1,812 research outputs found
Pionic BEC--BCS crossover at finite isospin chemical potential
We study the character change of the pionic condensation at finite isospin
chemical potential \mu_\mathrm{I} by adopting the linear sigma model as a
non-local interaction between quarks. At low |\mu_\mathrm{I}| the condensation
is purely bosonic, then the Cooper pairing around the Fermi surface grows
gradually as |\mu_\mathrm{I}| increases. This q-\bar q pairing is weakly
coupled in comparison with the case of the q-q pairing that leads to color
superconductivity.Comment: 17 pages, 3 figures, typos in eq.(6) and refs.[37] and [41] are
corrected, published in Phys. Rev.
High-K Precession modes: Axially symmetric limit of wobbling motion
The rotational band built on the high-K multi-quasiparticle state can be
interpreted as a multi-phonon band of the precession mode, which represents the
precessional rotation about the axis perpendicular to the direction of the
intrinsic angular momentum. By using the axially symmetric limit of the
random-phase-approximation (RPA) formalism developed for the nuclear wobbling
motion, we study the properties of the precession modes in W; the
excitation energies, B(E2) and B(M1) values. We show that the excitations of
such a specific type of rotation can be well described by the RPA formalism,
which gives a new insight to understand the wobbling motion in the triaxial
superdeformed nuclei from a microscopic view point.Comment: 14 pages, 8 figures (Spelling of the authors name was wrong at the
first upload, so it is corrected
Wobbling Motion in Atomic Nuclei with Positive-Gamma Shapes
The three moments of inertia associated with the wobbling mode built on the
superdeformed states in 163Lu are investigated by means of the cranked shell
model plus random phase approximation to the configuration with an aligned
quasiparticle. The result indicates that it is crucial to take into account the
direct contribution to the moments of inertia from the aligned quasiparticle so
as to realize J_x > J_y in positive-gamma shapes. Quenching of the pairing gap
cooperates with the alignment effect. The peculiarity of the recently observed
163Lu data is discussed by calculating not only the electromagnetic properties
but also the excitation spectra.Comment: 11 pages, 6 figure
Parametrizations of triaxial deformation and E2 transitions of the wobbling band
By the very definition the triaxial deformation parameter is related
to the expectation values of the K=0 and K=2 components of the intrinsic
quadrupole tensor operator. On the other hand, using the same symbol
"", various different parametrizations of triaxial deformation have
been employed, which are suitable for various types of the mean-field
potentials. It is pointed out that the values of various "" are quite
different for the same actual triaxial deformation, especially for the large
deformation; for example, the difference can be almost a factor two for the
case of the triaxial superdeformed bands recently observed in the Hf and Lu
nuclei. In our previous work, we have studied the wobbling band in Lu nuclei by
using the microscopic framework of the cranked Nilsson mean-field and the
random phase approximation, where the most serious problem is that the
calculated B(E2) value is about factor two smaller. It is shown that the origin
of this underestimation can be mainly attributed to the small triaxial
deformation; if is used the same triaxial deformation as in the analysis of the
particle-rotor model, the calculated B(E2) increases and gives correct
magnitude compared with the experimental data.Comment: 10 pages, 9 figure
One-Loop Corrections to the S and T Parameters in a Three Site Higgsless Model
In this paper we compute the the one-loop chiral logarithmic corrections to
the S and T parameters in a highly deconstructed Higgsless model with only
three sites. In addition to the electroweak gauge bosons, this model contains a
single extra triplet of vector states (which we denote \rho^{\pm} and \rho^0),
rather than an infinite tower of "KK" modes. We compute the corrections to S
and T in 'tHooft-Feynman gauge, including the ghost, unphysical
Goldstone-boson, and appropriate "pinch" contributions required to obtain
gauge-invariant results for the one-loop self-energy functions. We demonstrate
that the chiral-logarithmic corrections naturally separate into two parts, a
model-independent part arising from scaling below the \rho mass, which has the
same form as the large Higgs-mass dependence of the S or T parameter in the
standard model, and a second model-dependent contribution arising from scaling
between the \rho mass and the cutoff of the model. The form of the universal
part of the one-loop result allows us to correctly interpret the
phenomenologically derived limits on the S and T parameters (which depend on a
"reference" Higgs-boson mass) in this three-site Higgsless model. Higgsless
models may be viewed as dual to models of dynamical symmetry breaking akin to
"walking technicolor", and in these terms our calculation is the first to
compute the subleading 1/N corrections to the S and T parameters. We also
discuss the reduction of the model to the ``two-site'' model, which is the
usual electroweak chiral lagrangian, noting the ``non-decoupling''
contributions present in the limit as M_\rho goes to infinity.Comment: 58 pages; uses JHEP and axodraw. Extensively corrected to incorporate
consistent perturbative expansion, additional pinch contributions, and
running of delocalization parameter. Footnotes adde
A Solution for Little Hierarchy Problem and b --> s gamma
We show that all the parameters which destabilize the weak scale can be taken
around the weak scale in the MSSM without conflicting with the SM Higgs mass
bound set by LEP experiment. The essential point is that if the lightest
CP-even Higgs h in the MSSM has only a small coupling to Z boson, g_{ZZh}, LEP
cannot generate the Higgs sufficiently. In the scenario, the SM Higgs mass
bound constrains the mass of the heaviest CP-even Higgs H which has the SM like
g_{ZZH} coupling. However, it is easier to make the heaviest Higgs heavy by the
effect of off-diagonal elements of the mass matrix of the CP-even Higgs because
the larger eigenvalue of 2 times 2 matrix becomes larger by introducing
off-diagonal elements. Thus, the smaller stop masses can be consistent with the
LEP constraints. Moreover, the two excesses observed at LEP Higgs search can
naturally be explained as the signals of the MSSM Higgs h and H in this
scenario. One of the most interesting results in the scenario is that all the
Higgs in the MSSM have the weak scale masses. For example, the charged Higgs
mass should be around 130 GeV. This looks inconsistent with the lower bound
obtained by the b --> s gamma process as m_{H^\pm}>350GeV. However, we show
that the amplitude induced by the charged Higgs can naturally be compensated by
that of the chargino if we take the mass parameters by which the little
hierarchy problem can be solved. The point is that the both amplitudes have the
same order of magnitudes when all the fields in the both loops have the same
order of masses.Comment: 14 pages, 5 figures, input parameter slightly changed, figures
replaced, references correcte
AKARI-CAS --- Online Service for AKARI All-Sky Catalogues
The AKARI All-Sky Catalogues are an important infrared astronomical database
for next-generation astronomy that take over the IRAS catalog. We have
developed an online service, AKARI Catalogue Archive Server (AKARI-CAS), for
astronomers. The service includes useful and attractive search tools and visual
tools.
One of the new features of AKARI-CAS is cached SIMBAD/NED entries, which can
match AKARI catalogs with other catalogs stored in SIMBAD or NED. To allow
advanced queries to the databases, direct input of SQL is also supported. In
those queries, fast dynamic cross-identification between registered catalogs is
a remarkable feature. In addition, multiwavelength quick-look images are
displayed in the visualization tools, which will increase the value of the
service.
In the construction of our service, we considered a wide variety of
astronomers' requirements. As a result of our discussion, we concluded that
supporting users' SQL submissions is the best solution for the requirements.
Therefore, we implemented an RDBMS layer so that it covered important
facilities including the whole processing of tables. We found that PostgreSQL
is the best open-source RDBMS products for such purpose, and we wrote codes for
both simple and advanced searches into the SQL stored functions. To implement
such stored functions for fast radial search and cross-identification with
minimum cost, we applied a simple technique that is not based on dividing
celestial sphere such as HTM or HEALPix. In contrast, the Web application layer
became compact, and was written in simple procedural PHP codes. In total, our
system realizes cost-effective maintenance and enhancements.Comment: Yamauchi, C. et al. 2011, PASP..123..852
Quasiparticles and Energy Scaling in BiSrCaCuO (=1-3): Angle-Resolved Photoemission Spectroscopy
Angle-resolved photoemission spectroscopy (ARPES) has been performed on the
single- to triple-layered Bi-family high-{\it T} superconductors
(BiSrCaCuO, =1-3). We found a sharp
quasiparticle peak as well as a pseudogap at the Fermi level in the
triple-layered compound. Comparison among three compounds has revealed a
universal rule that the characteristic energies of superconducting and
pseudogap behaviors are scaled with the maximum {\it T}.Comment: 4 pages, 4 figure
An ocean–ice coupled response during the last glacial: a view from a marine isotopic stage 3 record south of the Faeroe Shetland Gateway
150 μm) lithic fraction (grain concentration) and the analysis of selected biogenic proxies (assemblages and stable isotope ratio of calcareous planktonic foraminifera, dinoflagellate cyst – e.g. dinocyst – assemblages). Results presented here are focussed on the dinocyst response, this proxy providing the reconstruction of past sea-surface hydrological conditions, qualitatively as well as quantitatively (e.g. transfer function sensu lato). Our study documents a very coherent and sensitive oceanic response to the MIS3 rapid climatic variability: strong fluctuations, matching those of stadial/interstadial climatic oscillations as depicted by Greenland ice cores, are recorded in the MD99-2281 archive. Proxies of terrigeneous and detritical material suggest increases in continental advection during Greenland Stadials (including Heinrich events), the latter corresponding also to southward migrations of polar waters. At the opposite, milder sea-surface conditions seem to develop during Greenland Interstadials. After 30 ka, reconstructed paleohydrological conditions evidence strong shifts in SST: this increasing variability seems consistent with the hypothesised coalescence of the British and Fennoscandian ice sheets at that time, which could have directly influenced sea-surface environments in the vicinity of core MD99-2281
Topcrosses in the selection of testers and inbred lines S3 for the yield and bromatological quality of silage maize.
The study aiming to evaluate the combining ability of maize partially inbred lines (S3) in crosses with testers ofnarrow genetic base aiming at the selection of the inbred lines, testers and topcross hybrids. Three simple latticetrials with 81 treatments were carried out in the 2014/2015 and 2015/2016 growing seasons. For each growingseason, trials were used to evaluate the topcross hybrids obtained in combination with the testers AG8088,DKB330 (single-cross hybrids) and 9.H33.3 (line). The hybrid AG8088 and line 9.H3.33 were the best testers forgrain yield. The line 9.H3.33 was the best tester for the traits related to yield and quality of silage maize. Theinbred lines that stood out for their combining abilities and capacity of generating great topcross hybrids with thetesters (i.e., 201-23.2, 201-59.1, 201-80.2, 201-81.5, 203-195.3, 201-100.4, 201-145.4, 201-169.3, 202-155, 202-159, 203-23, 203- 31, 203-32, 203-38, 203-75, 203-98, 203-111, 203-135, 203-139, 203-150, 203-188, 203-235,and 203-237) should be maintained in the UEM silage maize breeding program. Progenies 201-59.01, 201-100.4,203-135, 203-150, 203-235 and 203-254 were selected as tester lines of progenies derived from selfing of thetesters AG8088 and DKB330 to improve the silage maize quality. The topcross hybrids 201-95.3 x 9.H3.33, 203-71x 9.H3.33, 203-72 x 9.H3.33, 203-88 x 9.H3.33, 203-139 x 9.H3.33, and 203-150 x 9.H3.33 were selected for goodperformance for agronomic and bromatological silage maize traits. These hybrids are indicated for evaluationsin more environments, with a view to recommending commercial cultivars for grain and silage production in thefuture
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