October 1999 arXiv papers — page 24

Prabodh Shukla, Ratnadeep Roy, Emilia Ray

We consider the hysteretic response of a one-dimensional anti-ferromagnetic random-field Ising model at zero temperature for a uniform bounded distribution of quenched random fields, and present analytic results in a limited range of the applied field.

A. V. Lopatin

We consider a disordered superconducting film in the magnetic field close to the upper critical field. Assuming that the phase transition to the glassy superconducting state exists and it is of the second order we show that it is exactly described by a zero-dimensional replica model having a form of one describing the phase transition in the SK (Sherrington-

Tapash Chakraborty, Pekka Pietiläinen

We report our results on temperature dependence of spin polarizations at $ν=1$ in the lowest as well as in the next higher Landau level that compare well with recent experimental results. At $ν=3$, except having a much smaller magnitude the behavior of spin polarization is not much influenced by higher Landau levels. In sharp contrast, for filling factor $ν=

Jinqiao Duan, Peter E. Kloeden

The full nonlinear dissipative quasigeostrophic model is shown to have a unique temporally almost periodic solution when the wind forcing is temporally almost periodic under suitable constraints on the spatial square-integral of the wind forcing and the $β$ parameter, Ekman number, viscosity and the domain size. The proof involves the pullback attractor for

Xin-Chu Fu, Yibin Fu, Jinqiao Duan, Robert S. MacKay

The chaotic properties of some subshift maps are investigated. These subshifts are the orbit closures of certain non-periodic recurrent points of a shift map. We first provide a review of basic concepts for dynamics of continuous maps in metric spaces. These concepts include nonwandering point, recurrent point, eventually periodic point, scrambled set, sensi

Jinqiao Duan, James Brannan, Vincent Ervin

We investigate fluid transport in random velocity fields with unsteady drift. First, we propose to quantify fluid transport between flow regimes of different characteristic motion, by escape probability and mean residence time. We then develop numerical algorithms to solve for escape probability and mean residence time, which are described by backward Fokker

Matthew A. Bershady

I outline a quantitative method for characterizing galaxies both by photometric `form' and indices of spectral-type, applicable to both nearby and distant galaxies. Such a characterization provides insight on galaxy evolution because there are physical connections between galaxies' stellar populations and their light distribution. ``Normal''

Yoshiaki Taniguchi, Takashi Murayama, Tohru Nagao

Recently growing evidence has been accumulated that the NLS1s are viewed from nearly pole-on viewing angles. However, there has been no theoretical model which explains the following important correlations; 1) weaker optical Fe II emitters always have wider emission-line widths but stronger optical Fe II emitters have either wider or narrower line widths, an

T. Padmanabhan, Nissim Kanekar

We consider the problem of gravitational clustering in a D-dimensional expanding Universe and derive scaling relations connecting the exact mean two-point correlation function with the linear mean correlation function, in the quasi-linear and non-linear regimes, using the standard paradigms of scale-invariant radial collapse and stable clustering. We show th

Renata Kallosh, Andrei Linde, Marina Shmakova

We explain that supersymmetric attractors in general have several critical points due to the algebraic nature of the stabilization equations. We show that the critical values of the cosmological constant of the adS_5 vacua are given by the topological (moduli independent) formulae analogous to the entropy of the d=5 supersymmetric black holes. We present con

Ernesto Lozano-Tellechea, Tomas Ortin

We present the most general family of stationary point-like solutions of pure N=4, d=4 Supergravity characterized by completely independent electric and magnetic charges, mass, angular momentum and NUT charge plus the asymptotic values of the scalars. It includes, for specific values of the charges all previously known BPS and non-BPS, extreme and non-extrem

Erwin Schroedinger

Schroedinger's famous quadruple of factorizations of the hypergeometric equation is archived here

H. Tsunemi, K. Yoshita, A. D. Short, P. J. Bennie

We report here the results of a mesh experiment to measure the subpixel structure of the EPIC MOS CCDs on board the XMM X-ray observatory. The pixel size is 40$μ$m square while the mesh hole spacing is 48$μ$m, a combination quite different from our standard mesh experiment. We have verified that this combination functions properly and have analyzed the CCD s

B. Desplanques, B. Silvestre-Brac, F. Cano, P. Gonzalez

The nucleon form factors are calculated using a non-relativistic description in terms of constituent quarks. The emphasis is put on the reliability of present numerical methods used to solve the three-body problem in order to correctly reproduce the expected asymptotic behavior of form factors. Nucleon wave functions obtained in the hyperspherical formalism

Oleg Ogievetsky, Zorka Papadopolos

We introduce Dehn invariants as a useful tool in the study of the inflation of quasiperiodic space tilings. The tilings by ``golden tetrahedra'' are considered. We discuss how the Dehn invariants can be applied to the study of inflation properties of the six golden tetrahedra. We also use geometry of the faces of the golden tetrahedra to analyze thei

E. Brezin, S. Hikami

Number theorists have studied extensively the connections between the distribution of zeros of the Riemann $ζ$-function, and of some generalizations, with the statistics of the eigenvalues of large random matrices. It is interesting to compare the average moments of these functions in an interval to their counterpart in random matrices, which are the expecta

Katrina Deane Barron

The notions of N=1 Neveu-Schwarz vertex operator superalgebra over a Grassmann algebra and with odd formal variables and of N=1 Neveu-Schwarz vertex operator superalgebra over a Grassmann algebra and without odd formal variables are introduced, and we show that the respective categories of such objects are isomorphic. The weak supercommutativity and weak ass

Patricia Ball, J. -M. Frere, J. Matias

We investigate the pattern of CP violation in K, B_d and B_s mixing in a symmetrical SU(2)_R x SU(2)_L x U(1) model with spontaneous CP violation. We calculate the phases of the left and right quark mixing matrices beyond the small phase approximation and perform a careful analysis of all relevant restrictions on the model's parameters from Delta m_K, De

S. P. Baranov, H. Jung, N. P. Zotov

In the framework of semi-hard QCD approach, we present a consistent analysis of D^* meson production at HERA energies. The consideration is based on universal unintegrated gluon densities, which have BFKL behavior in the small x region. Predictions of the CCFM evolution equation for D^* production are obtained and show a good description of D^* data at HERA.

Michael E. Luke, Aneesh V. Manohar, Ira Z. Rothstein

We discuss the matching conditions and renormalization group evolution of non-relativistic QCD. A variant of the conventional MS-bar scheme is proposed in which a subtraction velocity nu is used rather than a subtraction scale mu. We derive a novel renormalization group equation in velocity space which can be used to sum logarithms of v in the effective theo

N. Yamada, S. Hashimoto, K-I. Ishikawa, H. Matsufuru

We present an update of our NRQCD calculation of $B_B$ at $β$=5.9 with increased statistics. We also discuss a calculation of $B_S$, which is relevant to the width difference in the $B_s-\bar{B}_s$ mixing.

L3 Collaboration

Single and multi-photon events with missing energy are analysed using data collected with the L3 detector at LEP at a centre-of-mass energy of 189 GeV, for a total of 176 pb^{-1} of integrated luminosity. The cross section of the process e+e- -> nu nu gamma (gamma) is measured and the number of light neutrino flavours is determined to be N_ν= 3.011 +/- 0.077

L3 Collaboration

We report on measurements of the triple-gauge-boson couplings of the W boson in e+e- collisions with the L3 detector at LEP. W-pair, single-W and single-photon events are analysed in a data sample corresponding to a total luminosity of 76.7 pb^{-1} collected at centre-of-mass energies between 161 GeV and 183 GeV. CP-conserving as well as both C- and P-conser

L3 Collaboration

We report the result of a search for charginos and neutralinos, in e+e- collisions at 189 GeV centre-of-mass energy at LEP. No evidence for such particles is found in a data sample of 176 pb^{-1}. Improved upper limits for these particles are set on the production cross sections. New exclusion contours in the parameter space of the Minimal Supersymmetric Sta

L3 Collaboration

We report the result of a search for scalar leptons in e+e- collisions at 189 GeV centre-of-mass energy at LEP. No evidence for such particles is found in a data sample of 176 pb^{-1}. Improved upper limits are set on the production cross sections for these new particles. New exclusion contours in the parameter space of the Minimal Supersymmetric Standard Mo

C. J. Isham, J. Butterfield

We discuss some ways in which topos theory (a branch of category theory) can be applied to interpretative problems in quantum theory and quantum gravity. In Section 1, we introduce these problems. In Section 2, we introduce topos theory, especially the idea of a topos of presheaves. In Section 3, we discuss several possible applications of topos theory to th

K. Das Gupta, G. Sambandamurthy, V. H. S. Moorthy, N. Chandrasekhar

We have studied the magnetoresistance (MR) and evolution of conductivity with thickness of quench-condensed Bismuth films on substrates of various dielectric constants. Our results indicate a negative intial MR proportional to the square of the magnetic field. The conductance shows a power-law kind of dependence on thickness, with an exponent close to 1.33,

C. J. Olson, C. Reichhardt

Using numerical simulations we investigate the transverse depinning of moving vortex lattices interacting with random disorder. We observe a finite transverse depinning barrier for vortex lattices that are driven with high longitudinal drives, when the vortex lattice is defect free and moving in correlated 1D channels. The transverse barrier is reduced as th

A. I. MacFadyen, S. E. Woosley, A. Heger

We consider the explosion of supernovae and the possible production of a variety of high energy transients by delayed black hole formation in massive stars endowed with rotation. Following the launch of a ``successful'' shock by the usual neutrino powered mechanism, the inner layers of the star move outwards, but lack adequate energy to eject all the

Hitoshi Hanami

In order to study the statistics of the objects with hierarchical merging, we propose the skeleton tree formalism, which can analytically distinguish the episodic merging and the continuous accretion in the mass growth processes. The distinction was not clear in extended Press-Schechter (PS) formalism. The skeleton tree formalism is a natural extension of th

M. Longhetti, A. Bressan, C. Chiosi, R. Rampazzo

In this paper we analyze the line-strength indices in the Lick-system measured by Longhetti et al. (1998a, b) for a sample of 51 early-type galaxies located in low density environments (LDE) and showing signatures of fine structures and/or interactions. The sample contains 21 shell-galaxies and 30 members of interacting pairs. Firstly we perform a preliminar

Barbara Lanzoni, Gary A. Mamon, Bruno Guiderdoni

We have constructed the merging history of dark matter halos in a SCDM cosmology, by means of a the {``Merging Cell Model''} (Rodrigues & Thomas 1996). It is based on the linear theory of growth of density fluctuations, and the Top-Hat model, and it takes into account mergers between halos through simplified criteria. The halo mass function, the prog

Makoto Ideta, Shunsuke Hozumi, Toshio Tsuchiya, Motokazu Takizawa

A recent observation with the Hipparcos satellite and some numerical simulations imply that the interaction between an oblate halo and a disc is inappropriate for the persistence of galactic warps. Then, we have compared the time evolution of galactic warps in a prolate halo with that in an oblate halo. The haloes were approximated as fixed potentials, while

D. B. Sanders

Our view of galaxy evolution has been dramatically enhanced by the recent deep field submm surveys carried out with the SCUBA camera on the JCMT. SCUBA has discovered a population of luminous infrared galaxies at redshifts ~1-4 that emit most of their energy at far-IR/submm wavelengths. The cumulative surface density of submm sources (~10,000 per sq.deg with

J. L. F. Barbon, E. Rabinovici

We study thermodynamical aspects of string theory in the limit in which it corresponds to Noncommutative Yang-Mills. We confirm, using the AdS/CFT correspondence, that for general Dp branes the entropy in the planar approximation depends neither on the value of the background magnetic field B nor on its rank. We find 1/N corrections to the planar entropy in

Jeeva S. Anandan

A unified and fully relativistic treatment of the interaction of the electric and magnetic dipole moments of a particle with the electromagnetic field is given. New forces on the particle due to the combined effect of electric and magnetic dipoles are obtained. Four new experiments are proposed, three of which would observe topological phase shifts.

H. O. Girotti, Victor O. Rivelles

We consider the AdS space formulation of the classical dynamics deriving from the Stueckelberg Lagrangian. The on-shell action is shown to be free of infrared singularities as the vector boson mass tends to zero. In this limit the model becomes Maxwell theory formulated in an arbitrary covariant gauge. Then we use the AdS/CFT correspondence to compute the tw

Massimo Bianchi, Stefano Kovacs

We show that extremal correlators of chiral primary operators in N=4 supersymmetric Yang-Mills theory with SU(N) gauge group are neither renormalised at first order in perturbation theory nor receive contribution from any instanton sector at leading order in the semiclassical expansion. This lends support to the strongest version of a new prediction recently

Ivo Sachs, William Weir

We determine the instanton corrections to the effective coupling in SU(2), N=2 Yang-Mills theory with four flavours to all orders. Our analysis uses the S(2,Z)-invariant curve and the two instanton contribution obtained earlier to fix the higher order contributions uniquely.

B. K. Jennings

Three related features of the astrophysical S-factor, (S_{17}), for low energies are an upturn as the energy of the proton goes to zero, a pole at the proton separation energy and a long ranged radial integral peaking at approximately 40 fm. These features, particularly the last, mean (S_{17}) at threshold is largely determined by the asymptotic normalizatio

Marc Henneaux, Liat Maoz, Adam Schwimmer

We investigate systematically the asymptotic dynamics and symmetries of all three-dimensional extended AdS supergravity models. First, starting from the Chern-Simons formulation, we show explicitly that the (super)anti-de Sitter boundary conditions imply that the asymptotic symmetry algebra is the extended superconformal algebra with quadratic nonlinearies i

Sergio De Filippo

The states of the physical algebra, namely the algebra generated by the operators involved in encoding and processing qubits, are considered instead of those of the whole system-algebra. If the physical algebra commutes with the interaction Hamiltonian, and the system Hamiltonian is the sum of arbitrary terms either commuting with or belonging to the physica

M. Urban, M. Buballa, R. Rapp, J. Wambach

The modification of the rho-meson self-energy due to the coupling to in-medium pions is calculated consistently at finite baryon density and temperature, keeping the full 3-momentum dependence in a gauge invariant way. As a function of nucleon density, the rho-meson spectral function is strongly enhanced in the invariant mass region M < 650 MeV, while the ma

A. P. Zuker, L. Waha Ndeuna, F. Nowacki, E. Caurier

On the basis of shell model simulations, it is conjectured that the Lanczos construction at fixed quantum numbers defines---within fluctuations and behaviour very near the origin---smooth canonical matrices whose forms depend on the rank of the Hamiltonian, dimensionality of the vector space, and second and third moments. A framework emerges that amounts to

Raja Q. Almukahhal, Tristan Hubsch

We present a systematic and &#39;from the ground up&#39; analysis of the &#39;minimal coupling&#39; type of gauging of Yang-Mills symmetries in (2,2)-supersymmetric 1+1-dimensional spacetime. Unlike in the familiar 3+1-dimensional N=1 supersymmetric case, we find several distinct types of minimal coupling symmetry gauging, and so several distinct types of ga

A. P. Zuker

It is shown that nuclear level densities in a finite space are described by a continuous binomial function, determined by the first three moments of the Hamiltonian, and the dimensionality of the underlying vector space. Experimental values for $^{55}$Mn, $^{56}$Fe, and $^{60}$Ni are very well reproduced by the binomial form, which turns out to be almost per

Sandip K. Chakrabarti, Sivakumar G. Manickam

We discover a definite correlation between the frequency of the quasi-periodic oscillations (QPO) in quiescence states and the duration of the quiescence state of the transient X-ray source GRS 1915+105. We find that while the QPO frequency can be explained with the oscillation of shocks in accretion flows, the switching of burst to quiescence states (and vi

Shigefumi Naka, Shinji Abe, Eizou Umezawa, Tetsu Matsufuji

The bi-local model of hadrons is studied from the viewpoint of non-commutative geometry formulated so that Higgs-like scalar fields play the role of a bridge, the bi-local fields, connecting different spacetime points. We show that the resultant action for Higgs-like scalar fields has a structure similar to that of the linear sigma model. According to this f

Nobuyuki Ishibashi, Satoshi Iso, Hikaru Kawai, Yoshihisa Kitazawa

We study the correlation functions of the Wilson loops in noncommutative Yang-Mills theory based upon its equivalence to twisted reduced models. We point out that there is a crossover at the noncommutativity scale. At large momentum scale, the Wilson loops in noncommmutative Yang-Mills represent extended objects. They coincide with those in ordinary Yang-Mil

H. T. Wong

Scintillating crystal detector offers potential advantages in low-energy (keV-MeV range) low-background experiments for particle physics and astrophysics. The merits are discussed using CsI(Tl) crystal as illustrations. The various physics topics which can be pursued with this detector technology are summarized. A conceptual design for a generic detector is

H. Kanno, Y. Yasui

The total space of the spinor bundle on the four dimensional sphere S^4 is a quaternionic line bundle that admits a metric of Spin(7) holonomy. We consider octonionic Yang-Mills instanton on this eight dimensional gravitational instanton. This is a higher dimensional generalization of (anti-)self-dual instanton on the Eguchi-Hanson space. We propose an ansat

Daniel Kabat, Gilad Lifschytz

We advocate a set of approximations for studying the finite temperature behavior of strongly-coupled theories in 0+1 dimensions. The approximation consists of expanding about a Gaussian action, with the width of the Gaussian determined by a set of gap equations. The approximation can be applied to supersymmetric systems, provided that the gap equations are f

Jin-Hwan Cho, Sung Sook Kim, Mikiya Masuda, Dong Youp Suh

In this paper we characterize the fiber representations of equivariant complex vector bundles over a circle and classify these bundles. We also treat the triviality of equivariant complex vector bundles over a circle by investigating the extensions of representations. As a corollary of our results, we calculate the reduced equivariant K-group of a circle for

Shuichi Murakami, Naoto Nagaosa

We study theoretically the multicritical phenomena of the superconductivity (SC) and antiferromagnetism (AF) in organic conductors $κ$-BEDT salts. The phase diagram and the experimental data on the NMR relaxation rate $1/T_1$ is analysed in terms of the renormalization group method. The bicritical phenomenon observed experimentally indicates the rotational s

M. Harada, Y. Keum, Y. Kiyo, T. Morozumi

We study the correlation between $\epe$ and $ΔI=1/2$ rule in the framework of non-linear $σ$ model including scalar mesons. The matrix elements of QCD and Electroweak (EW) penguin operators are computed within factorization approximation. Using the matrix elements and changing the scalar meson mass, we find that there is correlation between $\epe$ and $ΔI=1/

Elcio Abdalla, Roya Mohayaee, Marcelo B. Ribeiro

This paper seeks to check the validity of the &#34;apparent fractal conjecture&#34; (Ribeiro 2001ab: gr-qc/9909093, astro-ph/0104181), which states that the observed power-law behaviour for the average density of large-scale distribution of galaxies arises when some observational quantities, selected by their relevance in average density profile determinatio

Per Rekdal, Bo-Sture Skagerstam

A simple model of a two-mode non-resonant parametric amplifier is studied with special regard to non-classical features such as revivals and squeezing. The methods used apply for an arbitrary pump parameter. Detailed analytical and explicit expressions are given when the coupling of the two modes has an harmonic time-dependence. Despite its simplicity the mo

David Collins, K. W. Kim, W. C. Holton, H. Sierzputowska-Gracz

An NMR realization of a two-qubit quantum gate which processes quantum information indirectly via couplings to a spectator qubit is presented in the context of the Deutsch-Jozsa algorithm. This enables a successful comprehensive NMR implementation of the Deutsch-Jozsa algorithm for functions with three argument bits and demonstrates a technique essential for

S. M. Roy, Anu Venugopalan

Exact solutions of the Caldeira-Leggett Master equation for the reduced density matrix for a free particle and for a harmonic oscillator system coupled to a heat bath of oscillators are obtained for arbitrary initial conditions. The solutions prove that the Fourier transform of the density matrix at time t with respect to (x + x&#39;)/2, where x and x&#39; a

A. A. Suzko, E. P. Velicheva

A procedure of solving nonstationary Schredinger equations in the exact analytic form is elaborated on the basis of exactly solvable stationary models. The exact solutions are employed to study the nonadiabatic geometric phase.

Matthew J. Donald, Michal Horodecki

We show that an entanglement measure called relative entropy of entanglement satisfies a strong continuity condition. If two states are close to each other then so are their entanglements per particle pair in this measure. It follows in particular, that the measure is appropriate for the description of entanglement manipulations in the limit of an infinite n

A. Amghar, B. Desplanques

It is shown that field-theory based single boson exchange potentials cannot be identified to those of the Yukawa or Coulomb type that are currently inserted in the Schrödinger equation. The potential which is obtained rather corresponds to this current single boson exchange potential corrected for the probability that the system under consideration is in a t

Johann Rafelski, Jean Letessier

A Fermi statistical model analysis of hadron abundances and spectra obtained in several relativistic heavy ion collision experiments is utilized to characterize a particle source. Properties consistent with a disintegrating, hadron evaporating, deconfined quark-gluon plasma phase fireball are obtained, with a baryochemical potential μ_B=200-210MeV, and a tem

Gerhard Rein

Certain steady states of the Vlasov-Poisson system can be characterized as minimizers of an energy-Casimir functional, and this fact implies a nonlinear stability property of such steady states. In previous investigations by Y. Guo and the author stability was obtained only with respect to spherically symmetric perturbations. In the present investigation we

Richard Kenyon

Let U be a multiply-connected region in R^2 with smooth boundary. Let P_epsilon be a polyomino in epsilon Z^2 approximating U as epsilon tends to 0. We show that, for certain boundary conditions on P_epsilon, the height distribution on a random domino tiling (dimer covering) of P_epsilon is conformally invariant in the limit as epsilon tends to 0, in the sen

Emanuela Caliceti

It is proved that the divergent Rayleigh-Schrodinger perturbation expansions for the eigenvalues of any odd anharmonic oscillator are Borel summable in the distributional sense to the resonances naturally associated with the system.

Christodoulos Sophocleous

We consider the one-dimensional porous medium equation $u_t=\left (u^nu_x \right )_x+\fracμ{x}u^nu_x$. We derive point transformations of a general class that map this equation into itself or into equations of a similar class. In some cases this porous medium equation is connected with well known equations. With the introduction of a new dependent variable t

Boris A. Kupershmidt

The notion of classical $r$-matrix is re-examined, and a definition suitable to differential (-difference) Lie algebras, -- where the standard definitions are shown to be deficient, -- is proposed, the notion of an ${\mathcal O}$-operator. This notion has all the natural properties one would expect form it, but lacks those which are artifacts of finite-dimen

H. -O. Georgii

We discuss the interrelation between phase transitions in interacting lattice or continuum models, and the existence of infinite clusters in suitable random-graph models. In particular, we describe a random-geometric approach to the phase transition in the continuum Ising model of two species of particles with soft or hard interspecies repulsion. We comment

Ian Goulden, David Jackson, Ravi Vakil

Hurwitz numbers, which count certain covers of the projective line (or, equivalently, factorizations of permuations into transpositions), have been extensively studied for over a century. The Gromov-Witten potential F of a point, the generating series for Hodge integrals on the moduli space of curves, has been a central object of study in Gromov-Witten theor

Yasushi Komori

We study a family of mutually commutative difference operators associated with the affine root systems. These operators act on the space of meromorphic functions on the Cartan subalgebra of the affine Lie algebra. We show that the space spanned by the characters of a fixed positive level is invariant under the action of these operators.

Dominic Joyce

The exceptional holonomy groups are G2 in 7 dimensions, and Spin(7) in 8 dimensions. In a previous paper (Invent. math. 123 (1996), 507-552) the author constructed the first examples of compact 8-manifolds with holonomy Spin(7), by resolving orbifolds T^8/G, where T^8 is the 8-torus and G a finite group of automorphisms of T^8. This paper describes a differe

Alexander Beilinson, Alexander Polishchuk

We show that the Fourier transform on the Jacobian of a curve interchanges &#34;$δ$ functions&#34; at the curve and the theta divisor. The Torelli theorem is an immediate consequence.

Gary McCartor, Yuji Nakawaki

We present a representation independent solution to the continuum Schwinger model in light-cone ($A^+ = 0$) gauge. We then discuss the problem of finding that solution using various quantization schemes. In particular we shall consider equal-time quantization and quantization on either characteristic surface, $x^+ = 0$ or $x^- = 0$.

SDLCQ Collaboration, F. Antonuccio, I. Filippov, P. Haney

In this talk we describe the application of discrete light cone quantization (DLCQ) to supersymmetric field theories. We find that it is possible to formulate DLCQ so that supersymmetry is exactly preserved in the discrete approximation and call this formulation of DLCQ, SDLCQ. It combines the power of DLCQ with all of the beauty of supersymmetry. We have ap

P. S. Howe, C. Schubert, E. Sokatchev, P. C. West

Some aspects of correlation functions in N=4 SYM are discussed. Using N=4 harmonic superspace we study two and three-point correlation functions which are of contact type and argue that these contact terms will not affect the non-renormalisation theorem for such correlators at non-coincident points. We then present a perturbative calculation of a five-point

R. Acharya, P. Narayana Swamy

We utilize Coleman&#39;s theorem and show that quantum chromodynamics based on asymptotic freedom and confinement must have chiral symmetry realized as a spontaneously broken symmetry.

R. Acharya, P. Narayana Swamy

We re-examine Quantum Electrodynamics (QED) with massless electron as a finite quantum field theory as advocated by Gell-Mann-Low, Baker-Johnson, Adler, Jackiw and others. We analyze the Dyson-Schwinger equation satisfied by the massless electron in finite QED and conclude that the theory admits no nontrivial eigenvalue for the fine structure constant.

V. P. Frolov, D. V. Fursaev

The statistical origin of the entropy of charged black holes in models of induced Einstein-Maxwell gravity is investigated. The constituents inducing the Einstein-Maxwell action are charged and interact with an external gauge potential. This new feature, however, does not change divergences of the statistical-mechanical entropy of the constituents near the h

Hyun-Soo Min, Hungsoo Kim, D. K. Park, Soo-Young Lee

We investigate a bifurcation of periodic instanton in Euclidean action-temperature diagram in quantum mechanical models. It is analytically shown that multiple zero modes of fluctuation operator should be arised at bifurcation points. This fact is used to derive a condition for the appearance of bifurcation points in action-temperature diagram. This conditio

Alejandro Ayala, Juan Carlos D&#39;Olivo, Axel Weber

We examine the relation between the damping rate of a chiral fermion mode propagating in a hot plasma and the rate at which the mode approaches equilibrium. We show how these two quantities, obtained from the imaginary part of the fermion self-energy, are equal when the reaction rate is defined using the appropriate wave function of the mode in the medium. A

Hans-Thomas Elze, Yogiro Hama, Takeshi Kodama, Martín Makler

The variational principle for the special and general relativistic hydrodynamics are discussed in view of its application to obtain approximate solutions to these problems. We show that effective Lagrangians can be obtained for suitable ansatz for the dynamical variables such as density profile of the system. As an example, the relativistic version of spheri

Gia Dvali, Gregory Gabadadze, Goran Senjanovic

We discuss phenomenology of extra time dimensions in a scenario where the standard model particles are localized in ``our&#39;&#39; time, whereas gravity can propagate in all time dimensions. For an odd number of extra times, at small distances, the (real part of the) Newtonian potential is ``screened&#39;&#39; by tachyonic Kaluza-Klein gravitons. In general

U. Baur, T. Stelzer

We present a calculation of two photon radiation in W and Z boson production in hadronic collisions, based on the complete matrix elements for the processes q\bar q&#39;\to\ell^\pmνγγand q\bar q\to\ell^+\ell^-γγ, including finite charged lepton masses. In order to achieve stable numerical results over the full phase space, multiconfiguration Monte Carlo tech

D. Becirevic, Ph. Boucaud, J. P. Leroy, J. Micheli

We pursue the study of the high energy behaviour of the gluon propagator on the lattice in the Landau gauge in the flavorless case (n_f=0). It was shown in a precedin g paper that the gluon propagator did not reach three-loop asymptotic scaling at an energy scale as high as 5 GeV. Our present high statistics analysis includes also a simulation at $β=6.8$ ($a

Hans-Christian Pauli

Light-cone quantization of gauge theories is discussed from two perspectives: as a calculational tool for representing hadrons as QCD bound-states of relativistic quarks and gluons, and as a novel method for simulating quantum field theory on a computer. A general non-perturbative method for numerically solving quantum field theories, `discretized light-cone

V. N. Baier, V. M. Katkov

We present a derivation of the probability of bremsstrahlung from high-energy electrons in a screened Coulomb field using the quasiclassical operator method. It is shown that recent Zakharov&#39;s criticism is completely groundless and comes from misunderstanding of the method. We confirm all our published results.

Marvin Weinstein

The Contractor Renormalization Group method (CORE) is used to establish the equivalence of various Hamiltonian free fermion theories and a class of generalized frustrated antiferromagnets. In particular, after a detailed discussion of a simple example, it is argued that a generalized frustrated SU(3) antiferromagnet whose single-site states have the quantum

Z. Sroczynski

We present first results from calculations using O(a) improved (FNAL) space-time asymmetric action on a 12^3 x 24 quenched lattice at β= 5.7 and c_SW = 1.57. The asymmetry parameter is determined non-perturbatively from the energy-momentum dispersion relation. This improvement scheme is mass dependent, and the calculations have been done in the charm and bot

P. Bialas, B. Petersson, G. Thorleifsson

We investigate the weak-coupling limit, kappa going to infinity, of 3D simplicial gravity using Monte Carlo simulations and a Strong Coupling Expansion. With a suitable modification of the measure we observe a transition from a branched polymer to a crinkled phase. However, the intrinsic geometry of the latter appears similar to that of non-generic branched

J. Ambjorn, P. Bialas, J. Jurkiewicz

We analyze correlation functions in a toy model of a random geometry interacting with matter. We show that in general the connected correlator will contain a long-range scaling part which is in some sense a remnant of the disconnected part. This result supports the previously conjectured general form of correlation functions. We discuss the interplay between

J. Viehoff

We present a combined analysis of SESAM and TxL data for the flavor singlet axial coupling G_A^1 of the proton, which is very helpful to stabilize the disconnected signals at small quark masses. From connected and disconnected contributions we use the tadpole improved renormalization constant Z_A and obtain G_A^1=0.21(12).

E706 collaboration

We report on the production of J/psi mesons in 530 and 800 GeV/c proton - Be collisions in the Feynman-x range 0.0 < xf < 0.6. The J/psi mesons were detected via decays into opposite sign muon pairs. Differential distributions for J/psi production have been measured as functions of xf, pT^2, and cosine of the Gottfried-Jackson decay angle. These distribution

CDF Collaboration, F. Abe

We report the results of a search for a W&#39; boson produced in p-pbar collisions at a center-of-mass energy of 1.8 TeV using a 107 pb-1 data sample recorded by the Collider Detector at Fermilab. We consider the decay channel W&#39; -> mu nu and search for anomalous production of high transverse mass mu-nu lepton pairs. We observe no excess of events above

R. Cropp

CDF has obtained new results on quarkonium production in p\bar{p} collisions at \sqrt{s} = 1.8 TeV. We report on measurements of Upsilon meson production, Upsilon(1S) production from Chi_b feeddown, and the production polarization of Upsilon(1S), J/Psi and Psi(2S) mesons.

M. N. Achasov, V. M. Aulchenko, S. E. Baru, K. I. Beloborodov

In the experiment with the SND detector at VEPP-2M e^+e^- collider the process $e^+e^-\toπ^+π^-π^0$ was studied in the energy range 2E_0 from 1.04 to 1.38 GeV. A broad peak was observed with the visible mass $M_{vis}=1220\pm 20$ MeV and cross section in the maximum $σ_0\simeq 4$ nb. The peak can be interpreted as a $ω$-like resonance $ω(1200)$.

Ion I. Cotăescu

It is shown how can be derived the normalized energy eigenspinors of the free Dirac field on anti-de Sitter spacetime, by using a Cartesian tetrad gauge where the separation of spherical variables can be done like in special relativity.

Ion I. Cotăescu

Geometric models of quantum relativistic rotating oscillators in arbitrary dimensions are defined on backgrounds with deformed anti-de Sitter metrics. It is shown that these models are analytically solvable, deriving the formulas of the energy levels and corresponding normalized energy eigenfunctions. An important property is that all these models have the s

Michael Bradley, Gyula Fodor, Mattias Marklund, Zoltán Perjés

It is proven that the Wahlquist perfect fluid space-time cannot be smoothly joined to an exterior asymptotically flat vacuum region. The proof uses a power series expansion in the angular velocity, to a precision of the second order. In this approximation, the Wahlquist metric is a special case of the rotating Whittaker space-time. The exterior vacuum domain

Edith Hemaspaandra, Lane A. Hemaspaandra, Harald Hempel

Downward collapse (a.k.a. upward separation) refers to cases where the equality of two larger classes implies the equality of two smaller classes. We provide an unqualified downward collapse result completely within the polynomial hierarchy. In particular, we prove that, for k > 2, if $\psigkone = \psigktwo$ then $\sigmak = \pik = \ph$. We extend this to obt