345 research outputs found
Partial Disorder in the Periodic Anderson Model on a Triangular Lattice
We report our theoretical results on the emergence of a partially-disordered
state at zero temperature and its detailed nature in the periodic Anderson
model on a triangular lattice at half filling. The partially-disordered state
is characterized by coexistence of a collinear antiferromagnetic order on an
unfrustrated honeycomb subnetwork and nonmagnetic state at the remaining sites.
This state appears with opening a charge gap between a noncollinear
antiferromagnetic metal and Kondo insulator while changing the hybridization
and Coulomb repulsion. We also find a characteristic crossover in the
low-energy excitation spectrum as a result of coexistence of magnetic order and
nonmagnetic sites. The result demonstrates that the partially-disordered state
is observed distinctly even in the absence of spin anisotropy, in marked
contrast to the partial Kondo screening state found in the previous study for
the Kondo lattice model.Comment: 4 pages, 4 figures, accepted for publication in J. Phys. Soc. Jp
Thermal Properties of Heavy Fermion Compound YbP
Low-temperature specific heat and its field-dependence up to 16 T was
measured in a stoichiometric single crystal of YbP. A sharp peak was observed
at {\it T} = 0.53 K in zero magnetic field. Application of external
field seems to induce a new magnetic phase above 11 T. The field dependence of
the transition temperature in the high-field phase is different from that of
the low field phase. The linear coefficient of the electronic specific heat is
estimated as 120 mJ/mole K from low temperature specfic heat, suggesting
heavy Fermion state in YbP.Comment: to be published in J.Phys.Soc.Jpn on May, 200
Inner-shell ionization by ultrarelativistic electronsInner-shell ionization by ultrarelativistic electrons
Optimum Arrangement of Resonator in Micro-bunch Free Electron Laser(III. Accelerator, Synchrotron Radiation, and Instrumentation)
Using a short-bunched beam of electrons from a linear accelator, the output of the micro-bunch FEL has been studied experimentally to clarify the optimum arrangement of an open resonator on the electron orbit. The output depends sharply on the arrangement, and the maximum output is observed when the resonator axis intersects the electron orbit with the angle of 3°
Photo-production of neutral kaons on 12C in the threshold region
Kaon photo-production process on C has been studied by measuring
neutral kaons in a photon energy range of 0.81.1 GeV. Neutral kaons were
identified by the invariant mass constructed from two charged pions emitted in
the decay channel. The differential cross sections
as well as the integrated ones in the threshold photon energy region were
obtained. The obtained momentum spectra were compared with a Spectator model
calculation using elementary amplitudes of kaon photo-production given by
recent isobar models. Present result provides, for the first time, the
information on reaction which is expected to play an
important role to construct models for strangeness production by the
electromagnetic interaction. Experimental results show that cross section of
is of the same order to that of and suggest that slightly backward angular distribution
is favored in the process.Comment: 6 pages, 8 figure
Development of Hydrophones for Detecting High-Energy Reactions in Water(III. Accelerator, Synchrotron Radiation, and Instrumentation)
Acoustic detectors were developed using a piezo ceramic compound PZT. A shape of the PZT detector was essential to obtain a high sensitivity. A detector of a spherically shaped shell structure, whose size was 50 mm in diameter and 2 mm thick, was fabricated. Its sensitivity was calibrated to be about 40 mV/Pa at 54 kHz. Using the hydrophone, acoustic signals generated by an electron-induced cascade shower in water were detected. Experimental results were compared with simulation data and confirmed a consistency in between
Prevalence of equine piroplasmosis in Central Mongolia
Antigen for the indirect fluorescent antibody test (IFAT) was routinely prepared from infected erythrocytes from horses experimentally infected with Babesia equi and Babesia caballi. With the successful
establishment of in vitro cultures of B. equi and B. caballi, it is now possible to employ culture-
derived antigens in this test. In this study, in vitro-propagated B. equi- and B. caballi-infected
erythrocytes were used as antigen in the IFAT. Various modifications to an established protocol had
to be implemented to allow repeatable results. Cultures with 3-4% parasitized erythrocytes were
found to be most suitable. As cross-reactions of control sera on heterologous antigen were observed
at serum dilutions of up to 1/40, a reciprocal titre of 80 was considered to be positive. In positive
samples, specific fluorescence of Babesia parasites and/or erythrocyte membranes was observed.
Fifteen sera from Babesia-free horses from Japan all tested negative in the IFAT. One hundred and
ten field-horse sera from Central Mongolia were investigated in this study. The results indicate that
both B. equi and B. caballi are endemic in horses in Central Mongolia, with 88,2% and 84,5% of
horses being seropositive to B. equi and B. caballi, respectively.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi.
Adobe Acrobat X Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format
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