Skip to content

May 1998 arXiv papers — page 5

Showing 401500 of 1,919 papers

  1. Yue-Liang Wu

    When new CP-violating interactions are dominated by flavor changing neutral particle exchanges, that may occur in many extensions of the standard model. We examine a type 3 two Higgs doublet model and find that direct CP asymmetries can be as large as about 25% . Time-dependent and time-integrated mixing-induced CP asymmetries up to 85 and 40 %, respectively

  2. Steven S. Gubser, Igor R. Klebanov, Arkady A. Tseytlin

    The free energy of the maximally supersymmetric SU(N) gauge theory at temperature T is expected to scale, in the large N limit, as N^2 T^4 times a function of the 't Hooft coupling, f(g_{YM}^2 N). In the strong coupling limit the free energy has been deduced from the near-extremal 3-brane geometry, and its normalization has turned out to be 3/4 times tha

  3. Hideo Mabuchi, Jun Ye, H. Jeff Kimble

    We report the use of broadband heterodyne spectroscopy to perform continuous measurement of the interaction energy between one atom and a high-finesse optical cavity, during individual transit events of $\sim 250$ $μ$s duration. Measurements over a wide range of atom-cavity detunings reveal the transition from resonant to dispersive coupling, via the transfe

  4. Frank Antonsen, Karsten Bormann

    We present a generic way of thinking about time machines from the view of a far away observer. In this model the universe consists of three (or more) regions: One containing the entrance of the time machine, another the exit and the remaining one(s) the rest of the universe. In the latter we know ordinary quantum mechanics to be valid and thus are able to wr

  5. A. Tartaglia

    The EPR paradox and the meaning of the Bell inequality are discussed. It is shown that considering the quantum objects as carrying with them ''instruction kits'' telling them what to do when meeting a measurement apparatus any paradox disappears. In this view the quantum state is characterized by the prescribed behaviour rather than by the sp

  6. Denis Morineau, Christiane Alba-Simionesco, Marie-Claire Bellissent-Funel, Marie-France Lauthie

    We present the first experimental characterization in molecular fragile glassformers of a 'prepeak that appears significantly below the main peak of the static structure factor. The temperature and density dependences of this prepeak are studied via elastic neutron scattering experiments under high pressure (up to 300 MPa) in m-toluidine and m-fluoroanil

  7. Robert I McLachlan, GRW Quispel, Nicolas Robidoux

    Systems with a first integral (i.e., constant of motion) or a Lyapunov function can be written as ``linear-gradient systems'' $\dot x= L(x)\nabla V(x)$ for an appropriate matrix function $L$, with a generalization to several integrals or Lyapunov functions. The discrete-time analogue, $Δx/Δt = L \bar\nabla V$ where $\bar\nabla$ is a ``discrete gradie

  8. E. Getzler, R. Pandharipande

    We analyse the consequences of the Virasoro conjecture of Eguchi, Hori and Xiong for Gromov-Witten invariants, in the case of zero degree maps to the manifolds CP^1 and CP^2 (or more generally, smooth projective curves and smooth simply-connected projective surfaces). We obtain predictions involving intersections of psi and lambda classes on the compactifica

  9. James R. Brannan, Jinqiao Duan, Thomas Wanner

    The quasigeostrophic model is a simplified geophysical fluid model at asymptotically high rotation rate or at small Rossby number. We consider the quasigeostrophic equation with dissipation under random forcing in bounded domains. We show that global unique solutions exist for appropriate initial data. Unlike the deterministic quasigeostrophic equation whose

  10. Jinqiao Duan

    The quasigeostrophic equation is a prototypical geophysical fluid model. In this paper, we consider time-periodic motions of this model under dissipation and time-dependent wind forcing. We show that when the wind forcing is time-periodic and the spatial square-integral of the wind forcing is bounded in time, the full nonlinear quasigeostrophic model has tim

  11. Antoine Chambert-Loir

    Canonical heights and Arakelov geometry on semi-abelian varieties. In this paper, we propose a construction of the canonical heights on an extension of an abelian variety by the multiplicative group, in the framework of Arakelov geometry. These canonical heights are the sum of some height coming from the abelian variety and something we call a relative heigh

  12. Alan L. Horwitz

    We examine when the composition of two entire functions f and g is even, and extend some of our results to cyclic compositions in general. We prove some theorems for the cases when f or g is a polynomial. Two of the key theorems we use are a well-known result of Borel, and a theorem of Baker and Gross concerning when f(p(z))=f(q(z)).

  13. Thang T. Q. Le

    We construct power series invariants of rational homology 3-spheres from quantum PSU(n)-invariants. The power series can be regarded as perturbative invariants corresponding to the contribution of the trivial connection in the hypothetical Witten's integral. This generalizes a result of Ohtsuki (the $n=2$ case) which led him to the definition of finite t

  14. G. Kälbermann

    The nature of the interaction of a soliton with an attractive well is elucidated using a model of two interacting point particles. The model explains the existence of trapped states at positive kinetic energy, as well as reflection by an attractive impurity. The transition from a trapped soliton state to a bound state is studied. Bound states of the soliton

  15. Thomas C. Kraan, Pierre van Baal

    We present the detailed derivation of the charge one periodic instantons - or calorons - with non-trivial holonomy for SU(2). We use a suitable combination of the Nahm transformation and ADHM techniques. Our results rely on our ability to compute explicitly the relevant Green's function in terms of which the solution can be conveniently expressed. We als

  16. Raphael Bousso, Andrew Chamblin

    The four-form field recently considered by Hawking and Turok couples naturally to a charged membrane, across which the effective cosmological constant has a discontinuity. We present instantons for the creation of an open inflationary universe surrounded by a membrane. They can also be used to describe the nucleation of a membrane on a pre-existing inflation

  17. M. Faber, A. N. Ivanov, A. Mueller, N. I. Troitskaya

    The magnetic monopole condensate is calculated in the dual Monopole Nambu-Jona-Lasinio model with dual Dirac strings suggested in Refs.[1,2] as a functional of the dual Dirac string shape. The calculation is carried out in the tree approximation in the scalar monopole-antimonopole collective excitation field. The integration over quantum fluctuations of the

  18. P. A. Horváthy, J. -C. Yéra

    The most general vortex solution of the Liouville equation (which arises in non-relativistic Chern-Simons theory) is associated with rational functions, $f(z)=P(z)/Q(z)$ where $P(z)$ and $Q(z)$ are both polynomials, $°P<°Q\equiv N$. This allows us to prove that the solution depends on $4N$ parameters without the use of an index theorem, as well as the flux q

  19. H. Lu, C. N. Pope, J. Rahmfeld

    We derive simple general expressions for the explicit Killing spinors on the n-sphere, for arbitrary n. Using these results we also construct the Killing spinors on various AdS x Sphere supergravity backgrounds, including AdS_5 x S^5$, AdS_4 x S^7 and AdS_7 x S^4. In addition, we extend previous results to obtain the Killing spinors on the hyperbolic spaces

  20. Zhang Yang

    It is pointed out in this talk that ``the colorless objects&#39;&#39; in diffractive scattering in the small-$x_B$ region can be probed by measuring the scaled factorial moments of final-state-hadrons and the dependence of their scaling behavior upon the diffractive kinematic variables. The Monte Carlo implementation of RAPGAP and JETSET are discussed as ill

  21. R. Casalbuoni, S. De Curtis, D. Dominici, R. Gatto

    Present data, both from direct Higgs search and from analysis of electroweak data, are starting to become rather restrictive on the possible values for the mass of the standard model Higgs. We discuss a new physics scenario based on a model with decoupling (both in a linear and in a non linear version) showing how it allows for an excellent fit to the presen

  22. Stefan Dittmaier

    The Weyl-van-der-Waerden spinor technique for calculating helicity amplitudes of massive and massless particles is presented in a form that is particularly well suited to a direct implementation in computer algebra. Moreover, we explain how to exploit discrete symmetries and how to avoid unphysical poles in amplitudes in practice. The efficiency of the forma

  23. A. Denner, S. Dittmaier

    The complete QED corrections of O(alpha) to polarized Compton scattering are calculated for finite electron mass and including the real corrections induced by the processes e^- gamma -> e^- gamma gamma and e^- gamma -> e^- e^- e^+. All relevant formulas are listed in a form that is well suited for a direct implementation in computer codes. We present a detai

  24. Yoshio Koide

    Stimulated by the recent development of the ``universal seesaw mass matrix model&#34;, an application of the model to the neutrino mass matrix is investigated: For the charged lepton and down-quark sectors, the model explains the smallness of their masses $m_f$ by the conventional seesaw mechanism M_f\simeq m_L M_F^{-1}m_R (M_F is a mass matrix of hypothetic

  25. H. G. Ballesteros, L. A. Fernandez, V. Martin-Mayor, A. Munoz-Sudupe

    Using Finite-Size Scaling techniques, we numerically show that the first irrelevant operator of the lattice $λϕ^4$ theory in three dimensions is (within errors) completely decoupled at $λ=1.0$. This interesting result also holds in the Thermodynamical Limit, where the renormalized coupling constant shows an extraordinary reduction of the scaling-corrections

  26. N. M. Agababyan et al

    A factorial-moment analysis with real (integer and non-integer) phase space partition is applied to $π^+$p and K$^+$p collisions at 250 GeV/$c$. Clear evidence is shown for self-affine rather than self-similar power-law scaling in multiparticle production. The three-dimensional self-affine second-order scaling exponent is determined to be 0.061$\pm$0.010.

  27. G. Rizzi, A. Tartaglia

    It is often taken for granted that on board a rotating disk it is possible to operate a \QTR{it}{global}3+1 splitting of space-time, such that both lengths and time intervals are \QTR{it}{uniquely} defined in terms of measurements performed by real rods and real clocks at rest on the platform. This paper shows that this assumption, although widespread and ap

  28. Hong-Yi Zhou

    The experimental results of the two-photon absorption(TPA) and Mössbauer-rotor(MR) for testing the isotropy of the speed of light are explained in an ether drift model with a drift velocity of $\sim 10^{-3}c$. Further tests of the ether drift assumption are suggested.

  29. Gabor Csanyi, Sohrab Ismail-Beigi, T. A. Arias

    Based on ab initio calculation, we propose a new structure for the fundamental excitation of the reconstructed 30$^\circ$ partial dislocation in silicon. This soliton has a rare structure involving a five-fold coordinated atom near the dislocation core. The unique electronic structure of this defect is consistent with the electron spin resonance signature of

  30. D. S. Hall, M. R. Matthews, C. E. Wieman, E. A. Cornell

    We have measured the relative phase of two Bose-Einstein condensates (BEC) using a time-domain separated-oscillatory-field condensate interferometer. A single two-photon coupling pulse prepares the double condensate system with a well-defined relative phase; at a later time, a second pulse reads out the phase difference accumulated between the two condensate

  31. Dirk Helbing, Rolf Molini

    An analytical formula for the occurence probability of Markovian stochastic paths with repeatedly visited and/or equal departure rates is derived. This formula is essential for an efficient investigation of the trajectories belonging to random walk models and for a numerical evaluation of the `contracted path integral solution&#39; of the discrete master equ

  32. Przemyslaw Repetowicz, Uwe Grimm, Michael Schreiber

    We investigate exact eigenstates of tight-binding models on the planar rhombic Penrose tiling. We consider a vertex model with hopping along the edges and the diagonals of the rhombi. For the wave functions, we employ an ansatz, first introduced by Sutherland, which is based on the arrow decoration that encodes the matching rules of the tiling. Exact eigenst

  33. K. Yonemitsu, J. Zhong, H. -B. Schuttler

    We study the tunneling dynamics of dopant-induced hole polarons which are self-localized by electron-phonon coupling in a two-dimensional antiferro- magnet. Our treatment is based on a path integral formulation of the adia- batic approximation, combined with many-body tight-binding, instanton, con- strained lattice dynamics, and many-body exact diagonalizati

  34. Boris Neubert, Michel Pleimling

    Recently, Hlinka and Ishibashi [J. Phys. Soc. Jpn. 67, 495 (1998)] discussed the $T_S$-anomaly in betaine calcium chloride dihydrate (BCCD) in a Landau-type approach. We comment on the shortcomings of this approach and discuss the $T_S$-anomaly in the framework of a microscopical pseudo spin model based on a realistic description of BCCD in terms of symmetry

  35. G. G. Kozlov, V. A. Malyshev, F. Dominguez-Adame, A. Rodriguez

    We study a one-dimensional Frenkel Hamiltonian with off-diagonal disorder, focusing our attention on the physical nature of the zero-energy peak of the density of states. The character of excitonic states (localized or delocalized) is also examined in the vicinity of this peak. It is shown that the state being responsible for the peak is localized. A detaile

  36. N. A. Babushkina, L. M. Belova, V. I. Ozhogin, O. Yu. Gorbenko

    The effect of 16O-18O isotope exchange on the electric resistivity was studied for (La(1-y)Pr(y))0.7Ca0.3MnO3 ceramic samples. Depending on y, this mixed perovskite exhibited different types of low-temperature behavior ranging from ferromagnetic metal (FM) to charge ordered (CO) antiferromagnetic insulator. It was found that at y=0.75, the substitution of 16

  37. Ralf D. Tscheuschner, Sascha Hoch, Eva Leschinsky, Cedrik Meier

    We measure the IQHE on macroscopic (1.5cm x 1.5cm) &#34;quick &#39;n&#39; dirty&#34; prepared III-V heterostructure samples with van der Pauw and modified Corbino geometries at 1.3 K. We compare our results with (i) data taken on smaller specimens, among them samples with a standard Hall bar geometry, (ii) results of our numerical analysis taking inhomogenit

  38. A. Antillon, Jorge V. Jose, T. H. Seligman

    We investigate the two-dimensional classical dynamics of the scattering of point particles by two periodically oscillating disks. The dynamics exhibits regular and chaotic scattering properties, as a function of the initial conditions and parameter values of the system. The energy is not conserved since the particles can gain and loose energy from the collis

  39. V. V. Kuznetsov, E. E. Mendez, J. D. Bruno, J. T. Pham

    We have observed that the shot noise of tunnel current, I, in GaSb-AlSb-InAs-AlSb-GaSb double-barrier structure under a magnetic field can exceed 2qI. The measurements were done at T=4K in fields up to 5T parallel to the current. The noise enhancement occurred at each of the several negative-differential conductance regions induced by the tunneling of holes

  40. Frank Gibbons, A. Góngora-T, Jorge V. José

    We study the dynamic response to external currents of periodic arrays of Josephson junctions, in a resistively capacitively shunted junction (RCSJ) model, including full capacitance-matrix effects}. We define and study three different models of the capacitance matrix $C_{\vec{r},\vec{r}&#39;}$: Model A includes only mutual capacitances; Model B includes mutu

  41. Jinqiao Duan, Xin-Chu Fu, Pei-De Liu, Anthony Manning

    We show that a linear quantum harmonic oscillator is chaotic in the sense of Li-Yorke. We also prove that the weighted backward shift map, used as an infinite dimensional linear chaos model, in a separable Hilbert space is chaotic in the sense of Li-Yorke, in addition to being chaotic in the sense of Devaney.

  42. Xin-Chu Fu, Jinqiao Duan

    The authors present two results on infinite-dimensional linear dynamical systems with chaoticity. One is about the chaoticity of the backward shift map in the space of infinite sequences on a general Fréchet space. The other is about the chaoticity of a translation map in the space of real continuous functions. The chaos is shown in the senses of both Li-Yor

  43. Jinqiao Duan

    In this paper, the author investigates the impact of external sources on the pattern formation and long-time behavior of concentration profiles of passive tracers in a two-dimensional shear flow. It is shown that a time-periodic concentration profile exists for time-periodic external source, while for random source, the distribution functions of all concentr

  44. Dominik J. Schwarz, Jerome Martin

    Inflation predicts the generation of cosmological perturbations. Usually, the power spectra for the scalar and tensor modes are calculated with help of the slow roll approximation. In the case of power law inflation an exact result is available. We compare the predictions for the cosmic microwave background anisotropies from the slow roll approximation with

  45. Paola Marigo

    Until recently synthetic AGB models had not taken into account the break-down of the core mass-luminosity (Mc-L) relation due to the occurrence of envelope burning in the most massive (M > 3.5 Msun) and luminous (Mbol > -6) stars. Marigo et al. (1998) made the first attempt to consistently include the related over-luminosity effect (i.e. above the Mc-L relat

  46. Koji Takahashi, Simon Portegies Zwart

    Recent N-body simulations have shown that there is a serious discrepancy between the results of the N-body simulations and the results of Fokker-Planck simulations for the evolution of globular and rich open clusters under the influence of the galactic tidal field. In some cases, the lifetime obtained by Fokker-Planck calculations is more than an order of ma

  47. Gary Shiu, S. -H. Henry Tye

    Utilizing the idea of extra large dimensions, it has been suggested that the gauge and gravity couplings unification can happen at a scale as low as 1 TeV. In this paper, we explore this phenomenological possibility within string theory. In particular, we discuss how the proton decay bound can be satisfied in Type I string theory. The string picture also sug

  48. M. E. Portnoi, I. Galbraith

    We consider scattering state contributions to the partition function of a two-dimensional (2D) plasma in addition to the bound-state sum. A partition function continuity requirement is used to provide a statistical mechanical heuristic proof of Levinson&#39;s theorem in two dimensions. We show that a proper account of scattering eliminates singularities in t

  49. Ho-Meoyng Choi, Chueng-Ryong Ji

    We find that the zero mode($q^{+}=0$ mode of a continuum theory) contribution is crucial to obtain the correct values of the light-front current $J^{-}$ in the Drell-Yan($q^{+}=0$) frame. In the exactly solvable model of (1+1)-dimensional scalar field theory interacting with gauge fields, we quantify the zero mode contribution and observe that the zero mode

  50. Zhongbing Huang, Shiping Feng

    The spin dynamics at the finite temperature for the t-J model in the underdoped and optimal doped regimes is studied within the fermion-spin theory. It is shown that the dynamical spin structure factor spectrum at the antiferromagnetic wave vector $Q=(π,π)$ are separated as low- and high-frequency parts, respectively, but the high-frequency part is suppresse

  51. J. L. F. Barbon, J. Manes, M. A. Vazquez-Mozo

    The large N limit of extremal non-supersymmetric Type-I five-dimensional string black holes is studied from the point of view of D-branes. We find that the agreement between the D-brane and the black-hole picture is due to an asymptotic restoration of supersymmetry in the large $N$ limit in which both pictures are compared. In that limit Type-I string pertur

  52. V. V. Makhro

    A theoretical and numerical investigations of the quantum tunneling of the domain walls in ferromagnets and weak ferromagnets was performed taking into account the interaction between walls and thermal excitations of a crystal. The numerical method for calculations of the probability of a thermally stimulated quantum depinning as the function of temperature

  53. S. E. Barnes

    A new scheme is proposed which will permit electron spin resonance pulse techniques to be used to realize a quantum computer with a 100 qbits, or more. The computation is performed on effective pure states which correspond to off-diagonal blocks of the density matrix. Described is a scheme which very efficiently performs the preparation stage and which permi

  54. A. Yu. Voronin, J. Carbonell

    The main properties of the interaction of ultra low-energy antiprotons ($% E\le10^{-6}$ a.u.) with atomic hydrogen are established. They include the elastic and inelastic cross sections and Protonium (Pn) formation spectrum. The inverse Auger process ($Pn+e \to H+\bar{p}$) is taken into account in the framework of an unitary coupled-channels model. The annih

  55. M. A. Trump, W. C. Schieve

    The classical two-body system with Lorentz-invariant Coulomb interaction V=-k/rho is solved in 3+1 dimensions using the manifestly covariant Hamiltonian mechanics of Stueckelberg. Particular solutions for the reduced motion are obtained which correspond to bound attractive, unbound attractive, and repulsive scattering motion. A lack of perihelion precession

  56. A. Armoni, Y. Frishman, J. Sonnenschein, U. Trittmann

    Massless $QCD_2$ is dominated by classical configurations in the large $N_f$ limit. We use this observation to study the theory by finding solutions to equations of motion, which are the non-Abelian generalization of the Schwinger equation. We find that the spectrum consists of massive mesons with $M^2={e^2 N_f\over 2π}$ which correspond to Abelian solutions

  57. A. A. Bolokhov, V. A. Kozhevnikov, S. G. Sherman, D. N. Tatarkin

    The theoretical study of cross sections for polarized--target measurements of $ πN \to ππN $ reactions gives evidence that the interplay between the strong contribution from OPE mechanism and the one from isobar exchanges, which is equally strong within isobar half--widths energy region, must result in nontrivial polarization phenomena. The Monte--Carlo simu

  58. B. Pötter

    A complete next-to-leading order QCD calculation of deep inelastic electron-photon scattering including direct and resolved real photon components is presented. Soft and collinear singularities are extracted using the phase space slicing method. Application of the results for the prediction of single- and dijet cross sections at the LEP e+e- collider are pre

  59. The SLD Collaboration, K. Abe

    We have measured the differential production cross sections as a function of scaled momentum x_p=2p/E_cm of the identified hadron species pi+, K+, K0, K*0, phi, p, Lambda0, and of the corresponding antihadron species in inclusive hadronic Z0 decays, as well as separately for Z0 decays into light (u, d, s), c and b flavors. Clear flavor dependences are observ

  60. P. J. Forrester

    A Gaussian fluctuation formula is proved for linear statistics of complex random matrices in the case that the statistic is rotationally invariant. For a general linear statistic without this symmetry, Coulomb gas theory is used to predict that the distribution will again be a Gaussian, with a specific mean and variance. The variance splits naturally into a

  61. T. D. Engeness, T. A. Arias

    We introduce an approach to exploit the existence of multiple levels of description of a physical system to radically accelerate the determination of thermodynamic quantities. We first give a proof of principle of the method using two empirical interatomic potential functions. We then apply the technique to feed information from an interatomic potential into

  62. Amr El-Zant, Bjoern Hassler

    We study the stability of trajectories near the disk plane of galaxy models with a triaxial dark matter halo component. We also examine the effect of weak discreteness noise, rapidly rotating bar perturbations and weak dissipation on these trajectories. If the matter distribution is triaxial and has a constant density core, dissipation leads to inflow of mat

  63. E. Vesperini

    We investigate the evolution of the mass function of the Galactic globular cluster system (GCMF) taking into account the effects of stellar evolution, two-body relaxation, disk shocking and dynamical friction on the evolution of individual globular clusters.We have adopted a log-normal initial GCMF and we have studied in detail the dependence on the initial

  64. E. Kerins, N. W. Evans

    All previous attempts to understand the microlensing results towards the Large Magellanic Cloud (LMC) have assumed homogeneous present day mass functions (PDMFs) for the lensing populations. Here, we present an investigation into the microlensing characteristics of haloes with spatially varying PDMFs and anisotropic velocity dispersion tensors. One attractiv

  65. N. W. Evans, J. C. A. Read

    This paper reports on the in-plane normal modes in the self-consistent and the cut-out power-law disks. Although the cut-out disks are remarkably stable to bisymmetric perturbations, they are very susceptible to one-armed modes. For this harmonic, there is no inner Lindblad resonance, thus removing a powerful stabilising influence. A physical mechanism for t

  66. N. W. Evans, J. C. A. Read

    The power-law disks are a family of infinitesimally thin, axisymmetric stellar disks of infinite extent. The rotation curve can be rising, falling or flat. The self-consistent power-law disks are scale-free, so that all physical quantities vary as a power of radius. They possess simple equilibrium distribution functions depending on the two classical integra

  67. G. Gyuk, N. W. Evans, E. I. Gates

    This paper investigates the hypothesis that the lensing objects towards the Large Magellanic Cloud (LMC) are brown dwarfs by analysing the effects of velocity anisotropy on the inferred microlensing masses. To reduce the masses, the transverse velocity of the lenses with respect to the microlensing tube must be minimised. In the outer halo, radial anisotropy

  68. F. Douglas Swesty

    One of the major difficulties encountered in modeling core collapse supernovae is obtaining an accurate description of the transport of neutrinos through the collapsed stellar core. The behavior of the neutrino distribution function transitions from an LTE distribution in the center of the core to a non-LTE distribution in the outer regions of the core. One

  69. Prot Pakonski, Andrzej Ostruszka, Karol Zyczkowski

    We define a class of dynamical systems on the sphere analogous to the baker map on the torus. The classical maps are characterized by dynamical entropy equal to ln 2. We construct and investigate a family of the corresponding quantum maps. In the simplest case of the model the system does not possess a time reversal symmetry and the quantum map is represente

  70. Kei-Ichi Kondo

    We prove Abelian magnetic monopole dominance in the string tension of QCD. Abelian and monopole dominance in low energy physics of QCD has been confirmed for various quantities by recent Monte Carlo simulations of lattice gauge theory. In order to prove this dominance, we use the reformulation of continuum Yang-Mills theory in the maximal Abelian gauge as a

  71. O. Kiriyama, M. Maruyama, F. Takagi

    The chiral phase transition at high temperature is investigated using the effect ive potential in the framework of the QCD-like gauge theory with a variational a pproach. We have a second order phase transition at $T_c=136$MeV. We also investigate numerically the temperature dependence of condensate, $f_\pi$ a nd $a_2(T)$(coefficient of the quadratic term in

  72. J. -M. Chung, B. K. Chung

    We calculate analytically a class of three-loop vacuum diagrams with two different mass values, one of which is one-third as large as the other, using the method of Chetyrkin, Misiak, and Münz in the dimensional regularization scheme. All pole terms in ε=4-D (D being the space-time dimensions in a dimensional regularization scheme) plus finite terms containi

  73. Ruggero Maria Santilli

    In this paper we initiate studies of the emerging new forms of energy by using as a representative example the new combustible gas called AquaFuel, discovered and patented by William H. Richardson, jr., whose rights are now owned by Toups Technology Licensing, Inc. (TTL), of Largo, Florida. In essence, AquaFuel is a new energy converter capable of transformi

  74. Michael L. Gorodetsky, Vladimir S. Ilchenko

    A general model is presented for coupling of high-$Q$ whispering-gallery modes in optical microsphere resonators with coupler devices possessing discrete and continuous spectrum of propagating modes. By contrast to conventional high-Q optical cavities, in microspheres independence of high intrinsic quality-factor and controllable parameters of coupling via e

  75. F. M. Nunes, R. Shyam, I. J. Thompson

    Coulomb Dissociation provides an alternative method for determining the radiative capture cross sections at astrophysically relevant low relative energies. For the breakup of $^8$B on $^{58}$Ni, we calculate the total Coulomb Dissociation cross section and the angular distribution for E1, E2 and M1. Our calculations are performed first within the standard fi

  76. L. Prochniak, K. Zajac, K. Pomorski, S. G. Rohozinski

    The generalized Bohr Hamiltonian is applied to a description of low-lying collective excitations in even-even isotopes of Te, Xe, Ba, Ce, Nd and Sm. The collective potential and inertial functions are determined by means of the Strutinsky method and the cranking model, respectively. A shell-dependent parametrization of the Nilsson potential is used. An appro

  77. K. Hagino, N. Takigawa

    We discuss the effects of coupling of the relative motion to nuclear collective excitations which have a finite lifetime on heavy-ion fusion reactions at energies near and below the Coulomb barrier. Both spreading and escape widths are explicitly taken into account in the exit doorway model. The coupled-channels equations are numerically solved to show that

  78. Maks A. Akivis, Vladislav V. Goldberg

    The differential geometry of almost Grassmann structures defined on a differentiable manifold of dimension n = pq by a fibration of Segre cones SC (p, q) is studied. The peculiarities in the structure of almost Grassmann structures for the cases p=q=2; p = 2, q > 2 (or p > 2, q = 2), and p > 2, q > 2 are clarified. The fundamental geometric objects of these

  79. David P. Robbins

    Noam Elkies and Everett Howe independently noticed a certain elegant product formula for the multiple integral \int_R \prod_{1 \le i < j \le k} (x_j-x_i) dx_1 \cdots dx_k, where the region $R$ is the set of $k$-tuples satisfying $0 < x_1 < \cdots < x_k < 1$. Later this formula turned out to be a special case of a formula of Selberg. We prove an apparently di

  80. Maks A. Akivis, Vladislav V. Goldberg

    The main results on the theory of conformal and almost Grassmann structures are presented. The common properties of these structures and also the differences between them are outlined. In particular, the structure groups of these structures and their differential prolongations are found. A complete system of geometric objects of the almost Grassmann structur

  81. Maks A. Akivis, Vladislav V. Goldberg

    In the present paper we study locally semiflat (we also call them semiintegrable) almost Grassmann structures. We establish necessary and sufficient conditions for an almost Grassmann structure to be alpha- or beta-semiintegrable. These conditions are expressed in terms of the fundamental tensors of almost Grassmann structures. Since we are not able to prove

  82. N. Dragon, E. Ivanov, S. Kuzenko, E. Sokatchev

    We develop a general setting for N=2 rigid supersymmetric field theories with gauged central charge in harmonic superspace. We consider those N=2 multiplets which have a finite number of off-shell components and exist off shell owing to a non-trivial central charge. This class includes, in particular, the hypermultiplet with central charge and various versio

  83. Stanislaw Mrowczynski

    A few topics of the transport theory of quark-gluon plasma are reviewed. A derivation of the transport equations form the underlaying dynamical theory is discussed within the $ϕ^4$ model. Peculiarities of the kinetic equations of quarks and gluons are considered and the plasma (linear) response to the color field is studied. The chromoelectric tensor permeab

  84. Ralf Pantfoerder

    All derivations of the GDH sum rule are presented and discussed in detail, focussing particularly on the validity of the underlying assumptions. Several tests of the sum rule within perturbative models are reviewed. Various possible sources of modifications of the sum rule are examined. With respect to the current-algebra derivation, the crucial role of the

  85. Hai-cang Ren, Maw-kuen Wu

    The photon self energy tensor in a crystal with double exchange and ferromagnetic or canting magnetic orders is analyzed at zero temperature with emphasis on the signal of the time-reversal invariance breaking. Three comparable contributions, spin susceptibility, local magnetic field and spin-orbit coupling are estimated and the prospect of their experimenta

  86. A. P. Litvinchuk

    Both principal conclusions of Hirata and Takeya paper (Phys. Rev. B 57, 2671 (1998)) dealing with an analysis of the electron-phonon coupling strengths and stating the existence of two boron-related fully symmetric phonon modes in YNi_2B_2C are argued not to be supported by experimental data and not justified.

  87. E. Marinari, S. Mossa, G. Parisi

    We introduce a Potts model with quenched, frustrated disorder, that enjoys of a gauge symmetry that forbids spontaneous magnetization, and allows the glassy phase to extend from $T_c$ down to T=0. We study numerical the 4 dimensional model with $q=4$ states. We show the existence of a glassy phase, and we characterize it by studying the probability distribut

  88. Matthias Eschrig, J. A. Sauls, D. Rainer

    We calculate the response of a vortex core in a layered superconductor to {\em ac} electromagnetic fields with frequencies $ω\lsim 2Δ/\hbar$. In this frequency range the response is dominated by order parameter collective modes which are coupled to the vortex-core bound states of Caroli, de Gennes and Matricon. Our calculations show that a vortex core has a

  89. Ryo Maezono, Sumio Ishihara, Naoto Nagaosa

    We study theoretically the phase diagram of perovskite manganites taking into account the double degeneracy of the $e_g$ orbitals in a $Mn^{3+}$ ion. A rich phase diagram is obtained in the mean field theory at zero temperature as functions of $x$ (hole concentration) and $J_S$ (antiferromagnetic interaction between $t_{2g}$ spins). The global features of th

  90. Ross A. Lippert, T. A. Arias, Alan Edelman

    Multiresolution analyses based upon interpolets, interpolating scaling functions introduced by Deslauriers and Dubuc, are particularly well-suited to physical applications because they allow exact recovery of the multiresolution representation of a function from its sample values on a finite set of points in space. We present a detailed study of the applicat

  91. Ubi F. Wichoski, Jane H. MacGibbon, Robert H. Brandenberger

    Decaying topological defects, in particular cosmic strings, can produce a significant flux of high energy neutrinos, photons and cosmic rays. According to the prevailing understanding of cosmic string dynamics in an expanding Universe, the network of long strings loses its energy first into string loops, which in turn give off most of their energy as gravita

  92. Wentao T. Lu, F. Y. Wu

    We consider the Ising model on an $M\times N$ rectangular lattice with an asymmetric self-dual boundary condition, and derive a closed-form expression for its partition function. We show that zeroes of the partition function are given by the roots of a polynomial equation of degree $2M-1$, which trace out certain loci in the complex temperature plane. Partic

  93. N. Graham, R. L. Jaffe

    We calculate one-loop quantum energies in a renormalizable self-interacting theory in one spatial dimension by summing the zero-point energies of small oscillations around a classical field configuration, which need not be a solution of the classical field equations. We unambiguously implement standard perturbative renormalization using phase shifts and the

  94. M. A. Skvortsov, V. E. Kravtsov, M. V. Feigel&#39;man

    Microscopic theory of the type of Efetov&#39;s supermatrix sigma-model is constructed for the low-lying electron states in a mixed superconductive-normal system with disorder. The developed technique is used for the study of the localized states in the core of a vortex in a moderately clean superconductor (1/Δ<< τ<< 1/ω_0 = E_F/Δ^2). At sufficiently low ener

  95. Biswajoy Brahmachari, Rabindra N. Mohapatra

    The simplest way to simultaneously understand all existing indications of neutrino oscillations from solar and atmospheric neutrino deficits and the LSND experiment, seems to be to postulate a sterile neutrino. We present a realistic grand unified model based on the gauge group $SO(10)\times SO(10)^\prime$ that leads to the desired masses and mixings for the

  96. S. Deser

    The inevitability of Chern--Simons terms in constructing a variety of physical models, and the mathematical advances they in turn generate, illustrates the unexpected but profound interactions between the two disciplines.

  97. Artur Sergyeyev

    The $x$-dependence of the symmetries of (1+1)-dimensional scalar translationally invariant evolution equations is described. The sufficient condition of (quasi)polynomiality in time $t$ of the symmetries of evolution equations with constant separant is found. The general form of time dependence of the symmetries of KdV-like non-linearizable evolution equatio

  98. S. Abramsky, R. Blute, P. Panangaden

    We generalize the notion of nuclear maps from functional analysis by defining nuclear ideals in tensored *-categories. The motivation for this study came from attempts to generalize the structure of the category of relations to handle what might be called ``probabilistic relations&#39;&#39;. The compact closed structure associated with the category of relati

  99. Henk van Elst, George F R Ellis

    Exact dynamical equations for a generic dust matter source field in a cosmological context are formulated with respect to a non-comoving Newtonian-like timelike reference congruence and investigated for internal consistency. On the basis of a lapse function $N$ (the relativistic acceleration scalar potential) which evolves along the reference congruence acco

  100. T. Mannel, B. Postler

    We obtain model independent bounds for the form factors which arise in semileptonic B -> Pi decays. To this end we derive a theoretical restriction for possible combinations of the value of the form factor and its derivatives at the endpoint region. These restrictions are then used as an input in a - slightly modified - general formalism, which has already b