25,594 research outputs found
Formation of color-singlet gluon-clusters and inelastic diffractive scattering
This is the extensive follow-up report of a recent Letter in which the
existence of self-organized criticality (SOC) in systems of interacting soft
gluons is proposed, and its consequences for inelastic diffractive scattering
processes are discussed. It is pointed out, that color-singlet gluon-clusters
can be formed in hadrons as a consequence of SOC in systems of interacting soft
gluons, and that the properties of such spatiotemporal complexities can be
probed experimentally by examing inelastic diffractive scattering. Theoretical
arguments and experimental evidences supporting the proposed picture are
presented --- together with the result of a systematic analysis of the existing
data for inelastic diffractive scattering processes performed at different
incident energies, and/or by using different beam-particles. It is shown in
particular that the size- and the lifetime-distributions of such gluon-clusters
can be directly extracted from the data, and the obtained results exhibit
universal power-law behaviors --- in accordance with the expected
SOC-fingerprints. As further consequences of SOC in systems of interacting soft
gluons, the -dependence and the -dependence of the double
differential cross-sections for inelastic diffractive scattering off
proton-target are discussed. Here stands for the four-momentum-transfer
squared, for the missing mass, and for the total c.m.s.
energy. It is shown, that the space-time properties of the color-singlet
gluon-clusters due to SOC, discussed above, lead to simple analytical formulae
for and for , and that the obtained
results are in good agreement with the existing data. Further experiments are
suggested.Comment: 67 pages, including 11 figure
A Typical Medium Dynamical Cluster Approximation for the Study of Anderson Localization in Three Dimensions
We develop a systematic typical medium dynamical cluster approximation that
provides a proper description of the Anderson localization transition in three
dimensions (3D). Our method successfully captures the localization phenomenon
both in the low and large disorder regimes, and allows us to study the
localization in different momenta cells, which renders the discovery that the
Anderson localization transition occurs in a cell-selective fashion. As a
function of cluster size, our method systematically recovers the re-entrance
behavior of the mobility edge and obtains the correct critical disorder
strength for Anderson localization in 3D.Comment: 5 Pages, 4 Figures and Supplementary Material include
Finite density phase transition of QCD with and using canonical ensemble method
In a progress toward searching for the QCD critical point, we study the
finite density phase transition of and 2 lattice QCD at finite
temperature with the canonical ensemble approach. We develop a winding number
expansion method to accurately project out the particle number from the fermion
determinant which greatly extends the applicable range of baryon number sectors
to make the study feasible. Our lattice simulation was carried out with the
clover fermions and improved gauge action. For a given temperature, we
calculate the baryon chemical potential from the canonical approach to look for
the mixed phase as a signal for the first order phase transition. In the case
of , we observe an "S-shape" structure in the chemical potential-density
plane due to the surface tension of the mixed phase in a finite volume which is
a signal for the first order phase transition. We use the Maxwell construction
to determine the phase boundaries for three temperatures below . The
intersecting point of the two extrapolated boundaries turns out to be at the
expected first order transition point at with . This serves as a
check for our method of identifying the critical point. We also studied the
case, but do not see a signal of the mixed phase for temperature as
low as 0.83 .Comment: 28 pages, 11 figures,references added, final versio
Analytic continuation of single-particle resonance energy and wave function in relativistic mean field theory
Single-particle resonant states in spherical nuclei are studied by an
analytic continuation in the coupling constant (ACCC) method within the
framework of the self-consistent relativistic mean field (RMF) theory. Taking
the neutron resonant state in Ca as an example, we
examine the analyticity of the eigenvalue and eigenfunction for the Dirac
equation with respect to the coupling constant by means of a \pade
approximant of the second kind. The RMF-ACCC approach is then applied to
Zr and, for the first time, this approach is employed to investigate
both the energies, widths and wave functions for resonant states close
to the continuum threshold. Predictions are also compared with corresponding
results obtained from the scattering phase shift method.Comment: 19 pages, 9 figure
Constraining Radon Backgrounds in LZ
The LZ dark matter detector, like many other rare-event searches, will suffer
from backgrounds due to the radioactive decay of radon daughters. In order to
achieve its science goals, the concentration of radon within the xenon should
not exceed Bq/kg, or 20 mBq total within its 10 tonnes. The LZ
collaboration is in the midst of a program to screen all significant components
in contact with the xenon. The four institutions involved in this effort have
begun sharing two cross-calibration sources to ensure consistent measurement
results across multiple distinct devices. We present here five preliminary
screening results, some mitigation strategies that will reduce the amount of
radon produced by the most problematic components, and a summary of the current
estimate of radon emanation throughout the detector. This best estimate totals
mBq, sufficiently low to meet the detector's science goals.Comment: Low Radioactivity Techniques (LRT) 2017 Workshop Proceedings. 6
pages; 3 figure
Study the Heavy Molecular States in Quark Model with Meson Exchange Interaction
Some charmonium-like resonances such as X(3872) can be interpreted as
possible molecular states. Within the quark model, we study
the structure of such molecular states and the similar
molecular states by taking into account of the light meson exchange (,
, , and ) between two light quarks from different
mesons
Pressure dependence of the superconducting transition and electron correlations in Na_xCoO_2 \cdot 1.3H_2O
We report T_c and ^{59}Co nuclear quadrupole resonance (NQR) measurements on
the cobalt oxide superconductor Na_{x}CoO_{2}\cdot 1.3H_{2}O (T_c=4.8 K) under
hydrostatic pressure (P) up to 2.36 GPa. T_c decreases with increasing pressure
at an average rate of -0.49\pm0.09 K/GPa. At low pressures P\leq0.49 GPa, the
decrease of T_c is accompanied by a weakening of the spin correlations at a
finite wave vector and a reduction of the density of states (DOS) at the Fermi
level. At high pressures above 1.93 GPa, however, the decrease of T_c is mainly
due to a reduction of the DOS. These results indicate that the
electronic/magnetic state of Co is primarily responsible for the
superconductivity. The spin-lattice relaxation rate 1/T_1 at P=0.49 GPa shows a
T^3 variation below T_c down to T\sim 0.12T_c, which provides compelling
evidence for the presence of line nodes in the superconducting gap function.Comment: published on 19, Sept. 2007 on Phys. Rev.
Combining Syntactic and Semantic Bidirectionalization
Matsuda et al. [2007, ICFP] and Voigtlander [2009, POPL] introduced two techniques that given a source-to-view function provide an update propagation function mapping an original source and an updated view back to an updated source, subject to standard consistency conditions. Being fundamentally different in approach, both
techniques have their respective strengths and weaknesses. Here we develop a synthesis of the two techniques to good effect. On the intersection of their applicability domains we achieve more than what a simple union of applying the techniques side by side deliver
The pseudo-spin symmetry in Zr and Sn isotopes from the proton drip line to the neutron drip line
Based on the Relativistic continuum Hartree-Bogoliubov (RCHB) theory, the
pseudo-spin approximation in exotic nuclei is investigated in Zr and Sn
isotopes from the proton drip line to the neutron drip line. The quality of the
pseudo-spin approximation is shown to be connected with the competition between
the centrifugal barrier (CB) and the pseudo-spin orbital potential (PSOP). The
PSOP depends on the derivative of the difference between the scalar and vector
potentials . If , the pseudo-spin symmetry is exact. The
pseudo-spin symmetry is found to be a good approximation for normal nuclei and
to become much better for exotic nuclei with highly diffuse potential, which
have . The energy splitting of the pseudo-spin partners is
smaller for orbitals near the Fermi surface (even in the continuum) than the
deeply bound orbitals. The lower components of the Dirac wave functions for the
pseudo-spin partners are very similar and almost equal in magnitude.Comment: 22 pages, 9figure
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