries 30m
Discrete flavour symmetries are widely used to address flavour puzzles in quark and lepton sectors. A key cosmological consequence for spontaneous breaking of these symmetries are the formation of domain walls (DWs), 2D topological defects at the cosmic scale. DWs, if they are generated in the radiation era, should collapse before BBN in order to avoid overclosing the Universe. The collapsing DWs radiate gravitational waves (GWs), which has been considered as one of the main sources of GWs with particle origins. This framework has gained renewed traction as the resulting GW spectrum can gain excellent agreement with the 2023 Pulsar Timing Array (PTA) data. While literature predominantly focuses on $Z_2$ symmetry breaking, this presentation explores DWs from larger Abelian and non-Abelian discrete symmetries, both highly motivated by flavour models. After reviewing the standard $Z_2$ DW case, we characterize DWs from general $Z_N$ breaking. We then analyze non-Abelian DWs using octahedral ($S_4$) and tetrahedral ($A_4$) symmetries as benchmarks. CP-violating DWs arise when complex structures are included. We further discuss unique properties of SUSY and modular DWs with conventional non-SUSY scenarios.
Speaker: Ye-Ling Zhou (Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences) -
11:30
Indirect signals of QCD axion in nuclear or atomic electric dipole moments 30m
Electric dipole moments (EDMs) of nucleons, nuclei, and atoms provide highly sensitive probes of new sources of CP violation beyond the Standard Model. A central challenge is the “EDM inverse problem”: determining the underlying ultraviolet origin of CP violation from a pattern of low-energy EDM measurements. In this talk, I discuss how solutions to the strong CP problem, particularly the QCD axion, modify the expected correlations among EDM observables. We show that combined measurements of light systems, including the neutron, proton, deuteron, and helium nuclei, can identify the dominant hadronic CP-odd operator, whereas heavy-atom EDMs generally provide only suggestive discrimination. In particular, a pattern consistent with quark chromo-electric dipole moments as the dominant source of nucleon EDMs could offer indirect experimental evidence for the QCD axion.
Speaker: Sang Hui Im (Center for Theoretical Physics of the Universe, Institute for Basic Science, Korea) -
12:00
Hint of High Scale Supersymmetry from low scale 2HDM 30mSpeaker: Prof. Gautam Bhattacharyya
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12:30
Testing New Physics with Neutrinos at Dark Matter Experiments 30m
In this talk, I will present a new avenue for testing new physics with neutrinos - the observation of (solar) neutrino scattering in dark matter direct detection experiments. Recently, coherent elastic neutrino-nucleus scattering (CEvNS) has been detected for the first time from astrophysical neutrinos, as opposed to reactors or spallation sources. Simultaneously, there are first hints for complementary measurements of solar neutrinos via elastic neutrino-electron scattering. I will review the implications of this novel signal at dark matter experiments both for neutrino physics within and beyond the Standard Model.
Speaker: Patrick Foldenauer (IFT UAM-CSIC Madrid)
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Lunch 1h 10m
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Friday afternoon 1Convener: Patrick Foldenauer (IFT UAM-CSIC Madrid)
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Status of GLIMPSE 20m
We propose a novel detection strategy for super-light dark matter (DM), $m_{DM}$ ~ O(keV), using a detector based on Graphene Josephson Junctions (GJJ). By intimately integrating the π-bond electrons of graphene as the target material into a Josephson junction, we create a sensor capable of detecting energy deposits as small as O(meV). We evaluate the scattering rates between DM and free electrons in the two-dimensional graphene, incorporating Pauli-blocking factors and in-medium screening effects. Our analysis of pg- to µg-scale detectors demonstrates that this setup achieves superior experimental sensitivity due to its extremely low energy threshold. Furthermore, the event rates depend non-trivially on the orientation of the graphene plane relative to the DM flux due to the relative motion of the Earth through the Galactic DM halo. Experimental status including construction, calibration and preliminary data analysis will also be briefly presented.
Speaker: Jong-Chul Park (Chungnam National University) -
14:30
Taming lepton portal dark matter by a non-invertible selection rule 20m
In this talk, I will show that a non-invertible selection rule can tame flavor violation induced by the portal Yukawa couplings of dark matter. In ordinary Abelian discrete symmetries without additional spurions, flavor-dependent charge assignments that forbid flavor-violating portal couplings do not allow a realistic PMNS matrix. This tension between the absence of flavor violation in the portal couplings and realistic lepton mixing can be resolved by using a non-invertible selection rule.
Speaker: Junichiro Kawamura (Kumamoto HS University) -
14:50
Electromagnetic signatures of axion dark matter halos around primordial black holes 20m
Dark matter (DM) may accumulate in the gravitational potential of compact astrophysical objects, forming dense bound halos. In particular, if primordial black holes (PBHs) are present, their gravitational field can capture surrounding DM particles and produce a steep density spike in the inner halo region. The resulting compact DM structure provides an environment where microscopic particle processes can lead to macroscopic electromagnetic phenomena.
For axion or axion-like particle (ALP) dark matter, the large phase-space density in the spike can trigger efficient photon production through stimulated decay. Above a critical density, this process may lead to rapid amplification of low-frequency electromagnetic radiation. Such emission is expected to originate from the innermost region of the PBH-induced halo and could contribute to transient or persistent radio signals.
We discuss the formation and evolution of axion halos around PBHs and explore the resulting observational signatures. Photons generated in the DM halo can propagate over cosmological distances and may be detectable by current or future radio observations.
Speaker: Junghoon Joh (SungKyunKwan University) -
15:10
Mixed wave dark matter and implications in neutrino physics 20m
Ultralight wave dark matter exhibits oscillations that can modulate particle physics observables. The mixing of two wave dark matter fields can alter this simple oscillation, generating nontrivial temporal structures beyond a monochromatic signal. We discuss two scenarios: potential oscillation with periodic symmetry breaking and restoration, and wave-envelope dark matter with a slow beating envelope. These can imprint characteristic signatures on neutrino observables such as neutrinoless double beta decay and cosmic neutrino background. This talk is based on our recent papers JHEP 07 (2025) 269 and arXiv:2604.14480.
Speaker: Yechan Kim (KAIST) -
15:30
Multimessenger Probes of Heavy Neutrinos 20m
Heavy neutrinos provide one of the most compelling windows into physics beyond the Standard Model, offering a common framework for neutrino mass generation, the matter-antimatter asymmetry of the Universe, and potentially dark matter. Their rich phenomenology spans collider, intensity-frontier, and cosmological experiments, making them ideal targets for a multimessenger search strategy.
In this talk, I will present recent advances in heavy-neutrino searches across complementary experimental frontiers. I will discuss direct probes at the LHC, LHeC, FCC-ee, FCC-hh, and future muon colliders through prompt, displaced-vertex, and long-lived particle signatures, with emphasis on novel tests of the Majorana nature of neutrinos via lepton-number violation, heavy-neutrino oscillations, and high-multiplicity final states. I will also highlight the potential of forward and beam-dump experiments to probe light, feebly interacting heavy neutrinos and the role of additional gauge interactions. Together, these complementary approaches provide a comprehensive roadmap for exploring the heavy-neutrino parameter space and uncovering the origin of neutrino masses.
Speaker: SANJOY MANDAL (Korea Institute for Advanced Study, Seoul, South Korea)
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Coffee & Discussion 30m
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Friday afternoon 2Convener: Sang Hui Im (Center for Theoretical Physics of the Universe, Institute for Basic Science, Korea)
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16:20
Extracting Dark-Matter Mass from Angular Scanning 20m
Determining the dark-matter mass is important for interpreting signals in direct-detection experiments. However, this can be challenging for low-threshold detectors with limited recoil-energy information. We present a method to estimate the dark-matter mass using directional information in (effectively) two-dimensional detectors. The motion of the Solar System and the Earth through the Galactic halo induces a dark-matter wind, which makes the event rate depend on the angle between the detector plane and the dark-matter wind. We show that the shape of this angular dependence, especially how sharply it changes with angle, contains information on the dark-matter mass. As a concrete example, we apply the method to a graphene Josephson-junction detector and confirm the expected angular dependence with numerical rate calculations. We also develop a code, DarkWind, to calculate the angle between the detector plane and the dark-matter wind as a function of time and detector location in a realistic experimental setup.
Speaker: Daeyeong Jeong (Chungnam National University) -
16:40
Radiatively-generated top quark flavor-changing neutral currents from dark matter 20m
We discuss a class of models that simultaneously provide reliable dark-matter candidate and give rise to sizable flavor changing neutral currents (FCNC) of the top/bottom quark at the one-loop order. The models consist of color-charged mediators and $SU(2)_L$ singlet dark matter particles both are odd under a $Z_2$ symmetry. We will discuss both the correlations
between the top FCNC decay rates, dark-matter observables and LHC searches. We will then provide with benchmark points amenable to a potential discovery at the HL-LHC.Speaker: Adil Jueid (KIAS) -
17:00
General Perspective on Boosted Dark Matter from Semi-annihilation 20m
We develop a systematic approach for analyzing any dark matter (DM) model that produces boosted dark matter (BDM) through semi-annihilation. We emphasize three points. First, any BDM analysis must be grounded on the correct relic density. Second, any realistic BDM model that aims to be detectable also contains an annihilation channel, which plays a significant role in BDM detection. Finally, the detection of the semi-annihilation by-product must be investigated.
As a demonstration, we apply our approach to an electrophilic, single-component $Z_3$ fermionic DM model. We find that this model is severely constrained by both model-independent and model-specific experimental bounds, and that the BDM direct-detection rate is unobservably small and is everywhere overwhelmed by the detectability of the neutrino by-product.Speaker: Seongsik Kim (Chungnam National University) -
17:20
Peccei-Quinn genesis 20m
In the Peccei–Quinn (PQ) pole inflation scenario within the KSVZ model, we propose a spontaneous baryogenesis mechanism incorporating a type-I seesaw model to simultaneously explain the observed baryon asymmetry and axion dark matter abundance in the Universe.
Both the dark matter abundance and the baryon asymmetry originate from a non-zero axion velocity, naturally generated by an explicit PQ-symmetry-breaking potential during inflation. For the successful cogenesis, inflation and DM abundance, we need the limited axion decay constant, 4-9*10^8 GeV.Speaker: Junho Song (Chung ang university) -
17:40
Light Dark Matter Sensitivity at the J-PARC Intermediate Water Cherenkov Detector 20m
Light dark matter (LDM) below the WIMP scale has attracted growing interest, as it can be produced by comparatively low-energy accelerator beams through portal mediators such as the dark photon. A sensitivity study for the Deep Underground Neutrino Experiment (DUNE) near detector demonstrated that an off-axis "PRISM" configuration can effectively separate a dark matter signal from the neutrino background. In this work, we evaluate the LDM sensitivity of the Intermediate Water Cherenkov Detector (IWCD), a movable near detector under construction for the J-PARC. We simulate dark photon production from neutral-meson decays and proton bremsstrahlung, analyze the expected signal and neutrino background, and perform a profile-likelihood analysis with a realistic detector response at multiple off-axis positions. Our results indicate that IWCD can achieve a sensitivity comparable with that of DUNE-PRISM, with improved reach in certain dark photon mass regions.
Speaker: Seong ha Kim (Chungnam National University / IBS-CUP)
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Flavor 3Convener: Andre de Gouvea (Northwestern University)
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09:00
Non-invertible selection rules in string theory and particle physics 30m
Group-like symmetries and selection rules have been studied in particle physics. However, string compactifications can lead to not only group-like symmetries, but also "symmetries" without group actions, i.e., non-invertible selection rules. Recently, we have derived several non-invertible selection rules from string theory and applied them to particle physics. See e.g. arXiv:2408.13984, 2409.05270, 2503.09966, 2508.12287. For example, using our selection rules, we can derive interesting Yukawa textures, which cannot be derived simply by group-like symmetries. Our approach is quite novel and would be useful in particle physics, in particular flavor physics. In this talk, I will explain some stringy origins of non-invertible selection rules and also some applications to particle physics.
Speaker: Tatsuo Kobayashi (Hokkaido University) -
09:30
Flavor Physics of quarks and leptons in non-invertible symmetry 30m
We discuss the phenomenological aspects of non-invertible symmetries, in particular, the flavor structure of quarks and leptons. We start with a $Z_M$ discrete symmetry and gauge $Z_2$ so as to obtain a non-invertible symmetry. We derive Yukawa matrices with texture zeros which cannot be realized by a conventional symmetry. We also discuss the SMEFT imposing the non-invertible symmetries and apply to the new physics in the semileptonic decays.
Speaker: MORIMITSU TANIMOTO (Niigata University) -
10:00
Flavor Physics with Non-invertible Symmetry: Radiative Neutrino Mass and Beyond 30m
Symmetries have played a central role in understanding the structure of particle interactions, especially in flavor physics. Recently, non-invertible symmetries, described by fusion algebras instead of conventional groups, have opened a new direction in model building.
I will present a radiative neutrino mass model based on some non-invertible fusion rules. The framework provides a novel selection rule that differs fundamentally from ordinary discrete symmetries and leads to a naturally loop-induced neutrino mass. I will highlight how non-invertible structures can offer new perspectives on flavor model building and discuss possible phenomenological consequences.Speaker: Prof. Hiroshi Okada (Henan Normal University)
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Coffee & Discussion 30m
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Dark Matter 2Convener: Jae Hyeok Chang (Seoul National University)
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11:00
Dark matter induced mini black hole in red giants 30m
TBA
Speaker: Seokhoon Yun (KNU) -
11:30
Probing the Galactic-Center GeV Excess Using Continuous Gravitational-Wave Searches 30m
Over ten years ago, Fermi observed an excess of GeV gamma rays from the Galactic Center whose origin is still under debate. One explanation for this excess involves annihilating dark matter; another requires an unresolved population of millisecond pulsars concentrated at the Galactic Center. We use the results from LIGO/Virgo's most recent all-sky search for quasi-monochromatic, persistent gravitational-wave signals from isolated neutron stars to determine whether unresolved millisecond pulsars could actually explain this excess. We find that a large set of the parameter space in the pulsar luminosity function can be excluded.
Speaker: Yue Zhao (HKUST) -
12:00
As simple as possible, but not simpler 30m
When data anomalies are observed, it is a common practice to assume some toy models, simplified models, or EFT. In particular one tends to minimize the number of new physical degrees of freedom, as well as the couplings. In this talk, I will describe a number of examples in physics of flavors and dark matter, where this simple-minded approach results in wrong or unphysical results. Based on these observations, I will advocate a few physical conditions that the simplest setup for data analysis has to satisfy in order to avoid this problem.
Speaker: Pyungwon Ko (KIAS)
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Lunch 1h
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BSM 3Convener: Sin Kyu Kang (Seoul National University of Science and Technology)
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13:30
Conformal Journeys through SUSY GUTs: From Finiteness to Supergravity Models 30m
The Reduction of Couplings (RoC) method is a powerful tool reducing the number of free parameters in a field theory. In SUSY GUTs it is a prerequisite to construct all-loop finite models, where the beta functions vanish at all loops. This has lead previously to models relating the gauge and Yukawa sectors, that successfully predict the Higgs boson and third generation quark masses. In this talk we show how all-loop finite models of this type exhibit a conformal regime induced by superpotential operators compatible with the reduction of couplings method. In the soft-breaking sector, by assuming that the finite Grand Unified Theory is connected to an effective N = 1, d = 4 Weyl-invariant SUGRA theory, we find a connection between the RoC in the dimensionful SSB sector and the emergence of an anomaly-mediated (AMSB-like) pattern. This leads to a specific form of the Kähler potential, whose structure coincides with that studied in no-scale supergravity scenarios.
Speaker: Myriam Mondragon (Institute of Physics, National Autonomous University of Mexico UNAM) -
14:00
BSM Phenomenologies inspired by singlet-doublet vector-like fermion dark matter 30m
Non-refutable evidences from galaxy rotation curves, gravitational lensing and cosmic microwave backgroud (CMB) suggests that there exists non-baryonic matter, called dark matter (DM) in the present Universe. The latest data from satellite borne experiment-PLANCK precisely
measure the DM relic to be 26.8% of the total energy budget of the present Universe. However, the standard model of particle physics does not include any viable DM candidate. In this talk, we will discuss the DM to be a mixed state of singlet-doublet (SD) vector-like fermions. The DM stability can be guaranteed by assuming these fermions to be odd under a Z2 symmetry. We will find the parameter space satisfying the DM relic from direct, indirect and collider constraints. We will also discuss how this SD-dark matter can inspire other beyond standard model (BSM) phenomenologies, such as neutrino mass, baryon asymmetry and gravitational waves.Speaker: Prof. Narendra Sahu (Indian Institute of Technology Hyderabad)
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Closing remarkConvener: Eung Jin Chun (KIAS)
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