83 research outputs found
Daily Activities and Social Association of the Bongando in Central Zaire
Daily activities and association patterns of the Bongando, a Bantu speaking people in central Zaire, were studied, using a systematic "self-focal sampling" method. The time spent on the subsistence activities was unexpectedly short, whereas leisure time was abundant. The Bongando are engaged more frequently in non-agricultural activities such as hunting, fishing, and gathering than in agriculture. So they can be described as a "multi-subsistence people" rather than just "farmers." Men tended to concentrate their work on one activity at a time, and women tended to perform two or more activities simultaneously. In the social associations, men and wome rarely associated with each other. Men associated infrequently but evenly with many persons, while women associated more frequently but with only a few specific persons. Although the Bongando have a patrilineal lineage system, they do not clearly segregate the members of their own lineage from the non-members in the association behavior. In daliy life, they do not need to rely on the lineage coalition, probably because their subsistence activities tend to be conducted individually
NJL Model at Finite Chemical Potential in a Constant Magnetic Field
We investigate the influence of an external magnetic field on chiral symmetry
breaking in the Nambu-Jona-Lasinio (NJL) model at finite temperature and
chemical potential. According to the Fock-Schwinger proper-time method, we
calculate the effective potential in the leading order of the
expansion. The phase boundary dividing the symmetric phase and the broken phase
is illustrated numerically. A complex behavior of the phase boundary is found
for large chemical potential.Comment: 6 pages, 2 figures, Poster talk presented at the Workshop on Finite
Density QCD at Nara, Japan, 10-12 July 2003; replaced two reference
Phase structure of NJL model with finite quark mass and QED correction
We study QED corrections to the chiral symmetry breaking in
Nambu-Jona-Lasinio (NJL) model with two flavors of quarks. In the model the
isospin symmetry is broken by differences of the current quark masses and the
electromagnetic charges between up and down quarks. In the leading order of the
1/N expansion we calculate the effective potential of the model with one-loop
QED corrections. Evaluating the effective potential, we study an influence of
the isospin symmetry breaking on the orientation of chiral symmetry breaking.
The current quark mass has an important contribution for the orientation of
chiral symmetry breaking.Comment: 7 pages, 8 figures, To appear in the proceedings of the Workshop on
Origin of Mass and Strong Coupling Gauge Theories, Nagoya, Japan, 21-24
November 200
Four-fermion Interaction Model in a Constant Magnetic Field at Finite Temperature and Chemical Potential
We investigate an influence of an external magnetic field on chiral symmetry
breaking in a four-fermion interaction model at finite temperature and chemical
potential. By using the Fock-Schwinger proper-time method, we calculate the
effective potential for the four-fermion interaction model at the leading order
of the expansion. A phase structure of the chiral symmetry breaking is
shown on -, - and - planes. The external magnetic field
modifies the phase structure. It is found that a new phase appears for a large
chemical potential.Comment: 16 pages, 10 figure
CP violation of Extended Higgs sector and Its impact on D^0 -> mu^+ mu^- decay
We study the impact of the CP violation of the extra Higgs sector on
decay. The CP even and CP odd neutral Higgs mixing of the two Higgs doublet
model is studied and we show how the CP violating effect of the mixing may lead
to the longitudinal muon polarization asymmetry of . The
asymmetry of the short-distance contribution is sensitive to the CP violating
phase of the extended Higgs sector.Comment: 7 pages, 2 figures, presented as a poster in GUT2012
(YITP,Kyoto,15-17 March2012
Super Restoration of Chiral Symmetry in Massive Four-Fermion Interaction Models
The chiral symmetry is explicitly and spontaneously broken in a strongly
interacting massive fermionic system. We study the chiral symmetry restoration
in massive four-fermion interaction models with increasing temperature and
chemical potential. At high temperature and large chemical potential, we find
the boundaries where the spontaneously broken chiral symmetry can be fully
restored in the massive Gross--Neveu model. We call the phenomenon super
restoration. The phase boundary is obtained analytically and numerically. In
the massive Nambu--Jona-Lasinio model, it was found that whether super
restoration occurs depends on regularizations. We also evaluate the behavior of
the dynamical mass and show the super restoration boundaries on the ordinary
phase diagrams.Comment: 11 pages, 13 figure
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