Publications (86)
Predictions on the neutrinoless double beta decay from the leptogenesis via the LHu flat direction
Masaaki Fujii, K. Hamaguchi, T. Yanagida
If the baryon asymmetry in the present universe is generated by decays of the flat direction, the observed baryon asymmetry requires the mass of the lightest neutrino to be…
Search for neutron decay into an antineutrino and a neutral kaon in 0.401 megaton-years exposure of Super-Kamiokande
Kamiokande Collaboration, K. Yamauchi, K. Abe +261
We searched for bound neutron decay via predicted by the Grand Unified Theories in 0.401 Mtonyears exposure of all pure water phases in the Super-Kamiokande…
High-Energy Properties of the Enigmatic Be Star gamma Cassiopeiae
C. R. Shrader, K. Hamaguchi, S. J. Sturner +3
We present the results of a broad-band X-ray study of the enigmatic Be star Gamma Cassiopeiae (herein gamma Cas) based on observations made with both the Suzaku and INTEGRAL observ…
Leptogenesis in Inflaton Decay
T. Asaka, K. Hamaguchi, M. Kawasaki +1
We study a leptogenesis via decays of heavy Majorana neutrinos produced non-thermally in inflaton decays. We find that this scenario is fully consistent with existing supersymmetri…
He II 4686 emission from the massive binary system in Car: constraints to the orbital elements and the nature of the periodic minima
M. Teodoro, A. Damineli, B. Heathcote +27
η Carinae is an extremely massive binary system in which rapid spectrum variations occur near periastron. Most notably, near periastron the He II line increases rapidly i…
Composite Messenger Baryon as a Cold Dark Matter
K. Hamaguchi, S. Shirai, T. T. Yanagida
Among various supersymmetric (SUSY) models, gauge-mediated SUSY breaking models with an ultra-light gravitino of mass m_{3/2} \lesssim O(10) eV are very attractive, since they are…
Stau-catalyzed Nuclear Fusion
K. Hamaguchi, T. Hatsuda, T. T. Yanagida
We point out that the stau may play a role of a catalyst for nuclear fusions if the stau is a long-lived particle as in the scenario of gravitino dark matter. In this letter, we co…
Leptogenesis in Inflationary Universe
T. Asaka, K. Hamaguchi, M. Kawasaki +1
We investigate the leptogenesis via decays of heavy Majorana neutrinos which are produced non-thermally in inflaton decays. We make a comprehensive study on the leptogenesis assumi…
The X-ray Lightcurve of WR 140
M. F. Corcoran, A. M. T. Pollock, K. Hamaguchi +1
WR 140 is a canonical massive "colliding wind" binary system in which periodically-varying X-ray emission is produced by the collision between the wind of the WC7 and O4-5 star com…
Enhanced X-ray variability from V1647 Ori, the young star in outburst illuminating McNeil's Nebula
N. Grosso, J. H. Kastner, H. Ozawa +5
We report a ~38 ks X-ray observation of McNeil's Nebula obtained with XMM on 2004 April 4. V1647 Ori, the young star in outburst illuminating McNeil's Nebula, is detected with XMM…
X-ray Flare from a Herbig Be star, MWC297
K. Hamaguchi, H. Terada, A. Bamba +1
Hard X-ray emissions from a Herbig Be star MWC297 were discovered in three separate observations spanning 5 days in April 1994 with the Advanced Satellite for Cosmology and Astroph…
Waiting in the Wings: Reflected X-ray Emission from the Homunculus Nebula
M. F. Corcoran, K. Hamaguchi, T. Gull +14
We report the first detection of X-ray emission associated with the Homunculus Nebula which surrounds the supermassive star Eta Carinae. The emission is characterized by a temperat…
A Coordinated X-ray and Optical Campaign on the Nearest Massive Eclipsing Binary, Delta Ori Aa: I. Overview of the X-ray Spectrum
M. F. Corcoran, J. S. Nichols, H. Pablo +22
We present an overview of four phase-constrained Chandra HETGS X-ray observations of Delta Ori A. Delta Ori A is actually a triple system which includes the nearest massive eclipsi…
A Chandra Deep X-ray Exposure on the Galactic Plane and Near Infrared Identification
K. Ebisawa, A. Paizis, T. J. -L. Couvoisier +13
Using the Chandra ACIS-I instruments, we have carried out a deep X-ray observation on the Galactic plane region at (l,b) ~ (28.5, 0.0), where no discrete X-ray sources have been kn…
Chandra Deep X-ray Observation of a Typical Galactic Plane Region and Near-Infrared Identification
K. Ebisawa, M. Tsujimoto, A. Paizis +13
Using the Chandra Advanced CCD Imaging Spectrometer Imaging array (ACIS-I), we have carried out a deep hard X-ray observation of the Galactic plane region at (l,b) ~ (28.5, 0.0), w…
Reheating-temperature independence of cosmological baryon asymmetry in Affleck-Dine leptogenesis
Masaaki Fujii, K. Hamaguchi, T. Yanagida
In this paper we point out that the cosmological baryon asymmetry in our universe is generated almost independently of the reheating temperature in Affleck-Dine leptogenesis…
Chandra X-ray Grating Spectrometry of Eta Carinae near X-ray Minimum: I. Variability of the Sulfur and Silicon Emission Lines
D. B. Henley, M. F. Corcoran, J. M. Pittard +3
We report on variations in important X-ray emission lines in a series of Chandra grating spectra of the supermassive colliding wind binary star Eta Carinae, including key phases ar…
Detection of the compressed primary stellar wind in eta Carinae
M. Teodoro, T. I. Madura, T. R. Gull +2
A series of three HST/STIS spectroscopic mappings, spaced approximately one year apart, reveal three partial arcs in [Fe II] and [Ni II] emissions moving outward from eta Carinae.…
Eta Carinae across the 2003.5 minimum: Spectroscopic Evidence for Massive Binary Interactions
K. E. Nielsen, M. F. Corcoran, T. R. Gull +4
We have analyzed high spatial, moderate spectral resolution observations of Eta Carinae obtained with the STIS from 1998.0 to 2004.3. The spectra show prominent P-Cygni lines in H…
Chandra Observations of High Mass Young Stellar Objects in the Monoceros R2 molecular cloud
M. Kohno, K. Koyama, K. Hamaguchi
We observed the Monoceros R2 molecular cloud with the ACIS-I array onboard the Chandra X-ray Observatory. From the central 3.2' x 3.2' region, we detect 154 sources above the detec…
Leptogenesis via flat direction with a gauged
Masaaki Fujii, K. Hamaguchi, T. Yanagida
We study the supersymmetric leptogenesis via flat direction with a gauged symmetry. We find that the resultant baryon asymmetry is enhanced compared with the…
Affleck-Dine Leptogenesis with an Ultralight Neutrino
T. Asaka, Masaaki Fujii, K. Hamaguchi +1
We perform a detailed analysis on Affleck-Dine leptogenesis taking into account the thermal effects on the dynamics of the flat direction field . We find that an extremely smal…
Search for Diffuse Supernova Neutrino Background with 956.2 days of Super-Kamiokande Gadolinium Dataset
K. Abe, S. Abe, Y. Asaoka +245
We report the search result for the Diffuse Supernova Neutrino Background (DSNB) in neutrino energies beyond 9.3~MeV in the gadolinium-loaded Super-Kamiokande (SK) detector with $2…
Stau-catalyzed Li Production in Big-Bang Nucleosynthesis
K. Hamaguchi, T. Hatsuda, M. Kamimura +2
If the gravitino mass is in the region from a few GeV to a few 10's GeV, the scalar lepton X such as stau is most likely the next lightest supersymmetry particle. The negatively ch…
Determining the Mass for a Light Gravitino
K. Hamaguchi, S. Shirai, T. T. Yanagida
Gauge mediated supersymmetry breaking scenarios with an ultra-light gravitino of mass m_{3/2}=1-10 eV are very interesting, since there is no cosmological gravitino problem. We pro…
Development of Faster and More Accurate Supernova Localization at Super-Kamiokande
K. Abe, Y. Asaoka, M. Harada +272
The next nearby core-collapse supernova (SN) promises to yield a treasure of scientific information through multi-messenger astronomy. Early observations of the shock breakout (SBO…
Measurement of the solar neutrino interaction rate below 3.49 MeV in Super-Kamiokande-IV
Kamiokande Collaboration, A. Yankelevich, K. Abe +250
Super-Kamiokande (SK) has observed solar neutrino elastic scattering at recoil electron kinetic energies () as low as 3.49 MeV to study neutrino flav…
PDS 144: The First Confirmed Herbig Ae - Herbig Ae Wide Binary
J. B. Hornbeck, C. A. Grady, M. D. Perrin +13
PDS 144 is a pair of Herbig Ae stars that are separated by 5.35" on the sky. It has previously been shown to have an A2Ve Herbig Ae star viewed at 83\circ inclination as its northe…
Determining the mass for an ultralight gravitino at LHC
K. Hamaguchi, S. Shirai, T. T. Yanagida
In supersymmetric (SUSY) models with the gravitino being the lightest SUSY particle (LSP), the SUSY breaking scale (i.e., the gravitino mass) could be determined by measuring the l…
First Associated Neutrino Search for a Failed Supernova Candidate with Super-Kamiokande
F. Nakanishi, K. Abe, S. Abe +243
In 2024, a failed supernova candidate, M31-2014-DS1, was reported in the Andromeda galaxy (M31), located at a distance of approximately 770 kpc. In this paper, we search for neutri…
Superheavy Dark Matter with Discrete Gauge Symmetries
K. Hamaguchi, Yasunori Nomura, T. Yanagida
We show that there are discrete gauge symmetries protect naturally heavy X particles from decaying into the ordinary light particles in the supersymmetric standard model. This make…
The X-ray Lightcurve of the Supermassive star eta Carinae, 1996--2014
M. F. Corcoran, K. Hamaguchi, J. K. Liburd +9
Eta Carinae is the nearest example of a supermassive, superluminous, unstable star. Mass loss from the system is critical in shaping its circumstellar medium and in determining its…
Non-thermal dark matter via Affleck-Dine baryogenesis and its detection possibility
Masaaki Fujii, K. Hamaguchi
The formation and late time decays of Q-balls are generic consequences of the Affleck-Dine (AD) baryogenesis. A substantial amount of the lightest supersymmetry (SUSY) particles (L…
Searching for a link between the magnetic nature and other observed properties of Herbig Ae/Be stars and stars with debris disks
S. Hubrig, B. Stelzer, M. Schoeller +6
Among the 21 Herbig Ae/Be stars studied, new detections of a magnetic field were achieved in six stars. For three Herbig Ae/Be stars, we confirm previous magnetic field detections.…
Leptogenesis with Almost Degenerate Majorana Neutrinos
Masaaki Fujii, K. Hamaguchi, T. Yanagida
We investigate the leptogenesis with almost degenerate neutrinos, in the framework of democratic mass matrix, which naturally explains the large mixing angles for neutrino oscillat…
Variability monitoring of OB stars during the Mons campaign
T. Morel, G. Rauw, T. Eversberg +28
We present preliminary results of a 3-month campaign carried out in the framework of the Mons project, where time-resolved Halpha observations are used to study the wind and circum…
A XRISM/Resolve view of the dynamics in the hot gaseous atmosphere of M87
XRISM Collaboration, M. Audard, H. Awaki +138
The XRISM/Resolve microcalorimeter directly measured the gas velocities in the core of the Virgo Cluster, the closest example of AGN feedback in a cluster. This proximity allows us…
An X-ray Outburst from the Rapidly Accreting Young Star That Illuminates McNeil's Nebula
J. H. Kastner, M. Richmond, N. Grosso +6
Young, low-mass stars are luminous X-ray sources whose powerful X-ray flares may exert a profound influence over the process of planet formation. The origin of such emission is unc…
Eta Car and Its Surroundings: the X-ray Diagnosis
M. F. Corcoran, K. Hamaguchi
X-ray emission from the supermassive star Eta Carinae (\ec) originates from hot shocked gas produced by current stellar mass loss as well as ejecta from prior eruptive events. Abso…
Discovery of Rapidly Moving Partial X-ray Absorbers within gamma Cassiopeiae
K. Hamaguchi, L. Oskinova, C. M. P. Russell +4
Gamma Cassiopeiae is an enigmatic Be star with unusually strong hard X-ray emission. The Suzaku observatory detected six rapid X-ray spectral hardening events called "softness dips…
3D modelling of the colliding winds in Eta Carinae - evidence for radiative inhibition
E. R. Parkin, J. M. Pittard, M. F. Corcoran +2
The X-ray emission from the super-massive star Eta Carinae is simulated using a three dimensional model of the wind-wind collision. In the model the intrinsic X-ray emission is spa…
Leptogenesis from -dominated early universe
K. Hamaguchi, Hitoshi Murayama, T. Yanagida
We investigate in detail the leptogenesis by the decay of coherent right-handed sneutrino having dominated the energy density of the early universe, which was origi…
Variations on Supersymmetry Breaking and Neutrino Spectra
F. Borzumati, K. Hamaguchi, Y. Nomura +1
The problem of generating light neutrinos within supersymmetric models is discussed. It is shown that the hierarchy of scales induced by supersymmetry breaking can give rise to sup…
Search for nucleon decay via and in 0.484 Mton-year of Super-Kamiokande data
Kamiokande Collaboration, S. Jung, K. Abe +243
We present the results of searches for nucleon decays via and using a 0.484 Mtyr exposure of Super-Kamiokande I-V data covering…
Long Lived Superheavy Dark Matter with Discrete Gauge Symmetries
K. Hamaguchi, Yasunori Nomura, T. Yanagida
The recently observed ultra-high energy (UHE) cosmic rays beyond the Greisen-Zatsepin-Kuzmin bound can be explained by the decays of some superheavy particles forming a part of…
Search for proton decay via and in 0.401 megaton-years exposure of Super-Kamiokande I-V
Kamiokande Collaboration, K. Abe, S. Abe +310
We searched for proton decay via and in 0.401 megaton-years of data collected in all pure water detector phases of Super-Kamiok…
The three-dimensional structure of the Eta Carinae Homunculus
W. Steffen, M. Teodoro, T. I. Madura +6
We investigate, using the modeling code SHAPE, the three-dimensional structure of the bipolar Homunculus nebula surrounding Eta Carinae, as mapped by new ESO VLT/X-Shooter observat…
HD 100453: A Link Between Gas-Rich Protoplanetary Disks and Gas-Poor Debris Disks
K. A. Collins, C. A. Grady, K. Hamaguchi +15
HD 100453 has an IR spectral energy distribution (SED) which can be fit with a power-law plus a blackbody. Previous analysis of the SED suggests that the system is a young Herbig A…
V1647 Ori: The X-ray Evolution of a Pre-main Sequence Accretion Burst
J. H. Kastner, M. Richmond, N. Grosso +6
We present Chandra X-ray Observatory monitoring observations of the recent accretion outburst displayed by the pre-main sequence (pre-MS) star V1647 Ori. The X-ray observations wer…
The long-term spectral changes of eta Carinae: are they caused by a dissipating occulter as indicated by CMFGEN models?
A. Damineli, D. J. Hillier, F. Navarete +23
Eta Carinae (\,Car) exhibits a unique set of P Cygni profiles with both broad and narrow components. Over many decades, the spectrum has changed -- there has been an increase i…
Signatures of Axinos and Gravitinos at Colliders
A. Brandenburg, L. Covi, K. Hamaguchi +2
The axino and the gravitino are well-motivated candidates for the lightest supersymmetric particle (LSP) and also for cold dark matter in the Universe. Assuming that a charged slep…
Physics Interplay of the LHC and the ILC
LC Study Group, G. Weiglein, T. Barklow +120
Physics at the Large Hadron Collider (LHC) and the International e+e- Linear Collider (ILC) will be complementary in many respects, as has been demonstrated at previous generations…
Cosmological Constraint on the Zee model
N. Haba, K. Hamaguchi, Tomoharu Suzuki
It is well known that the Zee model induces small neutrino masses by radiative corrections, where the bi-maximal flavor mixing is possible. We analyze the cosmological condition in…
A Linear Collider Vision for the Future of Particle Physics
H. Abramowicz, E. Adli, F. Alharthi +446
In this paper we review the physics opportunities at linear colliders with a special focus on high centre-of-mass energies and beam polarisation, take a fresh look at the…
Affleck-Dine baryo/leptogenesis with a gauged U(1)(B-L)
Masaaki Fujii, K. Hamaguchi, T. Yanagida
We briefly review the present status of Affleck-Dine baryo/leptogenesis scenarios in the minimal supersymmetric standard model (MSSM) in the context of the gravity-mediated SUSY br…
Eluding the BBN constraints on the stable gravitino
W. Buchmuller, K. Hamaguchi, M. Ibe +1
We investigate how late-time entropy production weakens the Big-Bang Nucleosynthesis (BBN) constraints on the gravitino as lightest superparticle with a charged slepton as next-to-…
Suzaku Reveals Helium-burning Products in the X-ray Emitting Planetary Nebula BD+303639
M. Murashima, M. Kokubun, K. Makishima +7
BD+303639, the brightest planetary nebula at X-ray energies, was observed with Suzaku, an X-ray observatory launched on 2005 July 10. Using the X-ray Imaging Spectrometer, the K-li…
Cosmological Gravitino Problem in Gauge-Mediated Supersymmetry Breaking Models
T. Asaka, K. Hamaguchi, Koshiro Suzuki
We investigate the cosmological gravitino problem in gauge-mediated supersymmetry breaking models, where the gravitino becomes in general the lightest supersymmetric particle (LSP)…
Gauge Couplings at High Temperature and the Relic Gravitino Abundance
W. Buchmüller, K. Hamaguchi, M. Ratz
In higher-dimensional supersymmetric theories gauge couplings of the effective four-dimensional theory are determined by expectation values of scalar fields. We find that at temper…
Spiralling out of control: 3D hydrodynamical modelling of the colliding winds in Carinae
E. R. Parkin, J. M. Pittard, M. F. Corcoran +1
Three dimensional (3D) adaptive-mesh refinement (AMR) hydrodynamical simulations of the wind-wind collision between the enigmatic super-massive star \etacar and its mysterious comp…
Competitive X-ray and Optical Cooling in the Collisionless Shocks of WR 140
A. M. T. Pollock, M. F. Corcoran, I. R. Stevens +9
WR 140 is a long-period, highly eccentric Wolf-Rayet star binary system with exceptionally well-determined orbital and stellar parameters. Bright, variable X-ray emission is genera…
Panchromatic Imaging of a Transitional Disk: The Disk of GM Aur in Optical and FUV Scattered Light
Jeremy Hornbeck, Jeremy Swearingen, Carol Grady +18
We have imaged GM Aur with HST, detected its disk in scattered light at 1400A and 1650A, and compared these with observations at 3300A, 5550A, 1.1 microns, and 1.6 microns. The sca…
Long-Lived Superheavy Particles in Dynamical Supersymmetry-Breaking Models in Supergravity
K. Hamaguchi, K. -I. Izawa, Yasunori Nomura +1
Superheavy particles of masses with lifetimes are very interesting, since their decays may account for the ultra-high en…
XMM-Newton Observations of the 2003 X-ray Minimum of Eta Carinae
K. Hamaguchi, M. F. Corcoran, T. Gull +3
The XMM-Newton X-ray observatory took part in the multi-wavelength observing campaign of the massive, evolved star Eta Carinae in 2003 during its recent X-ray minimum. This paper r…
The high-energy emission from HD~93129A near periastron
S. del Palacio, F. GarcÃa, D. Altamirano +12
We conducted an observational campaign towards one of the most massive and luminous colliding wind binaries in the Galaxy, HD~93129A, close to its periastron passage in 2018. Durin…
High-Frequency Power Spectrum of AGN NGC 4051 Revealed by NICER
B. Rani, Jungeun Kim, I. Papadakis +6
Variability studies offer a compelling glimpse into black hole dynamics, and NICER's (Neutron Star Interior Composition Explorer) remarkable temporal resolution propels us even fur…
Supersymmetric seesaw model for the (1+3)-scheme of neutrino masses
F. Borzumati, K. Hamaguchi, T. Yanagida
A four-neutrino spectrum with a sterile neutrino without significant involvement in the atmospheric and solar neutrino oscillation experiments has been recently advocated as the co…
X-ray Gyrations of Eta Carinae, or, Is Presence of Evidence Evidence of Presence?
M. F. Corcoran, K. Hamaguchi, T. Gull +2
We review the properties of the variable X-ray emission from the extremely massive star Eta Carinae concentrating on the last X-ray minimum, and briefly consider the possible role…
The Linear Collider Facility (LCF) at CERN
H. Abramowicz, E. Adli, F. Alharthi +406
In this paper we outline a proposal for a Linear Collider Facility as the next flagship project for CERN. It offers the opportunity for a timely, cost-effective and staged construc…
Monte-Carlo Simulator and Ancillary Response Generator of Suzaku XRT/XIS System for Spatially Extended Source Analysis
Y. Ishisaki, Y. Maeda, R. Fujimoto +31
We have developed a framework for the Monte-Carlo simulation of the X-Ray Telescopes (XRT) and the X-ray Imaging Spectrometers (XIS) onboard Suzaku, mainly for the scientific analy…
TeV-scale neutrino cross-section measurement using upward through-going muons in Super-Kamiokande
N. Bhuiyan, K. Abe, Y. Asaoka +248
Neutrinos provide a unique probe of both particle physics and the high-energy universe, traversing astronomical distances with minimal interaction. Their charged-current scattering…
Stellar flares observed by LOFT: implications for the physics of coronae and for the "space weather" environment of extrasolar planets
S. A. Drake, E. Behar, J. G. Doyle +7
This is a White Paper in support of the mission concept of the Large Observatory for X-ray Timing (LOFT), proposed as a medium-sized ESA mission. We discuss the potential of LOFT f…
Cosmological Baryon Asymmetry and Neutrinos: Baryogenesis via Leptogenesis in Supersymmetric Theories
K. Hamaguchi
Leptogenesis in supersymmetric model is discussed comprehensively and in detail. In the first half, we discuss several leptogenesis mechanisms by the decay of heavy right-handed ne…
ASTRO-H White Paper - New Spectral Features
R. K. Smith, H. Odaka, M. Audard +27
This white paper addresses selected new (to X-ray astronomy) physics and data analysis issues that will impact ASTRO-H SWG observations as a result of its high-spectral-resolution…
Supersymmetric Inflation of Dynamical Origin
K. Hamaguchi, K. -I. Izawa, H. Nakajima
Dynamical models of inflation are given with composite inflatons by means of massive supersymmetric gauge theory. Nearly flat directions and stable massive ones in the potential ar…
Measurement of neutron production in atmospheric neutrino interactions at Super-Kamiokande
Kamiokande collaboration, S. Han, K. Abe +280
We present measurements of total neutron production from atmospheric neutrino interactions in water, analyzed as a function of electron-equivalent visible energy over a range of 30…
Nonanomalous Discrete R-Symmetry and Light Gravitino
K. Hamaguchi, Nobuhito Maru
We discuss nonanomalous R-symmetry in the supersymmetric grand unified theories. In particular, we explore anomaly-free solutions predicting the gravitino mass in the range of $10^…
Chandra Observation of the Trifid Nebula: X-ray emission from the O star complex and actively forming pre-main sequence stars
J. Rho, S. Ramirez, M. F. Corcoran +2
The Trifid Nebula, a young star-forming HII region, was observed for 16 hours by the Chandra X-ray Observatory. We detected 304 X-ray sources, thirty percent of which are hard sour…
On the origin of the X-ray emission from Herbig Ae/Be stars
B. Stelzer, G. Micela, K. Hamaguchi +1
We performed a systematic search for Chandra archival observations of Herbig Ae/Be stars. These stars are fully radiative and not expected to support dynamo action analogous to the…
Democratic (S)fermions and Lepton Flavor Violation
K. Hamaguchi, Mitsuru Kakizaki, Masahiro Yamaguchi
The democratic approach to account for fermion masses and mixing is known to be successful not only in the quark sector but also in the lepton sector. Here we extend this ansatz to…
Japan's Strategy for Future Projects in High Energy Physics
M. Endo, K. Hamaguchi, M. Ibe +11
The current strategy for future projects of the Japanese high energy physics community, Japan Association of High Energy Physicists (JAHEP), remains as described in the Final Repor…
Measurement of the branching ratio of , , , and isotopes through the nuclear muon capture reaction in the Super-Kamiokande detector
Y. Maekawa, K. Abe, S. Abe +263
The Super-Kamiokande detector has measured solar neutrinos for more than years. The sensitivity for solar neutrino measurement is limited by the uncertainties of energy scale…
A Coordinated X-ray and Optical Campaign of the Nearby Massive Binary Orionis Aa: II. X-ray Variability
J. S. Nichols, D. P. Huenemoerder, M. F. Corcoran +18
We present time-resolved and phase-resolved variability studies of an extensive X-ray high-resolution spectral dataset of the Orionis Aa binary system. The four observations,…
Non-thermal Dark Matter from Affleck-Dine Baryogenesis
Masaaki Fujii, K. Hamaguchi
In this talk we discuss the origin and nature of the dark matter in the Affleck-Dine (AD) baryogenesis. The AD baryogenesis via most of the flat directions predict formations of la…
ASTRO-H White Paper - Stars -- Accretion, Shocks, Charge Exchanges and Magnetic Phenomena
Y. Tsuboi, K. Ishibashi, M. Audard +8
X-ray emission from stars has origins as diverse as the stars themselves: accretion shocks, shocks generated in wind-wind collisions, or release of magnetic energy. Although the sc…
Higgsino and Wino Dark Matter from Q-ball Decay in Affleck-Dine Baryogenesis
Masaaki Fujii, K. Hamaguchi
We claim that the Higgsino-like and wino-like neutralinos can be good dark matter candidates if they are produced by the late time decay of Q-ball, which is generally formed in Aff…