15,557 research outputs found
Search for new physics in -mixing
We present the current status of the search for new physics effects in the
mixing quantities , and of the neutral
-system.Comment: Invited talk at Continuous Advances in QCD (CAQCD-08), May 15-18,
2008, Minneapolis; 9 pages; 2 References adde
Star formation in a diffuse high-altitude cloud?
A recent discovery of two stellar clusters associated with the diffuse
high-latitude cloud HRK 81.4-77.8 has important implications for star formation
in the Galactic halo. We derive a plausible distance estimate to HRK 81.4-77.8
primarily from its gaseous properties. We spatially correlate state-of-the-art
HI, far-infrared and soft X-ray data to analyze the diffuse gas in the cloud.
The absorption of the soft X-ray emission from the Galactic halo by HRK
81.4-77.8 is used to constrain the distance to the cloud. HRK 81.4-77.8 is most
likely located at an altitude of about 400 pc within the disk-halo interface of
the Milky Way Galaxy. The HI data discloses a disbalance in density and
pressure between the warm and cold gaseous phases. Apparently, the cold gas is
compressed by the warm medium. This disbalance might trigger the formation of
molecular gas high above the Galactic plane on pc to sub-pc scales.Comment: 6 pages, 4 figures, accepted for publication in Astronomy &
Astrophysic
Signatures of Confinement in Axial Gauge QCD
A comparative dynamical study of axial gauge QED and QCD is presented.
Elementary excitations associated with particular field configurations are
investigated. Gluonic excitations analogous to linearly polarized photons are
shown to acquire infinite energy. Suppression of this class of excitations in
QCD results from quantization of the chromelectric flux and is interpreted as a
dual Meissner effect, i.e. as expulsion from the QCD vacuum of chromo-electric
fields which are constant over significant distances. This interpretation is
supported by a comparative evaluation of the interaction energy of static
charges in the axial gauge representation of QED and QCD.Comment: 22 pages (no figures
The large CP phase in B(s)-anti-B(s) mixing from primary scalar unparticles
In this letter we consider the case of primary scalar unparticle
contributions to B(d,s) mixing. With particular emphasis on the impact of the
recent hint of new physics in the measurement of the B(s) mixing phase, phi(s),
we determine the allowed parameter space and impose bounds on the unparticle
couplings.Comment: 8 pages, 8 jpeg figures, using pdflatex. Typo corrected, reference
adde
Second constant of motion for two-dimensional positronium in a magnetic field
Recent numerical work indicates that the classical motion of positronium in a
constant magnetic field does not exhibit chaotic behavior if the system is
confined to two dimensions. One would therefore expect this system to possess a
second constant of the motion in addition to the total energy. In this paper we
construct a generalization of the Laplace-Runge-Lenz vector and show that a
component of this vector is a constant of the motion.Comment: 4 pages, no figure
Uniform existence of the integrated density of states for random Schr\"odinger operators on metric graphs over
We consider ergodic random magnetic Schr\"odinger operators on the metric
graph with random potentials and random boundary conditions
taking values in a finite set. We show that normalized finite volume eigenvalue
counting functions converge to a limit uniformly in the energy variable. This
limit, the integrated density of states, can be expressed by a closed
Shubin-Pastur type trace formula. It supports the spectrum and its points of
discontinuity are characterized by existence of compactly supported
eigenfunctions. Among other examples we discuss percolation models.Comment: 17 pages; typos removed, references updated, definition of subgraph
densities explaine
-approximation of the integrated density of states for Schr\"odinger operators with finite local complexity
We study spectral properties of Schr\"odinger operators on \RR^d. The
electromagnetic potential is assumed to be determined locally by a colouring of
the lattice points in \ZZ^d, with the property that frequencies of finite
patterns are well defined. We prove that the integrated density of states
(spectral distribution function) is approximated by its finite volume
analogues, i.e.the normalised eigenvalue counting functions. The convergence
holds in the space where is any finite energy interval and is arbitrary.Comment: 15 pages; v2 has minor fixe
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