A5090724107- Particle physics theoretical and experimental studies
- Cosmology and Gravitation Theories
- Dark Matter and Cosmic Phenomena
- GNSS positioning and interference
- Particle Detector Development and Performance
- Geophysics and Gravity Measurements
- Black Holes and Theoretical Physics
- Computational Physics and Python Applications
- Radio Astronomy Observations and Technology
- Particle Accelerators and Free-Electron Lasers
- High-Energy Particle Collisions Research
- Quantum Chromodynamics and Particle Interactions
- Scientific Measurement and Uncertainty Evaluation
- Particle accelerators and beam dynamics
- Astronomical Observations and Instrumentation
- Distributed and Parallel Computing Systems
- Superconducting Materials and Applications
- Astrophysics and Cosmic Phenomena
- Advanced Frequency and Time Standards
- Radiation Detection and Scintillator Technologies
- Fluid Dynamics and Turbulent Flows
- Organic and Molecular Conductors Research
- Pulsars and Gravitational Waves Research
- Advanced Thermoelectric Materials and Devices
- Ionosphere and magnetosphere dynamics
Institute for Basic Science
2017-2024
Florida State University
2019-2024
Korea Astronomy and Space Science Institute
2009-2016
Seoul National University
2013-2016
Korea University of Science and Technology
2015
International Centre for Radio Astronomy Research
2015
The University of Western Australia
2015
Spanish National Observatory
2015
Changwon National University
2012
University of Cambridge
2009
An analog hadron calorimeter (AHCAL) prototype of 5.3 nuclear interaction lengths thickness has been constructed by members the CALICE Collaboration. The AHCAL consists a 38-layer sandwich structure steel plates and highly-segmented scintillator tiles that are read out wavelength-shifting fibers coupled to SiPMs. signal is amplified shaped with custom-designed ASIC. A calibration/monitoring system based on LED light was developed monitor SiPM gain measure full response curve in order correct...
If the mass of dark matter is generated from a cosmological phase transition involving nucleation bubbles, corresponding bubble walls can filter out particles during transition. Only with sufficient momentum to overcome their inside bubbles pass through walls. As result, number density after has suppression factor $\mathrm{exp}(\ensuremath{-}{M}_{\ensuremath{\chi}}/2\stackrel{\texttildelow{}}{\ensuremath{\gamma}}T)$, where ${M}_{\ensuremath{\chi}}$ mass, and...
A bstract We explore the possibility of embedding thermal leptogenesis within a first-order phase transition (FOPT) such that RHNs remain massless until FOPT arises. Their sudden and violent mass gain allows neutrinos to become thermally decoupled, lepton asymmetry generated from their decay can be, in principle, free strong wash-out processes conventional scenarios suffer from, albeit at cost new washout channels. To quantify effect this enhancement, we consider simple setup classically...
We propose a leptogenesis scenario where baryon asymmetry generation is assisted by the kinetic motion of Majoron, <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:mi>J</a:mi></a:math>, in process lepton-number violating inverse decays right-handed neutrino, <c:math xmlns:c="http://www.w3.org/1998/Math/MathML" display="inline"><c:mi>N</c:mi></c:math>. investigate two distinct scenarios depending on sources Majoron motion: (1) misalignment mechanism, and (2) mechanism....
We consider a chiral gauge theory from which light composite Dirac neutrinos dynamically emerge, augmented by QCD axion to solve the strong $CP$ problem. show that an interplay between sector and can also simultaneously lead successful baryogenesis generate correct dark matter abundance via ``cogenesis'' without contradicting present constraints. predict $\mathrm{\ensuremath{\Delta}}{N}_{\mathrm{eff}}\ensuremath{\ge}0.14$ ${m}_{a}$ in range $O(10)\text{ }\text{...
Abstract The radio telescopes of the European VLBI Network (EVN) and University Tasmania (UTAS) conducted an extensive observation campaign Space Agency’s (ESA) Mars Express (MEX) spacecraft between 2013 2020. campaign, carried out under Planetary Radio Interferometry Doppler Experiment (PRIDE) framework, aimed to study interplanetary phase scintillation assess noise budget in closed-loop observations. average was determined be approximately 10 mHz at a 10-second integration time,...
An axionlike particle (ALP) offers a new direction in electroweak baryogenesis because the periodic nature enables it to trigger strong first-order phase transition insensitively decay constant $f$. For $f$ much above TeV, ALP-induced is approximately described by adiabatic processes, distinguishing our scenario for from conventional ones. We show that, coupled anomaly, ALP can naturally realize spontaneous solve matter-antimatter asymmetry problem range between about ${10}^{5}$ and...
We estimate the big bang nucleosynthesis (BBN) constraint on majoron in mass range between 1 MeV to 10 GeV which dominantly decays into standard model neutrinos. When Majoron lifetime is shorter than sec, injected neutrinos mainly heat up background plasma, alters relation photon temperature and neutrino temperature. For a longer most of directly contribute protons-to-neutrons conversion. In both cases, deuterium helium abundances are enhanced, while from stronger that helium. <a:math...
We study the possibility of production primordial black holes (PBHs) from bubble collisions during a first-order phase transition. While typical colliding bubbles are small and irrelevant for PBH production, we find that those can produce PBHs must have macroscopically thick fluid shell been born much before nucleation time. Particularly large uncertainties arise an exponential sensitivity rate on required duration growth which depends details evolution spacetime metric toward end introduce...
We discuss an extension of the standard model by fields not charged under gauge symmetry in which electroweak breaking is driven Higgs quartic coupling itself without need for a negative mass term potential. This achieved scalar field S with large to at scale very small values high energies hidden charged. can remain perturbative all way Planck scale. The boson fully standard-model-like its couplings fermions and bosons. However, effective cubic self-couplings are significantly enhanced.
A prototype silicon-tungsten electromagnetic calorimeter for an ILC detector was tested in 2007 at the CERN SPS test beam. Data were collected with electron and hadron beams energy range 8 to 80 GeV. The analysis described here focuses on interactions of pions calorimeter. One main objectives CALICE program is validate Monte Carlo tools available design a full-sized detector. Si-W are therefore confronted predictions various physical models implemented GEANT4simulation framework.
We propose a possibility of the 125 GeV Higgs being pseudo-Goldstone boson in supersymmetry with extra vectorlike fermions. mass is obtained from loops top quark and fermions global symmetry breaking scale $f$ at around TeV. The $\ensuremath{\mu}$, $B\ensuremath{\mu}/\ensuremath{\mu}\ensuremath{\sim}f$ are generated dynamics quartic coupling vanishes as $\mathrm{tan}\ensuremath{\beta}\ensuremath{\simeq}1$. relation ${m}_{\mathrm{soft}}\ensuremath{\sim}4\ensuremath{\pi}{M}_{Z}$...
Any new particle charged under $SU(3)_C$ and carrying electric charge will leave an imprint in the di-photon invariant mass spectrum as it can mediate $gg \to \gamma \gamma$ process through loops. The combination of properties loop functions, threshold resummation gluon pdfs result a peak-like feature around twice given even if is short-lived thus doesn't form narrow bound state. Using recent ATLAS analysis, we set upper limits on combined particles indicate future prospects. We also discuss...
We find that collisions of near-horizon-sized bubbles with a thick fluid shell can produce primordial black holes (PBHs) during first-order phase transition. predict an approximately monochromatic PBH mass spectrum. In terms few parameters to be obtained from future numerical simulation, we estimate the abundance in Abelian Higgs benchmark model and show it significant. particular, PBHs constitute entire dark matter or even over-close universe. Our result thus shows models transition...
Adding VLBI capability to the SKA arrays will greatly broaden science of SKA, and is feasible within current specifications.SKA-VLBI can be initially implemented by providing phased-array outputs for SKA1-MID SKA1-SUR using these extremely sensitive stations with other radio telescopes, in SKA2 realising a distributed configuration baselines up thousands km, merging it existing networks.The motivation possible realization SKA-VLBI described this paper.
An axion can make the electroweak phase transition strongly first-order as required for baryogenesis even if it is weakly coupled to Higgs sector. This essentially because periodicity naturally allows structure of be insensitive decay constant that determines strength interactions. Furthermore, serve a CP relevant one introduces an effective coupling top quark Yukawa operator. Then, $f$ between about TeV and order $10$~TeV, observed baryon asymmetry explained while avoiding current...
We consider a twin Higgs scenario where the $Z_2$ symmetry is broken spontaneously, not explicitly. This provides an interesting interpretation of metastability in standard model; $SU(4)$ breaking scale $f$ determined by self quartic coupling flips its sign. However, for misalignment nonzero vacuum expectation values fields, parameter tuning ${\cal O}(m_h^2/f^2)$ required like explicit scenarios. For minimal model with exact symmetry, O}$($10^{10}$ GeV), so very unnatural. point out that can...
A bstract We point out that the accidental U(1) B−L symmetry can arise from a finite modular Γ N in type-I seesaw. The is spontaneously broken such way residual $$ {\mathbb{Z}}_N^T <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msubsup> <mml:mi>ℤ</mml:mi> <mml:mi>N</mml:mi> <mml:mi>T</mml:mi> </mml:msubsup> </mml:math> discrete symmetry, associated with T -transformation which shifts modulus τ → + 1, remains unbroken. This mimics , and hence majoron appears as pseudo...
Solar interpretations of the recent XENON1T excess events, such as axion or dark photon emissions from Sun, are thought to be at odds with stellar cooling bounds horizontal branch stars and red giants. We propose a simple effective field theory in which ${Z}_{2}$ symmetry forbids single emission dense stars, thereby evading bounds, while is spontaneously broken vacuum explaining excess. The scalar responsible for breaking has an extremely flat potential, but flatness can maintained under...
We present the activities performed during first MadAnalysis 5 workshop on LHC recasting that has been organized at High 1 (Gangwon privince, Korea) August 20-27, 2017. This report includes details implementation in framework of eight ATLAS and CMS analyses, as well a description corresponding validation various issues have observed.
We explore the possibility of embedding thermal leptogenesis within a first-order phase transition (FOPT) such that RHNs remain massless until FOPT arises. Their sudden and violent mass gain allows neutrinos to become thermally decoupled, lepton asymmetry generated from their decay can be, in principle, free strong wash-out processes conventional scenarios suffer from, albeit at cost new washout channels. To quantify effect this enhancement, we consider simple setup classically...
We propose a spectral decomposition to systematically extract information of dark matter at hadron colliders. The differential cross section events with missing transverse energy (${\overline{)E}}_{T}$) can be expressed by linear combination basis functions. In the case $s$-channel mediator models for particle production, functions are identified sections subprocesses virtual and visible production while coefficients correspond invariant mass distribution in manner K\"all\'en-Lehmann...