361 research outputs found
Oval of Aurorae Borealis and the Ring Current in the Earth's Magnetosphere
Oval of aurora borealis and ring current in earth magnetospher
Magnetic Field in the Tail of the Magnetosphere and Its Dimensions
Index of magnetic activity and variations of geomagnetic dimensions of magnetosphere tai
Superrigid subgroups and syndetic hulls in solvable Lie groups
This is an expository paper. It is not difficult to see that every group
homomorphism from the additive group Z of integers to the additive group R of
real numbers extends to a homomorphism from R to R. We discuss other examples
of discrete subgroups D of connected Lie groups G, such that the homomorphisms
defined on D can ("virtually") be extended to homomorphisms defined on all of
G. For the case where G is solvable, we give a simple proof that D has this
property if it is Zariski dense. The key ingredient is a result on the
existence of syndetic hulls.Comment: 17 pages. This is the final version that will appear in the volume
"Rigidity in Dynamics and Geometry," edited by M. Burger and A. Iozzi
(Springer, 2002
The effects of the small t properties of hadronic scattering amplitude on the determination its real part
Taking into account the different forms of the Coulomb-hadron interference
phase and the possible spin-flip contribution the new analysis of the
experimental data of the proton-antiproton elastic scattering at GeV/c and small momentum transfer is carried out. It is shown that the
size of the spin-flip amplitude can be determined from the form of the
differential cross sections at small , and the deviation of
obtained from the examined experimental data of the scattering from
the analysis \cite{Kroll}, based on the dispersion relations, is conserved in
all xamined assumptions. The analysis of the proton-proton elastic scattering
at GeV/c also shows the impact of the examined effects on the
form of the differential cross sections.Comment: 13 pages, 3 figure
Hypernuclei as chiral solitons
The identification of flavored multiskyrmions with the ground states of known
hypernuclei is successful for several of them, e.g. for isodoublet H(Lambda) -
He(Lambda), A=4, isoscalars He(Lambda) (A=5) and Li(Lambda) (A=7). In other
cases agreement is not so good, but the behaviour of the binding energy with
increasing baryon number is in qualitative agreement with data. Charmed or
beauty hypernuclei within this approach are predicted to be bound stronger than
strange hypernuclei. This conclusion is stable against variation of poorly
known heavy flavor decay constants.Comment: 9 pages, 1 Fig. Presented at the International Workshops on Nuclear
and Particle Physics at 50-Gev PS, NP01 (KEK, Japan, December 2001) and NP02
(Kyoto, Japan, September 2002). Some additions and corrections of numerical
results are mad
Modelling of large-scale structures arising under developed turbulent convection in a horizontal fluid layer (with application to the problem of tropical cyclone origination)
International audienceThe work is concerned with the results of theoretical and laboratory modelling the processes of the large-scale structure generation under turbulent convection in the rotating-plane horizontal layer of an incompressible fluid with unstable stratification. The theoretical model describes three alternative ways of creating unstable stratification: a layer heating from below, a volumetric heating of a fluid with internal heat sources and combination of both factors. The analysis of the model equations show that under conditions of high intensity of the small-scale convection and low level of heat loss through the horizontal layer boundaries a long wave instability may arise. The condition for the existence of an instability and criterion identifying the threshold of its initiation have been determined. The principle of action of the discovered instability mechanism has been described. Theoretical predictions have been verified by a series of experiments on a laboratory model. The horizontal dimensions of the experimentally-obtained long-lived vortices are 4Γ·6 times larger than the thickness of the fluid layer. This work presents a description of the laboratory setup and experimental procedure. From the geophysical viewpoint the examined mechanism of the long wave instability is supposed to be adequate to allow a description of the initial step in the evolution of such large-scale vortices as tropical cyclones - a transition form the small-scale cumulus clouds to the state of the atmosphere involving cloud clusters (the stage of initial tropical perturbation)
Pion and Sigma Polarizabilities and Radiative Transitions
Fermilab E781 plans measurements of gamma-Sigma and -pion
interactions using a 600 GeV beam of Sigmas and pions, and a virtual photon
target. Pion polarizabilities and radiative transitions will be measured in
this experiment. The former can test a precise prediction of chiral symmetry;
the latter for a_1(1260) ----> pi + gamma is important for understanding the
polarizability. The experiment also measures polarizabilities and radiative
transitions for Sigma hyperons. The polarizabilities can test predictions of
baryon chiral perturbation theory. The radiative transitions to the
Sigma*(1385) provide a measure of the magnetic moment of the s-quark. Previous
experimental and theoretical results for gamma-pi and gamma-Sigma interactions
are given. The E781 experiment is described.Comment: 13 pages text (tex), Tel Aviv U. Preprint TAUP 2204-94, uses
Springer-Verlag TEX macro package lecproc.cmm (appended at end of tex file,
following \byebye), which requires extracting lecproc.cmm and putting this
file in your directory in addition to the tex file (mmcd.tex) before tex
processing. lecproc.cmm should be used following instructions and guidelines
available from Springer-Verlag. Submitted to the Proceedings of Workshop on
Chiral Dynamics, Massachusetts Institute of Technology, July 1994, Eds. A.
Bernstein, B. Holstein. Replaced Oct. 4 to add TAUP preprint number. Replaced
Oct. 12 to correct Pb target thickness from 1.3% interaction to 0.3
ΠΠ°ΠΏΡΡΠΆΠ΅Π½ΠΈΡ Π² ΠΏΠ»Π°ΡΡΠΈΠ½Π°Ρ ΠΊΡΠ΅ΠΌΠ½ΠΈΡ, Π²ΠΎΠ·Π½ΠΈΠΊΠ°ΡΡΠΈΠ΅ Π² ΡΠ΅Π·ΡΠ»ΡΡΠ°ΡΠ΅ Π»ΠΎΠΊΠ°Π»ΡΠ½ΠΎΠ³ΠΎ ΡΠΎΡΠΎΠ½Π½ΠΎΠ³ΠΎ ΠΎΡΠΆΠΈΠ³Π°
The effect of photon annealing on the occurrence of deformations in the crystal structure of boronβdoped silicon wafers produced by the Czochralski (CzβSi) was studied by the method of tripleβXβray diffraction. It was found that the traditional annealing of silicon wafers with polished surfaces on both sides by halogen lamps in Photonic Annealing (PA) and rapid thermal annealing modes (RTA) leads to compression deformation. The same process with the use of original photoβ mask, which allows local processing produces multiple, spatially separated regions of the plate produced by LΠΎΡΠ°l Photonic Annealing (LPA) at relatively low temperatures (less than 55 Β°C), gives rise to a tensile strain. This established effect is not observed if on the back side of the plates there is mechanical gettering layer. The mechanism explaining the experimental results can be used in the formation of the charge pump in the structure of the photo electric converters (PEC).ΠΠ΅ΡΠΎΠ΄ΠΎΠΌ ΡΡΠ΅Ρ
ΠΊΡΠΈΡΡΠ°Π»ΡΠ½ΠΎΠΉ ΡΠ΅Π½ΡΠ³Π΅Π½ΠΎΠ²ΡΠΊΠΎΠΉ Π΄ΠΈΡΡΠ°ΠΊΡΠΎΠΌΠ΅ΡΡΠΈΠΈ ΠΈΡΡΠ»Π΅Π΄ΠΎΠ²Π°Π½ΠΎ Π²Π»ΠΈΡΠ½ΠΈΠ΅ ΡΠΎΡΠΎΠ½Π½ΠΎΠ³ΠΎ ΠΎΡΠΆΠΈΠ³Π° Π½Π° Π²ΠΎΠ·Π½ΠΈΠΊΠ½ΠΎΠ²Π΅Π½ΠΈΠ΅ Π΄Π΅ΡΠΎΡΠΌΠ°ΡΠΈΠΉ Π² ΠΊΡΠΈΡΡΠ°Π»Π»ΠΈΡΠ΅ΡΠΊΠΎΠΉ ΡΡΡΡΠΊΡΡΡΠ΅ Π»Π΅Π³ΠΈΡΠΎΠ²Π°Π½Π½ΡΡ
Π±ΠΎΡΠΎΠΌ ΠΊΡΠ΅ΠΌΠ½ΠΈΠ΅Π²ΡΡ
ΠΏΠ»Π°ΡΡΠΈΠ½, ΠΏΠΎΠ»ΡΡΠ΅Π½Π½ΡΡ
ΠΏΠΎ ΠΌΠ΅ΡΠΎΠ΄Ρ Π§ΠΎΡ
ΡΠ°Π»ΡΡΠΊΠΎΠ³ΠΎ (CzβSi). Π£ΡΡΠ°Π½ΠΎΠ²Π»Π΅Π½ΠΎ, ΡΡΠΎ ΡΡΠ°Π΄ΠΈΡΠΈΠΎΠ½Π½ΡΠΉ ΠΎΡΠΆΠΈΠ³ Π²ΡΠ΅ΠΉ ΠΏΠΎΠ²Π΅ΡΡ
Π½ΠΎΡΡΠΈ Π΄Π²ΡΡΡΠΎΡΠΎΠ½Π½Π΅ ΠΏΠΎΠ»ΠΈΡΠΎΠ²Π°Π½Π½ΡΡ
ΠΏΠ»Π°ΡΡΠΈΠ½ ΠΊΡΠ΅ΠΌΠ½ΠΈΡ Π³Π°Π»ΠΎΠ³Π΅Π½Π½ΡΠΌΠΈ Π»Π°ΠΌΠΏΠ°ΠΌΠΈ (ΡΠ΅ΠΆΠΈΠΌ ΡΠΎΡΠΎΠ½Π½ΠΎΠ³ΠΎ ΠΎΡΠΆΠΈΠ³Π°) Π² ΡΠ΅ΠΆΠΈΠΌΠ°Ρ
Π±ΡΡΡΡΠΎΠ³ΠΎ ΡΠ΅ΡΠΌΠΈΡΠ΅ΡΠΊΠΎΠ³ΠΎ ΠΎΡΠΆΠΈΠ³Π° ΠΏΡΠΈΠ²ΠΎΠ΄ΠΈΡ ΠΊ Π²ΠΎΠ·Π½ΠΈΠΊΠ½ΠΎΠ²Π΅Π½ΠΈΡ Π΄Π΅ΡΠΎΡΠΌΠ°ΡΠΈΠΉ ΡΠΆΠ°ΡΠΈΡ. Π’ΠΎΡ ΠΆΠ΅ ΠΏΡΠΎΡΠ΅ΡΡ Ρ ΠΈΡΠΏΠΎΠ»ΡΠ·ΠΎΠ²Π°Π½ΠΈΠ΅ΠΌ ΠΎΡΠΈΠ³ΠΈΠ½Π°Π»ΡΠ½ΡΡ
ΡΠΎΡΠΎΠΌΠ°ΡΠΎΠΊ, ΠΏΠΎΠ·Π²ΠΎΠ»ΡΡΡΠΈΡ
Π»ΠΎΠΊΠ°Π»ΡΠ½ΠΎ ΠΏΡΠΎΠ²ΠΎΠ΄ΠΈΡΡ ΠΎΠ±ΡΠ°Π±ΠΎΡΠΊΡ ΠΌΠ½ΠΎΠΆΠ΅ΡΡΠ²Π΅Π½Π½ΡΡ
, ΠΏΡΠΎΡΡΡΠ°Π½ΡΡΠ²Π΅Π½Π½ΠΎ ΡΠ°Π·Π΄Π΅Π»Π΅Π½Π½ΡΡ
ΠΎΠ±Π»Π°ΡΡΠ΅ΠΉ ΠΏΠ»Π°ΡΡΠΈΠ½Ρ (ΡΠ΅ΠΆΠΈΠΌ Π»ΠΎΠΊΠ°Π»ΡΠ½ΠΎΠ³ΠΎ ΡΠΎΡΠΎΠ½Π½ΠΎΠ³ΠΎ ΠΎΡΠΆΠΈΠ³Π°) ΠΏΡΠΈ ΠΎΡΠ½ΠΎΡΠΈΡΠ΅Π»ΡΠ½ΠΎ Π½ΠΈΠ·ΠΊΠΈΡ
ΡΠ΅ΠΌΠΏΠ΅ΡΠ°ΡΡΡΠ°Ρ
ΠΎΠ±ΡΠ°Π±Π°ΡΡΠ²Π°Π΅ΠΌΠΎΠΉ ΠΏΠ»Π°ΡΡΠΈΠ½Ρ (ΠΌΠ΅Π½Π΅Π΅ 55Β°Π‘), ΠΏΡΠΈΠ²ΠΎΠ΄ΠΈΡ ΠΊ Π²ΠΎΠ·Π½ΠΈΠΊΠ½ΠΎΠ²Π΅Π½ΠΈΡ Π΄Π΅ΡΠΎΡΠΌΠ°ΡΠΈΠΉ ΡΠ°ΡΡΡΠΆΠ΅Π½ΠΈΡ. Π£ΡΡΠ°Π½ΠΎΠ²Π»Π΅Π½Π½ΡΠΉ ΡΡΡΠ΅ΠΊΡ Π½Π΅ Π½Π°Π±Π»ΡΠ΄Π°Π΅ΡΡΡ ΠΏΡΠΈ Π½Π°Π»ΠΈΡΠΈΠΈ Π½Π° ΡΡΠ»ΡΠ½ΠΎΠΉ ΡΡΠΎΡΠΎΠ½Π΅ ΠΏΠ»Π°ΡΡΠΈΠ½ ΠΌΠ΅Ρ
Π°Π½ΠΈΡΠ΅ΡΠΊΠΎΠ³ΠΎ Π³Π΅ΡΡΠ΅ΡΠΈΡΡΡΡΠ΅Π³ΠΎ ΡΠ»ΠΎΡ. ΠΡΠ΅Π΄Π»ΠΎΠΆΠ΅Π½ ΠΌΠ΅Ρ
Π°Π½ΠΈΠ·ΠΌ, ΠΎΠ±ΡΡΡΠ½ΡΡΡΠΈΠΉ ΠΏΠΎΠ»ΡΡΠ΅Π½Π½ΡΠ΅ ΡΠΊΡΠΏΠ΅ΡΠΈΠΌΠ΅Π½ΡΠ°Π»ΡΠ½ΡΠ΅ ΡΠ΅Π·ΡΠ»ΡΡΠ°ΡΡ, ΠΊΠΎΡΠΎΡΡΠΉ ΠΌΠΎΠΆΠ΅Ρ Π±ΡΡΡ ΠΈΡΠΏΠΎΠ»ΡΠ·ΠΎΠ²Π°Π½ ΠΏΡΠΈ ΡΠΎΡΠΌΠΈΡΠΎΠ²Π°Π½ΠΈΠΈ Π·Π°ΡΡΠ΄ΠΎΠ²ΡΡ
Π½Π°ΡΠΎΡΠΎΠ² Π² ΡΡΡΡΠΊΡΡΡΠ΅ ΡΠΎΡΠΎΡΠ»Π΅ΠΊΡΡΠΈΡΠ΅ΡΠΊΠΈΡ
ΠΏΡΠ΅ΠΎΠ±ΡΠ°Π·ΠΎΠ²Π°ΡΠ΅Π»Π΅ΠΉ
Recent Developments And Validations in Geant4 Hadronic Physics
The Geant4 hadronic models cover the entire range of energies required by calorimeters in new and planned experiments. The extension and improvement of the elastic, cascade, parameterized and quark-gluon string models will be discussed. Such improvements include the extension to more particle types, a review and correction of cross sections, and a better treatment of energy and momentum conservation. Concurrent with this development has been a validation program which includes comparisons with double differential cross sections. An ongoing hadronic shower validation will also be discussed which includes the examination of longitudinal shower shapes and the performance of the above models as well as their interaction with electromagnetic processes such as multiple scattering
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