N. Katayama
A5103256566- Radio Astronomy Observations and Technology
- Superconducting and THz Device Technology
- Cosmology and Gravitation Theories
- Particle physics theoretical and experimental studies
- Quantum Chromodynamics and Particle Interactions
- High-Energy Particle Collisions Research
- Galaxies: Formation, Evolution, Phenomena
- Geophysics and Gravity Measurements
- Dark Matter and Cosmic Phenomena
- Astronomy and Astrophysical Research
- Particle Detector Development and Performance
- Adaptive optics and wavefront sensing
- Superconducting Materials and Applications
- Neutrino Physics Research
- Optical Coatings and Gratings
- Photonic and Optical Devices
- Astrophysics and Cosmic Phenomena
- Physics of Superconductivity and Magnetism
- Computational Physics and Python Applications
- Magnetic Bearings and Levitation Dynamics
- Particle Accelerators and Free-Electron Lasers
- Stellar, planetary, and galactic studies
- Particle accelerators and beam dynamics
- Pulsars and Gravitational Waves Research
- Solar and Space Plasma Dynamics
Kavli Institute for the Physics and Mathematics of the Universe
2015-2024
The University of Tokyo
2015-2024
Campbell Collaboration
2022
Institute for Physics
2021
University of California, Berkeley
2018
University of California, San Diego
2014-2018
Nagoya University
2017
Yokohama National University
2016-2017
Max Planck Institute for Astrophysics
2017
Cardiff University
2016
Hyper Suprime-Cam (HSC) is a wide-field imaging camera on the prime focus of 8.2m Subaru telescope summit Maunakea in Hawaii. A team scientists from Japan, Taiwan and Princeton University using HSC to carry out 300-night multi-band survey high-latitude sky. The includes three layers: Wide layer will cover 1400 deg$^2$ five broad bands ($grizy$), with $5\,\sigma$ point-source depth $r \approx 26$. Deep covers total 26~deg$^2$ four fields, going roughly magnitude fainter, while UltraDeep goes...
The Hyper Suprime-Cam Subaru Strategic Program (HSC-SSP) is a three-layered imaging survey aimed at addressing some of the most outstanding questions in astronomy today, including nature dark matter and energy. has been awarded 300 nights observing time Telescope it started March 2014. This paper presents first public data release HSC-SSP. includes taken 1.7 years observations (61.5 nights) each Wide, Deep, UltraDeep layers covers about 108, 26, 4 square degrees down to depths i~26.4, ~26.5,...
Abstract LiteBIRD, the Lite (Light) satellite for study of B-mode polarization and Inflation from cosmic background Radiation Detection, is a space mission primordial cosmology fundamental physics. The Japan Aerospace Exploration Agency (JAXA) selected LiteBIRD in May 2019 as strategic large-class (L-class) mission, with an expected launch late 2020s using JAXA’s H3 rocket. planned to orbit Sun–Earth Lagrangian point L2, where it will map microwave over entire sky three years, telescopes 15...
We present an improved measurement of the standard model CP violation parameter $\mathrm{sin}2{\ensuremath{\varphi}}_{1}$ (also known as $\mathrm{sin}2\ensuremath{\beta})$ based on a sample $85\ifmmode\times\else\texttimes\fi{}{10}^{6}$ $B\overline{B}$ pairs collected at $\ensuremath{\Upsilon}(4S)$ resonance with Belle detector KEKB asymmetric-energy ${e}^{+}{e}^{\ensuremath{-}}$ collider. One neutral B meson is reconstructed in $J/\ensuremath{\psi}{K}_{S}^{0},$...
A detection of B-mode polarization the cosmic microwave background (CMB) anisotropies would confirm presence a primordial gravitational wave (GWB). In inflation paradigm, this be an unprecedented probe energy scale as it is directly proportional to power spectrum GWB. However, similar tensor perturbations can produced by matter fields present during inflation, breaking simple relationship between and tensor-to-scalar ratio $r$. It therefore important find ways distinguishing generation...
Abstract We report an improved measurement of the cosmic microwave background B -mode polarization power spectrum with Polarbear experiment at 150 GHz. By adding new data collected during second season observations (2013–2014) to re-analyzed from first (2012–2013), we have reduced twofold band-power uncertainties. The band powers are reported over angular multipoles , where dominant signal is expected be due gravitational lensing E -modes. reject null hypothesis no a confidence 3.1 σ...
We constrain anisotropic cosmic birefringence using four-point correlations of even-parity $E$-mode and odd-parity $B$-mode polarization in the microwave background measurements made by POLARization Background Radiation (POLARBEAR) experiment its first season observations. find that signal from any parity-violating processes is consistent with zero. The Faraday rotation can be compared equivalent quantity generated primordial magnetic fields if they existed. POLARBEAR nondetection translates...
Abstract We show that the cosmic birefringence and miscalibrated polarization angles can be determined simultaneously by microwave background (CMB) experiments using cross-correlation between $E$- $B$-mode data. This is possible because of CMB are rotated both miscalibration effects, whereas those Galactic foreground emission only latter. Our method does not require prior knowledge power spectra emission, but uses spectra. Specifically, we relate observed $EB$ correlation to difference...
We present a high-statistics measurement of differential cross sections and the total section for process $\ensuremath{\gamma}\ensuremath{\gamma}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{0}{\ensuremath{\pi}}^{0}$ in kinematic range $0.6\text{ }\text{ }\mathrm{GeV}\ensuremath{\le}W\ensuremath{\le}4.0\text{ }\mathrm{GeV}$ $|\mathrm{cos}{\ensuremath{\theta}}^{*}|\ensuremath{\le}0.8$, where $W$ ${\ensuremath{\theta}}^{*}$ are energy pion scattering angle, respectively,...
LiteBIRD [Lite (Light) satellite for the studies of B-mode polarization and Inflation from cosmic background Radiation Detection] is a small to map microwave (CMB) radiation over full sky at large angular scales with unprecedented precision. Cosmological inflation, which leading hypothesis resolve problems in Big Bang theory, predicts that primordial gravitational waves were created during inflationary era. Measurements CMB are known as best probe detect waves. The working group authorized...
POLARBEAR-2 (PB-2) is a cosmic microwave background (CMB) polarization experiment that will be located in the Atacama highland Chile at an altitude of 5200 m. Its science goals are to measure CMB signals originating from both primordial gravitational waves and weak lensing. PB-2 designed tensor scalar ratio, r, with precision {\sigma}(r) < 0.01, sum neutrino masses, {\Sigma}m{\nu}, {\sigma}({\Sigma}m{\nu}) 90 meV. To achieve these goals, employ 7588 transition-edge sensor bolometers 95 GHz...
Recent developments of transition-edge sensors (TESs), based on extensive experience in ground-based experiments, have been making the sensor techniques mature enough for their application future satellite CMB polarization experiments. LiteBIRD is most advanced phase among such satellites, targeting its launch Japanese Fiscal Year 2027 (2027FY) with JAXA's H3 rocket. It will accommodate more than 4000 TESs focal planes reflective low-frequency and refractive medium-and-high-frequency...
We report a determination of the B(0)(d)-&B_(0)(d) mixing parameter Deltam(d) based on time evolution dilepton yields in Upsilon(4S) decays. The measurement is 5.9 fb(-1) data sample collected by Belle detector at KEKB. proper-time difference distributions for same-sign and opposite-sign events are simultaneously fitted to an expression containing as free parameter. Using both muons electrons, we obtain = 0.463+/-0.008 (stat)+/-0.016 (syst) ps(-1). This first from measurements Upsilon(4S)....
We reconsider the pixel-based, "template" polarized foreground removal method within context of a next-generation, low-noise, low-resolution (05 FWHM) space-borne experiment measuring cosmological B-mode polarization signal in cosmic microwave background (CMB). This was first applied to data by Wilkinson Microwave Anisotropy Probe (WMAP) team and further studied Efstathiou et al. need at least three frequency channels: one is used for extracting CMB signal, whereas other two are estimate...
Using only cosmic microwave background polarization data from the POLARBEAR experiment, we measure $B$-mode delensing on subdegree scales at more than $5\sigma$ significance. We achieve a 14% power variance reduction, highest to date for internal delensing, and improve this result 2% by applying first time an iterative maximum posteriori method. Our analysis demonstrates capability of as means improving constraints inflationary models, paving way optimal next-generation primordial experiments.
We report the first observation of a b -> u type charmless baryonic B decay, B+ p pbar pi+, as well s B0 K0 and K*+ decays. The analysis is based on 78fb^{-1} data sample recorded Upsilon(4S) resonance with Belle detector at KEKB. find BF(B+ pi+) = (3.06^{+0.73}_{-0.62} \pm 0.37)*10^{-6}, BF(B0 K0) =(1.88^{+0.77}_{-0.60} 0.23)*10^{-6}, K*+) (10.3^{+3.6 + 1.3}_{-2.8 -1.7})*10^{-6}. also update K+) (5.66^{+0.67}_{-0.57} 0.62)* 10^{-6}, present an upper limit K*0) 90% confidence level. A common...
The differential cross sections for the process $\ensuremath{\gamma}\ensuremath{\gamma}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{0}{\ensuremath{\pi}}^{0}$ have been measured in kinematic range $0.6\text{ }\text{ }\mathrm{GeV}<W<4.1\text{ }\mathrm{GeV}$, $|\mathrm{cos}{\ensuremath{\theta}}^{*}|<0.8$ energy and pion scattering angle, respectively, $\ensuremath{\gamma}\ensuremath{\gamma}$ center-of-mass system. results are based on a $223\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ data...
The Simons Array is an expansion of the POLARBEAR cosmic microwave background (CMB) polarization experiment currently observing from Atacama Desert in Northern Chile. This will create array three 3.5m telescopes each coupled to a multichroic bolometric receiver. have sensitivity produce ≥ 5σ detection inationary gravitational waves with tensor-to-scalar ratio r 0:01, detect known minimum 58 meV sum neutrino masses 3σ confidence when combined next-generation baryon acoustic oscillation...
LiteBIRD is a next generation satellite aiming for the detection of Cosmic Microwave Background (CMB) B-mode polarization imprinted by primordial gravitational waves generated in era inflationary universe. The science goal to measure tensor-to-scaler ratio r with precision δr < 10<sup>-3</sup>♦, offering us crucial test major large-single-field slow-roll inflation models. planned conduct an all sky survey at sun-earth second Lagrange point (L2) angular resolution about 0.5...
Abstract The characterization and modeling of polarized foregrounds has become a critical issue in the quest for primordial B -modes. A typical method to proceed is factorize parametrize spectral properties their scale dependence (i.e. assuming that foreground spectra are well described everywhere by sky average). Since reality vary across Galaxy, this assumption leads inaccuracies model manifest themselves as biases final cosmological parameters (in case tensor-to-scalar ratio r ). This...
Atmosphere is one of the most important noise sources for ground-based cosmic microwave background (CMB) experiments. By increasing optical loading on detectors, it amplifies their effective noise, while its fluctuations introduce spatial and temporal correlations between detected signals. We present a physically motivated 3d-model atmosphere total intensity emission in millimeter sub-millimeter wavelengths. derive new analytical estimate correlation detectors time-ordered data as function...