1,376 research outputs found
Color Superconductivity in Dense QCD and Structure of Cooper Pairs
The two-flavor color superconductivity is examined over a wide range of
baryon density with a single model. To study the structural change of Cooper
pairs, quark correlation in the color superconductor is calculated both in the
momentum space and in the coordinate space. At extremely high baryon density,
our model becomes equivalent to the usual perturbative QCD treatment and the
gap is shown to have a sharp peak near the Fermi surface due to the
weak-coupling nature of QCD. On the other hand, the gap is a smooth function of
the momentum at lower densities due to strong color magnetic and electric
interactions. The size of the Cooper pair is shown to become comparable to the
averaged inter-quark distance at low densities, which indicates a crossover
from BCS to BEC (Bose-Einstein condensation) of tightly bound Cooper pairs may
take place at low density.Comment: 6 pages, 5 figures. Invited talk at the Joint CSSM/JHF Workshop on
Physics at Japan Hadron Facility (March 14-21, Adelaide, 2002
Gender and conversational dominance in Japanese conversation
A number of studies have been conducted on "dominance" as reflected in spoken interactional features, most of which deal with English. Many of these studies adopt a quantitative approach, examining the amount and distribution of interactional features such as amount of talk, interruptions and overlaps, turn-taking, questions, and topic initiations, and they have drawn conclusions on "dominance" accordingly. The present study explores gender dominance in conversation by analyzing conversational data from eight Japanese dyads by integrating quantitative and qualitative analyses. The quantitative analysis of two dimensions of conversational dominance, sequential dominance and participatory dominance, does not show any obvious gender dominance; however, the qualitative analysis of three of the dyads finds a clear pattern of male speakers' self-oriented conversational style, which is manifested in their storytelling and claiming expertise, and this is supported by female speakers' other-oriented conversational style. Gender dominance therefore is seen as a mutual construction. The conclusion discusses the importance of integrating findings from both quantitative and qualitative analyses in situated contexts to deepen understanding of the complexity of gender dominance.published_or_final_versio
Branching mechanism of intergranular crack propagation in three dimensions
We investigate the process of slow intergranular crack propagation by the
finite element method model, and show that branching is induced by partial
arresting of crack front owing to the geometrical randomness of grain
boundaries. A possible scenario for branching instability of crack propagation
in disordered continuum medium is also discussed.Comment: 4 pages, submitted to Phys.Rev.E; v2:corrected typos v3: final
version to be publishe
A debris-flow monitoring devices and methods bibliography
International audienceDebris-flow monitoring has two functions, warning and modeling. The warning function includes the following parameters: occurrence prediction and detection, proximity sensing, and discharge-estimation. The parameters obtained from debris-flow measurements can deduce a numerical model for creating a hazard map and designing various types of control structures to mitigate the hazards. Many devices and methods of monitoring are tabulated here for comparative study. Some of them are in operation. Advanced comparative studies lead to an improvement in debris-flow monitoring, an integrated system that can be applied to any torrent, and a breakthrough in future developments
Dynamical Chiral Symmetry Breaking on the Light Front.II. The Nambu--Jona-Lasinio Model
An investigation of dynamical chiral symmetry breaking on the light front is
made in the Nambu--Jona-Lasinio model with one flavor and N colors. Analysis of
the model suffers from extraordinary complexity due to the existence of a
"fermionic constraint," i.e., a constraint equation for the bad spinor
component. However, to solve this constraint is of special importance. In
classical theory, we can exactly solve it and then explicitly check the
property of ``light-front chiral transformation.'' In quantum theory, we
introduce a bilocal formulation to solve the fermionic constraint by the 1/N
expansion. Systematic 1/N expansion of the fermion bilocal operator is realized
by the boson expansion method. The leading (bilocal) fermionic constraint
becomes a gap equation for a chiral condensate and thus if we choose a
nontrivial solution of the gap equation, we are in the broken phase. As a
result of the nonzero chiral condensate, we find unusual chiral transformation
of fields and nonvanishing of the light-front chiral charge. A leading order
eigenvalue equation for a single bosonic state is equivalent to a leading order
fermion-antifermion bound-state equation. We analytically solve it for scalar
and pseudoscalar mesons and obtain their light-cone wavefunctions and masses.
All of the results are entirely consistent with those of our previous analysis
on the chiral Yukawa model.Comment: 23 pages, REVTEX, the version to be published in Phys.Rev.D; Some
clarifications in discussion of the LC wavefunctions adde
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