3,714 research outputs found
Constraining CP-Violating TGCs and Measuring W-Polarization at OPAL
A measurement of the polarization of W bosons in semi-leptonically decaying W
pairs produced at 189 GeV is presented. Rates of longitudinally and
transversely polarized W bosons and correlation between two W bosons are
studied. The spin properties of the leptonically decaying W boson in the W
pairs was used to measure the CP-violating trilinear gauge boson couplings.
These results are compared with Standard Model expectations.Comment: Proceedings of the XXXth International Symposium on Multiparticle
Dynamics (ISMD2000), 9-15 October 2000, Tihany, Hungary. 6 pages, 2 figures
(LaTex, encapsulated PostScript
Anomalous Transport in Velocity Space, from Fokker-Planck to General Equation
The problem of anomalous diffusion in momentum (velocity) space is considered
based on the master equation and the appropriate probability transition
function (PTF). The approach recently developed by the author for coordinate
space, is applied with necessary modifications to velocity space. A new general
equation for the time evolution of the momentum distribution function in
momentum space is derived. This allows the solution of various problems of
anomalous transport when the probability transition function (PTF) has a long
tail in momentum space. For the opposite cases of the PTF rapidly decreasing as
a function of transfer momenta (when large transfer momenta are strongly
suppressed), the developed approach allows us to consider strongly
non-equilibrium cases of the system evolution. The stationary and
non-stationary solutions are studied. As an example, the particular case of the
Boltzmann-type PT-function for collisions of heavy and light particles with the
determined (prescribed) distribution function, which can be strongly
non-equilibrium, is considered within the proposed general approach. The
appropriate diffusion and friction coefficients are found. The Einstein
relation between the friction and diffusion coefficients is shown to be
violated in these cases.Comment: 23 pages, 0 figure
Quantum nature of the critical points of substances
Thermodynamics of chemical elements, based on the two-component
electron-nuclear plasma model shows that the critical parameters for the
liquid-vapor transition are the quantum values for which the classical limit is
absent.Comment: 4 pages, no figure
Inhomogeneity of dusty crystals and plasma diagnostics
Real dusty crystals are inhomogeneous due to the presence of external forces. We suggest approximations for calculations of different types of inhomogeneous DC (chain and DC with a few slabs) in the equilibrium state. The results are in a good agreement with experimental results and can be used as an effective diagnostic method for many dusty systems
On anomalous diffusion in a plasma in velocity space
The problem of anomalous diffusion in momentum space is considered for
plasma-like systems on the basis of a new collision integral, which is
appropriate for consideration of the probability transition function (PTF) with
long tails in momentum space. The generalized Fokker-Planck equation for
description of diffusion (in momentum space) of particles (ions, grains etc.)
in a stochastic system of light particles (electrons, or electrons and ions,
respectively) is applied to the evolution of the momentum particle distribution
in a plasma. In a plasma the developed approach is also applicable to the
diffusion of particles with an arbitrary mass relation, due to the small
characteristic momentum transfer. The cases of an exponentially decreasing in
momentum space (including the Boltzmann-like) kernel in the PT-function, as
well as the more general kernels, which create the anomalous diffusion in
velocity space due to the long tail in the PT-function, are considered.
Effective friction and diffusion coefficients for plasma-like systems are
found.Comment: 18 pages, no figure
Identity of electrons and ionization equilibrium
It is perhaps appropriate that, in a year marking the 90th anniversary of
Meghnad Saha seminal paper (1920), new developments should call fresh attention
to the problem of ionization equilibrium in gases. Ionization equilibrium is
considered in the simplest "physical" model for an electronic subsystem of
matter in a rarefied state, consisting of one localized electronic state in
each nucleus and delocalized electronic states considered as free ones. It is
shown that, despite the qualitative agreement, there is a significant
quantitative difference from the results of applying the Saha formula to the
degree of ionization. This is caused by the fact that the Saha formula
corresponds to the "chemical" model of matter.Comment: 9 pages, 2 figure
Study of charge collection and noise in non-irradiated and irradiated silicon detectors
The large collection and noise were studied in non-irradiated and irradiated silicon detectors as a function of temperature (T), shaping time (0) and fluence , up to about 1,2 x 10(14) protons per cm2 for minimum-ionizing electrons yielded by a 106 Ru source. The noise of irradiated detectors is found to be dominted for short shaping times (¾50ns) by a series noise compo- nent, while for longer shaping times (80ns) a parallel noise component (correlated with the reverse current) prevails. For non-irradiated detectors, where the reverse current is three orders of magnetude smaller compared with irradiated detectors, the series noises dominates over the whole range of shaping times investigated (20-150ns). A signal degradation is observed for irradiated detectors. However, the signal ca be distinguished from noise, even after a fluence of about 1.2 x10(14) protons per cm2, at a temperature of 6øC and with a shaping time tipical of rge LHC inter-bunch crossing time (20-30ns). The measurements of the signal as a function of voltage shows that irradiated detectors depleted at 50% of the full depletion voltage can still provide a measurable signal-to-noise ratio
Network analysis of a corpus of undeciphered Indus civilization inscriptions indicates syntactic organization
Archaeological excavations in the sites of the Indus Valley civilization
(2500-1900 BCE) in Pakistan and northwestern India have unearthed a large
number of artifacts with inscriptions made up of hundreds of distinct signs. To
date there is no generally accepted decipherment of these sign sequences and
there have been suggestions that the signs could be non-linguistic. Here we
apply complex network analysis techniques to a database of available Indus
inscriptions, with the aim of detecting patterns indicative of syntactic
organization. Our results show the presence of patterns, e.g., recursive
structures in the segmentation trees of the sequences, that suggest the
existence of a grammar underlying these inscriptions.Comment: 17 pages (includes 4 page appendix containing Indus sign list), 14
figure
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