44,146 research outputs found
Gluon Propagators and Confinement
We present SU(3) gluon propagators calculated on 48*48*48*N_t lattices at
beta=6.8 where N_t=64 (corresponding the confinement phase) and N_t=16
(deconfinement) with the bare gauge parameter,alpha, set to be 0.1. In order to
avoid Gribov copies, we employ the stochastic gauge fixing algorithm. Gluon
propagators show quite different behavior from those of massless gauge fields:
(1) In the confinement phase, G(t) shows massless behavior at small and large
t, while around 5<t<15 it behaves as massive particle, and (2) effective mass
observed in G(z) becomes larger as z increases. (3) In the deconfinement phase,
G(z) shows also massive behavior but effective mass is less than in the
confinement case. In all cases, slope masses are increasing functions of t or
z, which can not be understood as addtional physical poles.Comment: 6 pages in Postscrip
A Case Report of Folie\u27a Deux: Husband-and-Wife
Shared paranoid disorder is a relatively rare psychiatric disorder in which paranoid delusions are transferred from one individual to one or more other susceptible person(s) in close association. Folie a deux describes a shared paranoid disorder involving two people and is characterized by a complex dependant relationship between the involved individuals. Provided there is no additional underlying psychopathology, there is a good prognosis for the submissive partner. Here we present a case report and discussion off folie a deux involving a husband and wife. Although folie a deux is a relatively uncommon disorder, it is important to recognize such cases due to the potential for recovery in the submissive partner
Localization length of a soliton from a non-magnetic impurity in a general double-spin-chain model
A localization length of a free-spin soliton from a non-magnetic impurity is
deduced in a general double-spin-chain model ( model). We have
solved a variational problem which employs the nearest-neighbor singlet-dimer
basis. The wave function of a soliton is expressed by the Airy function, and
the localization length is found to obey a power law of the
dimerization with an exponent -1/3; .
This explains why NaV_2O_5 does not show the antiferromagnetic order, while
CuGeO_3 does by impurity doping. When the gap exists by the bond-dimerization,
a soliton is localized and no order is expected. Contrary, there is a
possibility of the order when the gap is mainly due to frustration.Comment: 4 pages, REVTeX, Figures are in eps-file
Universal low-temperature properties of quantum and classical ferromagnetic chains
We identify the critical theory controlling the universal, low temperature,
macroscopic properties of both quantum and classical ferromagnetic chains. The
theory is the quantum mechanics of a single rotor. The mapping leads to an
efficient method for computing scaling functions to high accuracy.Comment: 4 pages, 2 tables and 3 Postscript figure
Exotic Properties of Light Nuclei and their Neutron Capture Cross Sections
We have investigated the implications of the neutron halo configuration,
observed in the ground-state of some neutron-rich light nuclei, on neutron
radiative transition processes. In particular, we have studied the influence of
the neutron halo on the direct radiative capture (DRC) process. The energy
dependence as well as the strength of E1 emission due to incident p-wave
neutrons is strongly influenced by the halo configuration of the residual
nucleus capturing state. We have compared the calculated 10Be(n,gamma)11Be DRC
cross section with that derived from the experiment in the inverse kinematics
(Coulomb dissociation of 11Be). We show from the comparison that some important
information on the structure of the halo nucleus 11Be can be derived.Comment: Contribution to the 4th International Seminar on Interaction of
Neutrons with Nuclei, Dubna (Russia), April 199
Theoretical analysis of the experiments on the double-spin-chain compound -- KCuCl
We have analyzed the experimental susceptibility data of KCuCl and found
that the data are well-explained by the double-spin-chain models with strong
antiferromagnetic dimerization. Large quantum Monte Carlo calculations were
performed for the first time in the spin systems with frustration. This was
made possible by removing the negative-sign problem with the use of the dimer
basis that has the spin-reversal symmetry. The numerical data agree with the
experimental data within 1% relative errors in the whole temperature region. We
also present a theoretical estimate for the dispersion relation and compare it
with the recent neutron-scattering experiment. Finally, the magnitude of each
interaction bond is predicted.Comment: 4 pages, REVTeX, 5 figures in eps-file
Quantum Phase Transitions and the Hidden Order in a Two-Chain Extended Boson Hubbard Model at Half-Odd-Integer Fillings
We study the phase diagram of two weakly coupled one-dimensional dipolar
boson chains at half-odd-integer fillings. We find that the system contains a
rich phase diagram. Four different phases are found. They are the Mott
insulators, the single-particle resonant superfluid, the paired superfluid, and
the bond- or inter-chain density waves. Moreover, the Mott insulating phase can
be further classified according to a hidden string order parameter, which is
analogous to the one investigated recently in the one-dimensional boson Mott
insulator at integer fillings.Comment: 7 pages, 2 figure
Effects of Chemical Potential on Hadron Masses at Finite Temperature
We study the effects of the chemical potential on the meson mass at
finite temperature. Our preliminary results show that some effects are seen in
the vicinity of the phase transition point. Although the signal is still too
noisy to obtain conclusive physical results within limited statistics, the mass
susceptibility is consistent with zero.Comment: LATTICE98(hightemp), 3 page
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