Masahiro Kawasaki

Formation mechanisms of oxygen atoms in the O(1D2) state from the 157 nm photoirradiation of amorphous water ice at 90 K (2009)

We revisit the new-type of the Q ball (the gravity-mediation type of the Q ball in the gauge-mediation), in order to clarify its properties and correct some misunderstandings found in the recent...

Hama, Tetsuya, Yabushita, Akihiro, Yokoyama, Masaaki, Kawasaki, Masahiro, Watanabe, Naoki

Vacuum ultraviolet photolysis of water ice in the first absorption band was studied at 157 nm. Translational and internal energy distributions of the desorbed species, O(1D) and OH(ν = 0,1), were...

Formation mechanisms of oxygen atoms in the O(3PJ) state from the 157 nm photoirradiation of amorphous water ice at 90 K (2009)

Hama, Tetsuya, Yabushita, Akihiro, Yokoyama, Masaaki, Kawasaki, Masahiro, Watanabe, Naoki

Desorption of ground state O(3P_[J= 2,1,0]) atoms following the vacuum ultraviolet photolysis of water ice in the first absorption band was directly measured with resonance-enhanced multiphoton...

Constraining light gravitino mass from cosmic microwave background (2009)

Ichikawa, Kazuhide, Kawasaki, Masahiro, Nakayama, Kazunori, Sekiguchi, Toyokazu, Takahashi, Tomo

We investigate the possibilities of constraining the light gravitino mass m3/2 from future cosmic microwave background (CMB) surveys. A model with light gravitino with the mass m3/2< O (10)eV is of...

Effects of Dark Matter Annihilation on the Cosmic Microwave Background (2009)

Kanzaki, Toru, Kawasaki, Masahiro, Nakayama, Kazunori

We study the effects of dark matter annihilation during and after the cosmic recombination epoch on the cosmic microwave background anisotropy, taking into account the detailed energy deposition of...

Direct Emission of I_2 Molecule and IO Radical from the Heterogeneous Reactions of Gaseous Ozone with Aqueous Potassium Iodide Solution (2009)

Sakamoto, Yosuke, Yabushita, Akihiro, Kawasaki, Masahiro, Enami, Shinichi

Recent studies indicated that gaseous halogens mediate key tropospheric chemical processes. The inclusion of halogen-ozone chemistry in atmospheric box models actually closes the ~50% gap between...

Constraining Light Gravitino Mass from Cosmic Microwave Background (2009)

Ichikawa, Kazuhide, Kawasaki, Masahiro, Nakayama, Kazunori, Sekiguchi, Toyokazu, Takahashi, Tomo

We investigate the possibilities of constraining the light gravitino mass m_{3/2} from future cosmic microwave background (CMB) surveys. A model with light gravitino with the mass m_{3/2}

Non-Gaussianity from Isocurvature Perturbations : Analysis of Trispectrum (2009)

Kawakami, Etsuko, Kawasaki, Masahiro, Nakayama, Kazunori, Takahashi, Fuminobu

Non-Gaussianity may exist in the CDM isocurvature perturbation. We provide general expressions for the bispectrum and trispectrum of both adiabatic and isocurvature pertubations. We apply our result...

Axion isocurvature fluctuations with extremely blue spectrum (2009)

Diffuse gamma-ray background and cosmic-ray positrons from annihilating dark matter (2009)

We construct an axion model for generating isocurvature fluctuations with blue spectrum, n_{iso}=2-4, which is suggested by recent analyses of admixture of adiabatic and isocurvature perturbations...

Kawasaki, Masahiro, Kohri, Kazunori, Nakayama, Kazunori

We study the annihilating dark matter contribution to the extra-galactic diffuse gamma-ray background spectrum, motivated by the recent observations of cosmic-ray positron/electron anomalies. The...

Axion braneworld cosmology (2009)

Bambi, Cosimo, Kawasaki, Masahiro, Urban, Federico R.

We study axion cosmology in a 5D Universe, in the case of flat and warped extra dimension. The comparison between theoretical predictions and observations constrains the 5D axion decay constant and...

Cosmic Rays from Dark Matter Annihilation and Big-Bang Nucleosynthesis (2009)

Hisano, Junji, Kawasaki, Masahiro, Kohri, Kazunori, Moroi, Takeo, Nakayama, Kazunori

Recent measurements of cosmic-ray electron and positron fluxes by PAMELA and ATIC experiments may indicate the existence of annihilating dark matter with large annihilation cross section. We show...

Neutrino Signals from Annihilating/Decaying Dark Matter in the Light of Recent Measurements of Cosmic Ray Electron/Positron Fluxes (2008)

Hisano, Junji, Kawasaki, Masahiro, Kohri, Kazunori, Nakayama, Kazunori

The excess of cosmic-ray electron and positron fluxes measured by the PAMELA satellite and ATIC balloon experiments may be interpreted as the signals of the dark matter annihilation or decay into...

Positron/Gamma-Ray Signatures of Dark Matter Annihilation and Big-Bang Nucleosynthesis (2008)

Hisano, Junji, Kawasaki, Masahiro, Kohri, Kazunori, Nakayama, Kazunori

The positron excess observed by the PAMELA experiment may come from dark matter annihilation, if the annihilation cross section is large enough. We show that the dark matter annihilation scenarios to...

Hilltop Non-Gaussianity (2008)

Kawasaki, Masahiro, Nakayama, Kazunori, Takahashi, Fuminobu

We study non-Gaussianity induced by a pseudo Nambu-Goldstone boson with a cosine-type scalar potential. We focus on how the non-Gaussianity is affected when the pseudo Nambu-Goldstone boson rolls...

A General Analysis of Non-Gaussianity from Isocurvature Perturbations (2008)

Kawasaki, Masahiro, Nakayama, Kazunori, Sekiguchi, Toyokazu, Suyama, Teruaki, Takahashi, Fuminobu

Light scalars may be ubiquitous in nature, and their quantum fluctuations can produce large non-Gaussianity in the cosmic microwave background temperature anisotropy. The non-Gaussianity may be...

Non-Gaussianity from Baryon Asymmetry (2008)

Kawasaki, Masahiro, Nakayama, Kazunori, Takahashi, Fuminobu

We study a scenario that large non-Gaussianity arises from the baryon asymmetry of the Universe. There are baryogenesis scenarios containing a light scalar field, which may result in baryonic...

Non-Gaussianity from isocurvature perturbations (2008)

Kawasaki, Masahiro, Nakayama, Kazunori, Sekiguchi, Toyokazu, Suyama, Teruaki, Takahashi, Fuminobu

We develop a formalism to study non-Gaussianity in both curvature and isocurvature perturbations. It is shown that non-Gaussianity in the isocurvature perturbation between dark matter and photons...

Isocurvature fluctuations in Affleck-Dine mechanism and constraints on inflation models (2008)

Kasuya, Shinta, Kawasaki, Masahiro, Takahashi, Fuminobu

We reconsider the Affleck-Dine mechanism for baryogenesis and show that the baryonic isocurvature fluctuations are generated in many inflation models in supergravity. The inflationary scale and the...

Electron and Photon Energy Deposition in Universe (2008)

Kanzaki, Toru, Kawasaki, Masahiro

We consider energy deposition of high energy electrons and photons in universe. We carry out detailed calculations of fractions of the initial energy of the injected electron or photon which are used...

Big-Bang Nucleosynthesis and Gravitino (2008)

Kawasaki, Masahiro, Kohri, Kazunori, Moroi, Takeo, Yotsuyanagi, Akira

We derive big-bang nucleosynthesis (BBN) constraints on both unstable and stable gravitino taking account of recent progresses in theoretical study of the BBN processes as well as observations of...

For permissions, please (2008)

Jun-mo Yang, Joong Jung Kim, Kyung-seob Kim, Wan-gyu Lee, Masahiro Kawasaki

Full-length paper High-resolution transmission electron microscopy and electron energy-loss spectroscopy study of polycrystalline-Si/ZrO 2/SiO 2/Si metal-oxidesemiconductor structures

氷表面の光分解から生成する振動回転励起した水素分子 (2008)

薮下, 彰啓, 飯田, 大輔, 羽馬, 哲也, 川﨑, 昌博, Yabushita, Akihiro, Iida, Daisuke, ...

1章分子雲における氷と低温化学過程

Solving Cosmological Problems of Supersymmetric Axion Models in an Inflationary Universe (2008)

Study of the temperature dependence of the reaction of NO3 with CH3I and the estimation of its impact on atmospheric iodine chemistry (2008)

We revisit inflationary cosmology of axion models in the light of recent developments on the inflaton decay in supergravity. We find that all the cosmological difficulties, including gravitino, axino...

Nakano, Yukio, Ukeguchi, Hiromi, Ishiwata, Takashi, Kanaya, Yugo, Tachikawa, Hiroto, Ikeda, Atsushi, ...

Formation of intermediate-mass black holes as primordial black holes in the inflationary cosmology with running spectral index (2007)

Kawaguchi, Toshihiro, Kawasaki, Masahiro, Takayama, Tsutomu, Yamaguchi, Masahide, Yokoyama, Jun'ichi

Formation of primordial black holes (PBHs) on astrophysical mass scales is a natural consequence of inflationary cosmology if the primordial perturbation spectrum has a large and negative running of...

Cosmological implications of supersymmetric axion models (2007)

Kawasaki, Masahiro, Nakayama, Kazunori, Senami, Masato

We derive general constraints on supersymmetric extension of axion models, in particular paying careful attention to the cosmological effects of saxion. It is found that for every mass range of the...

Solving the cosmic lithium problems with primordial late-decaying particles (2007)

Cumberbatch, Daniel, Ichikawa, Kazuhide, Kawasaki, Masahiro, Kohri, Kazunori, Silk, Joseph, Starkman, Glenn D.

We investigate the modifications to predictions for the abundances of light elements from standard Big-Bang nucleosynthesis when exotic late-decaying particles with lifetimes exceeding ~1 sec are...

Cosmological Constraints on Isocurvature and Tensor Perturbations (2007)

Kawasaki, Masahiro, Sekiguchi, Toyokazu

We investigate cosmological constraints on primordial isocurvature and tensor perturbations, using recent observations of the cosmic microwave background and the large scale structure. We find that...

Cosmological Constraints on Neutrino Injection (2007)

Kanzaki, Toru, Kawasaki, Masahiro, Kohri, Kazunori, Moroi, Takeo

We derive general constraints on the relic abundances of a long-lived particle which mainly decays into a neutrino (and something else) at cosmological time scales. Such an exotic particle may show...

Baryon Asymmetry in a Heavy Moduli Scenario (2007)

Big-Bang Nucleosynthesis with Long-Lived Charged Slepton (2007)

In some models of supersymmetry breaking, modulus fields are heavy enough to decay before BBN. But the large entropy produced via moduli decay significantly dilutes the preexisting baryon asymmetry...

Increasing the effective number of neutrinos with decaying particles (2007)

We consider constraints on long-lived charged scalar leptons \tilde{l}^\pm in supersymmetric models, where gravitino is the lightest superparticle. We study the decay and hadronization processes of...

Ichikawa, Kazuhide, Kawasaki, Masahiro, Nakayama, Kazunori, Senami, Masato, Takahashi, Fuminobu

We present models of decaying particles for increasing the effective number of neutrinos N_nu after big bang nucleosynthesis but before the structure formation begins. We point out that our scenario...

A kinetic study of the gas-phase reactions of OIO with NO, NO2, and Cl-2 (2007)

Enami, Shinichi, Hoshino, Yosuke, Kawasaki, Masahiro

Vacuum ultraviolet photodissociation and surface morphology change of water ice films dosed with hydrogen chloride (2007)

Yabushita, Akihiro, Kanda, Daichi, Kawanaka, Noboru, Kawasaki, Masahiro

Formation of the iodine monoxide radical from gas-phase reactions of iodoalkyl radicals with molecular oxygen (2007)

Enami, Shinichi, Yamanaka, Takashi, Hashimoto, Satoshi, Kawasaki, Masahiro, Tonokura, Kenichi, Tachikawa, Hiroto

Release of oxygen atoms and nitric oxide molecules from the ultraviolet photodissociation of nitrate adsorbed on water ice films at 100 K (2007)

Yabushita, Akihiro, Kawanaka, Noboru, Kawasaki, Masahiro, Hamer, Paul D., Shallcross, Dudley E.

Buffer-gas pressure broadening for the (00(0)3) (2007)

Nakayama, Tomoki, Fukuda, Hisato, Sugita, Akihiro, Hashimoto, Satoshi, Kawasaki, Masahiro, Aloisio, Simone, ...

A gas-phase kinetic study of the reaction between bromine monoxide and methylperoxy radicals at atmospheric temperatures (2007)

Enami, Shinichi, Yamanaka, Takashi, Nakayama, Tomoki, Hashimoto, Satoshi, Kawasaki, Masahiro, Shallcross, Dudley E., ...

Multiphoton ionization detection of aromatic hydrocarbons at 157.6 nm (2007)

Kanno, Nozomu, Yabushita, Akihiro, Kawasaki, Masahiro, Tonokura, Kenichi

Constraint on the Effective Number of Neutrino Species from the WMAP and SDSS LRG Power Spectra (2006)

Ichikawa, Kazuhide, Kawasaki, Masahiro, Takahashi, Fuminobu

We derive constraint on the effective number of neutrino species N_nu from the cosmic microwave background power spectrum of the WMAP and galaxy clustering power spectrum of the SDSS luminous red...

Affleck-Dine baryogenesis in anomaly-mediated SUSY breaking (2006)

The Gravitino-Overproduction Problem in Inflaton Decay (2006)

It has been known that in anomaly-mediated SUSY breaking model Affleck-Dine baryogenesis does not work due to trapping of Affleck-Dine field into charge-breaking minima. We show that when...

Kawasaki, Masahiro, Takahashi, Fuminobu, Yanagida, T. T.

We show that the gravitino-overproduction problem is prevalent among inflation models in supergravity. An inflaton field generically acquires (effective) non-vanishing auxiliary field, if the Kahler...

Direct observation and reactions of Cl3 radical (2006)

Enami, Shinichi, Yamanaka, Takashi, Hashimoto, Satoshi, Kawasaki, Masahiro, Aloisio, Simone, Tachikawa, Hiroto

The broad absorption of Cl3 radical was observed between 1150 and 1350 nm using cavity ring-down spectroscopy at 213–265 K and 50–200 Torr with He, N2, Ar, or SF6 diluents. The absorption...

Direct observation and reactions of Cl(3) radical. (2006)

Enami, Shinichi, Yamanaka, Takashi, Hashimoto, Satoshi, Kawasaki, Masahiro, Aloisio, Simone, Tachikawa, Hiroto

The broad absorption of Cl3 radical was observed between 1150 and 1350 nm using cavity ring-down spectroscopy at 213–265 K and 50–200 Torr with He, N2, Ar, or SF6 diluents. The absorption...

Direct observation and reactions of Cl(3) radical. (2006)

Enami, Shinichi, Yamanaka, Takashi, Hashimoto, Satoshi, Kawasaki, Masahiro, Aloisio, Simone, Tachikawa, Hiroto

The broad absorption of Cl3 radical was observed between 1150 and 1350 nm using cavity ring-down spectroscopy at 213–265 K and 50–200 Torr with He, N2, Ar, or SF6 diluents. The absorption...

Cosmological Constraints on Gravitino LSP Scenario with Sneutrino NLSP (2006)

Kanzaki, Toru, Kawasaki, Masahiro, Kohri, Kazunori, Moroi, Takeo

We study the scenario where a sneutrino is the next lightest supersymmetric particle (NLSP) and decays into a gravitino and standard model particles. The daughter particles such as neutrinos and...

Late-time Affleck-Dine baryogenesis after thermal inflation (2006)

Early reionization by decaying particles in the light of three year WMAP data (2006)

Thermal inflation can solve serious cosmological problems such as overproduction of gravitinos and moduli. However, it also dilutes the preexisting baryon asymmetry. We investigate a possibility that...

Inflaton Decay through Supergravity Effects (2006)

We study the reionization histories where ionizing UV photons are emitted from decaying particles, in addition to usual contributions from stars and quasars, taking account of the fact that the...

Endo, Motoi, Kawasaki, Masahiro, Takahashi, Fuminobu, Yanagida, T. T.

We point out that supergravity effects enable the inflaton to decay into all matter fields, including the visible and the supersymmetry breaking sectors, once the inflaton acquires a non-vanishing...

Towards the robustness of the Affleck-Dine baryogenesis (2006)

The Gravitino-Overproduction Problem in Inflationary Universe (2006)

We study the Affleck-Dine mechanism with various types of the Kahler potential, and investigate whether or not the Affleck-Dine field could acquire a large VEV as an initial condition for successful...

Kawasaki, Masahiro, Takahashi, Fuminobu, Yanagida, T. T.

We show that the gravitino-overproduction problem is prevalent among inflation models in supergravity. An inflaton field \phi generically acquires (effective) non-vanishing auxiliary field G_\phi, if...

Power Spectrum of the Density Perturbations From Smooth Hybrid New Inflation Model (2006)

Kawasaki, Masahiro, Takayama, Tsutomu, Yamaguchi, Masahide, Yokoyama, Jun'ichi

We numerically investigate density perturbations generated in the smooth hybrid new inflation model, a kind of double inflation model that is designed to reproduce the running spectral index...

Implication of Dark Energy Parametrizations on the Determination of the Curvature of the Universe (2006)

Ichikawa, Kazuhide, Kawasaki, Masahiro, Sekiguchi, Toyokazu, Takahashi, Tomo

We investigate how the nature of dark energy affects the determination of the curvature of the universe from recent observations. For this purpose, we consider the constraints on the matter and dark...

Limit on the Neutrino Mass from the WMAP Three Year Data (2006)

Fukugita, Masataka, Ichikawa, Kazuhide, Kawasaki, Masahiro, Lahav, Ofer

We derive an upper limit on the neutrino mass from the WMAP three-year data alone by employing a deterministic minimisation method based on a grid search in multi-parameter space. Assuming the flat...

Gravitino Overproduction in Inflaton Decay (2006)

Kawasaki, Masahiro, Takahashi, Fuminobu, Yanagida, T. T.

Most of the inflation models end up with non-vanishing vacuum expectation values of the inflaton fields \phi in the true vacuum, which induce, in general, nonvanishing auxiliary field G_\phi for the...

Primordial Helium Abundance: A Reanalysis of the Izotov-Thuan Spectroscopic Sample (2006)

Fukugita, Masataka, Kawasaki, Masahiro

A reanalysis is made for the helium abundance determination for the Izotov-Thuan (2004) spectroscopic sample of extragalactic H II regions. We find that the effect of underlying stellar absorption of...

CMB constraints on the fine structure constant (2006)

Ichikawa, Kazuhide, Kanzaki, Toru, Kawasaki, Masahiro

We study constraints on time variation of the fine structure constant alpha from cosmic microwave background (CMB) taking into account simultaneous change in alpha and the electron mass m_e which...

511 keV line and diffuse gamma rays from moduli (2006)

High-resolution transmission electron microscopy and electron energy-loss spectroscopy study of polycrystalline-Si/ZrO2/SiO2/Si metal-oxide-semiconductor structures (2006)

We obtain the spectrum of gamma ray emissions from the moduli whose decay into $e^+ e^-$ accounts for the 511 keV line observed by SPI/INTERGRAL. The moduli emit gamma rays through internal...

Yang, Jun-Mo, Kim, Joong Jung, Kim, Kyung-Seob, Lee, Wan-Gyu, Kawasaki, Masahiro

Crystallographic and interfacial characteristics of polycrystalline-Si/ZrO2/SiO2/Si metal-oxide-semiconductor (MOS) structures were investigated at the atomic scale by high-resolution transmission...

High-resolution transmission electron microscopy and electron energy-loss spectroscopy study of polycrystalline-Si/ZrO2/SiO2/Si metal-oxide-semiconductor structures (2006)

Yang, Jun-Mo, Kim, Joong Jung, Kim, Kyung-Seob, Lee, Wan-Gyu, Kawasaki, Masahiro

Crystallographic and interfacial characteristics of polycrystalline-Si/ZrO2/SiO2/Si metal-oxide-semiconductor (MOS) structures were investigated at the atomic scale by high-resolution transmission...

High-resolution transmission electron microscopy and electron energy-loss spectroscopy study of polycrystalline-Si/ZrO2/SiO2/Si metal-oxide-semiconductor structures (2006)

Yang, Jun-Mo, Kim, Joong Jung, Kim, Kyung-Seob, Lee, Wan-Gyu, Kawasaki, Masahiro

Crystallographic and interfacial characteristics of polycrystalline-Si/ZrO2/SiO2/Si metal-oxide-semiconductor (MOS) structures were investigated at the atomic scale by high-resolution transmission...

The oscillation effects on thermalization of the neutrinos in the universe with low reheating temperature (2005)

Ichikawa, Kazuhide, Kawasaki, Masahiro, Takahashi, Fuminobu

We study how the oscillations of the neutrinos affect their thermalization process during the reheating period with temperature O(1) MeV in the early universe. We follow the evolution of the neutrino...

Q-ball Instability due to U(1) Breaking (2005)

Kawasaki, Masahiro, Konya, Kenichiro, Takahashi, Fuminobu

Q-ball is a non-topological soliton whose stability is ensured by global U(1) symmetry. We study a Q-ball which arises in the Affleck-Dine mechanism for baryogenesis and consider its possible...

Hadronic decay of the gravitino in the early universe and its implications to inflation (2004)

Late-time entropy production due to the decay of domain walls (2004)

We discuss the effects of the gravitino on the big-bang nucleosynthesis (BBN), paying particular attention to the hadronic decay mode of the gravitino. We will see that the hadronic decay of the...

Constraining Neutrino Masses by CMB Experiments Alone (2004)

It is shown that late-time decay of domain walls can dilute unwanted relics such as moduli, if the universe was dominated by frustrated domain walls with tension $\sigma = (1 - 100 TeV)^3$. Since...

Ichikawa, Kazuhide, Fukugita, Masataka, Kawasaki, Masahiro

It is shown that a subelectronvolt upper limit can be derived on the neutrino mass from the CMB data alone in the Lambda CDM model with the power-law adiabatic perturbations, without the aid of any...

Big-Bang Nucleosynthesis and Hadronic Decay of Long-Lived Massive Particles (2004)

Making waves on CMB power spectrum and inflaton dynamics (2004)

We study the big-bang nucleosynthesis (BBN) with the long-lived exotic particle, called X. If the lifetime of X is longer than \sim 0.1 sec, its decay may cause non-thermal nuclear reactions during...

Kawasaki, Masahiro, Takahashi, Fuminobu, Takahashi, Tomo

We discuss cosmic microwave background anisotropies in models with an unconventional primordial power spectrum. In particular, we consider an initial power spectrum with some ``spiky'' corrections....

D-term Instability in Flat Directions and its Cosmological Implication (2004)

Condition for Primordial Black Hole Formation in Randall-Sundrum Cosmology (2004)

We study dynamics of flat directions in the minimal supersymmetric standard model taking account of its constituent fields. It is found that there exist new instabilities due to the D-term potential...

Kawasaki, Masahiro

We consider spherical collapse in the Randall-Sundrum type II model and estimate the critical over density for black hole formation in the radiation dominated era. It is found that when...

Q-ball Metamorphosis (2004)

Solving the discrepancy among the light elements abundances and WMAP (2004)

Flat directions in the minimal supersymmetric standard model are known to deform into non-topological solitons, Q-balls, which generally possess both baryon and lepton asymmetries. We investigate how...

Ichikawa, Kazuhide, Kawasaki, Masahiro, Takahashi, Fuminobu

Within the standard big bang nucleosynthesis (BBN) and cosmic microwave background (CMB) framework, the baryon density measured by the Wilkinson Microwave Anisotropy Probe (WMAP) or the primordial D...

Hadronic Decay of Late-Decaying Particles and Big-Bang Nucleosynthesis (2004)

Big bang nucleosynthesis with a varying fine structure constant and non-standard expansion rate (2004)

We study the big-bang nucleosynthesis (BBN) scenario with late-decaying exotic particles with lifetime longer than $\sim 1$ sec. With a late-decaying particle in the early universe, predictions of...

Ichikawa, Kazuhide, Kawasaki, Masahiro

We calculate primordial abundances of light elements produced during big bang nucleosynthesis when the fine structure constant and/or the cosmic expansion rate take non-standard values. We compare...

Curvatons in Supersymmetric Models (2003)

Hamaguchi, Koichi, Kawasaki, Masahiro, Moroi, Takeo, Takahashi, Fuminobu

We study the curvaton scenario in supersymmetric framework paying particular attention to the fact that scalar fields are inevitably complex in supersymmetric theories. If there are more than one...

Inflation model with lower multipoles of the CMB suppressed (2003)

Comments on the Evolution of Strongly Degenerate Neutrinos in the Early Universe (2003)

The recent observation of the cosmic microwave background anisotropy by the WMAP confirmed that the lower multipoles are considerably suppressed. From the standpoint of the cosmic variance, it is...

Ichikawa, Kazuhide, Kawasaki, Masahiro

We reconsider the evolution of strongly degenerate neutrinos in the early universe. Our chief concern is the validity of the entropy conservation after the neutrino annihilation process has frozen...

Cosmic String from D-term Inflation and Curvaton (2003)

Endo, Motoi, Kawasaki, Masahiro, Moroi, Takeo

We study effects of the cosmic string in the D-term inflation model on the cosmic microwave background (CMB) anisotropy. In the D-term inflation model, gauged cosmic string is usually formed, which...

ASCA Observations of the Supernova Remnant IC 443: Thermal Structure and Detection of Overionized Plasma (2002)

Kawasaki, Masahiro, Ozaki, Masanobu, Nagase, Fumiaki, Masai, Kuniaki, Ishida, Manabu, Petre, Robert

We present the results of X-ray spatial and spectral studies of the ``mixed-morphology'' supernova remnant IC 443 using ASCA. IC 443 has a center-filled image in X-ray band, contrasting with the...

Moduli problem and Q-ball baryogenesis in gauge-mediated SUSY breaking models (2002)

Kawasaki, Masahiro

We investigate whether the Affleck-Dine mechanism can produce sufficient baryon number of the universe in the gauge-mediated SUSY breaking models, while evading the cosmological moduli problem by...

Retrieval process of high-resolution HAADF-STEM images (2002)

Nakanishi, Nobuto, Yamazaki, Takashi, Recnik, Aleksander, Ceh, Miran, Kawasaki, Masahiro, Watanabe, Kazuto, ...

A process for retrieving experimental high‐resolution high‐angle annular dark field (HAADF) scanning transmission electron microscopy (STEM) images, which are systematically distorted...

Isocurvature Fluctuations in Tracker Quintessence Models (2001)

Kawasaki, Masahiro, Moroi, Takeo, Takahashi, Tomo

We consider effects of the isocurvature perturbation in the framework of the tracker-type quintessence models. During the inflation, fluctuations in the amplitude of the quintessence field are...

Adiabatic and isocurvature fluctuations of Affleck-Dine field in D-term inflation model (2001)

Cosmic Microwave Background Anisotropy with Cosine-Type Quintessence (2001)

We reconsider fluctuations of Affleck-Dine (AD) field in a D-term inflation model. Contrary to the previous analysis, we find that the spectrum of the adiabatic fluctuations is almost scale invariant...

Kawasaki, Masahiro, Moroi, Takeo, Takahashi, Tomo

We study the Cosmic Microwave Background (CMB) anisotropies produced by cosine-type quintessence models. In our analysis, effects of the adiabatic and isocurvature fluctuations are both taken into...

Above-Threshold Dissociative Ionization in the Intermediate Intensity Regime (2001)

Du, Yan, Gordon, Robert J., Kawasaki, Masahiro, Matsumi, Yutaka, Seideman, Tamar, Sugita, Akihiro, ...

Artificial bright spots in atomic-resolution high-angle annular dark field STEM images (2001)

Yamazaki, Takashi, Kawasaki, Masahiro, Watanabe, Kazuto, Hashimoto, Iwao, Shiojiri, Makoto

Artificial bright spots, which appear in some atomic resolution high‐angle annular dark field scanning transmission electron microscope (HAADF STEM) images, have been accounted for by...

Vacuum Instability in Anomaly Mediation Models with Massive Neutrinos (2000)

Kawasaki, Masahiro, Watari, T., Yanagida, T.

We study the vacuum stability in the anomaly mediated supersymmetry (SUSY) breaking models with massive neutrinos. It is shown that, because of the seesaw-induced mass terms for neutrinos, the true...

Double Inflation in Supergravity and the Boomerang Observations (2000)

Kanazawa, Toshiyuki, Kawasaki, Masahiro, Sugiyama, Naoshi, Yanagida, T.

One of the biggest mystery of the recent observation of cosmic microwave background anisotropies by the boomerang team is insignificance of the second acoustic peak in the angular power spectrum. It...

The structure of an AI3Pd-based modulated structure studied by atomic-scale electron microscopy observations (2000)

Hiraga, Kenji, Ohsuna, Tetsu, Kawasaki, Masahiro

A modulated structure based on an Al3Pd structure in an A170Co25pd5 alloy has been studied by atomic-scale observations with high-resolution transmission electron microscopy (HREM) and high-angle...

Simulation of atomic-scale high-angle annular dark field scanning transmission electron microscopy images (2000)

Yamazaki, Takashi, Watanabe, Kazuto, Recnik, Aleksander, Ceh, Miran, Kawasaki, Masahiro, Shiojiri, Makoto

Image simulations for high-angle annular dark field (HAADF) scanning transmission electron microscopy (STEM) based on the Bethe's eigen-value method are presented. The effects of aperture size and...

High-resolution transmission electron microscopy of Fe-Al powder particles (1999)

Shiojiri, Makoto, Kawasaki, Masahiro, Fujii, Mari, Wakayama, Katsuhiko, Yoshioka, Tadanori

Sections of a few μm-sized particles of Fe1−xAlx (x = 0.35–0.42) powders, produced by the atomizing method, were prepared for transmission electron microscopy (TEM) using new specimen supporting...

A new specimen preparation method for cross-section TEM using diamond powders (1999)

Kawasaki, Masahiro, Yoshioka, Tadanori, Shiojiri, Makoto

A new ion-milling specimen preparation method for the cross-sectional transmission electron microscope (TEM) observation has been developed, which enables fast preparation with thinning quality...

Structure and chemistry of planar defects in bulk and thin film MoSi2 (1999)

Inui, Haruyuki, Hashimoto, Takashi, Ito, Kazuhiro, Yamaguchi, Masaharu, Kawasaki, Masahiro

Atomistic structures, as well as the local chemical compositions of planar defects in bulk and thin film MoSi2 have been characterized by high-resolution transmission electron microscopy combined...

Wavelength and temperature dependence of the absolute O(^1D) production yield from the 305–329 nm photodissociation of ozone (1998)

Takahashi, Kenshi, Taniguchi, Nori, Matsumi, Yutaka, Kawasaki, Masahiro, Ashfold, Michael N. R.

O(^1D) and O(^3P_j) photofragments produced in the photodissociation of ozone in the wavelength range 305–329 nm both at 295 and 227 K have been detected directly using a technique of laser induced...

EELS elemental mapping of a DRAM with FE-TEM (1998)

Kawasaki, Masahiro, Oikawa, Tetsuo, Ibe, Katsuhiko, Park, Kyung-ho, Shiojiri, Makoto

The elemental distribution in an oxide-nitride-oxide (O-N-O ) dielectric multi-layer in a dynamic random access memory (DRAM) device has been investigated by elemental mapping using an electron...

Transmission electron microscopy study of a semiconducting SrTiO3 ceramic condenser (1998)

Hitomi, Atsushi, Nomura, Takeshi, Kawasaki, Masahiro, Isshiki, Toshiyuki, Nishio, Koji, Shiojiri, Makoto

(Sr0.94Ba0.01Ca0.05)0.99TiO3 ceramic condensers, activated with Bi, Cu, and Pb, were produced by sintering at an oxygen partial pressure of Po2 = 10−8 Pa and by reoxidization at 1200�C in air....

EDS elemental mapping of a DRAM with an FE-TEM (1998)

Kawasaki, Masahiro, Oikawa, Tetsuo, Ibe, Katsuhiko, Park, Kyung-ho, Shiojiri, Makoto

The elemental distribution in an O-N-O dielectric multi-layer within a dynamic random access memory (DRAM) device was investigated by X-ray elemental mapping using a field-emission (scanning)...

A preparation method of sections of fine particles and cross-sectional transmission electron microscopy of Ni powder (1997)

Yoshioka, Tadanori, Kawasaki, Masahiro, Yamamatsu, Junko, Nomura, Takeshi, Isshiki, Toshiyuki, Shiojiri, Makoto

A preparation method for sections of powder particles has been developed, where the particles are embedded in the Ni(P) foil deposited on a Ni substrate by electroless plating and then ion-thinned...

Restriction to Parametric Resonant Decay after Inflation (1996)