2,557 research outputs found
The Experimental plan of the 4m Resonant Sideband Extraction Prototype for The LCGT
The 4m Resonant Sideband Extraction (RSE) interferometer is a planned prototype of the LCGT interferometer. The aim of the experiment is to operate a powerrecycled Broadband RSE interferometer with suspended optics and to achieve diagonalization of length signals of the central part of the interferometer directly through the optical setup. Details of the 4m RSE interferometer control method as well as the design of the experimental setup will be presented
The three-flavor chiral phase structure in hot and dense QCD matter
Chiral symmetry restoration at nonzero temperature and quark densities are
investigated in the framework of a linear sigma model with N_f=3 light quark
flavors. After the derivation of the grand potential in mean-field
approximation, the nonstrange and strange condensates, the in-medium masses of
the scalar and pseudoscalar nonets are analyzed in hot and dense medium. The
influence of the axial anomaly on the nonet masses and the isoscalar mixings on
the pseudoscalar \eta-\eta' and scalar \sigma(600)-f_0(1370) complex are
examined. The sensitivity of the chiral phase transition as well as the
existence and location of a critical end point in the phase diagram on the
value of the sigma mass is explored. The chiral critical surface with and
without the influence of the axial U(1)_A anomaly is elaborated as a function
of the pion and kaon masses for several values of the sigma mass.Comment: 19 pages, 12 figures, 2 tables, RevTex4; revised version, accepted
for publication in PR
Low-energy theorems of QCD and bulk viscosity at finite temperature and baryon density in a magnetic field
The nonperturbative QCD vacuum at finite temperature and a finite baryon
density in an external magnetic field is studied. Equations relating
nonperturbative condensates to the thermodynamic pressure for , and are obtained, and low-energy theorems are derived. A bulk
viscosity is expressed in terms of basic thermodynamical
quantities describing the quark-gluon matter at , , and
. Various limiting cases are also considered.Comment: 12 pages; v2: title changed, new section about bulk viscosity and new
references added; v3: new discussion adde
A Review of Object Detection Models based on Convolutional Neural Network
Convolutional Neural Network (CNN) has become the state-of-the-art for object
detection in image task. In this chapter, we have explained different
state-of-the-art CNN based object detection models. We have made this review
with categorization those detection models according to two different
approaches: two-stage approach and one-stage approach. Through this chapter, it
has shown advancements in object detection models from R-CNN to latest
RefineDet. It has also discussed the model description and training details of
each model. Here, we have also drawn a comparison among those models.Comment: 17 pages, 11 figures, 1 tabl
Element Stratification in the Middle-Aged Type Ia Supernova Remnant G344.7-0.1
Despite their importance, a detailed understanding of Type Ia supernovae (SNe
Ia) remains elusive. X-ray measurements of the element distributions in
supernova remnants (SNRs) offer important clues for understanding the explosion
and nucleosynthesis mechanisms for SNe Ia. However, it is challenging to
observe the entire ejecta mass in X-rays for young SNRs, because the central
ejecta may not have been heated by the reverse shock yet. Here we present over
200 kilosecond Chandra observations of the Type Ia SNR G344.7-0.1, whose age is
old enough for the reverse shock to have reached the SNR center, providing an
opportunity to investigate the distribution of the entire ejecta mass. We
reveal a clear stratification of heavy elements with a centrally peaked
distribution of the Fe ejecta surrounded by intermediate-mass elements (IMEs:
Si, S, Ar Ca) with an arc-like structure. The centroid energy of the Fe K
emission is marginally lower in the central Fe-rich region than in the outer
IME-rich regions, suggesting that the Fe ejecta were shock-heated more
recently. These results are consistent with the prediction for standard SN Ia
models, where the heavier elements are synthesized in the interior of an
exploding white dwarf. We find, however, that the peak location of the Fe K
emission is slightly offset to the west with respect to the geometric center of
the SNR. This apparent asymmetry is likely due to the inhomogeneous density
distribution of the ambient medium, consistent with our radio observations of
the ambient molecular and neutral gas.Comment: 16 pages, 10 figures, Accepted for publication in Astrophysical
Journa
Gluonic phase versus LOFF phase in two-flavor quark matter
We study the gluonic phase in a two-flavor color superconductor as a function
of the ratio of the gap over the chemical potential
mismatch,. We find that the gluonic phase resolves the
chromomagnetic instability encountered in a two-flavor color superconductor for
. We also calculate approximately the free
energies of the gluonic phase and the single plane-wave LOFF phase and show
that the former is favored over the latter for a wide range of coupling
strengths.Comment: 6 pages, 3 figures, references added, revisions to text, version
accepted for publication in Phys. Lett.
Phase diagram at finite temperature and quark density in the strong coupling limit of lattice QCD for color SU(3)
We study the phase diagram of quark matter at finite temperature (T) and
finite chemical potential (mu) in the strong coupling limit of lattice QCD for
color SU(3). We derive an analytical expression of the effective free energy as
a function of T and mu, including baryon effects. The finite temperature
effects are evaluated by integrating over the temporal link variable exactly in
the Polyakov gauge with anti-periodic boundary condition for fermions. The
obtained phase diagram shows the first order phase transition at low
temperatures and the second order phase transition at high temperatures
separated by the tri-critical point in the chiral limit. Baryon has effects to
reduce the effective free energy and to extend the hadron phase to a larger mu
direction at low temperatures.Comment: 18 pages, 10 figure
Fluctuations as probe of the QCD phase transition and freeze-out in heavy ion collisions at LHC and RHIC
We discuss the relevance of higher order moments of net baryon number
fluctuations for the analysis of freeze-out and critical conditions in heavy
ion collisions at LHC and RHIC. Using properties of O(4) scaling functions, we
discuss the generic structure of these higher moments at vanishing baryon
chemical potential and apply chiral model calculations to explore their
properties at non-zero baryon chemical potential. We show that the ratios of
the sixth to second and eighth to second order moments of the net baryon number
fluctuations change rapidly in the transition region of the QCD phase diagram.
Already at vanishing baryon chemical potential they deviate considerably from
the predictions of the hadron resonance gas model which reproduce the second to
fourth order moments of the net proton number fluctuations at RHIC. We point
out that the sixth order moments of baryon number and electric charge
fluctuations remain negative at the chiral transition temperature. Thus, they
offer the possibility to probe the proximity of the thermal freeze-out to the
crossover line.Comment: 24 pages, 12 EPS files, revised version, to appear in EPJ
Genetic background determines the nature of immune responses and experimental immune-mediated blepharoconjunctivitis (EC)
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