256 research outputs found
Calculation of the Membrane Thickness of Magnetite Nanoparticles on the Surface of the Transparent Conductive Electrode in the Electric Field
We observe and study the reflection and interference in the two-layer thin film composed of a conductive
layer of ITO and dispersed particles of magnetic fluid (magnetite). In an electric field the equivalent
thickness of the membrane is increased by varying the thickness of the second layer. At a certain value of
the electric field the layer becomes unstable, its thickness varies periodically, autowave process leading to
the characteristic active centers (pacemakers), spiral waves (reverberators) was observed
Calculation of the Membrane Thickness of Magnetite Nanoparticles on the Surface of the Transparent Conductive Electrode in the Electric Field
We observe and study the reflection and interference in the two-layer thin film composed of a conductive
layer of ITO and dispersed particles of magnetic fluid (magnetite). In an electric field the equivalent
thickness of the membrane is increased by varying the thickness of the second layer. At a certain value of
the electric field the layer becomes unstable, its thickness varies periodically, autowave process leading to
the characteristic active centers (pacemakers), spiral waves (reverberators) was observed
Thickness Calculation of Thin Transparent Conductive Membrane on the Border with a Magnetic Fluid
The determination method of the membrane thickness of ITO (InSnO2). The magnetite nanoparticles in the electric field migrate, forming the thin layer near conductive ITO membrane with varying thickness. Lighting this structure by monochromatic plane polarized light the interference of light in the thin membrane was observed. The experimental values of the intensity of the reflected light from the surface of «ITO â layer of magnetite particles" for samples with different thickness of the conductive coating
Jets in Deep Inelastic Scattering and High Energy Photoproduction at HERA
Recent results on jet production in neutral current deep inelastic scattering
and high energy photoproduction at the HERA electron-proton-collider are
briefly reviewed. The results are compared to QCD expectations in NLO and
determinations using these data are summarized.Comment: 12 pages, 10 figures, talk given at the 9th Adriatic Meeting
"Particle Physics and the Universe" in Dubrovnik/Croatia, 4.-24.9.200
Thickness Calculation of Thin Transparent Conductive Membrane on the Border with a Magnetic Fluid
The determination method of the membrane thickness of ITO (InSnO2). The magnetite nanoparticles in the electric field migrate, forming the thin layer near conductive ITO membrane with varying thickness. Lighting this structure by monochromatic plane polarized light the interference of light in the thin membrane was observed. The experimental values of the intensity of the reflected light from the surface of «ITO â layer of magnetite particles" for samples with different thickness of the conductive coating
Bose-Einstein Correlations and Color Reconnection in W-pair production
We propose a systematic study of Bose-Einstein correlations between identical
hadrons coming from different W decays. Experimentally accessible signatures of
these correlations as well as of possible color reconnection effects are
discussed on the basis of two-particle inclusive densities.Comment: 24 pages, 9 eps figures, submitted to Eur. J. Phys.
Expanding running coupling effects in the hard Pomeron
We study QCD hard processes at scales of order k^2 > Lambda^2 in the limit in
which the beta-function coefficient - b is taken to be small, but alphas(k) is
kept fixed. The (nonperturbative) Pomeron is exponentially suppressed in this
limit, making it possible to define purely perturbative high-energy Green's
functions. The hard Pomeron exponent acquires diffusion and running coupling
corrections which can be expanded in the b parameter and turn out to be
dependent on the effective coupling b alphas^2 Y. We provide a general setup
for this b-expansion and we calculate the first few terms both analytically and
numerically.Comment: 36 pages, 15 figures, additional references adde
Next-to-leading BFKL phenomenology of forward-jet cross sections at HERA
We show that the forward-jet measurements performed at HERA allow for a
detailed study of corrections due to next-to-leading logarithms (NLL) in the
Balitsky-Fadin-Kuraev-Lipatov (BFKL) approach. While the description of the
d\sigma/dx data shows small sensitivity to NLL-BFKL corrections, these can be
tested by the triple differential cross section d\sigma/dxdk_T^2dQ^2 recently
measured. These data can be successfully described using a
renormalization-group improved NLL kernel while the standard
next-to-leading-order QCD or leading-logarithm BFKL approaches fail to describe
the same data in the whole kinematic range. We present a detailed analysis of
the NLL scheme and renormalization-scale dependences and also discuss the
photon impact factors.Comment: 15 pages, 9 figures, new title, NLL-BFKL saddle-point approximation
replaced by exact integratio
Heavy quarkonium: progress, puzzles, and opportunities
A golden age for heavy quarkonium physics dawned a decade ago, initiated by
the confluence of exciting advances in quantum chromodynamics (QCD) and an
explosion of related experimental activity. The early years of this period were
chronicled in the Quarkonium Working Group (QWG) CERN Yellow Report (YR) in
2004, which presented a comprehensive review of the status of the field at that
time and provided specific recommendations for further progress. However, the
broad spectrum of subsequent breakthroughs, surprises, and continuing puzzles
could only be partially anticipated. Since the release of the YR, the BESII
program concluded only to give birth to BESIII; the -factories and CLEO-c
flourished; quarkonium production and polarization measurements at HERA and the
Tevatron matured; and heavy-ion collisions at RHIC have opened a window on the
deconfinement regime. All these experiments leave legacies of quality,
precision, and unsolved mysteries for quarkonium physics, and therefore beg for
continuing investigations. The plethora of newly-found quarkonium-like states
unleashed a flood of theoretical investigations into new forms of matter such
as quark-gluon hybrids, mesonic molecules, and tetraquarks. Measurements of the
spectroscopy, decays, production, and in-medium behavior of c\bar{c}, b\bar{b},
and b\bar{c} bound states have been shown to validate some theoretical
approaches to QCD and highlight lack of quantitative success for others. The
intriguing details of quarkonium suppression in heavy-ion collisions that have
emerged from RHIC have elevated the importance of separating hot- and
cold-nuclear-matter effects in quark-gluon plasma studies. This review
systematically addresses all these matters and concludes by prioritizing
directions for ongoing and future efforts.Comment: 182 pages, 112 figures. Editors: N. Brambilla, S. Eidelman, B. K.
Heltsley, R. Vogt. Section Coordinators: G. T. Bodwin, E. Eichten, A. D.
Frawley, A. B. Meyer, R. E. Mitchell, V. Papadimitriou, P. Petreczky, A. A.
Petrov, P. Robbe, A. Vair
Towards Jetography
As the LHC prepares to start taking data, this review is intended to provide
a QCD theorist's understanding and views on jet finding at hadron colliders,
including recent developments. My hope is that it will serve both as a primer
for the newcomer to jets and as a quick reference for those with some
experience of the subject. It is devoted to the questions of how one defines
jets, how jets relate to partons, and to the emerging subject of how best to
use jets at the LHC.Comment: 95 pages, 28 figures, an extended version of lectures given at the
CTEQ/MCNET school, Debrecen, Hungary, August 2008; v2 includes additional
discussion in several places, as well as other clarifications and additional
references
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