410 research outputs found
Diquark Bose-Einstein condensation
Bose-Einstein condensation (BEC) of composite diquarks in quark matter (the
color superconductor phase) is discussed using the quasi-chemical equilibrium
theory at a relatively low density region near the deconfinement phase
transition, where dynamical quark-pair fluctuations are assumed to be described
as bosonic degrees of freedom (diquarks). A general formulation is given for
the diquark formation and particle-antiparticle pair-creation processes in the
relativistic flamework, and some interesting properties are shown, which are
characteristic for the relativistic many-body system. Behaviors of transition
temperature and phase diagram of the quark-diquark matter are generally
presented in model parameter space, and their asymptotic behaviors are also
discussed. As an application to the color superconductivity, the transition
temperatures and the quark and diquark density profiles are calculated in case
with constituent/current quarks, where the diquark is in bound/resonant state.
We obtained MeV for constituent quarks and MeV
for current quarks at a moderate density (). The method
is also developed to include interdiquark interactions into the quasi-chemical
equilibrium theory within a mean-field approximation, and it is found that a
possible repulsive diquark-diquark interaction lowers the transition
temperature by nearly 50%.Comment: 21 pages, 23 figure
Baryons in Holographic QCD
We study the baryon in holographic QCD with multi- brane
system. In holographic QCD, the baryon appears as a topologically non-trivial
chiral soliton in a four-dimensional effective theory of mesons. We call this
topological soliton as Brane-induced Skyrmion. Some review of
holographic QCD is presented from the viewpoints of recent hadron physics and
phenomenologies. Four-dimensional effective theory with pions and mesons
is uniquely derived from the non-abelian Dirac-Born-Infeld (DBI) action of
brane with supergravity background, without small amplitude expansion of
meson fields to discuss chiral solitons. For the hedgehog configuration of pion
and -meson fields, we derive the energy functional and the Euler-Lagrange
equation of Brane-induced Skyrmion from the meson effective action induced by
holographic QCD. Performing the numerical calculation, we obtain the pion
profile and the -meson profile of the Brane-induced
Skyrmion, and estimate its total energy, energy density distribution, and
root-mean-square radius. These results are compared with the experimental
quantities of baryons and also with the profiles of standard Skyrmion without
mesons. We analyze interaction terms of pions and mesons in
Brane-induced Skyrmion, and consider the role of -meson component
appearing in baryons.Comment: 28 pages, 11 figure
Brane-induced Skyrmion on S^3: baryonic matter in holographic QCD
We study baryonic matter in holographic QCD with D4/D8/\bar{D8} multi-D brane
system in type IIA superstring theory. The baryon is described as the
"brane-induced Skyrmion", which is a topologically non-trivial chiral soliton
in the four-dimensional meson effective action induced by holographic QCD. We
employ the "truncated-resonance model" approach for the baryon analysis,
including pion and \rho meson fields below the ultraviolet cutoff scale M_KK
\sim 1GeV, to keep the holographic duality with QCD. We describe the baryonic
matter in large N_c as single brane-induced Skyrmion on the three-dimensional
closed manifold S^3 with finite radius R. The interactions between baryons are
simulated by the curvature of the closed manifold S^3, and the decrease of the
size of S^3 represents the increase of the total baryon-number density in the
medium in this modeling. We investigate the energy density, the field
configuration, the mass and the root-mean-square radius of single baryon on S^3
as the function of its radius R. We find a new picture of "pion dominance" near
the critical density in the baryonic matter, where all the (axial) vector meson
fields disappear and only the pion field survive. We also find the "swelling"
phenomena of the baryons as the precursor of the deconfinement, and propose the
mechanism of the swelling in general context of QCD. The properties of the
deconfinement and the chiral symmetry restoration in the baryonic matter are
examined by taking the proper order parameters. We also compare our
truncated-resonance model with another "instanton" description of the baryon in
holographic QCD, considering the role of cutoff scale M_KK.Comment: 25 pages, 12 figure
A note on fermions in holographic QCD
We study the fermionic sector of a probe D8-brane in the supergravity
background made of D4-branes compactified on a circle with supersymmetry broken
explicitly by the boundary conditions. At low energies the dual field theory is
effectively four-dimensional and has proved surprisingly successful in
recovering qualitative and quantitative properties of QCD. We investigate
fluctuations of the fermionic fields on the probe D8-brane and interpret these
as mesinos (fermionic superpartners of mesons). We demonstrate that the masses
of these modes are comparable to meson masses and show that their interactions
with ordinary mesons are not suppressed.Comment: 21+1 pp, 1 figure; v2: typos corrected, refs. adde
Skyrmions with holography and hidden local symmetry
We study baryons as Skyrmions in holographic QCD with D4/D8/D8-bar multi-D
brane system in type IIA superstring theory, and also in the non-linear sigma
model with hidden local symmetry (HLS). Comparing these two models, we find
that the extra-dimension and its nontrivial curvature can largely change the
role of (axial) vector mesons for baryons in four-dimensional space-time. In
the HLS approach, the rho-meson field as a massive Yang-Mills field has a
singular configuration in Skyrmion, which gives a strong repulsion for the
baryon as a stabilizer. When a_1 meson is added in this approach, the stability
of Skyrmion is lost by the cancellation of rho and a_1 contributions. On the
contrary, in holographic QCD, the rho-meson field does not appear as a massive
Yang-Mills field due to the extra-dimension and its nontrivial curvature. We
show that the rho-meson field has a regular configuration in Skyrmion, which
gives a weak attraction for the baryon in holographic QCD. We argue that
Skyrmion with pi, rho and a_1 mesons become stable due to the curved
extra-dimension and also the presence of the Skyrme term in holographic QCD.
From this result, we also discuss the features of our truncated-resonance
analysis on baryon properties with pi and rho mesons below the cutoff scale
M_KK about 1GeV in holographic QCD, which is compared with other 5D instanton
analysis.Comment: 7 pages, 7 figure
Dynamics of Baryons from String Theory and Vector Dominance
We consider a holographic model of QCD from string theory, a la Sakai and
Sugimoto, and study baryons. In this model, mesons are collectively realized as
a five-dimensional \ Yang-Mills field and baryons
are classically identified as solitons with a unit Pontryagin number
and electric charges. The soliton is shown to be very small in the large
't Hooft coupling limit, allowing us to introduce an effective field . Its coupling to the mesons are dictated by the soliton structure, and
consists of a direct magnetic coupling to the field strength as well
as a minimal coupling to the gauge field. Upon the dimensional
reduction, this effective action reproduces all interaction terms between
nucleons and an infinite tower of mesons in a manner consistent with the large
expansion. We further find that all electromagnetic interactions, as
inferred from the same effective action via a holographic prescription, are
mediated by an infinite tower of vector mesons, rendering the baryon
electromagnetic form factors completely vector-dominated as well. We estimate
nucleon-meson couplings and also the anomalous magnetic moments, which compare
well with nature.Comment: 65pages, 3 figures, vector mesons and axial-vector mesons are now
canonically normalized (comparisons with data and conclusions unaffected
Expression of the SmB′ splicing protein in rodent cells capable of following an alternative RNA splicing pathway
AbstractThe expression of the SmB and SmB′ spliceosome proteins in a variety of cell types and tissues has been investigated. Although SmB is found in all cells studied, the SmB′ protein is found only in a small number of rodent cell types. The presence of this protein is correlated with the ability to utilize an alternative pathway of RNA splicing which is not available in most cell types. This is the first demonstration of tissue specific expression of a protein component of the spliceosome and suggests a role for SmB′ in the regulation of some cases of alternative RNA splicing
Holographic aspects of three dimensional QCD from string theory
We study two aspects of 3D QCD with massless fermions in a holographic set-up
from string theory, based on D3/D7 branes; parity anomaly and baryons as baby
Skyrmions. We first give a novel account of parity anomaly of 3D QCD with odd
number of flavors from the IR holographic viewpoint by observing a subtle point
in D7 brane embeddings with a given fixed UV theory. We also discuss its UV
origin in terms of weakly coupled D-brane pictures. We then focus on the
parity-symmetric case of even number of N_F flavors, and study baryons in the
holographic model. We identify the monopoles of U(N_F) gauge theory dynamically
broken down to U(N_F/2)x U(N_F/2) in the holographic 4 dimensional bulk as a
holographic counter-part of 3D baby-Skyrmions for baryons in large N limit, and
work out some details how the mapping goes. In particular, we show that the
correct baryon charges emerge from the Witten effect with a space-varying theta
angle.Comment: 33 pages, 10 figures; v2: references added with comments, typos
corrected; v3: more references added; v4: holographic baryon profile and the
analysis of its baryon charge is significantly revised, correcting errors in
the previous discussio
Confront Holographic QCD with Regge Trajectories of vectors and axial-vectors
We derive the general 5-dimension metric structure of the system in
type II superstring theory, and demonstrate the physical meaning of the
parameters characterizing the 5-dimension metric structure of the
\textit{holographic} QCD model by relating them to the parameters describing
Regge trajectories. By matching the spectra of vector mesons with
deformed soft-wall model, we find that the spectra of vector mesons
can be described very well in the soft-wall model, i.e,
soft-wall model. We then investigate how well the soft-wall
model can describe the Regge trajectory of axial-vector mesons . We find
that the constant component of the 5-dimension mass square of axial-vector
mesons plays an efficient role to realize the chiral symmetry breaking in the
vacuum, and a small negative correction in the 5-dimension mass square is
helpful to realize the chiral symmetry restoration in high excitation states.Comment: 9 pages, 3 figure and 3 tables, one section adde
UPAYA PENCEGAHAN PENYEBARAN AFRICAN SWINE FEVER DI NUSA TENGGARA TIMUR
The outbreak of African Swine Fever (ASF) disease as a disease that can affect the swine has distributed in many countries including Indonesia. The Province of Nusa Tenggara Timur (NTT) is the biggest swine population in Indonesia being risk because Timor Island directly bordered Timor Leste, which an area that affected ASF. The outbreak of ASF caused a big loss to the economy and the public's fear of consumption of pork and other swine products. The purpose of this activity is to given information about characteristics of good pork quality and appeal public to control and prevent dissemination of ASF. According to this activity, the public knowing ASF as a danger and zoonotic disease, which caused public anxiety to consumption pork and other swine products. Although the public knowing about the danger of ASF, there is no preventive action they know. This activity is a tool for breeders to prevent ASF in their animal husbandry and for the public to know that ASF, not a zoonotic disease. However, consumption of pork and other swine products infected with ASF can spread ASF continuously
- …