Results for "Y. Aoki"

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Chiral properties of domain-wall fermions from eigenvalues of 4 dimensional Wilson-Dirac operatorSep 21 2001Oct 03 2001We investigate chiral properties of the domain-wall fermion (DWF) system by using the four-dimensional hermitian Wilson-Dirac operator. We first derive a formula which connects a chiral symmetry breaking term in the five dimensional DWF Ward-Takahashi ... More
Anomaly through Gauge Invariant Regularization with Infinite Number of Pauli-Villars FieldsJun 15 1993Jun 17 1993Abelian anomaly is examined by means of the recently proposed gauge invariant regularization for SO(10) chiral gauge theory and its generalization for a theory of arbitrary gauge group with anomaly-free chiral fermion contents. For both cases it is shown ... More
One loop calculation of QCD with domain-wall quarksSep 26 1997We calculate one loop corrections to the domain-wall quark propagator in QCD. We show how the wave function is renormalized in this theory. Especially we are interested in the behavior of the massless fermion mode, which exists near the domain wall at ... More
Prospects of Very Long Base-Line Neutrino Oscillation Experiments with the JAERI-KEK High Intensity Proton AcceleratorApr 23 2001In this paper, we discuss physics potential of the Very Long Base-Line (VLBL) Neutrino-Oscillation Experiments with the High Intensity Proton Accelerator (HIPA), which is planned to be built by 2006 in Tokaimura, Japan. We propose to use conventional ... More
Superconducting and ferromagnetic phase diagram of UCoGe probed by thermal expansionFeb 03 2017We report thermal expansion measurements on a single crystal of the superconducting ferromagnet UCoGe for magnetic fields applied along the main orthorhombic axes. The thermal expansion cell was mounted on a piezo-electric rotator in order to fine-tune ... More
One loop calculation in lattice QCD with domain-wall quarksNov 05 1997One loop corrections to the domain-wall quark propagator are calculated in massless QCD. It is shown that no additative counter term to the current quark mass is generated in this theory, and the wave function renormalization factor of the massless quark ... More
Detector Backaction on the Self-Consistent Bound State in Quantum Point ContactsSep 10 2008Bound-state (BS) formation in quantum point contacts (QPCs) may offer a convenient way to localize and probe single spins. In this letter, we investigate how such BSs are affected by monitoring them with a second QPC, which is coupled to the BS via wavefunction ... More
Tuning the Fano Resonance with an Intruder ContinuumMar 11 2014Through a combination of experiment and theory we establish the possibility of achieving strong tuning of Fano resonances (FRs), by allowing their usual two-path geometry to interfere with an additional, 'intruder', continuum. As the coupling strength ... More
Characterizations of indicator functions and contrast representations of fractional factorial designs with multi-level factorsOct 19 2018Feb 14 2019A polynomial indicator function of designs is first introduced by Fontana, Pistone and Rogantin (2000) for two-level designs. They give the structure of the indicator function of two-level designs, especially from the viewpoints of the orthogonality of ... More
Reverberation Measurements of the Inner Radius of the Dust Torus in 17 Seyfert GalaxiesJun 09 2014We present the results of a dust reverberation survey for 17 nearby Seyfert 1 galaxies, which provides the largest homogeneous data collection for the radius of the innermost dust torus. A delayed response of the K-band light curve after the V-band light ... More
Symmetries of spatial meson correlators in high temperature QCDFeb 08 2019Jun 12 2019Based on a complete set of $J = 0$ and $J=1$ spatial isovector correlation functions calculated with $N_F = 2$ domain wall fermions we identify an intermediate temperature regime of $T \sim 220 - 500$ MeV ($1.2T_c$--$2.8T_c$), where chiral symmetry is ... More
Ir 5$d$-band Derived Superconductivity in LaIr$_3$Jan 15 2019We have studied the superconducting properties of LaIr$_3$ with a rhombohedral structure using magnetization, heat capacity, and muon-spin rotation/relaxation ($\mu$SR) measurements. The zero-field cooled and field cooled susceptibility measurements exhibit ... More
Atomic displacements and lattice distortion in the magnetic-field-induced charge ordered state of SmRu$_{4}$P$_{12}$Nov 02 2016Structural properties of SmRu$_4$P$_{12}$ in the anomalous magnetic ordered phase between $T^*\sim 14 $ K and $T_{\text{N}}=16.5$ K in magnetic fields has been studied by x-ray diffraction. Atomic displacements of Ru and P, reflecting the field-induced ... More
Anisotropic two-gap superconductivity and the absence of a Pauli paramagnetic limit in single-crystalline LaO$_{0.5}$F$_{0.5}$BiS$_2$Oct 30 2017Mar 20 2018Ambient-pressure-grown LaO$_{0.5}$F$_{0.5}$BiS$_2$ with a superconducting transition temperature $T_{c}\sim$3K possesses a highly anisotropic normal state. By a series of electrical resistivity measurements with a magnetic field direction varying between ... More
Chiral Symmetry and Electron-Electron Interaction in Many-Body Gap Formation in GrapheneAug 08 2011We study a many-body ground state of graphene in perpendicular magnetic fields. Chiral symmetry in graphene enables us to determine the many-body ground state, which turns out to be a doubly degenerate chiral condensate for the half-filled (undoped) case. ... More
Coupling Remote States through the Continuum: Multi-State Fano ResonancesNov 14 2009We demonstrate a fully-tunable multi-state Fano system in which remotely-implemented quantum states interfere with each other through their coupling to a mutual continuum. On tuning these resonances near coincidence a robust avoided crossing is observed, ... More
Quenched QCD with domain-wall fermions on coarse latticesSep 08 1999We investigate the existence of chiral zero modes at a^{-1} \simeq 1 GeV in quenched domain-wall QCD. Simulations are carried out for the plaquette and an RG-improved gauge actions on a 12^3x24xN_s lattice with N_s=10-50. We find that the pion mass in ... More
Kaon B parameter from quenched domain-wall QCDMay 18 2001We report on a calculation of $B_K$ with domain wall fermion action in quenched QCD. Simulations are made with a renormalization group improved gauge action at $\beta=2.6$ and 2.9 corresponding to $a^{-1}\approx 2$GeV and 3GeV. Effects due to finite fifth ... More
Topological analysis of the quantum Hall effect in graphene: Dirac-Fermi transition across van Hove singularities and the edge vs bulk quantum numbersJul 26 2006Inspired by a recent discovery of a peculiar integer quantum Hall effect (QHE) in graphene, we study QHE on a honeycomb lattice in terms of the topological quantum number, with two-fold interests: First, how the zero-mass Dirac QHE around the center of ... More
Proton decay matrix elements on the latticeApr 28 2013Jan 13 2014Hadronic matrix elements of proton decay are essential ingredients to bridge the grand unification theory to low energy observables like proton lifetime. In this paper we non-perturbatively calculate the matrix elements, relevant for the process of a ... More
Nucleon axial charge in 2+1 flavor dynamical lattice QCD with domain wall fermionsJan 25 2008Jul 03 2008We present results for the nucleon axial charge g_A at a fixed lattice spacing of 1/a=1.73(3) GeV using 2+1 flavors of domain wall fermions on size 16^3x32 and 24^3x64lattices (L=1.8 and 2.7 fm) with length 16 in the fifth dimension. The length of the ... More
Flat bands in Weaire-Thorpe model and siliceneOct 29 2014Jan 31 2015In order to analytically capture and identify peculiarities in the electronic structure of silicene, Weaire-Thorpe(WT) model, a standard model for treating three-dimensional (3D) silicon, is applied to silicene with the buckled 2D structure. In the original ... More
Lattice realization of the generalized chiral symmetry in two dimensionsSep 24 2016While it has been pointed out that the chiral symmetry, which is important for the Dirac fermions in graphene, can be generalized to tilted Dirac fermions as in organic metals, such a generalized symmetry was so far defined only for a continuous low-energy ... More
Fermion spectrum in the quenched U(1) chiral Wilson-Yukawa modelNov 11 1992Nature of charged fermion state is investigated in the quenched U(1) chiral Wilson-Yukawa model. Fitting the charged fermion propagator with a single hyperbolic cosine does not yield reliable result. On the other hand the behaviour of the propagator including ... More
New Dissipation Relaxation Phenomenon in Oscillating Solid He-4Mar 19 2008We describe the first observations on the time-dependent dissipation when the drive level of a torsional oscillator containing solid He-4 is abruptly changed. The relaxation of dissipation in solid He-4 shows rich dynamical behavior including exponential ... More
Oscillation Frequency Dependence of Non-Classical Rotation Inertia of Solid $^4$HeMay 04 2007May 07 2007The non-classical rotational inertia fraction of the identical cylindrical solid $^4$He below 300 mK is studied at 496 and 1173 Hz by a double resonance torsional oscillator. Below 35 mK, the fraction is the same at sufficiently low rim velocities. Above ... More
Topological aspects of graphene: Dirac fermions and the bulk-edge correspondence in magnetic fieldsJan 18 2007We discuss topological aspects of electronic properties of graphene, including edge effects, with the tight-binding model on a honeycomb lattice and its extensions to show the following: (i) Appearance of the pairn of massless Dirac dispersions, which ... More
Full QCD calculation of neutron electric dipole moment with the external electric field methodMar 06 2008Jul 22 2008We have calculated the neutron electric dipole moment (NEDM) in the presence of the CP violating $\theta$ term in lattice QCD with 2-flavor dynamical clover quarks, using the external electric field method. Accumulating a large number of statistics by ... More
Charged fermion states in the quenched U(1) chiral Wilson-Yukawa modelApr 08 1993Apr 13 1993Property of charged fermion states is investigated in the quenched U(1) chiral Wilson-Yukawa model. Fitting the charged fermion propagator with a single hyperbolic cosine does not yield reliable results. On the other hand the behavior of the propagator ... More
Chiral zero modes on the domain-wall model in 4+1 dimensionsOct 24 1996We investigate an original domain-wall model in 4+1 dimensions numerically in the presence of U(1) dynamical gauge field only in an extra dimension, corresponding to a weak coupling limit of 4-dimensional physical gauge coupling. Using a quenched approximation ... More
Vainshtein mechanism in massive gravity nonlinear sigma modelsJul 01 2016We study the stability of the Vainshtein screening solution of the massive/bi-gravity based on the massive nonlinear sigma model as the effective action inside the Vainshtein radius. The effective action is obtained by taking the $\Lambda_2$ decoupling ... More
Democratic summary of public opinions in free-response surveysJul 09 2019Social surveys have been widely used as a method of obtaining public opinion. Sometimes it is more ideal to collect opinions by presenting questions in free-response formats than in multiple-choice formats. Despite their advantages, free-response questions ... More
Manipulation of the Dirac cones and the anomaly in the graphene related quantum Hall effectSep 10 2010The quantum Hall effect in graphene is regarded to be involving half-integer topological numbers associated with the massless Dirac particle, this is usually not apparent due to the doubling of the Dirac cones. Here we theoretically consider two classes ... More
Scale-Free Structure Emerging from Co-Evolution of a Network and the Concentration of Diffusive Resources on ItAug 04 2011Nov 13 2012Co-evolution exhibited by a network system, involving the intricate interplay between the dynamics of the network itself and the subsystems connected by it, is a key concept for understanding the self-organized, flexible nature of real-world network systems. ... More
Effect of Synchronous Incoming Spikes on Activity Pattern in A Network of Spiking NeuronsOct 25 2004Although recent neurophysiological experiments suggest that synchronous neural activity is involved in some perceptual and cognitive processes, the functional role of such coherent neuronal behavior is not well understood. As a first step in clarifying ... More
The Lattice $Λ$ Parameter in Domain Wall QCDJun 07 2003Jun 26 2003We evaluate the ratio of the scale parameter $\Lambda$ in domain wall QCD to the one in the continuum theory at one loop level incorporating the effect of massless quarks. We show that the Pauli-Villars regulator is required to subtract the unphysical ... More
A family of pairs of imaginary cyclic fields of degree $(p-1)/2$ with both class numbers divisible by $p$Sep 21 2018We construct a new infinite family of pairs of imaginary cyclic fields of degree $(p-1)/2$ explicitly with both class numbers divisible by a given prime number $p$. For the proof, we use the fundamental unit of $\mathbb Q(\sqrt{p})$, certain units which ... More
On the Laxton GroupSep 21 2018Sep 26 2018We redefine a multiplicative group structure on the set of equivalence classes of rational sequences satisfying a fixed linear recurrence of degree two, which was defined by R. R. Laxton in his paper "On groups of linear recurrences I" published in Duke ... More
Lattice QCD with Domain-Wall FermionsSep 24 1999We study the quenched lattice QCD using domain-wall fermions at $\beta=6.0$. Behaviors of both pion mass and the explicit breaking term in the axial Ward-Takahashi identity support the existence of the chiral zero modes. We observe a good agreement between ... More
On-shell improvement of the massive Wilson quark actionSep 01 2004We review a relativistic approach to the heavy quark physics in lattice QCD by applying a relativistic $O(a)$ improvement to the massive Wilson quark action on the lattice. After explaining how power corrections of $m_Q a$ can be avoided and remaining ... More
Sea Quark Effects on QuarkoniaMay 26 2000Oct 28 2000We study the effects of two dynamical sea quarks on the spectrum of heavy quarkonia. Within the non-relativistic approach to Lattice QCD we found sizeable changes to the hyperfine splitting, but we could not observe any changes for the fine structure. ... More
Hybrid Quarkonia with Dynamical Sea QuarksMar 15 2001Aug 03 2001We present a dynamical lattice calculation with 2 flavours for bottomonium states with an additional gluonic excitation. Using improved actions for the quarks and gauge fields at a lattice spacing of $a \approx 0.1$ fm, we find 10.977(61)(62) GeV for ... More
Phase structure and critical temperature of two-flavor QCD with a renormalization group improved gauge action and clover improved Wilson quark actionAug 14 2000Nov 20 2000We study the finite-temperature phase structure and the transition temperature of QCD with two flavors of dynamical quarks on a lattice with the temporal size $N_t=4$, using a renormalization group improved gauge action and the Wilson quark action improved ... More
Probing Landau quantisation with the presence of insulator-quantum Hall transition in a GaAs two-dimensional electron systemFeb 11 2008Magneto-transport measurements are performed on the two-dimensional electron system (2DES) in an AlGaAs/GaAs heterostructure. By increasing the magnetic field perpendicular to the 2DES, magnetoresistivity oscillations due to Landau quantisation can be ... More
Chiral symmetry and its manifestation in optical responses in graphene: interaction and multi-layersOct 02 2012Chiral symmetry, fundamental in the physics of graphene, guarantees the existence of topologically stable doubled Dirac cones and anomalous behaviors of the zero-energy Landau level in magnetic fields. The crucial role is inherited in the optical responses ... More
Eta meson mass and topology in QCD with two light flavorsSep 07 1999We present results for the mass of the flavor singlet meson calculated on two-flavor full QCD configurations generated by the CP-PACS full QCD project. We also investigate topological charge fluctuations and their dependence on the sea quark mass.
Topological Susceptibility in Lattice QCD with Two Flavors of Dynamical QuarksJun 16 2001We present a study of the topological susceptibility in lattice QCD with two degenerate flavors of dynamical quarks. The topological charge is measured on gauge configurations generated with a renormalization group improved gauge action and a mean field ... More
Heavy Quarkonia from Anisotropic and Isotropic LatticesSep 17 1999We report on recent results for the spectrum of heavy quarkonia. Using coarse and anisotropic lattices we achieved an unprecedented control over statistical and systematic errors for higher excited states such as exotic hybrid states. In a parallel study ... More
On-site underground background measurements for the KASKA reactor-neutrino experimentJul 12 2006Sep 04 2006On-site underground background measurements were performed for the planned reactor-neutrino oscillation experiment KASKA at Kashiwazaki-Kariwa nuclear power station in Niigata, Japan. A small-diameter boring hole was excavated down to 70m underground ... More
Topological Susceptibility in $N_f=2$ QCD at Finite TemperatureNov 20 2017We study the topological charge in $N_f=2$ QCD at finite temperature using M\"obius domain-wall fermions. The susceptibility $\chi_t$ of the topological charge defined either by the index of overlap Dirac operator or a gluonic operator is investigated ... More
The JHF-Kamioka neutrino projectJun 05 2001The JHF-Kamioka neutrino project is a second generation long base line neutrino oscillation experiment that probes physics beyond the Standard Model by high precision measurements of the neutrino masses and mixing. A high intensity narrow band neutrino ... More
Universality of the Nf=2 Running CouplingMar 06 2009We investigate universality of the Nf=2 running coupling in the Sch\"odinger functional scheme, by calculating the step scaling function in lattice QCD with the renorm alization group (RG) improved gauge action at both weak(u=0.9796) and strong(u=3.3340) ... More
Magnetic Phase Diagram of the Heavy-Fermion Superconductor PrOs4Sb12Mar 26 2003We investigated the magnetic phase diagram of the first Pr-based heavy fermion superconductor PrOs4Sb12 by means of high-resolution dc magnetization measurements in low temperatures down to 0.06K. The temperature dependence of the magnetization M(T) at ... More
The endpoint of the first-order phase transition of the SU(2) gauge-Higgs model on a 4-dimensional isotropic latticeJan 27 1999We study the first-order finite-temperature electroweak phase transition of the SU(2) gauge-Higgs model defined on a 4-dimensional isotropic lattice with temporal extension N_t=2. Finite-size scaling study of Lee-Yang zeros yields the value of the Higgs ... More
The end point of the first-order phase transition of the SU(2) gauge-Higgs model on a four-dimensional isotropic latticeSep 16 1998We report results of a study of the end point of the electroweak phase transition of the SU(2) gauge-Higgs model defined on a four-dimensional isotropic lattice with N_t=2. Finite-size scaling study of Lee-Yang zeros yields lambda_c=0.00116(16) for the ... More
Proton decay matrix elements with domain-wall fermionsJul 04 2006Sep 18 2006Hadronic matrix elements of operators relevant to nucleon decay in grand unified theories are calculated numerically using lattice QCD. In this context, the domain-wall fermion formulation, combined with non-perturbative renormalization, is used for the ... More
Damping of the Collective Amplitude Mode in Superconductors with Strong Electron-Phonon CouplingApr 27 2016Sep 18 2016We study the effect of strong electron-phonon interactions on the damping of the Higgs amplitude mode in superconductors by means of non-equilibrium dynamical mean-field simulations of the Holstein model. In contrast to the BCS dynamics, we find that ... More
Novel features in the flux-flow resistivity of the heavy fermion superconductor PrOs$_{4}$Sb$_{12}$Apr 16 2005Jul 19 2005We have investigated the electrical resistivity of the heavy fermion superconductor PrOs$_{4}$Sb$_{12}$ in the mixed state. We found unusual double minima in the flux-flow resistivity as a function of magnetic field below the upper critical field for ... More
The QCD transition temperature: results with physical masses in the continuum limitSep 28 2006Nov 28 2006The transition temperature ($T_c$) of QCD is determined by Symanzik improved gauge and stout-link improved staggered fermionic lattice simulations. We use physical masses both for the light quarks ($m_{ud}$) and for the strange quark ($m_s$). Four sets ... More
The equation of state in lattice QCD: with physical quark masses towards the continuum limitOct 17 2005Mar 07 2006The equation of state of QCD at vanishing chemical potential as a function of temperature is determined for two sets of lattice spacings. Coarser lattices with temporal extension of N_t=4 and finer lattices of N_t=6 are used. Symanzik improved gauge and ... More
Very early multi-color observations of the plateau phase of GRB 041006 afterglowDec 21 2006Observations of the optical afterglow of GRB 041006 with the Kiso Observatory 1.05 m Schmidt telescope, the Lulin Observatory 1.0 m telescope and the Xinglong Observatory 0.6 m telescope. Three-bands (B, V and R) of photometric data points were obtained ... More
End point of the electroweak phase transitionJan 14 1999We study the hot electroweak phase transition (EWPT) by 4-dimensional lattice simulations on lattices with symmetric and asymmetric lattice spacings and give the phase diagram. A continuum extrapolation is done. We find first order phase transition for ... More
Chiral symmetry and fermion doubling in the zero-mode Landau levels of massless Dirac fermions with disorderAug 11 2012Dec 09 2013The effect of disorder on the Landau levels of massless Dirac fermions is examined for the cases with and without the fermion doubling. To tune the doubling a tight-binding model having a complex transfer integral is adopted to shift the energies of two ... More
Space-Time Structures from IIB Matrix ModelFeb 12 1998We derive a long distance effective action for space-time coordinates from a IIB matrix model. It provides us an effective tool to study the structures of space-time. We prove the finiteness of the theory for finite $N$ to all orders of the perturbation ... More
Enhanced spin-dependent parity non-conservation effect in the $7s {}^2S_{1/2} \to 6d {}^2D_{5/2}$ transition in Fr: A possibility for unambiguous detection of nuclear anapole momentDec 07 2015Employing the relativistic coupled-cluster method, comparative studies of the parity non-conserving electric dipole amplitudes for the $7s \ ^2S_{1/2} \rightarrow 6d \ ^2D_{5/2}$ transitions in $^{210}$Fr and $^{211}$Fr isotopes have been carried out. ... More
Multi-color Shallow Decay and Chromatic Breaks in the GRB 050319 Optical AfterglowNov 10 2006Multi-wavelength B, V, R, I observations of the optical afterglow of GRB 050319 were performed by the 1.05-m telescope at Kiso Observatory and the 1.0-m telescope at Lulin Observatory from 1.31 hours to 9.92 hours after the burst. Our R band lightcurves, ... More
Perturbative Renormalization Factors of Baryon Number Violating Operators for Improved Quark and Gauge Actions in Lattice QCDJan 05 2000We calculate one-loop renormalization factors of three-quark operators, which appear in the low energy effective Lagrangian of the nucleon decay, for $O(a)$-improved quark action and gauge action including six-link loops. This calculation is required ... More
Tensor Charge of the Nucleon in Lattice QCDAug 22 1996First results of lattice QCD simulation on the nucleon tensor-charge $\delta q$ are presented. From the quenched QCD simulations with the Wilson quark action at $\beta = 5.7$ on a 16$^3\times$ 20 lattice and on a $12^3\times 20$ lattice, we find (i) the ... More
Spin Fluid Dynamics Observed by Magnetic Fountain Effect and Mechano-Spin Effect in the Ferromagnetic Superfluid $^3$He A$_1$ PhaseAug 10 2010Systematic observations of the magnetically generated fountain pressure in the superfluid $^3$He A$_1$ have been carried out in a newly built apparatus designed to reduce the effect of thermal gradients. In the same apparatus, mechanical pumping and filtering ... More
Measurement of the Xi-p Scattering Cross Sections at Low EnergyFeb 08 2005In this paper we report cross-section measurements for $\Xi^-p$ elastic and inelastic scatterings at low energy using a scintillating fiber active target. Upper limit on the total cross-section for the elastic scattering was found to be 24 mb at 90% confidence ... More
Generalizations of Ho-Lee's binomial interest rate model I: from one- to multi-factorJun 08 2006In this paper a multi-factor generalization of Ho-Lee model is proposed. In sharp contrast to the classical Ho-Lee, this generalization allows for those movements other than parallel shifts, while it still is described by a recombining tree, and is stationary ... More
Several properties of hypergeometric Bernoulli numbersMar 21 2018Sep 30 2018In this paper, we give the determinant expressions of the hypergeometric Bernoulli numbers, and some relations between the hypergeometric and the classical Bernoulli numbers which include Kummer's congruences. By applying Trudi's formula, we have some ... More
The Steady Boltzmann and Navier-Stokes EquationsApr 10 2015Jan 24 2016The paper discusses the similarities and the differences in the mathematical theories of the steady Boltzmann and incompressible Navier-Stokes equations posed in a bounded domain. First we discuss two different scaling limits in which solutions of the ... More
Probing the microscopic structure of bound states in quantum point contactsMay 21 2007Using an approach that allows us to probe the electronic structure of strongly pinched-off quantum point contacts (QPCs), we provide evidence for the formation of self-consistently realized bound states (BSs) in these structures. Our approach exploits ... More
Energy Transport in Weakly Anharmonic ChainsFeb 03 2006Feb 05 2006We investigate the energy transport in a one-dimensional lattice of oscillators with a harmonic nearest neighbor coupling and a harmonic plus quartic on-site potential. As numerically observed for particular coupling parameters before, and confirmed by ... More
Foundation of Symbol Theory for Analytic Pseudodifferential Operators. IAug 20 2013Aug 21 2013A new symbol theory for pseudodifferential operators in the complex analytic category is given. This theory provides a cohomological foundation of symbolic calculus.
Chemical composition of UV-bright star ZNG 4 in the globular cluster M13Feb 12 2004We present a detailed model-atmosphere analysis of ZNG 4, a UV-bright star in the globular cluster M13. From the analysis of a high resolution ($ R \approx 45,000 $) spectrum of the object, we derive the atmospheric parameters to be $\rm T_{eff} = 8500\pm ... More
High magnetic field phase diagram of PrOs4Sb12May 08 2003Sep 02 2003The magnetic phase diagram of PrOs$_4$Sb$_{12}$ has been investigated by specific heat measurements between 8 and 32 T. A new Schottky anomaly due to excitations between two lowest crystalline-electric-field (CEF) singlets, has been found for both $H ... More
Optical evidence of type-II Weyl semimetals MoTe$_2$ and WTe$_2$Feb 26 2019The carrier dynamics and electronic structures of type-II Weyl semimetal candidates MoTe$_2$ and WTe$_2$ have been investigated by using temperature-dependent optical conductivity [$\sigma(\omega)$] spectra. Two kinds of Drude peaks (narrow and broad) ... More
Light hadron spectrum and quark masses in QCD with two flavors of dynamical quarksSep 08 1999We present updated results of the CP-PACS calculation of the light hadron spectrum in $N_{\rm f}=2$ full QCD. Simulations are made with an RG-improved gauge action and a tadpole-improved clover quark action for sea quark masses corresponding to $m_{\rm ... More
Coexistence of Antiferromagnetism and Superconductivity near the Quantum Criticality in Heavy Fermion Compound CeRhIn$_5$Nov 26 2002We report a study on the interplay between antiferromagnetism (AFM) and superconductivity (SC) in a heavy-fermion compound CeRhIn$_5$ under pressure $P=1.75$ GPa. The onset of the magnetic order is evidenced from a clear split of $^{115}$In-NQR spectrum ... More
Gapless Magnetic and Quasiparticle Excitations due to the Coexistence of Antiferromagnetism and Superconductivity in CeRhIn$_5$ : A study of $^{115}$In-NQR under PressureMar 07 2003Sep 24 2003We report systematic measurements of ac-susceptibility, nuclear-quadrupole-resonance spectrum, and nuclear-spin-lattice-relaxation time ($T_1$) on the pressure ($P$)- induced heavy-fermion (HF) superconductor CeRhIn$_5$. The temperature ($T$) dependence ... More
Fermi surfaces and orbital polarization in superconducting CeO$_{0.5}$F$_{0.5}$BiS$_{2}$ revealed by angle-resolved photoemission spectroscopyMay 08 2015Jul 01 2015We have investigated the electronic structure of BiS$_2$-based CeO$_{0.5}$F$_{0.5}$BiS$_2$ superconductor using polarization-dependent angle-resolved photoemission spectroscopy (ARPES), and succeeded in elucidating the orbital characters on the Fermi ... More
Tomography of pairing symmetry from magnetotunneling spectroscopy -- a case study for quasi-1D organic superconductorsApr 18 2002Apr 19 2002We propose that anisotropic $p$-, $d$-, or $f$-wave pairing symmetries can be distinguished from a tunneling spectroscopy in the presence of magnetic fields, which is exemplified here for a model organic superconductor ${(TMTSF)}_{2}X$. The shape of the ... More
Unusual behaviors in the transport properties of REFe$_{4}$P$_{12}$ (RE: La, Ce, Pr, and Nd)Oct 02 2000We have investigated the resistivity ($\rho$), thermoelectric power (TEP) and Hall coefficient ($R_{H}$) on high quality single crystals of REFe$_{4}$P$_{12}$. TEP in CeFe$_{4}$P$_{12}$ is extremely large ($\sim$ 0.5mV/K at 290K) with a peak of $\sim$ ... More
Full QCD Light Hadron Spectrum and Quark Masses: Final Results from CP-PACSOct 31 2000We present the final results of the CP-PACS calculation of the light hadron spectrum and quark masses with two flavors of dynamical quarks. Simulations are made with a renormalization-group improved gauge action and a mean-field improved clover quark ... More
Continuum Limit Physics from 2+1 Flavor Domain Wall QCDNov 03 2010Jul 04 2011We present physical results obtained from simulations using 2+1 flavors of domain wall quarks and the Iwasaki gauge action at two values of the lattice spacing $a$, ($a^{-1}$=\,1.73\,(3)\,GeV and $a^{-1}$=\,2.28\,(3)\,GeV). On the coarser lattice, with ... More
Pressure-induced anomalous magnetism and unconventional superconductivity in CeRhIn5 : 115In-NQR Study under PressureMar 09 2001Mar 12 2001We report $^{115}$In nuclear-quadrupole-resonance (NQR) measurements of the pressure($P$)-induced superconductor CeRhIn$_5$ in the antiferromagnetic (AF) and superconducting (SC) states. In the AF region, the internal field $H_{int}$ at the In site is ... More
Exotic Heavy Fermion State in the Filled Skutterudite PrFe$_4$P$_{12}$ Uncovered by the de Haas-van Alphen EffectSep 30 2000Aug 19 2002We report the de Haas-van Alphen (dHvA) experiment on the filled skutterudite PrFe$_4$P$_{12}$ exhibiting apparent Kondo-like behaviors in the transport and thermal properties. We have found enormously enhanced cyclotron effective mass $m^{\rm \ast}_{\rm ... More
First Nonperturbative Test of a Relativistic Heavy Quark Action in Quenched Lattice QCDNov 28 2006Feb 08 2007We perform a numerical test of a relativistic heavy quark(RHQ) action, recently proposed by Tsukuba group, in quenched lattice QCD at $a\simeq 0.1$ fm. With the use of the improvement parameters previously determined at one-loop level for the RHQ action, ... More
Unique Spin Dynamics and Unconventional Superconductivity in the Layered Heavy Fermion Compound CeIrIn_5:NQR EvidenceFeb 27 2001May 12 2001We report measurements of the ^{115}In nuclear spin-lattice relaxation rate (1/T_1) between T=0.09 K and 100 K in the new heavy fermion (HF) compound CeIrIn_5. At 0.4 K < T < 100 K, 1/T_1 is strongly T-dependent, which indicates that CeIrIn_5 is much ... More
Neutron electric dipole moment from lattice QCDMay 19 2005Aug 01 2005We carry out a feasibility study for the lattice QCD calculation of the neutron electric dipole moment (NEDM) in the presence of the $\theta$ term. We develop the strategy to obtain the nucleon EDM from the CP-odd electromagnetic form factor $F_3$ at ... More
Fermi surface of the filled-skutterudite superconductor LaRu4P12: A clue to the origin of the metal-insulator transition in PrRu4P12Apr 24 2005We report the de Haas-van Alphen (dHvA) effect and magnetoresistance in the filled-skutterudite superconductor LaRu4P12, which is a reference material of PrRu4P12 that exhibits a metal-insulator (M-I) transition at T_MI~60 K. The observed dHvA branches ... More
Detecting weak coupling in mesoscopic systems with a nonequilibrium Fano resonanceDec 28 2015Apr 26 2016A critical aspect of quantum mechanics is the nonlocal nature of the wavefunction, a characteristic that may yield unexpected coupling of nominally-isolated systems. The capacity to detect this coupling can be vital in many situations, especially those ... More
Multiband Superconductivity in Filled-Skutterudite Compounds (Pr_{1-x}La_{x})Os_{4}Sb_{12}: An Sb Nuclear-Quadruple-Resonance (NQR) StudyOct 09 2006We report on Sb nuclear-quadrupole-resonance (NQR) study in filled-skutterudite compounds (Pr_1-xLa_x)Os_4Sb_12. The Sb-NQR spectra have split into two sets, arising from different Sb_12 cages containing either Pr or La, which enables us to measure two ... More
Neutron-capture elements in the very metal-poor star HD122563Feb 06 2006We obtained high resolution, high S/N spectroscopy for the very metal-poor star HD122563 with the Subaru Telescope High Dispersion Spectrograph. Previous studies have shown that this object has excesses of light neutron-capture elements, while its abundances ... More
Drastic change in transport of entropy with quadrupolar ordering in PrFe$_{4}$P$_{12}$Dec 19 2005May 16 2006The antiferroquadrupolar ordering of PrFe$_{4}$P$_{12}$ is explored by probing thermal and thermoelectric transport. The lattice thermal conductivity drastically increases with the ordering, as a consequence of a large drop in carrier concentration and ... More
Heavy-quark free energy at finite temperature with 2+1 flavors of improved Wilson quarks in fixed scale approachNov 02 2009The free energy between a static quark and an antiquark is studied by using the color-singlet Polyakov-line correlation at finite temperature. We perform simulations on $32^3 \times 12$, 10, 8, 6, 4 lattices in the high temperature phase with the RG-improved ... More
Phase structure of finite temperature QCD in the heavy quark regionJun 06 2011Feb 29 2012We study the quark mass dependence of the finite temperature QCD phase transition in the heavy quark region using an effective potential defined through the probability distribution function of the average plaquette. Performing a simulation of SU(3) pure ... More
Equation of state at finite density in two-flavor QCD with improved Wilson quarksOct 27 2008We study the equation of state in two-flavor QCD at finite temperature and density. Simulations are made with the RG-improved gluon action and the clover-improved Wilson quark action. Along the lines of constant physics for $m_{\rm PS}/m_{\rm V} = 0.65$ ... More