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T. Suzuki

Publications and source records attributed to T. Suzuki.

263 records · Page 15Linked to original sources
arXiv1998

Two-dimensional Liouville Gravity Theory with Non-Trivial Classical Background

We examine a possibility to introduce a non-trivial classical background metric into the 2-d Liouville gravity theory. The classical background appears as a part of the Weyl factor of the physical metric of 2-d surfaces with some conformal dimension. On the other hand, the rest part of the factor corresponds to the quantum fluctuating sector, having another conformal dimension such that these two conformal dimensions sum up to just (1,1). Consequently we conclude that, in the 2-d Liouville gravity, the target space dimensions D can be beyond 1.

hep-th↗
arXiv1998

Longitudinal momentum distributions of {16,18}C fragments after one-neutron removal from {17,19}C

The fragment separator FRS at GSI was used as an energy-loss spectrometer to measure the longitudinal momentum distributions of {16,18}C fragments after one-neutron removal reactions in {17,19}C impinging on a carbon target at about 910 MeV/u. The distributions in the projectile frames are characterized by a FWHM of 141+-6 MeV/c for {16}C and 69+-3 MeV/c for {18}C. The results are compared with experimental data obtained at lower energies and discussed within existing theoretical models.

nucl-ex↗
arXiv1998

A `Hypernova' model for SN 1998bw associated with gamma-ray burst of 25 April 1998

The discovery of the peculiar supernova (SN) 1998bw and its possible association with the gamma-ray burst (GRB) 980425$^{1,2,3}$ provide new clues to the understanding of the explosion mechanism of very massive stars and to the origin of some classes of gamma-ray bursts. Its spectra indicate that SN~1998bw is a type Ic supernova$^{3,4}$, but its peak luminosity is unusually high compared with typical type Ic supernovae$^3$. Here we report our findings that the optical spectra and the light curve of SN 1998bw can be well reproduced by an extremely energetic explosion of a massive carbon+oxygen (C+O) star. The kinetic energy is as large as $\sim 2-5 \times 10^{52}$ ergs, more than ten times the previously known energy of supernovae. For this reason, the explosion may be called a `hypernova'. Such a C+O star is the stripped core of a very massive star that has lost its H and He envelopes. The extremely large energy, suggesting the existence of a new mechanism of massive star explosion, can cause a relativistic shock that may be linked to the gamma-ray burst.

astro-ph↗
arXiv1998

Widths of Isobaric Analog Resonances: a microscopic approach

A self-consistent particle-phonon coupling model is used to investigate the properties of the isobaric analog resonance in $^{208}$Bi. It is shown that quantitative agreement with experimental data for the energy and the width can be obtained if the effects of isospin-breaking nuclear forces are included, in addition to the Coulomb force effects. A connection between microscopic model predictions and doorway state approaches which make use of the isovector monopole resonance, is established via a phenomenological ansatz for the optical potential.

nucl-th↗
arXiv1998

Degenerate Double Affine Hecke Algebra And Conformal Field Theory

We introduce a class of induced representations of the degenerate double affine Hecke algebra of gl_N and analyze their structure mainly by means of intertwiners. We also construct them from modules of the affine Lie algebra using Knizhnik-Zamolodchikov connections in the conformal field theory. This construction provides a natural quotient of induced modules, which turns out to be the unique irreducible one under a certain condition. Some cunjectual formulas are presented for the symmetric part of these quotients.

q-alg↗
arXiv1998

Lie algebras and degenerate Affine Hecke Algebras of type A

We construct a family of exact functors from the BGG category of representations of the Lie algebra sl to the category of finite-dimensional representations of the degenerate (or graded) affine Hecke algebra H of GL. These functors transform Verma modules to standard modules or zero, and simple modules to simple modules or zero. Any simple H-module can be thus obtained.

q-alg↗
arXiv1998

Monopoles and hadron spectrum in quenched QCD

We study quenched hadron spectra with Wilson fermion in abelian gauge fields extracted by maximal abelian projection and in fields induced by monopoles on $16^3 \times 32 $ and $ 12^3 \times 24$ lattices. Pion mass squared and quark mass defined through the axial Ward identity satisfy the PCAC relation. Gross features of the light hadron spectra are almost similar to those in SU(3) gauge fields if normalization is made by the square root of the string tension. It is also shown that no sizable dynamical mass generation is found in the present range of $κ$ when the monopole degree of freedom is removed from the abelian fields or from the SU(3) gauge fields.

hep-lat↗
arXiv1997

Ferromagnetic Mixed-Valence and Kondo-Lattice State in TmTe at High Pressure

Neutron diffraction experiments on TmTe at pressures up to 7 GPa are reported. The semiconductor-to-metal transition occurring at 2 GPa in this compound is accompanied by the appearance of strong ferromagnetic exchange interactions producing a Curie temperature as high as 14 K. This behavior is characteristic for the incipient mixed-valence regime just above the transition pressure and traced back to the release of a small concentration of free charge carriers in the material. The steep decrease of both the Curie temperature and ordered magnetic moment occurring at higher pressures emphasizes the role of Kondo fluctuations, and raises the interesting possibility that a quantum critical transition to a non-magnetic ground state of mixed-valence Tm might take place around 6 GPa.

cond-mat.str-el↗
arXiv1997

Exchange Currents for Hypernuclear Magnetic Moments

The meson(K and $π$) exchange currents for the hypernuclear magnetic moments are calculated using the effective Lagrangian method. The seagull diagram, the mesonic diagram and the $Σ^0$-excitation diagram are considered. The $Λ$-N exchange magnetic moments for the ${}^5_ΛHe$, ${}^6_ΛHe$ and ${}^6_ΛLi$ are calculated employing the harmonic oscillator shell model. It is found that the two-body correction is about -9% of the single particle value for ${}^5_ΛHe$. The $π$ exchange current, induced only in the $Σ^0$-excitation diagram, is found to give dominant contribution for the isovector magnetic moments of hypernuclei with A=6.

nucl-th↗
arXiv1993

The (dual) Meissner effect in SU(2) and SU(3) QCD

After making an abelian projection in the maximally abelian gauge, we measure the distribution of abelian electric flux and monopole currents around an abelian Wilson loop in $SU(2)$ and $SU(3)$ QCD. The (dual) Meissner effect is observed clearly. The vacua in the confinement phases of $SU(2)$ and $SU(3)$ are both at around the border between type-1 and type-2 (dual) superconductor.

hep-lat↗