arXiv papers from February 1995

K. Moon, S. M. Girvin

We report on Monte Carlo studies of the critical behaviour of superfluid $^4$He in the presence of quenched disorder with long-range fractal correlations. According to the heuristic argument by Harris, uncorrelated disorder is irrelevant when the specific heat critical exponent $\alpha$ is negative, which is the case for the pure $^4$He. However, experiments

G. F. Chew

Guided by a linearized approximation to Einstein theory, an interim prescription for ``weak source of gravity'' - - in ``particle'' energy-momentum distributed along standpoint light cone - - is formulated for (classical) standpoint cosmology.

Bao-An Li, C. M. Ko, G. Q. Li

The question whether mean field effects exist in heavy-ion collisions at AGS energies is studied in the framework of A Relativistic Transport (ART) model. It is found that in central collisions of Au+Au at $P_{beam}/A=$11.6 GeV/c a simple, Skyrme-type nuclear mean field satisfying the causality requirement reduces the maximum baryon and energy densities reac

Stanley J. Brodsky, Ivan Schmidt

We use a quantum loop expansion to derive sum rule constraints on polarized photoabsorption cross sections in the Standard Model, generalizing earlier results obtained by Altarelli, Cabibbo, and Maiani. We show that the logarithmic integral of the spin-dependent photoabsorption cross section $\int^\infty_{\nu_{th}} {d\nu\over \nu} \Delta \sigma_{\rm Born}(\n

W. H. Zurek, J. P. Paz

We show that the rate of increase of von Neumann entropy computed from the reduced density matrix of an open quantum system is an excellent indicator of the dynamical behavior of its classical hamiltonian counterpart. In decohering quantum analogs of systems which exhibit classical hamiltonian chaos entropy production rate quickly tends to a constant which i

David H. Lyth, Ewan D. Stewart

The most natural way to break the GUT gauge symmetry is with a Higgs field whose vacuum expectation value is of order $10^{16}\,\mbox{GeV}$ but whose mass is of order $10^2$ to $10^3\,\mbox{GeV}$. This can lead to a cosmological history radically different from what is usually assumed to have occurred between the standard inflationary and nucleosynthesis epo

L. A. Bernstein, J. A. Cizewski, H. -Q. Jin, W. Younes

We have studied via in-beam $\gamma$-ray spectroscopy $^{196}$Po and $^{198}$Po, which are the first neutron-deficient Po isotopes to exhibit a collective low-lying structure. The ratios of yrast state energies and the E2 branching ratios of transitions from non-yrast to yrast states are indicative of a low-lying vibrational structure. The onset of collectiv

S. Klimek, A. Lesniewski

We study the quantization of two examples of classically chaotic dynamics, the Anosov dynamics of "cat maps" on a two dimensional torus, and the dynamics of baker's maps. Each of these dynamics is implemented as a discrete group of automorphisms of a von Neumann algebra of functions on a quantized torus. We compute the non- commutative generalization of the

Wojciech H. Zurek

Evolution of the order parameter in condensed matter analogues of cosmological phase transitions is discussed. It is shown that the density of the frozen-out topological defects is set by the competition between the quench rate -- the rate at which the phase transition is taking place -- and the relaxation rate of the order parameter. More specifically, the

E. J. Valeo, N. J. Fisch

The mode-converted ion-Bernstein wave excited in tokamaks is shown to exhibit certain very interesting behavior, including the attainment of very small poloidal phase velocities, the reversal of poloidal direction, and up-down asymmetries in propagation and damping. Because of these effects, this wave holds promise for channeling {$\alpha$-particle}\ power t

Paul Horja

In this paper we show that on a complete Riemannian manifold of negative curvature and dimension $n>1$ every two points which realize a local maximum for the distance function are connected by at least $2n+1$ geometrically distinct geodesic segments (i.e. length minimizing). Using a similar method, we obtain that in the case of non-positive curvature, for ev

W. Siegel

We generalize the Gervais-Neveu gauge to four-dimensional N=1 superspace. The model describes an N=2 super Yang-Mills theory. All chiral superfields (N=2 matter and ghost multiplets) exactly cancel to all loops. The remaining hermitian scalar superfield (matrix) has a renormalizable massive propagator and simplified vertices. These properties are associated

Emmanuel Giguet

In this paper, we describe an approach to sentence categorization which has the originality to be based on natural properties of languages with no training set dependency. The implementation is fast, small, robust and textual errors tolerant. Tested for french, english, spanish and german discrimination, the system gives very interesting results, achieving i

S. Dalley

A polymer folding model on the square lattice is constructed with attractive contact interactions of strength 1/c^2, 0<c<1. The corresponding model on a dynamical random lattice, with freely fluctuating co-ordination number at each vertex, is formulated as a random two-matrix model and an expression for the partition function of a length-L chain is derived.

Bohdan Grzadkowski, Jose Wudka

We consider non-Standard Model physics effects using an effective lagrangian parameterization. We determine the operators whose effects are most significant and extract the sensitivity to the scale of new physics generated by the existing data. We then consider processes containing the Higgs particle in $e^+e^-$ colliders as a probe for new physics effects,

Fernando Falceto, Krzysztof Gawedzki

This letter continues the program aimed at analysis of the scalar product of states in the Chern-Simons theory. It treats the elliptic case with group SU(2). The formal scalar product is expressed as a multiple finite dimensional integral which, if convergent for every state, provides the space of states with a Hilbert space structure. The convergence is che

K. Wodkiewicz

The classical and the quantum Malus' Laws for light and spin are discussed. It is shown that for spin-1/2, the quantum Malus' Law is equivalent in form to the classical Malus' Law provided that the statistical average involves a quasi-distribution function that can become negative. A generalization of Malus' Law for arbitrary spin-s is obtained in the form o

James C. Lombardi,, Frederic A. Rasio, Stuart L. Shapiro

We report the results of new SPH calculations of parabolic collisions between main-sequence (MS) stars. The stars are assumed to be close to the MS turn-off point in a globular cluster and are therefore modeled as $n=3$, $\Gamma=5/3$ polytropes. We find that the high degree of central mass concentration in these stars has a profound effect on the hydrodynami

Frederic A. Rasio, Douglas C. Heggie

Low-mass binary millisecond pulsars (LMBPs) are born with very small orbital eccentricities, typically of order $e_i\sim10^{-6}$--$10^{-3}$. In globular clusters, however, higher eccentricities $e_f\gg e_i$ can be induced by dynamical interactions with passing stars. Here we show that the cross section for this process is much larger than previously estimate

G. H. Arakelyan, P. E. Volkovitsky

In the framework of Quark--Gluon--String Model developed recently in ITEP we calculate spectra of charmed particles $D$, $D_s$, $\Lambda_c$, $\Xi_c$, $\Omega_c$ in hadron--hadron collisions taking into account the decays of $S$--wave resonances like $D^*$, $D^*_s$, $\Sigma_c$, $\Sigma^*_c$, $\Xi^*_c$, $\Xi'_c$, and $\Omega^*_c$. We describe the bulk of the e

Jürgen König, Herbert Schoeller, Gerd Schön

The influence of quantum fluctuations on electron transport through small metallic islands with Coulomb blockade effects is studied beyond the perturbative regime. In tunnel junctions with low resistance higher order coherent processes and ``inelastic resonant tunneling'' become important. We present a path integral real-time description, which allows a syst

J. Lopez, D. Nanopoulos, A. Zichichi

We propose a string-derived model based on the gauge group $SU(5)\times U(1)$ which satisfies the stringent constraints from no-scale supergravity, allows gauge coupling unification at the string scale, and entails previously unexplored correlations among various sectors of the model. All supersymmetric observables are given in terms of a single mass paramet

M. Wybo, H. Dejonghe

Along with data on radial velocities, more and more data on proper motions of individual stars in globular clusters are becoming available. Their usage was until now rather limited. It was mostly restricted to determining cluster membership of individual stars and to determining the spatial velocity of the cluster. We study the two dimensional distribution o

Wolfgang Eholzer

We introduce the notion of (nondegenerate) strongly-modular fusion algebras. Here strongly-modular means that the fusion algebra is induced via Verlinde's formula by a representation of the modular group whose kernel contains a congruence subgroup. Furthermore, nondegenerate means that the conformal dimensions of possibly underlying rational conformal field

B. L. Ioffe, A. Oganesian

Gluon distributions in real and virtual photons are calculated using evolution equations in the NLO approximation. The quark distributions in the photon determined on the basis of the QCD sum rule approach in ref.[1] are taken as an input. It is shown that gluon distribution in the photon can be reliably determined up to $x = 0.03 \div 0.05$ much lower than

Shogo Tanimura

The abelian sigma model in (1+1) dimensions is a field theoretical model which has a field $ \phi : S^1 \to S^1 $. An algebra of the quantum field is defined respecting the topological aspect of the model. It is shown that the zero-mode has an infinite number of inequivalent quantizations. It is also shown that when a central extension is introduced into the

R. Anni, G. Co'

We propose a method to extract nuclear charge distributions from elastic electron scattering data based upon a mean field approach. The nuclear charge distributions are generated by solving the Schroedinger equation with a mean-field potential expanded in terms of Hermite functions. The coefficients of the potential are changed in order to obtain the best fi

Shinji HAMAMOTO

The usual prescription for constructing gauge-invariant Lagrangian is generalized to the case where a Lagrangian contains second derivatives of fields as well as first derivatives. Symmetric tensor fields in addition to the usual vector fields are introduced as gauge fields. Covariant derivatives and gauge-field strengths are determined.

E. A. Kuraev, Z. K. Silagadze

The manifestations of the $\omega \to 3\pi$ contact term and its unitary partners are investigated in the framework of the chiral effective lagrangian theory with vector mesons. We conclude that nowadays the existence and magnitude of the contact term can be extracted neither from theory, nor experiment. The theoretical uncertainty is caused by the one-loop

Giovanni Felder, Alexander Varchenko

We give an integral representation of solutions of the elliptic Knizhnik-Zamolodchikov-Bernard equations for arbitrary simple Lie algebras. If the level is a positive integer, we obtain formulas for conformal blocks of the WZW model on a torus. The asymptotics of our solutions at critical level gives eigenfunctions of Euler-Calogero-Moser integrable $N$-body

Giovanni Felder, Alexander Varchenko

The structure constants $N_{\lambda, \mu}^{\mu+\nu}$ of the $sl_2$ Verlinde algebra as functions of $\mu$ either vanish or can be expressed after a change of variable as the weight function of an irreducible representation of $sl_2$. We give a similar formula in the $sl_3$ case.

A. Ballesteros, F. J. Herranz, M. A. del Olmo, M. Santander

A new quantum deformation, which we call null-plane, of the (3+1) Poincar\'e algebra is obtained. The algebraic properties of the classical null-plane description are generalized to this quantum deformation. In particular, the classical isotopy subalgebra of the null-plane is deformed into a Hopf subalgebra, and deformed spin operators having classical commu

R. A. Leese, N. S. Manton, B. J. Schroers

The deuteron is described as a quantum state on a ten-dimensional manifold $M_{10}$ of Skyrme fields of degree two, which are obtained by calculating the holonomy of $SU(2)$ instantons. The manifold $M_{10}$ includes both toroidal configurations of minimal energy and configurations which are approximately the product of two Skyrmions in the most attractive r

M. Stingl

An outline is given of an extended perturbative solution of Euclidean QCD which systematically accounts for a class of nonperturbative effects, while allowing renormalization by the perturbative counterterms. Proper vertices Gamma are approximated by a double sequence Gamma[r,p], with r the degree of rational approximation w.r.t. the QCD mass scale Lambda, n

S. V. Goloskokov, S. P. Kuleshov, O. V. Selyugin

The intercept of the supercritical Pomeron is examined with the use of different forms of the scattering amplitudes of the bare Pomeron. The one-to-one correspondence between the eikonal phase and the ratio of the elastic and total cross section is shown. Based on new experimental data of the CDF Collaboration, the intercept and power of the logarithmic grow

M. Thunman, G. Ingelman, P. Gondolo

Production of muons and neutrinos in cosmic ray interactions with the atmosphere has been investigated with a cascade simulation program based on Lund Monte Carlo programs. The resulting `conventional' muon and neutrino fluxes (from $\pi ,K$ decays) agree well with earlier calculations, whereas the improved charm particle treatment used in this study gives s

U. Mosel

We study elementary processes for production of dileptons from nucleons, either through NN bremsstrahlung or through photon-induced reactions. We emphasize the dependence of the expected cross-sections on the electromagnetic formfactor of the nucleon in the time-like regime and point out that the mentioned reactions can provide important information on the v

V. D. Freilikher, A. A. Maradudin, A. R. McGurn, B. A. Liansky

The transmissivity of a one-dimensional random system that is periodic on average is studied. It is shown that the transmission coefficient for frequencies corresponding to a gap in the band structure of the average periodic system increases with increasing disorder while the disorder is weak enough. This property is shown to be universal, independent of the

P. Di Vecchia, A. Lerda, L. Magnea, R. Marotta

We present a unified point of view on the different methods available in the literature to extract gauge theory renormalization constants from the low-energy limit of string theory. The Bern-Kosower method, based on an off-shell continuation of string theory amplitudes, and the construction of low-energy string theory effective actions for gauge particles, c

K. T. Chao

On the basis of the recent results of $\xi(2230)\rightarrow \pi^+\pi^-, p\bar p$ and $\xi(2230)\rightarrow K^+K^-,~K_SK_S$, measured by the BES Collaboration in $J/\psi$ radiative decays, combined with the PS185 experiment of $p\bar p\rightarrow \xi(2230)\rightarrow K\bar K$, we argue that because of its very narrow partial decay widths to $\pi\pi$ and $K\ba

N. G. Chen, K. T. Chao

Form factors and decay widths for $D^{\ast}\rightarrow D \gamma$ and $D^{\ast}\rightarrow D \pi$ decays are estimated in a relativistic constituent quark model. Relativistic corrections due to light quarks are found to be substantial and to suppress the vector and axial vector form factors. The CLEO experimental value of $R^0_{\gamma}\equiv \Gamma (D^{\ast 0

Y. B. Ding, K. T. Chao, D. H. Qin

Possible effects of the color screened confinement potential are investigated. Color screened linear potential with a large string tension $T=(0.26-0.32)GeV^2$ is suggested by a study of the $c\bar c$ and $b\bar b$ spectra. The $\psi (4160)$ and $\psi (4415)$ are respectively assigned as the $\psi (4S)$-dominated and the $\psi (5S)$ $c\bar c$ states. Satisfa

J. Tang, J. H. Liu, K. T. Chao

Within the standard model, we calculate the radiative $B\rightarrow K^{\star}\gamma$ decay rate based on a Bethe-Salpeter description for the meson wave functions and the hadronic matrix elements. With a reasonable choice of parameters the branching ratio BR($B \rightarrow K^{\star}\gamma$) is found to be $(3.8-4.6)\times 10^{-5}$, which is in agreement with

V. Freilikher, M. Pustilnik, I. Yurkevich

Effect of weak disorder on tunneling through a potential barrier is studied analytically. A diagrammatic approach based on the specific behavior of subbarrier wave functions is developed. The problem is shown to be equivalent to that of tunneling through rectangular barriers with Gaussian distributed heights. The distribution function for the transmission co

H. Kleinert, I. Mustapic

Variational perturbation theory is used to determine the decay rates of metastable states across a cubic barrier of arbitrary height. For high barriers, a variational resummation procedure is applied to the complex energy eigenvalues obtained from a WKB expansion; for low barriers, the variational resummation procedure converts the non-Borel-summable Rayleig

Kengo Ichiki, Hisao Hayakawa

A numerical simulation of a gas-fluidized bed is performed without introduction of any empirical parameters. Realistic bubbles and slugs are observed in our simulation. It is found that the convective motion of particles is important for the bubbling phase and there is no convection in the slugging phase. From the simulation results, non-Gaussian distributio

C. Balland, A. Blanchard

The temperature distribution function (TDF) of X-ray clusters is derived for different normalizations of the HDM power spectrum in an Omega_0=1 universe using the statistics of peaks of a random Gaussian field. Concerning cluster formation only, the neutrino picture appears to be marginally consistent with observations for H_0=70 km/s/Mpc provided the normal

M. Yu. Kuchiev, O. P. Sushkov

We consider modified $t-J$ model with minimum of single-hole dispersion at the points $(0,\pm \pi)$, $(\pm \pi,0)$. It is shown that two holes on antiferromagnetic background produce a bound state which properties strongly differs from the states known in the unmodified $t-J$ model. The bound state is d-wave, it has four nodes on the face of the magnetic Bri

Eric D'Hoker

We construct the most general local effective actions for Goldstone boson fields associated with spontaneous symmetry breakdown from a group $G$ to a subgroup $H$. In a preceding paper, it was shown that any $G$-invariant term in the action, which results from a non-invariant Lagrangian density, corresponds to a non-trivial generator of the de Rham cohomolog

Ioannis Giannakis, D. V. Nanopoulos, Kajia Yuan

In string theory there seems to be an intimate connection between spacetime and world-sheet physics. Following this line of thought we investigate the family problem in a particular class of string solutions, namely the free fermionic string models. We find that the number of generations $N_g$ is related to the index of the supersymmetry generator of the und

David Mukamel

The dynamical behavior of two types of non-equilibrium systems is discussed: $(a)$ two-dimensional cellular structures, and $(b)$ living polymers. Simple models governing their evolution are introduced and steady state distributions (cell side in the case of cellular structures and length in the case of living polymers) are calculated. In both cases the mode

M. Yu. Kalmykov

The parametrization and gauge dependencies of the one-loop counterterms on the mass-shell in the Einstein gravity are investigated. The physical meaning of the loop calculation results on the mass shell and the parametrization dependence of the renormgroup functions in the nonrenormalizable theories are discussed.

Mark A. Miller

The convergence properties of numerical Regge calculus as an approximation to continuum vacuum General Relativity is studied, both analytically and numerically. The Regge equations are evaluated on continuum spacetimes by assigning squared geodesic distances in the continuum manifold to the squared edge lengths in the simplicial manifold. It is found analyti

X. -G. Wu, S. L. Sondhi

We calculate the energies of quasiparticles with large numbers of reversed spins (``skyrmions'') for odd integer filling factors 2k+1, k is greater than or equals 1. We find, in contrast with the known result for filling factor equals 1 (k = 0), that these quasiparticles always have higher energy than the fully polarized ones and hence are not the low energy

Toby Falk, Keith Olive, Mark Srednicki

We consider the effect of CP violating phases in the MSSM on the relic density of the lightest supersymmetric particle (LSP). In particular, we find that the upper limits on the LSP mass are relaxed when phases in the MSSM are allowed to take non-zero values when the LSP is predominantly a gaugino (bino). Previous limits of $\mb \la 250$ GeV for $\Omega h^2

P. Bamert, C. P. Burgess, I. Maksymyk

We study the implications of possible off-peak measurements in the 1995 LEP run, in regard to probing physics beyond the Standard Model. To do so, we determine the accuracy with which various nonstandard couplings can be expected to be measured in the three different scan scenarios recently discussed by Clarke and Wyatt. We find that each scan scenario allow

Keith A. Olive, Gary Steigman

We take a fresh look at the limits on the number of neutrino flavors derived from big bang nucleosynthesis. In particular, recent measurements of the \he4 abundance enable one to estimate the primordial \he4 mass fraction at $Y_p = 0.232 \pm .003(stat) \pm .005(syst)$. For a baryon to photon ratio, $\eta$, consistent with the other light elements, this leads

E. Diehl, G. Kane, C. Kolda, J. Wells

One of the great attractions of minimal super-unified supersymmetric models is the prediction of a massive, stable, weakly interacting particle (the lightest supersymmetric partner, LSP) which can have the right relic abundance to be a cold dark matter candidate. In this paper we investigate the identity, mass, and properties of the LSP after requiring gauge

Markus A. Luty, Raman Sundrum

We use the observed $SU(3)$ breaking in the mass spectrum of mesons containing a single heavy quark to place restrictions on the light quark current masses. A crucial ingredient in this analysis is our recent first-principles calculation of the electromagnetic contribution to the isospin-violating mass splittings. We also pay special attention to the role of

Robert Friedman, John W. Morgan

In this revised version, we add some expository material and references and make some minor corrections.

Savas Dimopoulos, Alex Pomarol, .

We give examples of minimal extensions of the simplest SU(5) SUSY-GUT in which all squarks and sleptons of a family have different tree level masses at the unification scale. This phenomenon is general; it occurs when the quarks and leptons are the light remnants of a theory which contains extra heavy families at the unification scale. The examples have inte

Helmut Feldweg

A German language model for the Xerox HMM tagger is presented. This model's performance is compared with two other German taggers with partial parameter re-estimation and full adaption of parameters from pre-tagged corpora. The ambiguity types resolved by this model are analysed and compared to ambiguity types of English and French. Finally, the model's erro

V. I. Man'ko, G. Marmo, F. Zaccaria

q-deformed nonlinear field equations are constructed including Klein-Gordon and Maxwell equations. The q-deformation is interpreted as mathematical structure describing specific nonlinearity for which frequency of vibration exponentially depends on the energy

R. Ansari, M. Auriére, P. Baillon, A. Bouquet

The status of the Agape experiment to detect Machos in the direction of the andromeda galaxy is presented.

A. Brandhuber, S. Emery, K. Landsteiner, M. Schweda

We quantize the three-dimensional $BF$-model using axial gauge conditions. Exploiting the rich symmetry-structure of the model we show that the Green-functions correspond to tree graphs and can be obtained as the unique solution of the Ward-Identities. Furthermore, we will show that the theory can be uniquely determined by symmetry considerations without the

T. H. Moos, W. Hübner, K. H. Bennemann

The magnetocrystalline anisotropy energy $E_{anis}$ for a monolayer of Fe and Ni is determined using a fully convergent tight-binding calculation including $s$-$d$ hybridization. The spin-orbit interaction $\lambda_{so}$ is treated non-perturbatively. Remarkably, we find $E_{anis}\propto\lambda_{so}^2$ and important contributions to $E_{anis}$ due to the lif

Karl Fisher, John Huchra, Michael Strauss, Marc Davis

We present the redshift data for a survey of galaxies selected from the data base of the Infrared Astronomical Satellite (IRAS). This survey extends the 1.936 Jy sample of Strauss et al. (1992) from a flux limit of 1.936 Jy at 60 microns to 1.2 Jy. The survey extension consists of 3920 sources in the flux interval 1.2 - 1.936 Jy, of which 2663 are galaxies w

S. A. Gurvitz

We show that parton confinement in the final state generates large $1/Q^2$ corrections to Bjorken scaling, thus leaving less room for the logarithmic corrections. In particular, the $x$-scaling violations at large $x$ are entirely described in terms of power corrections. For treatment of these non-perturbative effects, we derive a new expansion in powers of

Z. Y. Weng, D. N. Sheng, C. S. Ting

A real spin-charge separation scheme is found based on a saddle-point state of the $t-J$ model. In the one-dimensional (1D) case, such a saddle-point reproduces the correct asymptotic correlations at the strong-coupling fixed-point of the model. In the two-dimensional (2D) case, the transverse gauge field confining spinon and holon is shown to be gapped at {

Janusz M. Holender, Mike J. Gillan, Mike C. Payne, Allan Simpson

First-principles molecular dynamics simulations having a duration of 8 ps have been used to study the static, dynamic and electronic properties of l-Ga at the temperatures 702 K and 982 K. The simulations use the density-functional pseudopotential method and the system is maintained on the Born-Oppenheimer surface by conjugate gradients relaxation. The stati

Oscar Jofre, Carmen Núñez

A homogeneous anisotropic four dimensional spacetime with Lorentzian signature is constructed from an ungauged WZW model based on a non-semisimple Lie group. The associated non-linear $\sigma $-model describes string propagation in an expanding-contracting universe with antisymmetric tensor and dilaton backgrounds. The current algebra of SL(2,R)$\times $R is

Kevin C. K. Chan, James H. Horne, Robert B. Mann

We present a new class of black hole solutions in Einstein-Maxwell-dilaton gravity in $n \ge 4$ dimensions. These solutions have regular horizons and a singularity only at the origin. Their asymptotic behavior is neither asymptotically flat nor (anti-) de Sitter. Similar solutions exist for certain Liouville-type potentials for the dilaton.

K. A. Milton, R. Das

The finite-element approach to lattice field theory is both highly accurate (relative errors $\sim 1/N^2$, where $N$ is the number of lattice points) and exactly unitary (in the sense that canonical commutation relations are exactly preserved at the lattice sites). In this paper we construct matrix elements for the time evolution operator for the anharmonic

David Tugwell

This paper presents a grammar formalism designed for use in data-oriented approaches to language processing. The formalism is best described as a right-linear indexed grammar extended in linguistically interesting ways. The paper goes on to investigate how a corpus pre-parsed with this formalism may be processed to provide a probabilistic language model for

J. Katriel, B. Abdesselam, A. Chakrabarti

The traces of the Murphy operators of the Hecke algebra $H_n(q)$, and of products of sets of Murphy operators with non-consecutive indices, can be evaluated by a straightforward recursive procedure. These traces are shown to determine all the reduced traces in this algebra, which, in turn, determine all other traces. To illustrate the procedure we obtain the

Paul H. Frampton, Otto C. W. Kong

Using as a flavor symmetry a finite nonabelian dicyclic $Q_{2N}$ group, we show how to derive quark mass matrices with two arrangements of symmetric texture zeros which are phenomenologically viable. Three other such acceptable textures in the recent literature are unattainable in this approach and hence disfavored. We assume massive vector-like fermions and

V. I. Man'ko

Particle distributions in squeezed states, even and odd coherent states are given in terms of multivariable Hermite polynomials. The Q--function and Wigner function for nonclassical field states are discussed.

V. I. Man'ko

Time--dependent integrals of motion which are linear forms in position and momentum are discussed for Husimi parametric forced oscillator. Generalization of these integrals of motion for q--oscillator is presented. Squeezing and quadrature correlation phenomena are discussed on the base of Schr\"odinger uncertainty relation. The properties of the generalized

V. I. Man'ko

The geometrical phase is shown to be integral of motion. Deformation of particle distribution function corresponding to nonstationary Casimir effect is expressed in terms of multivariable Hermite polynomials. Correction to Planck distribution due to q--nonlinearity is discussed.

Johan Bijnens

A short overview of the current state of Chiral Perturbation Theory is given. This includes a description of the basic assumptions, the usefulness of the external field method is emphasized using a simple lowest order example. Then at next-to-leading order the determination of the parameters is discussed. We also present the status of calculations at ${\cal

Leo Brewin

We will ask the question of whether or not the Regge calculus (and two related simplicial formulations) is a consistent approximation to General Relativity. Our criteria will be based on the behaviour of residual errors in the discrete equations when evaluated on solutions of the Einstein equations. We will show that for generic simplicial lattices the resid

O. V. Man'ko

There are discussed the exact solution of the time--dependent Schr\"{o}dinger equation for a damped quantum oscillator subject to a periodical frequency delta--kicks describing squeezed states which are expressed in terms of Chebyshev polynomials. The cases of strong and weak damping are investigated in the frame of Caldirola--Kanai model.

V. V. Dodonov, I. M. Dremin, O. V. Man'ko, V. I. Man'ko

The primary aim of the present paper is to attract the attention of particle physicists to new developments in studying squeezed and correlated states of the electromagnetic field as well as of those working on the latest topic to new findings about multiplicity distributions in quantum chromodynamics. The new types of nonclassical states used in quantum opt

Patrick Petitjean, Jan P. Mücket, Ron Kates

We study the distribution of low-redshift Ly$\alpha$ clouds in a CDM model using numerical simulations including photoionization and cooling of the baryonic component. The ionizing background is found to be efficient enough to keep most of the gas warm ($T$~=~1--5~10$^4$~K) and to prevent most of it from collapsing. In this scenario, the numerous low redshif

Gang Xiao

We prove: Let $G$ be a finite abelian group acting faithfully on a complex smooth project variety $X$ of general type with numerically effective canonical divisor, of dimension $n$. Then $$|G| \le C(n)K_X^n ,$$ where $C(n)$ depends only on $n$.

A. V. Yung

The topological $\sigma$ model with the black hole metric of the target space is considered. It has been shown before that this model is in the phase with BRST-symmetry broken. In particular, vacuum energy is non-\-zero and correlation functions of observables show the coordinate dependence. However these quantities turned out to be infrared (IR) divergent.

Takashi Inoue, Sachiko Takeuchi, Makoto Oka

The weak $\Lambda N\to NN$ transition is studied in the valence quark model approach. The quark component of the two baryon system is described in the quark cluster model and the weak transition potential is calculated by evaluating the matrix elements of the $\Delta S=1$ effective weak Hamiltonian. The transition potential is applied to the decay of hypernu

Vladimir A. Kazakov

We present the exact and explicit solution of the principal chiral field in two dimensions for an infinitely large rank group manifold. The energy of the ground state is explicitly found for the external Noether's fields of an arbitrary magnitude. At small field we found an inverse logarithmic singularity in the ground state energy at the mass gap which indi

Rajamani Narayanan, Ulli Wolff

We compute the two loop coefficient in the relation between the lattice bare coupling and the running coupling defined through the Schroedinger functional for the case of pure SU(2) gauge theory. This result is needed as one computational component to relate the latter to the MSbar-coupling, and it allows us to implement O(a) improvement of the Schroedinger

I. L. Buchbinder, S. M. Kuzenko, A. G. Sibiryakov

We describe a Lagrangian quantization of the free massless gauge superfield theories of higher superspins both in the anti-de Sitter and flat global superspaces.

H. C. Pan, G. K. Skinner, R. A. Sunyaev, K. N. Borozdin

We report the first detection of a hard power-law tail in the X-ray spectrum of the black hole candidate (BHC) binary X1755-338, which was observed in 1989 March-September during the TTM Galactic Centre survey. In addition, an ultrasoft thermal component with a temperature of ~1.1-1.4 keV was also detected. We demonstrate that the soft and hard X-ray compone

Annius V. Groenink

Literal movement grammars (LMGs) provide a general account of extraposition phenomena through an attribute mechanism allowing top-down displacement of syntactical information. LMGs provide a simple and efficient treatment of complex linguistic phenomena such as cross-serial dependencies in German and Dutch---separating the treatment of natural language into

Mario Feingold, Oreste Piro

We show that the energy averaged entropy localization length for the eigenstates of the Ce atom is well approximated by the prediction of the Wigner ensemble.

Kenneth Holmlund, Petter Minnhagen

It has recently been suggested from scaling arguments that the non-linear IV-exponent a, for a two-dimensional superconductor is different from the exponent originally suggested by Ambegaokar et al. The relation between the new and the old exponent is a=a_AHNS-3. The new scaling behaviour is linked to the logarithmic vortex interaction and the long range tim

M. Braun

The bootstrap condition is generalized to $n$ reggeized gluons. As a result it is demonstrated that the intercept generated by $n$ reggeized gluons cannot be lower than the one for $n=2$. Arguments are presented that in the limit $N_{c}\rightarrow\infty$ the bootstrap condition reduces the $n$ gluon chain with interacting neighbours to a single BFKL pomeron.

Hai-Yang Cheng, B. Tseng

Weak current-induced baryonic form factors at zero recoil are evaluated in the rest frame of the heavy parent baryon using the nonrelativistic quark model. Contrary to previous similar work in the literature, our quark model results do satisfy the constraints imposed by heavy quark symmetry for heavy-heavy baryon transitions at the symmetric point $v\cdot v'

K. Kanaya

The deconfining chiral transition in finite-temperature QCD is studied on the lattice using Wilson quarks. After discussing the nature of chiral limit with Wilson quarks, we first study the case of two degenerate quarks $N_F=2$, and find that the transition is smooth in the chiral limit on both $N_t=4$ and 6 lattices. For $N_F=3$, on the other hand, clear tw

D. Xu, S. K. Yip, J. A. Sauls

We examine the long-wavelength current response in anisotropic superconductors and show how the field-dependence of the Meissner penetration length can be used to detect the structure of the order parameter. Nodes in the excitation gap lead to a nonlinear current-velocity constitutive equation at low temperatures which is distinct for each symmetry class of

Ugo Aglietti

Non perturbative corrections to deep inelastic scattering are computed.

Witold Skiba

We investigate decays of the scalar bound state present in the Abbott-Farhi model. We show that decays with photons in the final state may have large branching ratios. We also show that operators coupling the scalar particle to two photons or to a photon and a Z^0 are not seriously constrained by electroweak data, unlike other sectors of the Abbott-Farhi mod