3,025 research outputs found
Twist tori and pseudo toric structures
Twist tori are examples of exotic monotone lagrangian tori, presented in [1].
This tree of examples grew up over the first one --- the torus , constructured in [2] and [3]. On the other hand, in [4] and [5] we
proposed a new structure which generalizes the notion of toric structure. One
calls this generalization pseudo toric structure, and several examples were
given which show that certain toric symplectic manifolds can carry the structre
and that certain non toric symplectic manifolds do the same. Below we show that
any twist torus , defined in [1], can be
constructed via pseudo toric considerations. Due to this one can explicitly
show that every is displaceable
Hard diffraction from parton rescattering in QCD
We analyze the QCD dynamics of diffractive deep inelastic scattering. The
presence of a rapidity gap between the target and diffractive system requires
that the target remnant emerges in a color singlet state, which we show is made
possible by the soft rescattering of the struck quark. This rescattering is
described by the path-ordered exponential (Wilson line) in the expression for
the parton distribution function of the target. The multiple scattering of the
struck parton via instantaneous interactions in the target generates dominantly
imaginary diffractive amplitudes, giving rise to an "effective pomeron"
exchange. The pomeron is not an intrinsic part of the proton but a dynamical
effect of the interaction. This picture also applies to diffraction in
hadron-initiated processes. Due to the different color environment the
rescattering is different in virtual photon- and hadron-induced processes,
explaining the observed non-universality of diffractive parton distributions.
This framework provides a theoretical basis for the phenomenologically
successful Soft Color Interaction model which includes rescattering effects and
thus generates a variety of final states with rapidity gaps. We discuss
developments of the SCI model to account for the color coherence features of
the underlying subprocesses.Comment: 12 pages, 9 figures, REVTeX4. Somewhat expanded and modified version,
two new subsections added. To appear in PR
Color Glass Condensate and BFKL dynamics in deep inelastic scattering at small x
The proton structure function F_2(x,Q^2) for x < 0.01 and 0.045< Q^2 < 45
GeV^2, measured in the deep inelastic scattering at HERA, can be well described
within the framework of the Color Glass Condensate.Comment: 4 pages, 1 figure, incl. IOP style files. Talk given at the 17th
International Conference on Ultra-Relativistic Nucleus-Nucleus Collisions
(Quark Matter 2004), Oakland, CA USA, 11-17 Jan 200
Autowave Processes in Magnetic Fluid: Electrically Controlled Interference
The chapter considers autowaves that were observed in the thin near-electrode layer of concentrated magnetic fluid. Autowave process is a unique object for the study of self-organization. We observed pacemakers (leading centers), reverberators (spiral waves), and wave diffraction. A mechanism for the appearance of an autowave process has been developed; its mathematical model has been proposed and realized by means of computer simulation. As a basic method of observation, we used electrically controlled interference. This method watches the changes in the spectrum of reflected light from a two-layer structure with variable thickness: “conductive ITO coating—a layer of concentrated magnetic fluid” in an electric field
A possible explanation why the Theta+ is seen in some experiments and not in others
To understand the whole set of positive and null data on the
Theta+(1530)-production, we suggest the hypothesis that multiquark hadrons are
mainly generated from many-quark states, which emerge either as short-term
hadron fluctuations, or as hadron remnants in hard processes. This approach
allows us to describe both non-observation of the Theta+ in current null
experiments and peculiar features of its production in positive experiments.
Further, we are able to propose new experiments that might be decisive for the
problem of the Theta+ existence. Distributions of the Theta+ in such
experiments can give important information both on higher Fock components of
conventional hadrons and about structure and hadronization properties of hadron
remnants produced in hard processes. We also explain that description of
multiquark hadrons may require a modified form of the constituent quark model,
with quark masses and couplings being intermediate between their values for the
familiar constituent quarks and the current ones.Comment: 18 pages. Some changes in the text; experimental suggestions
collected in a special subsection, references added and refreshe
Jets in deep-inelastic scattering at HERA
Jet cross sections in deep-inelastic scattering over a wide region of phase
space have been measured at HERA. These cross section measurements provide a
thorough test of the implementation of Quantum Chromodynamics in
next-to-leading order (NLO) calculations. They also provide the opportunity to
test the consistency of the gluon distribution in the proton as extracted from
(mainly) inclusive DIS measurements. Comparison of the cross sections with NLO
enables accurate extractions of the strong coupling constant, , to be
made, several of which are reported here.Comment: Talk presented at "New Trends in HERA Physics", Ringberg Workshop,
June 2001. 13pages, 12figure
ПРО ДОСВІД ІНТЕГРАЦІЇ ХМАРНОГО СЕРВІСУ GOOGLE APPS FOR EDUCATION ТА НАЯВНОЇ ІНФОРМАЦІЙНОЇ ІНФРАСТРУКТУРИ МЕДИЧНОГО ВНЗ
Some aspects of informatization of the medical ed ucation field are considered. The problem of providing the interoperabilitybetween cloud services and information systems that can exist in the medical university is determined. The approach of the integration of the Google Apps for Education cloud services with the existing information systems based on the Google Apps For Developers features is propose d. The example of the integration solution in Ternopil State Medical University by I. Ya. Horbachevsky which is based on the "SysAdminka" information system development is shown. Practical recipes of the application of the School Directory Sync util as the "SysAdminka" information system component are offered.Рассмотрены некоторые аспекты информатизации отрасли медицинского образования. Отмечено проблему обеспечения интероперабельности при применении отдельных информационных систем и облачных сервисов в высшем учебном заведении медицинского образования. Разработана методика интеграции существующих информационных систем и облачного сервиса Google Apps For Education, основанный на использовании возможностей сервиса Google Apps For Developers. Приведен пример реализации указанной методики в Тернопольскомгосударственном медицинском университете имени И. Я. Горбачевского, путем разработки информационнойсистемы "SysAdminka". Показано практическую методику применения утилиты School Directory Sync как элементаинформационной системы "SysAdminka".Розглянуто деякі аспекти інформатизації галузі медичної освіти. Означено проблему забезпечення інтероперабельності при застосуванні окремих інформаційних систем та хмарних сервісів у вищому навчальному закладі медичної освіти. Розроблено методику інтеграції існуючих інформаційних систем та хмарного сервісу Google Apps For Education, що базується на використанні можливостей сервісу Google Apps For Developers. Наведено приклад реалізації вказаної методики в Тернопільському державному медичному університеті імені І. Я. Горбачевського, шляхом розробки інформаційної системи "SysAdminka". Показано практичну методику застосування утиліти School Directory Sync як елемента інформаційної системи "SysAdminka"
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