bluuebunny/crossref_metadata_2025_split huggingface dataset:
Problems of Separating Reaction Subchannels Demonstrated by a Multidimensional Study of the Reaction K−p → K* (890) Δ (1236) at 10 GeV/c
Authors: Naumann Thomas , Schiller H. 
Published: May 2007

AbstractWe investigate a subchannel which was separated by a cluster analysis and has the expected effective mass distributions, cross section, and angular distributions, but shows in the t‐dependence of spin density matrix elements strong influence of another subchannel. A cluster analysis helps to answer the question of overlap in multidimensional space.We warn against considering cuts as efficient means of separation if physical analysis relies upon angular distributions. The effects of overlap and interference are shown to be important in this case.
Conductance Theory of Nonideal Plasmas
Authors: Ebeling W. , Röpke G. 
Published: May 2007

AbstractThe conductivity of nonideal plasmas is investigated by using the kinetic theory as well as the Kubo‐type correlation function theory. The effects of dynamical screening, short range forces and the Debye‐Onsager relaxation effect on the conductance problem are considered without and with quantum mechanical corrections. For some special plasmas it is found that deviations from Coulomb's law and quantum effects have only a small effect on the conductivity, whereas the numerically most important effects are connected with the dynamical screening and with the Debye‐Onsager relaxation force.
Streuung elektromagnetischer Oberflächen‐ und Volumenwellen an rauhen Oberflächen. Teil I. Allgemeine Grundlagen
Authors: Ponath H.‐E. 
Published: May 2007

AbstractEs wird eine klassische Theorie der Streuung von elektromagnetischen Volumen‐ oder Oberflächenwellen an rauhen Oberflächen (Dielektrika oder Leiter) dargelegt. Die Erregerwelle erzeugt an der rauhen Grenzfläche eine Oberflächenpolarisation, die die Quelle für die Streustrahlung darstellt; sowohl in den Wellengleichungen als auch in den Grenzbedingungen für die Felder muß diese rauhigkeitsbedingte Polarisation berücksichtigt werden. Es werden allgemeine Ausdrücke für die Spektraldichten von Oberflächen‐ und Volumenstreuwellen angegeben, wobei die Erregung der Oberflächenpolarisation durch die Primärwellen sowohl homogen als auch inhomogen erfolgen kann.
Streuung elektromagnetischer Oberflächen‐ und Volumenwellen an rauhen Oberflächen. Teil II. Die Streulichtverteilung; Ein‐ und Auskopplung von Oberflächenwellen
Authors: Ponath H.‐E. 
Published: May 2007

AbstractIn dieser Arbeit erfolgt die Berechnung der Spektraldichte der Streustrahlung für die Streuung von Volumen‐ oder Oberflächenwellen an homogenen isotropen rauhen Oberflächen. In Abhängigkeit von den in den Medien z > O und z < O entstehenden Wellentypen wird eine Klassifikation aller möglichen Streuvarianten vorgenommen und die Winkelabhängigkeiten der verschiedenen Polarisationsvarianten (∥ und ⟂) der Streustrahlung ermittelt. Der Zusammenhang zwischen der Rauhigkeits‐Korrelationsfunktion und der Effektivität der Ein‐ bzw. Auskopplung von Oberflächen‐ und Volumenwellen wird diskutiert und ein Vergleich mit den Resultaten anderer Autoren angestellt.
Alpha Cluster in Hartree‐Fock Calculations
Authors: Hassan M. Y. M. , Moharram S. , Osman M. M. 
Published: May 2007

AbstractHartree‐Fock (HF) calculations have been performed fcr 12C nucleus assuming a trigonal D3h equilibrium configuration. Different aspects including symmetry, kinds of two‐body interactions are investigated. The HF calculations have been carried out using a velocity dependent effective potential of s‐wave interaction. The results are compared with previous calculations. In all HF calculations no deviation from axial symmetry is obtained.
An Analytical Calculation of the Equation of State and the Critical Point in a Dense Classical Fluid of Charged Hard Spheres
Authors: Ebeling W. , Grigo M. 
Published: May 2007

AbstractA theoretical expression for the equation of state is developed which is based on the mass action law, the Carnahan‐Starling expression for the hard‐sphere contributions and the mean‐spherical approximation for the Coulombic interactions. Numerical calculations of the pressure and the critical data show good agreement with other methods (HNC, MC etc.).
Die Berücksichtigung der Ionisation durch Elektronenstoß in der Elektronenkinetik des schwachionisierten anisothermen Plasmas III. Das instationäre Verhalten bei großer impulsförmiger Feldstörung
Authors: Wilhelm J. , Winkler R. 
Published: May 2007

AbstractEs wird das Zeitverhalten der Elektronenkomponente bei einmaliger impulsförmiger Störung des elektrischen Feldes im Plasma berechnet. Die Untersuchungen erfolgen am Beispiel des schwachionisierten Neon‐Plasmas, wobei neben elastischen und anregenden Stößen zusätzlich die Direktionisation durch Elektronenstoß sowie ein Elektronenverlustterm mit konstanter Lebensdauer in die Berechnungen einbezogen werden. Die Bestimmung der Zeitentwicklung aller interessierenden makroskopischen Größen der Elektronen erfolgt ausgehend von stationären Zuständen durch Lösung der zeitabhängigen Boltzmanngleichung. Neben der Berechnung der ausgeprägten zeitlichen Änderungen z. B. der Elektronenkonzentration, der Elektronenstoßfrequenzen für Anregung und Ionisierung und der einzelnen Energieübertragungsraten wird insbesondere das Relaxationsverhalten der Elektronenkomponente nach dem Ein‐ und Ausschalten der rechteckförmigen Feldstörung analysiert.
The Initial Process of Superfluorescence in Microscopic Description
Authors: Steudel H. 
Published: May 2007

AbstractThe initiation of superfluorescence is studied by a method starting from the N‐atom master equation in the high‐excitation limit. By numerical calculation cooperation numbers and the temporal growth of the radiation pattern are determined for atomic numbers between 24 and 48. For randomly distributed atoms there is a particle density of maximum cooperation.
Grenzbedingungen der Elektrodynamik für Medien mit räumlicher Dispersion und Übergangsschichten
Authors: Wünsche A. 
Published: May 2007

AbstractAusgehend von den Maxwellschen Gleichungen der makroskopischen Elektrodynamik räumlich inhomogener anisotroper Medien mit räumlicher Dispersion werden mit einer wesentlich neuen Methode durch Benutzung von verallgemeinerten Funktionen und Momenteentwicklungen der Felder die Grenzbedingungen abgeleitet. Wir finden ein vollständiges unendliches System von Grenzbedingungen, das näherungsweise in endliche Systeme überführt werden kann. Für die Spezialfälle räumlicher Dispersion erster Ordnung und für Übergangsschichten erhalten wir in erster Näherung Grenzbedingungen, welche die üblichen verbessern und verallgemeinern.
Calculation of Oscillator Strength in the Sc I‐Spectrum
Authors: Siefart E. 
Published: May 2007

AbstractThe oscillator strengths of the main transition from the 3d 4s 4p‐states to the groundstate 3d 4s2 of Sc I are calculated on using wave functions derived by diagnolization of the interaction matrix elements of the 3d 4s 4p‐, 3d2 4p‐ and 4s2 4p‐configurations. The relevant dipole matrix elements are reduced by application of tensor algebra to the unknown one‐electron matrix elements 〈4s‖r‖4p> and <3d‖r‖4p〉. These radial integrals are calculated from experimental lifetimes and oscillator strengths as well as from theoretical models. The resulting absolute oscillator strengths show a fairly good agreement with the experimental data, the uncertainties being smaller than 10 percent for the strongest transitions.
Characteristic of Cluster Production in Hadronic Interaction in Emulsion at Accelerator Energy
Authors: Ghosh Dipak 
Published: May 2007

Charakteristika der Cluster‐Produktion durch Hadron‐Wechselwirkungen in Emulsionen bei Beschleuniger‐EnergienIn dieser Arbeit wird die Bestimmung der Größe der Cluster im Pionisierungsgebiet von Proton‐Nukleon‐Wechselwirkungen in Emulsionen bei 22,6 GeV/c dargestellt. Hierbei wird eine modellunabhängige Methode benutzt, die kürzlich in einer Arbeit von Shivpuri und anderen vorgeschlagen wurde. Es wurde beobachtet, daß bei Beschleuniger‐Energien ein Cluster aus maximal drei geladenen Teilchen (Pionen) besteht.
Space‐Dispersion Approach to the Explanation of the Higgs‐Mechanism
Authors: Papp E. 
Published: May 2007

AbstractProofs have been given that gauge transformations are needed in order to make finite the divergent space‐dispersions evaluations occurring as a result of the scalar‐field translation. So, the Higgs‐mechanism works only if there is a finite maximum value of the emerging space‐dispersion evaluation of the scalar field. The space dispersion thus used is expressed by the imaginary part of the average‐value of the non‐hermitian space‐operator.
Superharmonic Approximation for Crystal
Authors: Yukalov V. I. 
Published: May 2007

AbstractThe localized approximation for a quantum crystal considered earlier by the author is taken here as the initial step of an iteration, and the higher approximations for the propagators and thermodynamic functions are calculated. This generalization is based on a new type of a double iterative procedure for the equation of motion. The method is illustrated with a three‐dimensional crystal.
An Extensive Survey of the Characteristics of Pseudorapidity Distributions in Hadron‐Nucleus Collisions at High and Ultra High Energies
Authors: Ghosh Dipak 
Published: May 2007

AbstractThis paper presents an extensive study of the nature of the pseudorapidity distribution in hadron‐nucleus collision in emulsion from accelerator energy to super high cosmic ray energies (24 GeV/c to 4 TeV). The energy and the target dependence of the distributions and their possible significance are also discussed.
Shortening of the Energy Relaxation Time of Excited Molecular Vibrations of Small XH Molecules in a Dense Medium by Formation of H‐Bonds XH…Y
Authors: Mühle S. , Süsse K.‐E. , Welsch D.‐G. 
Published: May 2007

AbstractBy applying the models developed by Bixon and Jortner and by Konoplev and Plotnikov, respectively, for describing the energy relaxation of excited electronic levels and by using the results of the authors recently found from the study of the IR absorption spectra of H‐bonded species XH…Y the depopulation of excited vibrational levels of smal (two‐atomic) molecules in a dense medium (solid matrix) is studied. It is found that by formation of H‐bonds the depopulation times may be shortened essentially (more than five orders of magnitude).
Adjusting Conditions for High‐resolution Pulsed NMR in Solids
Authors: Döhler H. , Döhler T. , Fenzke D. 
Published: May 2007

AbstractAdjusting conditions of pulse sequences for high‐resolution nmr in solids are demonstrated by the example of the WHH4 cycle. For this pulse sequence the well‐known adjusting condition [1] occurs as limiting case at sufficiently weak dipolar interaction. The relations between the pulse rotation angle and interval time proved to be dependent on the dipolar interaction. Therefore it is impossible to suppress the dipolar interaction in ordinary solids completely.If the strength of the dipolar interaction varies in a range depending on the allowable inhomogeneity of the rf field a spectrometer for high‐resolution nmr in solids can be adjusted in an almost optimal way.
On the Decay Rate of Bound Muons
Authors: Chatterjee L. , Roy T. 
Published: May 2007

AbstractThe rigorous calculation of the Bound muon decay rate performed by Überall seems exhaustive. However an important effect not considered by him is the recoil of the nucleus.The present paper reports the computation of the decay rate using a perturbative type of wavefunction, similar to that used by Überall. In addition, the nuclear recoil effect has been taken into account and the results, as expected, exhibit a light increase over Überall's values, in particular for the lighter elements, where recoil is more pronounced.Screening by the atomic electrons and the effect of vacuum polarisation have also been considered, but eventually found to be negligible.
Lepton‐Pair Production in a Nucleon Field
Authors: Allam S. H. , El‐Kheshin M. , El‐Shawarbi A. 
Published: May 2007

AbstractThe total cross‐sections for the photo‐nucleon reactions y + p → p + v + v− and y + n → n + v + v− are calculated according to Weinberg‐Salam theory. The effect of the form factors is taken in the electromagnetic vertex. The dependence of the total cross‐sections on the energy of the incident photon is explicitly shown.
The Two‐Nucleon Stripping Process with Skyrme Type Potential
Authors: Osman Ahmed , Ismail M. Y. 
Published: May 2007

AbstractTheory of two‐nucleon stripping reactions is reconsidered. The nucleon‐nucleon interactions are taken as Skyrme type potentials. Differential cross‐sections for two‐nucleon stripping reactions are calculated using DWBA approximation with different Skyrme type potentials of different parameters. The angular distributions for different two‐nucleon stripping reactions (t, p) with incident triton on the different targets of 31P, 40Ca, 96Zr, 118Sn and 206Pb are calculated giving good agreement with the experimental data. Better values are extracted for the spectroscopic factors.
On the Calculation of the Electrical Conductivity of a Nonideal Hydrogen Plasma
Authors: Blümlein J. , Kraeft W.‐D. , Meyer Th. 
Published: May 2007

AbstractThe electrical conductivity of a nonideal hydrogen plasma is calculated within the linear response formalism. The approximation given involves the first term with respect to the density expansion in the low degenerate case. The contributions of the free‐free scattering of the particles as well as the bound‐bound, bound‐scattering, and scattering‐scattering parts due to multiple scattering are discussed up to this level.
Begründung einer Integralgleichung für die Bewegung eines strahlenden Elektrons
Authors: Petzold J. 
Published: May 2007

AbstractFür eine früher als Bewegungsgleichung für ein strahlendes Elektron vorgeschlagene Integro‐Differentialgleichung wird eine Begründung auf der Grundlage der Maxwell‐Lorentz‐Theorie gegeben. In erster Näherung und im nicht‐relativistischen Grenzfall erhalten wir die Theorien von Herglotz (1903) und Kaup (1966).
Statistics in a Trilinear Interacting Stokes‐Antistokes Boson System
Authors: Tänzler W. , Schütte F.‐J. 
Published: May 2007

AbstractThe statistics of a system of four boson modes is treated with simultaneous Stokes‐Antistokes interaction taking place. The time evolution is calculated in full quantum manner but in short time approximation. Mean photon numbers and correlations of second order are calculated. Antibunching can be found in the laser mode and in the system of Stokes and Antistokes mode.
Statistics of a Stokes‐Antistokes Interacting Boson System with Damping
Authors: Germey K. , Schütte F.‐J. , Tiebel R. 
Published: May 2007

AbstractThe statistics of a system of four boson modes in Stokes‐Antistokes interaction is considered with respect to the influence of damping in one mode. The time evolution of the system is calculated. The mean particle numbers and the factorial moments of photon number distribution are calculated. Numerical results show strong dependence on bath temperature but only weak influence of the bath coupling strength. In the combined Stokes‐Antistokes system Antibunching appears if the bath temperature is low.
Hermitesche Relativitätstheorie, Chromodynamik und Confinement
Authors: Treder H.‐J. 
Published: May 2007

AbstractDie Ausdehnung der Riemannschen Metrik der Allgemeinen Relativitätstheorie ins Komplexe bedeutet die Ersetzung der Symmetrie‐Bedingungen

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für den metrischen Tensor, Affinität und Ricci‐Tensor durch die Hermiteschen Bedingungen

equation image

Mit diesen Bedingungen führt das Einstein‐Hilbert‐Hamilton‐Prinzip

equation image

zu einer erweiterten Gravitationstheorie (Einstein), die im Sinne der EIH‐Approximation neben der Newton‐Einsteinschen Gravodynamik, auch die Chromodynamik der Elementarteilchenphysik enthält.Die von den Einstein‐Schrödingerschen Feldgleichungen der Hermiteschen Relativitätstheorie implizierte Wechselwirkung zwischen Gravo‐ und Chromodynamik erzwingt das „Confinement”︁. Ohne dieses Confinement würde das Gravitationspotential divergieren, d.h., es könnte keine — nach Maßgabe der Einstein‐Schrödingerschen Feldgleichungen — Riemannsche Raum‐Zeit‐Metrik gik = aik geben.
Equilibrium Statistical Mechanics in Mach‐Einstein‐Universes
Authors: Mücket Jan P. 
Published: May 2007

AbstractWithin the framework of the Mach‐Einstein‐doctrine as formulated by TREDERthe thermodynamical quantities and the relations between them are derived for a simple N‐particle‐gas in equilibrium by means of a statistical‐mechanical description of the particle system. Because of the induction of inertia for each particle due to the gravitational interaction with all other particles the corresponding equations of state are modified essentially in some cases.
Über zweidimensionale Turbulenz
Authors: Szablewski W. 
Published: May 2007

AbstractAus der Gleichung der Turbulenzenergie bei zweidimensionaler Turbulenz folgt neben dem Transfer der Enstrophie und Turbulenzenergie in Richtung großer Wellenzahlen ein Energie‐ nd Enstrophie‐Transfer in Richtung kleiner Wellenzahlen für einen Bereich O < k < k1 (k Wellenzahl).Es wird die der k−1‐Gesetzmäßigkeit des Spektrums der Enstrophie im Konvektionsunterbereich äqivalente Form des Enstrophietransfers abgeleitet. Auf dieser Basis erhalten wir für den Konvektionsbereich k≫ k0 (k0 Wellenzahl der großen Wirbel) in einfacher Form ein Ähnlichkeitsgesetz des Spektrums, das in der Asymptote eine logarithmische Modifikation der k−1‐Gesetzmäßigkeit enthält.Für den viskosen Bereich bei großen Wellenzahlen ergibt sich ein exponentielles Abklingen des Spektrums.Schließlich beschreiben wir auf der Grundlage des Transfers für den Konvektionsbereich k ≫ k0 approximativ den Übergang des Spektrums vom Konvektions‐ in den Zähigkeitsbereich. Die gewonnene Formel enthält sowohl das Ähnlichkeitsgesetz des Spektrums im Konvektionsbereich k ≫ k0 wie das exponentielle Abklingen des viskosen Bereiches.Die mittels des Ähnlichkeitsgesetzes herzuleitenden Spektren des Enstrophie‐ und Energietransfers im Konvektionsbereich k ≫ k0 ergeben, daß hier – jeweils mit Null startend – der Transfer der Enstrophie zu großen Wellenzahlen hin und der Transfer der Energie zu kleinen Wellenzahlen hin erfolgt.
Effect of Fluctuation on Plane Front Propagation in Bistable Nonequilibrium Systems
Authors: Schimansky‐Geier L. , Mikhailov A. S. , Ebeling W. 
Published: May 2007

AbstractA theory of front propagation in bistable stochastic media is developed. The effect of fluctuations is twofold: 1) they lead to random variations of the front shape. 2) they result in random motion of the front positions. Its general expression for the dispersion of the position for arbitrary stochastic noises with spatial correlation length lc and correlation time τc is given. For rate functions with cubic nonlinearities the dispersion formula is further analysed.
Derivation of the Finslerian Gauge Field Equations
Authors: Asanov G. S. 
Published: May 2007

AbstractAs is well known the simplest way of formulating the equations for the Yang‐Mills gauge fields consists in taking the Lagrangian to be quadratic in the gauge tensor [1 ‐ 5], whereas the application of such an approach to the gravitational field yields equations which are of essentially more complicated structure than the Einstein equations. On the other hand, in the gravitational field theory the Lagrangian can be constructed to be of forms which may be both quadratic and linear in the curvature tensor, whereas the latter possibility is absent in the current gauge field theories. In previous work [6] it has been shown that the Finslerian structure of the space‐time gives rise to certain gauge fields provided that the internal symmetries may be regarded as symmetries of a three‐dimensional Riemannian space. Continuing this work we show that appropriate equations for these gauge fields can be formulated in both ways, namely on the basis of the quadratic Lagrangian or, if a relevant generalization of the Palatini method is applied, on the basis of a Lagrangian linear in the gauge field strength tensor. The latter possibility proves to result in equations which are similar to the Einstein equations, a distinction being that the Finslerian Cartan curvature tensor rather than the Riemann curvature tensor enters the equations.
On the Renormalization Group Method for the Problem of Random Walk without Self‐Intersections
Authors: Alkhimov V. I. 
Published: May 2007

AbstractRandom walk without self‐intersections for a particle in the Euclidean n‐dimensional space is investigated. Renormalization group equations for the probability density of the end‐to‐end distance of a particle trajectory are derived. The asymptotics for this probability density are defined for 4 ‐ n ≪ 1.
Examples of Finslerian Metric Tensors of the Space‐Time Signature
Authors: Asanov G. S. 
Published: May 2007

AbstractContinuing the previous work [1], where a way of associating the gauge fields with Finslerian metrics has been indicated, in the present note we propose a class of Finslerian metrics which are of interest for the following two reasons. Firstly, the metrics give rise to the Finslerian metric tensors of the space‐time signature (+ − − −). Secondly, the associated indicatrices prove to be spaces of constant curvature, yielding examples of the Finslerian metrics which reflect the internal symmetry groups SU(2) and SU(2)⊗SU(2).
On the Nuclear Energy Generation Rate in a Simple Analytic Stellar Model
Authors: Haubold H. J. , Mathai A. M. 
Published: May 2007

AbstractThis paper is concerned with the hydrostatic equilibrium of a purely gaseous star generating energy at a rate . By the common technique of integration theory of special functions the total net rate of nuclear energy generation is evaluated analytically for a linear density distribution function assumed for a simple stellar model.
Gravitationsphysik und Lorentzraum
Authors: Burghardt R. 
Published: May 2007

AbstractFür statische und stationäre Gravitationsfelder lassen sich koordinateninvariante Erhaltungssätze aufstellen. Die Erhaltungsgrößen werden im Lorentzraum dargestellt, sind einer physikalischen Interpretation zugänglich und umfassen Feld‐ und Materieterme. An einigen Modellen wird die Nützlichkeit des Verfahrens gezeigt.
Derivation of Absolute Depth‐Intensity Spectrum under Standard Rock from the Recently Estimated Primary Cosmic Ray Spectrum
Authors: Bhattacharyya D. P. , Pal Pratibha , Mukhopadhyay A. 
Published: May 2007

AbstractUsing the recently derived primary cosmic ray nucleon spectrum from JACEE and GSFC balloon flight data and Fermilab results for pp → π± + X anything inclusive reaction data in the light of Feynman scaling the depth‐intensity spectrum under standard rock has been estimated. A precisely constructed range‐energy relation has been applied in this analysis. The derived spectrum when corrected for range fluctuation agrees approximately with the experimental data under standard rocks measured by MIYAZAKI, BARTON, CASTAGNOLI et al., MEYER et al., BERGAMASCO et al., SHELDON et al. and BASCHIERA et al.
Noise Influence on a Dispersive Optical Bistable System with Trilinear Interaction
Authors: Germey K. , Herger R.‐L. , Herklotz R. , Mareyen M. , Schütte F.‐J. , Tiebel R. , Worlitzer K. 
Published: May 2007

AbstractThe influence of fluctuations in the driving fields on an optical bistable multimode system inside a ring resonator with a second order nonlinear material is considered. Steady state solutions of the resulting Fokker‐Planck equations are found for different approximations in which one or two of the modes can be eliminated adiabatically. The results of the stochastics are compared with the deterministic behaviour.