101 research outputs found
Adventures of the Coupled Yang-Mills Oscillators: II. YM-Higgs Quantum Mechanics
We continue our study of the quantum mechanical motion in the
potentials for , which arise in the spatially homogeneous limit of the
Yang-Mills (YM) equations. In the present paper, we develop a new approach to
the calculation of the partition function beyond the Thomas-Fermi (TF)
approximation by adding a harmonic (Higgs) potential and taking the limit , where is the vacuum expectation value of the Higgs field. Using the
Wigner-Kirkwood method to calculate higher-order corrections in , we
show that the limit leads to power-like singularities of the type
, which reflect the possibility of escape of the particle along the
channels in the classical limit. We show how these singularities can be
eliminated by taking into account the quantum fluctuations dictated by the form
of the potential
Adventures of the Coupled Yang-Mills Oscillators: I. Semiclassical Expansion
We study the quantum mechanical motion in the potentials with
, which arise in the spatially homogeneous limit of the Yang-Mills (YM)
equations. These systems show strong stochasticity in the classical limit
() and exhibit a quantum mechanical confinement feature. We
calculate the partition function going beyond the Thomas-Fermi (TF)
approximation by means of the semiclassical expansion using the Wigner-Kirkwood
(WK) method. We derive a novel compact form of the differential equation for
the WK function. After separating the motion in the channels of the
equipotential surface from the motion in the central region, we show that the
leading higher-order corrections to the TF term vanish up to eighth order in
, if we treat the quantum motion in the hyperbolic channels correctly by
adiabatic separation of the degrees of freedom. Finally, we obtain an
asymptotic expansion of the partition function in terms of the parameter
Regular and chaotic interactions of two BPS dyons at low energy
We identify and analyze quasiperiodic and chaotic motion patterns in the time
evolution of a classical, non-Abelian Bogomol'nyi-Prasad-Sommerfield (BPS) dyon
pair at low energies. This system is amenable to the geodesic approximation
which restricts the underlying SU(2) Yang-Mills-Higgs dynamics to an
eight-dimensional phase space. We numerically calculate a representative set of
long-time solutions to the corresponding Hamilton equations and analyze
quasiperiodic and chaotic phase space regions by means of Poincare surfaces of
section, high-resolution power spectra and Lyapunov exponents. Our results
provide clear evidence for both quasiperiodic and chaotic behavior and
characterize it quantitatively. Indications for intermittency are also
discussed.Comment: 22 pages, 6 figures (v2 contains a few additional references, a new
paragraph on intermittency and minor stylistic corrections to agree with the
published version
The Partition Function and Level Density for Yang-Mills-Higgs Quantum Mechanics
We calculate the partition function and the asymptotic integrated
level density for Yang-Mills-Higgs Quantum Mechanics for two and three
dimensions (). Due to the infinite volume of the phase space
on energy shell for , it is not possible to disentangle completely the
coupled oscillators (-model) from the Higgs sector. The situation is
different for for which is finite. The transition from order
to chaos in these systems is expressed by the corresponding transitions in
and , analogous to the transitions in adjacent level spacing
distribution from Poisson distribution to Wigner-Dyson distribution. We also
discuss a related system with quartic coupled oscillators and two dimensional
quartic free oscillators for which, contrary to YMHQM, both coupling constants
are dimensionless.Comment: 10 pages, LaTeX; minor changes; version accepted for publication as a
Letter in J. Phys.
Azimuthal asymmetry in transverse energy flow in nuclear collisions at high energies
The azimuthal pattern of transverse energy flow in nuclear collisions at RHIC
and LHC energies is considered. We show that the probability distribution of
the event-by-event azimuthal disbalance in transverse energy flow is
essentially sensitive to the presence of the semihard minijet component.Comment: 6 pages, 2 figure
Buffer therapy in metabolic acidosis after surgery-associated hemorrhage in pediatric oncology
Symmetry Decomposition of Potentials with Channels
We discuss the symmetry decomposition of the average density of states for
the two dimensional potential and its three dimensional
generalisation . In both problems, the energetically
accessible phase space is non-compact due to the existence of infinite channels
along the axes. It is known that in two dimensions the phase space volume is
infinite in these channels thus yielding non-standard forms for the average
density of states. Here we show that the channels also result in the symmetry
decomposition having a much stronger effect than in potentials without
channels, leading to terms which are essentially leading order. We verify these
results numerically and also observe a peculiar numerical effect which we
associate with the channels. In three dimensions, the volume of phase space is
finite and the symmetry decomposition follows more closely that for generic
potentials --- however there are still non-generic effects related to some of
the group elements
Threshold production in nucleon-nucleon collisions
We analyze production in nucleon-nucleon collisions near threshold
in the framework of a general model independent formalism, which can be applied
to any reaction , where , , or . Such
reactions show large isotopic effects: a large difference for - and
-collisions, which is due to the different spin structure of the
corresponding matrix elements. The analysis of the spin structure and of the
polarization observables is based on symmetry properties of the strong
interaction. Using existing experimental data on the different decays of
meson, we suggest a model for , based on
channel -exchanges. We predict polarization phenomena for the
-reaction and the ratio of cross sections for and
-collisions. For the processes we apply two
different approaches: vector meson exchange and local four-particle
interaction. In both cases we find larger -production in
-collisions, with respect to -collisions.Comment: 17 pages, 6 figure
Злокачественная гипертермия (обзор литературы)
The objective – to summarize the current literature data on the etiology, pathogenesis, diagnosis and treatment of malignant hyperthermia. The search and analysis of literature data on malignant hyperthermia in the medical information systems PubMed, Сochrane librarу, Cyberleninka for the last 10 years was performed with using the keywords: «malignant hyperthermia», «dantrolene», «general anesthesia», «succinylcholine», «inhalation anesthetics». The search criteria were met by 96 publications. In addition, references to selected articles were manually checked for applicable articles including recent reports of malignant hyperthermia, in addition to works of historical significance. It was shown that malignant hyperthermia develops in susceptible individuals during or after general anesthesia with the use of trigger agents – inhaled halogen-containing anesthetics and succinylcholine. Until recently, the problem of treatment in Russia remained unresolved, since specific therapy for this syndrome was not available. In connection with the official registration of Dantrolene in the Russian Federation, this problem no longer has a life-threatening potential. Doctors should recognize the symptoms of this disease as early as possible in order to quickly begin the pathogenetic treatment of malignant hyperthermia in order to prevent fatal complications. The material is intended for a wide audience of anesthesiologists, resuscitators and surgeons who may encounter this pathology in clinical practice. Цель – обобщить текущие литературные данные по этиологии, патогенезу, диагностике и лечению злокачественной гипертермии. Выполнен поиск и анализ литературных данных по злокачественной гипертермии в медицинских информационных системах PubMed, Сochrane librarу, Cyberleninka за последние 10 лет с использованием ключевых слов: «злокачественная гипертермия», «дантролен», «общая анестезия», «сукцинилхолин», «ингаляционные анестетики». Критериям поиска удовлетворяли 96 публикаций. В дополнение к этому ссылки на выбранные статьи были вручную проверены на наличие применимых статей, включающих последние сообщения о злокачественной гипертермии, помимо работ, имеющих историческое значение. Показано, что злокачественная гипертермия развивается у восприимчивых к ней лиц во время или после проведения общей анестезии с применением триггерных агентов – ингаляционных галогенсодержащих анестетиков и сукцинилхолина. До недавнего времени проблема лечения в России оставалась нерешенной, поскольку специфическая терапия данного синдрома была недоступна. В связи с официальной регистрацией препарата «Дантролен» в Российской Федерации данная проблема более не носит жизнеугрожающий потенциал. Врачу следует как можно раньше распознать симптомы данного заболевания, чтобы быстрее начать патогенетическое лечение злокачественной гипертермии с целью предотвращения фатальных осложнений. Материал предназначен для широкой аудитории врачей анестезиологов-реаниматологов, хирургов, которые могут встретиться с данной патологией в клинической практике
The initial gluon multiplicity in heavy ion collisions
The initial gluon multiplicity per unit area per unit rapidity, dN/L^2/d\eta,
in high energy nuclear collisions, is equal to f_N (g^2\mu L) (g^2\mu)^2/g^2,
with \mu^2 proportional to the gluon density per unit area of the colliding
nuclei. For an SU(2) gauge theory, we compute f_N (g^2\mu L)=0.14\pm 0.01 for a
wide range in g^2\mu L. Extrapolating to SU(3), we predict dN/L^2/d\eta for
values of g^2\mu L in the range relevant to the Relativistic Heavy Ion Collider
and the Large Hadron Collider. We compute the initial gluon transverse momentum
distribution, dN/L^2/d^2 k_\perp, and show it to be well behaved at low
k_\perp.Comment: LaTex 10 pgs., 3 figure
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