Program
5 Nov. (Sat)
Ki-Young Choi : The Cold and Light Dark Matter
Youngjoon Kwon : Dark sector search from Belle (II) (talk file)
In this talk, we present the recent highlights of dark sector searches from Belle and Belle II experiments.
Choong Sun Kim (by zoom) : New Physics Effects on sub-eV Neutrino for Dirac or Majorana properties
Bumseok Kyae : Flavon-induced FCNC
We will discuss flavor mixing when extra gauge symmetries are introduced,
Younggeun Kim : CX-Band Axion Search using Josephson Parametric Convertor at CAPP (talk file)
Sungjae Bae : Photonic crystal axion haloscope for high mass axion search
The axion is a hypothetical particle which could address both the strong CP problem and favored dark matter mystery with a interesting theorectical model. Most of the high sensitivity cavity haloscope experiments are conducted at frequencies (mass) less than 10 GHz (40 μeV). A novel axion haloscope design with an array of periodically deployed dielectric rods in an ordinary cavity was developed by IBS-CAPP to extend the search range above 10 GHz with high sensitivity. Furthermore, an auxetic-inspired deformable structure, which allows 2-dimensional movement of the rods, was implemented for frequency tuning. We present the characteristics of this new cavity design and demonstrate the experimental feasibility.
6 Nov. (Sun)
Eung Jin Chun : Particle dispersion in classical vector dark matter background (talk file)
Interactions with a background medium modify in general the dispersion relation and canonical normalization of propagating particles. This can have an important phenomenological consequence when considering light dark matter coupling to quarks and leptons. In this paper, we address this issue in the vector dark matter background with the randomly distributed polarizations or a fixed polarization to the single direction. The observations associated with particle dispersion can give constraints on new light Abelian gauge boson models. Considering the solar neutrino transition and the electron mass measurement, stringent bounds can be put on the gauged Lμ−Lτ model and the dark photon model. Moreover, the classical vector field turns out to induce drastic changes in the particle normalization, which rule out a significant parameter region of the generic vector dark matter model.
Sungwoo Youn : Searches for invisible axions (talk file)
Woohyun Chung : Main Axion eXperiment at CAPP (CAPP-MAX)
IBS-CAPP has established the state-of-the-art axion detector facility in Korea with multiple dilution refrigerator systems of which four axion detectors are running in parallel on the low vibration pads now. New 12 T big bore (32 cm) Nb3Sn superconducting magnet was added to the line-up early last year with quantum noise-limited amplifiers, starting to produce the axion dark matter physics data with a DFSZ level sensitivity. This milestone reflects the CAPP’s effort of successfully applying cutting-edge technologies and innovative R&Ds in building axion dark matter search experiments. The critical R&Ds include the development of quantum noise limited amplifiers in collaboration with the Nakamura group in the U. of Tokyo and the high temperature superconducting cavity that sustains high Q-factor even at 8 T. We are now collecting axion dark matter physics data with quantum amplifiers in the frequency range of 1 to 2 GHz and a superconducting cavity will be added within next year. I will present the status of CAPP’s axion search and R&D efforts, including future plans.
Seong Chan Park : Axion quality Problem & its solution (talk file)
In axion models, the global U(1) Peccei-Quinn (PQ) symmetry is explicitly broken by non-perturbative effects of gravity such as axionic wormholes. The gravitational violation of the PQ symmetry due to wormholes is large enough to invalidate the PQ mechanism, which is entitled as the axion quality problem. Recently, a novel solution to this quality problem was suggested, where the non-minimal coupling of the axion field to gravity,
ξ, is introduced to suppress the wormhole contribution. In this work, we revisit the problem in a different but equally valid formulation of gravity, namely the Palatini formulation, where the Ricci scalar is solely determined by connection. We first find the axionic wormhole solution in the Palatini formulation, taking the full dynamical radial mode as well as the axial mode, then show that the quality problem is still resolved with the non-minimal coupling ξ. The requested lower bound of ξ in the Palatini formulation turns out to be slightly higher than that in the metric formulation.
Kang Sin Choi : Test of String Theory in the Gravity Sector (talk file)
Seong Moon Yoo : Direct detection of Relic Sterile Neutrino in PTOLEMY-like experiment (talk file)
Shaaban Khalil (by zoom) : Probing New Physics Through Flavor Anomalies
Flavor Changing Neutral Currents (FCNC) play an important role in testing the Standard Model (SM) while probing the possibility of having New Physics (NP) beyond the SM. In this talk, We focus on the appealing possibility that such NP is given by 2HDM and a supersymmetric extension of the SM. We analyzed the NP implications in the
avor violating processes: B -> D \tau \nu and B -> K \mu^+ \mu^-.
7 Nov. (Mon)
Yein Lee : Holographic duals of M5-branes on an irregularly punctured sphere (talk file)
Sergey Uchaikin : Josephson Parametric Amplifiers for CAPP Axion Search experiments
CAPP has several axion search experiments based on cavity haloscopes in the frequency range of 1–6 GHz. The main effort focuses on operation of the experiments with the highest possible sensitivity. It requires maintenance of the haloscopes at the lowest physical temperature in the range of mK and usage of low noise components to amplify the weak axion signal. We report our recent development of low noise amplifiers for 5 haloscope experiments targeting at different frequency ranges. The amplifiers show noise temperatures approaching the quantum limit.
Sunkun Oh (by zoom) : TBA
J. E. Kim : Quintessential Axion Review
Student Session : 10 minutes talk
Junhyeon Heo : Introduction to Noether’s theorem: with focus on Noether’s first theorem
BongGyun Han : Klein Gordon equation
Myeong Bo Kang : About terrell rotation
Junghoon Joh : Review of Gravitational dark matter: free streaming and phase space distribution
Minkyeu Cho : Why Quantum? - introduction to Bell's inequality