20,662 research outputs found
Cold Compressed Baryonic Matter with Hidden Local Symmetry and Holography
I describe a novel phase structure of cold dense baryonic matter predicted in
a hidden local symmetry approach anchored on gauge theory and in a holographic
dual approach based on the Sakai-Sugimoto model of string theory. This new
phase is populated with baryons with half-instanton quantum number in the
gravity sector which is dual to half-skyrmion in gauge sector in which chiral
symmetry is restored while light-quark hadrons are in the color-confined phase.
It is suggested that such a phase that aries at a density above that of normal
nuclear matter and below or at the chiral restoration point can have a drastic
influence on the properties of hadrons at high density, in particular on
short-distance interactions between nucleons, e.g., multi-body forces at short
distance and hadrons -- in particular kaons -- propagating in a dense medium.
Potentially important consequences on the structure of compact stars will be
predicted.Comment: 15 pages, to appear in proceedings of "Strong Coupling Gauge Theories
in LHC Era (SCGT09)," Nagoya, Japa
Magnetic helicity transported by flux emergence and shuffling motions in Solar Active Region NOAA 10930
We present a new methodology which can determine magnetic helicity transport
by the passage of helical magnetic field lines from sub-photosphere and the
shuffling motions of foot-points of preexisting coronal field lines separately.
It is well known that only the velocity component which is perpendicular to the
magnetic field () has contribution to the helicity
accumulation. Here, we demonstrate that can be deduced
from horizontal motion and vector magnetograms, under a simple relation of
as suggested by
Dmoulin & Berger (2003). Then after dividing
into two components, as one is tangential and the other is normal to the solar
surface, we can determine both terms of helicity transport. Active region (AR)
NOAA 10930 is analyzed as an example during its solar disk center passage by
using data obtained by the Spectro-Polarimeter and the Narrowband Filter Imager
of Solar Optical Telescope on board Hinode. We find that in our calculation,
the helicity injection by flux emergence and shuffling motions have the same
sign. During the period we studied, the main contribution of helicity
accumulation comes from the flux emergence effect, while the dynamic transient
evolution comes from the shuffling motions effect. Our observational results
further indicate that for this AR, the apparent rotational motion in the
following sunspot is the real shuffling motions on solar surface
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