582 research outputs found
Sensitivity of depth of maximum and absorption depth of EAS to hadron production mechanism
Comparison of experimental data on depth of extensive air showers (EAS) development maximum in the atmosphere, T sub M and path of absorption, lambda, in the lower atmosphere of EAS with fixed particle number in the energy region eV with the results of calculation show that these parameters are sensitive mainly to the inelastic interaction cross section and scaling violation in the fragmentation and pionization region. The data are explained in a unified manner within the framework of a model in which scaling is violated slightly in the fragmentation region and strongly in the pionization region at primary cosmic rays composition close to the normal one and a permanent increase of inelastic interaction cross section. It is shown that, while interpreting the experimental data, disregard of two methodical points causes a systematic shift in T sub M: (1) shower selection system; and (2) EAS electron lateral distribution when performing the calculations on basis of which the transfer is made from the Cerenkov pulse FWHM to the depth of shower maximum, T sub M
Lateral-angular and temporal characteristics of EAS optical radiation
Characteristics of the direct and scattered components of electron-photon shower optical radiation for distances R 500 m from the shower core to a detector, allowing for the Cerenkov and fluorescent mechanism of photon generation are presented. The results of calculations are employed to clarify the techniques for determination of the shower parameters detected by both installations registering fluorescent light and those recording Cerenkov light
Alignment in Gamma-Hadron Families of Cosmic Rays
Alignment of main fluxes of energy in a target plane is found in families of
cosmic ray particles detected in deep lead X-ray chambers. The fraction of
events with alignment is unexpectedly large for families with high energy and
large number of hadrons. This can be considered as evidence for the existence
of coplanar scattering of secondary particles in interaction of particles with
superhigh energy, eV. Data analysis suggests that production of
most aligned groups occurs low above the chamber and is characterized by a
coplanar scattering and quasiscaling spectrum of secondaries in the
fragmentation region. The most elaborated hypothesis for explanation of
alignment is related to the quark-gluon string rupture. However, the problem of
theoretical interpretation of our results still remains open.Comment: 15 pages, 2 tables, 6 figures (not included), Stanford University
preprint SU-ITP-94-2
Gluonic phases, vector condensates, and exotic hadrons in dense QCD
We study the dynamics in phases with vector condensates of gluons (gluonic
phases) in dense two-flavor quark matter. These phases yield an example of
dynamics in which the Higgs mechanism is provided by condensates of gauge (or
gauge plus scalar) fields. Because vacuum expectation values of spatial
components of vector fields break the rotational symmetry, it is naturally to
have a spontaneous breakdown both of external and internal symmetries in this
case. In particular, by using the Ginzburg-Landau approach, we establish the
existence of a gluonic phase with both the rotational symmetry and the
electromagnetic U(1) being spontaneously broken. In other words, this phase
describes an anisotropic medium in which the color and electric
superconductivities coexist. It is shown that this phase corresponds to a
minimum of the Ginzburg-Landau potential and, unlike the two-flavor
superconducting (2SC) phase, it does not suffer from the chromomagnetic
instability. The dual (confinement) description of its dynamics is developed
and it is shown that there are light exotic vector hadrons in the spectrum,
some of which condense. Because most of the initial symmetries in this system
are spontaneously broken, its dynamics is very rich.Comment: 33 pages, RevTeX; v.2: Published PRD versio
Color-flavor locked superconductor in a magnetic field
We study the effects of moderately strong magnetic fields on the properties
of color-flavor locked color superconducting quark matter in the framework of
the Nambu-Jona-Lasinio model. We find that the energy gaps, which describe the
color superconducting pairing as well as the magnetization, are oscillating
functions of the magnetic field. Also, we observe that the oscillations of the
magnetization can be so strong that homogeneous quark matter becomes metastable
for a range of parameters. We suggest that this points to the possibility of
magnetic domains or other types of magnetic inhomogeneities in the quark cores
of magnetars.Comment: 12 pages, 3 figures. Version accepted for publication in Phys. Rev.
SOME PROPERTIES OF THE KERR SOLUTION TO LOW ENERGY STRING THEORY
The Kerr solution to axidilaton gravity is analyzed in the
Debney--Kerr--Schild formalism. It is shown that the Kerr principal null
congruence retains its property to be geodesic and shear free, however, the
axidilatonic Kerr solution is not algebraically special. A limiting form of
this solution is considered near the ring-like Kerr singularity. This limiting
solution coincides with the field around a fundamental heterotic string
obtained by Sen.Comment: 14 pages., LaTe
Понятие конкурентоспособности продукции в современных условиях
У роботі досліджується суть поняття конкурентоспроможності продукції підприємства в сучасних умовах. Зосереджено увагу на недоліках визначення цього поняття різних авторів. Викладено власні погляди до розуміння конкурентоспроможності продукції та сформульовано власне визначення цього поняття.This article enlightens essence of concept of competitiveness of products of enterprise in the modern terms. Concentrated attention on the defects of determination of this concept of different authors. Expounded own looks to understanding of competitiveness of products and worded own determination of this concept.В работе исследуется суть понятия конкурентоспособности продукции предприятия в современных условиях. Сосредоточено внимание на недостатках определения этого понятия разными авторами. Изложены собственные взгляды к пониманию конкурентоспособности продукции и сформулировано собственное определение этого понятия
Results of investigation of muon fluxes of superhigh energy cosmic rays with X-ray emulsion chambers
The overall data from the investigation of the cosmic ray muon flux in the range of zenith angles (0-90) deg within the energy range (3.5 to 5.0) TeV is presented. The exposure of large X-ray emulsion chambers underground was 1200 tons. year. The data were processe using the method which was applied in the experiment Pamir and differred from the earlier applied one. The obtained value of a slope power index of the differential energy spectrum of the global muon flux is =3.7 that corresponds to the slope of the pion generation differential spectrum, gamma sub PI = 2.75 + or - .04. The analysis of the muon zenith-angular distribution showed that the contribution of rapid generation muons in the total muon flux agree the best with the value .2% and less with .7% at a 90% reliability level
Shape of primary proton spectrum in multi-TeV region from data on vertical muon flux
It is shown, that primary proton spectrum, reconstructed from sea-level and
underground data on muon spectrum with the use of QGSJET 01, QGSJET II, NEXUS
3.97 and SIBYLL 2.1 interaction models, demonstrates not only model-dependent
intensity, but also model-dependent form. For correct reproduction of muon
spectrum shape primary proton flux should have non-constant power index for all
considered models, except SIBYLL 2.1, with break at energies around 10-15 TeV
and value of exponent before break close to that obtained in ATIC-2 experiment.
To validate presence of this break understanding of inclusive spectra behavior
in fragmentation region in p-air collisions should be improved, but we show,
that it is impossible to do on the basis of the existing experimental data on
primary nuclei, atmospheric muon and hadron fluxes.Comment: Submitted to Phys. Rev.
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