May 1995 arXiv papers — page 5

E. I. Guendelman, E. Nissimov, S. Pacheva

We present a new form of Quantum Electrodynamics where the photons are composites made out of zero-dimensional scalar ``primitives''. The rôle of the local gauge symmetry is taken over by an {\em infinite-dimensional global Noether symmetry} -- the group of volume-preserving (symplectic) diffeomorphisms of the target space of the scalar primitives. S

Biswajoy Brahmachari, Rabindra N Mohapatra

We show that one of the ways of obtaining consistency between the idea of supersymmetric grand unification and an apparent low value of $α_{strong}(M_Z)\simeq .11$ indicated by several low energy experiments is to have an intermediate scale corresponding to a local $B-L$ symmetry breaking around the mass scale of $10^{10}$ to $10^{12}$ GeV. We discuss the re

Roeland P. van der Marel

A common target acquisition strategy with the Faint Object Spectrograph (FOS) on board the Hubble Space Telescope (HST) is to use a sequence of so-called ACQ/PEAK stages. Standard sequences and exposure times are given in the FOS Instrument Handbook (Keyes et al.~1995). The success of a given strategy is difficult to predict a priori for targets other than p

Dan Abramovich

The purpose of this note is to wish a happy birthday to Professor Lucia Caporaso.* We prove that Conjecture H of Caporaso et. al. ([CHarM], sec. 6) together with Lang's conjecture implies the uniformity of rational points on varieties of general type, as predicted in [CHarM]; a few applications in arithmetic and geometry are stated. Let X be a variety of

Jan Freund, Thorsten Pöschel

A two--dimensional cellular automaton is introduced to model the flow and jamming of vehicular traffic in cities. Each site of the automaton represents a crossing where a finite number of cars can wait approaching the crossing from each of the four directions. The flow of cars obeys realistic traffic rules. We investigate the dependence of the average veloci

L. V. Verozub

Proceeding from the new gravitation equations (Phys.Lett.A,v.156, p.404 (1991)) we argue that the theory in principle allows equilibrium stable configurations of a degenerate electron or neutron gas with very large masses.

Y. Sota, S. Suzuki, K. Maeda

We study the motion of test particle in static axisymmetric vacuum spacetimes and discuss two criteria for strong chaos to occur: (1) a local instability measured by the Weyl curvature, and (2) a tangle of a homoclinic orbit, which is closely related to an unstable periodic orbit in general relativity. We analyze several static axisymmetric spacetimes and fi

Hans J. Haubold, Arak Mathai Mathai

This paper examines a number of analytic models which can describe the gravitationally stabilized fusion reactor of the Sun. An analytical multiparameter model is shown to reproduce various structure parameters such as density, mass, pressure and temperature throughout the solar core, which have been obtained by solving numerically the system of solar struct

Matthias Heyssler, Alex C. Kalloniatis

Using DLCQ as a nonperturbative method, we test Fock-space truncations in ${\rm QCD}_{1+1}$ by studying the mass spectra of hadrons in colour SU(2) and SU(3) at finite harmonic resolution $K$. We include $q\bar q q\bar q$ states for mesons and up to $qqq q\bar q$ states for baryons. With this truncation, we give `predictions' for the masses of the first

Gustavo Burdman

We study the potential of $B\to K^{(*)} \ell^+\ell^-$ decays as tests of the standard model. After discussing the reliability of theoretical predictions for the hadronic matrix elements involved, we examine the impact of different new physics scenarios on various observables. We show that the angular information in \bks together with the dilepton mass distri

L. Del Debbio, A. Di Giacomo, G. Paffuti, P. Pieri

We demonstrate that confinement in $SU(2)$ gauge theory is produced by dual superconductivity of the vacuum. We show that for $T < T_c$ (temperature of deconfining phase transition) the $U(1)$ symmetry related to monopole charge conservation is spontaneously broken; for $T > T_c$ the symmetry is restored.

L. Sriramkumar

For want of a more natural proposal, it is generally assumed that the back-reaction of a quantised matter field on a classical metric is given by the expectation value of its energy-momentum tensor, evaluated in a specified state. This proposal can be expected to be quite sound only when the fluctuations in the energy-momentum tensor of the quantum field are

Victor Barzykin, Lev P. Gor&#39;kov

We consider singlet magnetism for the uranium ions in UPt$_3$ and URu$_2$Si$_2$ assuming that time-reversal symmetry is broken for the {\em coherent state of intermediate valence}. The relative weight of the two involved configurations should be different for UPt$_3$ and URu$_2$Si$_2$. If in UPt$_3$ the configuration $5f^1$ on the U-ion prevails in the coher

V. Barzykin, D. Pines

We determine the magnetic phase diagram for the YBa$_2$Cu$_3$O$_{6+x}$ and La$_{2-x}$Sr$_x$CuO$_4$ systems from various NMR experiments. We discuss the possible interpretation of NMR and neutron scattering experiments in these systems in terms of both the non-linear $σ$-model of nearly localized spins and a nearly antiferromagnetic Fermi liquid description o

David Garcia, Joan Sola

Recent calculations of supersymmetric corrections to the conflicting ratios $R_b$ and $R_c$ have shown that an alleged discrepancy between the SM predictions of these observables and the corresponding experimental values can be cured in the MSSM within a certain region of the parameter space. Here we show that, in this very same region, also a well-known dis

N. J. MacKay

We examine the reflection matrix acting on the $SO(N)$ vector multiplet and fuse it to obtain that acting on the rank two particle multiplet, and give its decomposition.

M. Billo&#39;, R. D&#39;Auria, S. Ferrara, P. Fre&#39;

We discuss R-symmetries in locally supersymmetric N=2 gauge theories coupled to hypermultiplets which can be thought of as effective theories of heterotic superstring models. In this type of supergravities a suitable R-symmetry exists and can be used to topologically twist the theory: the vector multiplet containing the dilaton-axion field has different R-ch

Todor Stanev, Peter Biermann, Jeremy Lloyd-Evans, Joerg Rachen

In this Letter we examine the arrival directions of the most energetic cosmic rays (E > 2 * 10^19 eV) detected by several air shower experiments. We find that data taken by different air shower arrays show positive correlations, indicating a non--uniform arrival direction distribution. We also find that the events with energy $ > 4 * 10^19 eV exhibit a corre

Hermann Riecke, Wouter-Jan Rappel

We address the striking coexistence of localized waves (`pulses&#39;) of different lengths which was observed in recent experiments and full numerical simulations of binary-mixture convection. Using a set of extended Ginzburg-Landau equations, we show that this multiplicity finds a natural explanation in terms of the competition of two distinct, physical loc

V. Barone, M. Genovese, N. N. Nikolaev, E. Predazzi

We discuss the latest CCFR determination of the strange sea density of the proton. We comment on the differences with a previous, leading--order, result and point out the relevance of quark mass effects and current non--conservation effects. By taking them into account it is possible to solve the residual discrepancy with another determination of the strange

Sidney van den Bergh

Luminosities and tidal radii of globular clusters have been used to estimate the perigalactic distances P of well-observed Galactic globulars that do not have collapsed cores. It is found that the cluster metallicity [Fe/H] correlates somewhat more strongly with P than it does with the present Galactocentric distances R of globular clusters. It is also found

Yuji Kodama, Jian Ye

We consider a generalization of the full symmetric Toda hierarchy where the matrix $\tilde {L}$ of the Lax pair is given by $\tilde {L}=LS$, with a full symmetric matrix $L$ and a nondegenerate diagonal matrix $S$. The key feature of the hierarchy is that the inverse scattering data includes a class of noncompact groups of matrices, such as $O(p,q)$. We give

Jiang-Hua Lu

We introduce the notion of Hopf algebroids, in which neither the total algebras nor the base algebras are required to be commutative. We give a class of Hopf algebroids associated to module algebras of the Drinfeld doubles of Hopf algebras when the $R$-matrices act properly. When this construction is applied to quantum groups, we get examples of quantum grou

K. Clubok, M. B. Halpern

We review developments in the world-sheet action formulation of the generic irrational conformal field theory, including the non-linear and the linearized forms of the action. These systems form a large class of spin-two gauged WZW actions which exhibit exotic gravitational couplings. Integrating out the gravitational field, we also speculate on a connection

Shogo Aoyama, Yuji Kodama

Based on the dispersionless KP (dKP) theory, we give a comprehensive study of the topological Landau-Ginzburg (LG) theory characterized by a rational potential. Writing the dKP hierarchy in a general form, we find that the hierarchy naturally includes the dispersionless (continuous) limit of Toda hierarchy and its generalizations having finite number of prim

Eric Benedict, So-Young Pi

We study the entanglement entropy arising from coherent states and one--particle states. We show that it is possible to define a finite entanglement entropy by subtracting the vacuum entropy from that of the considered states, when the unobserved region is the same.

M. Kreuzer, H. Skarke

For a large class of $N=2$ SCFTs, which includes minimal models and many $\s$ models on Calabi-Yau manifolds, the mirror theory can be obtained as an orbifold. We show that in such a situation the construction of the mirror can be extended to the presence of discrete torsions. In the case of the $\ZZ_2\ex\ZZ_2$ torus orbifold, discrete torsion between the tw

G. Papadopoulos

We explicitly construct the metric and torsion couplings of two-dimensional (4,0)-super\-sym\-metric sigma models with target space a four-manifold that are invariant under a $U(1)$ symmetry generated by a tri-holomorphic Killing vector field that leaves in addition the torsion invariant. We show that the metric couplings arise from magnetic monopoles on the

C. R. Fernández-Pousa, M. V. Gallas, J. L. Miramontes, J. Sánchez Guillén

The basic concepts underlying our analysis of {\it W-algebras} as extended symmetries of integrable systems are summarized. The construction starts from the second hamiltonian structure of ``Generalized Drinfel&#39;d-Sokolov&#39;&#39; hierarchies, and its correspondence with the $A_1$-embeddings is established, providing a rather simple and general scheme.

Roger Brooks, Renata Kallosh, Tomas Ortin

The gravitini zero modes riding on top of the extreme Reissner-Nordstrom black-hole solution of N=2 supergravity are shown to be normalizable. The gravitini and dilatini zero modes of axion-dilaton extreme black-hole solutions of N=4 supergravity are also given and found to have finite norms. These norms are duality invariant. The finiteness and positivity o

Thorsten Ohl

Feynmf is a LaTeX package for easy drawing of professional quality Feynman diagrams with Metafont (or Metapost). Feynmf lays out most diagrams satisfactorily from the structure of the graph without any need for manual intervention. Nevertheless all the power of Metafont (or Metapost) is available for the most complicated cases.

C. P. Burgess

The sum-energy spectrum of electrons emitted in double-beta decay is a well-known diagnostic for the nature of the physics which is responsible for the decay. Three types of spectra are usually considered when these experiments are analysed: one each for the standard two-neutrino decay, the neutrinoless process and a scalar-emitting decay. It has recently be

Christophe Bruno, Elisabetta Pallante

Within the Extended Nambu Jona-Lasinio model we analyse the $1/N_c$-corrections to the leading order result $M_S=2M_Q$ where $M_Q$ is the constituent quark mass.

Marshall Baker

We describe long distance QCD by a dual theory in which the fundamental variables are dual potentials coupled to monopole fields and use this dual theory to determine the effective Lagrangian for constituent quarks. We find the color field distribution surrounding a quark anti-quark pair to first order in their velocities. Using these distributions we elimin

D. Kharzeev, H. Satz

We survey how quarkonia can be used to probe colour deconfinement in relativistic nuclear collisions.

Vittorio Del Duca

We give a unified description of tree-level multigluon amplitudes in the high-energy limit. We represent the Parke-Taylor amplitudes and the Fadin-Kuraev-Lipatov amplitudes in terms of color configurations that are ordered in rapidity on a two-sided plot. We show that for the helicity configurations they have in common the Parke-Taylor amplitudes and the Fad

Akio Sugamoto

A talk was given on the baryon asymmetry of our universe within the electroweak energy scale which was the theme for the 23rd INS Symposium. It was intended for non-experts by a non-expert speaker. A model is analized explicitly in which the lepton number produced from the bubble walls is converted afterwards to the baryon asymmetry.Phase transition dynamics

K. Enqvist, A. Riotto, I. Vilja

We consider the role played by subcritical bubbles during the electroweak phase transition, estimate their average size, amplitude and formation rate taking into account the crucial role played by thermalization. We also study the influence of subcritical bubbles on the formation of critical bubbles in the thin wall regime and show that, contrary to some rec

J. Ellis, J. Lopez, N. Mavromatos, D. Nanopoulos

We present a systematic phenomenological analysis of the tests of CPT symmetry that are possible within an {\em open} quantum-mechanical description of the neutral kaon system that is motivated by arguments based on quantum gravity and string theory. We develop a perturbative expansion in terms of the three small CPT-violating parameters admitted in this des

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

We analyze LEP and SLC data from the 1995 Winter Conferences for signals of new physics. We compare the data with the Standard Model (SM) as well as a number of test hypotheses concerning the nature of new physics: (i) nonstandard Zbb couplings, (ii) nonstandard Zff couplings for the entire third generation, (iii) nonstandard oblique corrections, (iv) nonsta

John L. Friedman, Atsushi Higuchi

We examine quantum field theory in spacetimes that are time nonorientable but have no other causal pathology. These are Lorentzian universes-from-nothing, spacetimes with a single spacelike boundary that nevertheless have a smooth Lorentzian metric. Classically, such spacetimes are locally indistinguishable from their globally hyperbolic covering spaces. How

Vladimir S. Mashkevich

This paper is a continuation of the paper [V.S.Mashkevich, gr-qc/9409010]. Indeterministic quantum gravity is a theory that unifies general relativity and quantum theory involving indeterministic conception, i.e., quantum jumps. By the same token the theory claims to describe all the universe. Spacetime is the direct product of cosmic time and space. The sta

B. Linet

In Rindler space, we consider the Feynman Green&#39;s functions associated with either the Fulling-Rindler vacuum or the Minkowski vacuum. In Euclidean field theory, they becomes respectively the Euclidean Green&#39;s functions $G_{\infty}$ and $G_{\2π}$, whose we give different suitable forms. In the case of the massive spin-$\frac{1}{2}$ field, we determin

Mariano Cadoni, Salvatore Mignemi

We study a two-dimensional dilaton gravity model related by a conformal transformation of the metric to the Callan-Giddings-Harvey-Strominger model. We find that most of the features and problems of the latter can be simply understood in terms of the classical and semiclassical dynamics of accelerated observers in two-dimensional Minkowski space.

T. P. Pareek, A. M. Jayannavar

We present a systematic analysis of ground state properties of a tunneling system coupled to an Ohmic bath. The nonadiabatic effects induced by coupling with tunneling particle , on the ground state properties of phonons are taken into account. For this we have considered both displacement and deformation of phonons via a variational treatment. The symmetry

Frank Gaitan, Subodh R. Shenoy

We examine the dynamical consequences of Berry&#39;s phase for Josephson junctions, junction arrays, and their vortices. Josephson&#39;s equation and the related phase slip voltages are shown to be uneffected by Berry&#39;s phase. In an annular Josephson junction, Berry&#39;s phase is seen to generate a new current drive on a vortex. In the continuum limit,

S. M. Girvin, A. H. MacDonald

The physics of the fractional quantum Hall effect is the physics of interacting electrons confined to a macroscopically degenerate Landau level. In this Chapter we discuss the theory of the quantum Hall effect in systems where the electrons have degrees of freedom in addition to the two-dimensional orbital degree of freedom. We will be primarily interested i

U. Schollwoeck, Th. Jolicoeur, T. Garel

Most of the present understanding of the S=1 quantum spin chains displaying the Haldane gap is coming from the so-called valence-bond-solid Hamiltonian which has an exactly known ground state. We show that this point is characterized by the onset of short-range incommensurate spin correlations in the one-parameter family of Hamiltonians with biquadratic coup

P. Beran, D. Poilblanc, R. B. Laughlin

It is shown that the dynamics of a single hole in a quantum antiferromagnet (described by the t--J model) can be simply understood in terms of a composite quasiparticle. This description provides naturally two different energy scales t and J corresponding to the inverse masses of the charge (holon) and spin (spinon) elementary excitations respectively. This

U. Nowak

A model is introduced for the theoretical description of nanoscale magnetic films with high perpendicular anisotropy. In the model the magnetic film is described in terms of single domain magnetic grains, interacting via exchange as well as via dipolar forces. Additionally, the model contains anisotropy energy and a coupling to an external magnetic field. Di

Rebecca J. Passonneau

This paper concerns how to generate and understand discourse anaphoric noun phrases. I present the results of an analysis of all discourse anaphoric noun phrases (N=1,233) in a corpus of ten narrative monologues, where the choice between a definite pronoun or phrasal NP conforms largely to Gricean constraints on informativeness. I discuss Dale and Reiter&#39

Fernando Sánchez León, Amalio F. Nieto Serrano

This paper describes work performed withing the CRATER ({\em C}orpus {\em R}esources {\em A}nd {\em T}erminology {\em E}xt{\em R}action, MLAP-93/20) project, funded by the Commission of the European Communities. In particular, it addresses the issue of adapting the Xerox Tagger to Spanish in order to tag the Spanish version of the ITU (International Telecomm

G. E. Brown, J. C. Weingartner, R. A. M. J. Wijers

Recently (Brown \& Bethe 1994) it was suggested that most stars with main sequence mass in the range of about $18 - 30 M_{\odot}$ explode, returning matter to the Galaxy, and then go into low-mass ($\geq 1.5 M_{\odot}$) black holes. Even more massive main-sequence stars would, presumably, chiefly g o into high-mass ($\sim 10 M_{\odot}$) black holes. The Brow

Ofer Lahav

The rapid increase in data on galaxy images at low and high redshift calls for re-examination of the classification schemes and for new automatic objective methods. Here we present a classification method by Artificial Neural Networks. We also show results from a comparative study we carried out using a new sample of 830 APM digitised galaxy images. These ga

P. Ruiz-Lapuente, A. Burkert, R. Canal

The dependence of the Type Ia supernova (SN Ia) rate on galaxy type is examined for three currently proposed scenarios: merging of a Chandrasekhar--mass CO white dwarf (WD) with a CO WD companion, explosion of a sub--Chandrasekhar mass CO WD induced by accretion of material from a He star companion, and explosion of a sub--Chandrasekhar CO WD in a symbiotic

A. Doroshkevich, R. Fong, S. Gottloeber, J. P. Muecket

A quantitative theory, based on the Zeldovich approximation, to provide an approximate description of the evolution of structure is presented. We give an expression for the characteristic scale of superlarge-scale structure which can also be applied to power spectra with a Harrison-Zeldovich asymptotic. The evolution of the characteristic scale of large-scal

Andrew Gould, John N. Bahcall, Chris Flynn

We study a sample of 257 Galactic disk M dwarfs (8<M_V<18.5) found in images obtained using HST. These include 192 stars in 22 fields imaged with the repaired WFC2 with mean limiting mag I=23.7 and 65 stars in 162 fields imaged with the pre-repair Planetary Camera with mean limiting mag V=21.3. We find that the disk luminosity function (LF) drops sharply for

Carmen Schuhmann

We prove that the degree of a nonconstant morphism from a smooth projective 3-fold $X$ with Néron-Severi group ${\bf Z}$ to a smooth 3-dimensional quadric is bounded in terms of numerical invariants of $X$. In the special case where $X$ is a 3-dimensional cubic we show that there are no such morphisms. The main tool in the proof is Miyaoka&#39;s bound on the

J. L. Cortes, M. S. Plyushchay

A model-independent formulation of anyons as spinning particles is presented. The general properties of the classical theory of (2+1)-dimensional relativistic fractional spin particles and some properties of their quantum theory are investigated. The relationship between all the known approaches to anyons as spinning particles is established. Some widespread

D. T. Son

We propose a semiclassical approach to calculate multiparticle cross sections in scalar theories, which have been strongly argued to have the exponential form $\exp(λ^{-1}F(λn,ε))$ in the regime $λ\to0$, $λn$, $ε=$ fixed, where $λ$ is the scalar coupling, $n$ is the number of produced particles, and $ε$ is the kinetic energy per final particle. The formalism

D. Wesolowski, Y. Hosotani

In a class of three-dimensional Abelian gauge theories with both light and heavy fermions, heavy chiral fermions can trigger dynamical generation of a magnetic field, leading to the spontaneous breaking of the Lorentz invaiance. Finite masses of light fermions tend to restore the Lorentz invariance.

F. Hussain, J. G. Körner, J. Landgraf, Salam Tawfiq

We study the current-induced bottom baryon to charm baryon transitions in the Heavy Quark Symmetry limit as $m_{q}\rightarrow \infty$. Our discussion involves $s$-wave to $s$-wave as well as $s$-wave to $p$-wave transitions. Using a constituent quark model picture for the light diquark system with an underlying $SU(2N_{f})\otimes O(3)$ symmetry and the heavy

Vittorio Lubicz, Pietro Santorelli

Walking technicolor (WTC) models predict the existence of heavy neutral pseudo-Goldstone bosons (PGBs), whose masses are typically expected to be larger than 100 GeV. In this paper, we investigate the production and decay of these particles at the high energy e^+ e^- experiments, LEP II and NLC. We find that, in WTC models, the production of neutral PGBs can

S. E. Derkachov, A. N. Manashov

The spectrum of the anomalous dimensions of the composite operators (with arbitrary number of fields $n$ and derivatives $l$) in the scalar $ϕ^4$ - theory in the first order of the $ε$ -expansion is investigated. The exact solution for the operators with number of fields $\leq 4$ is presented. The behaviour of the anomalous dimensions in the large $l$ limit

Yoshio Koide, Morimitu Tanimoto

In a model where quark and lepton masses and family-mixings are caused not by a variety of Yukawa couplings $y_{ij}$ ($i,j=1,2,3$: family indices) with one vacuum expectation value (VEV) $v=\langleϕ_L^0\rangle_0$, but by a variety of VEV&#39;s of a U(3)-family nonet Higgs boson $ϕ_L$, $v_{i}^j=\langleϕ_{L i}^{0j}\rangle_0$, with a single coupling constant, t

O. Yu. Shvedov

The problem of large order behaviour of perturbation theory for quantum mechanical systems is considered. A new approach to it is developed. An explicit mechanism showing the connection between large order recursive relations and classical euclidean equations of motion is found. Large order asymptotics of the solution to the recursive relations is constructe

Paolo Aschieri, Peter Schupp

We construct the space of vector fields on a generic quantum group. Its elements are products of elements of the quantum group itself with left invariant vector fields. We study the duality between vector fields and 1-forms and generalize the construction to tensor fields. A Lie derivative along any (also non left invariant) vector field is proposed and a pu

J. Lepowsky, R. L. Wilson

The elimination theorem for free Lie algebras, a general principle which describes the structure of a free Lie algebra in terms of free Lie subalgebras, has been recently used by E. Jurisich to prove that R. Borcherds&#39; ``Monster Lie algebra&#39;&#39; has certain large free Lie subalgebras, illuminating part of Borcherds&#39; proof that the moonshine modu

Andreas Engel, Eiji I. Tanaka, Tomoyuki Maruyama, Akira Ono

Delta degrees of freedom are introduced into antisymmetrized molecular dynamics (AMD). This is done by increasing the number of basic states in the AMD wave function, introducing a Skyrme-type delta-nucleon potential, and including $NN\leftrightarrow NΔ$ reactions in the collision description. As a test of the delta dynamics, the extended AMD is applied to (

K. M. Rabe, U. V. Waghmare

An effective Hamiltonian for the ferroelectric transition in $PbTiO_3$ is constructed from first-principles density-functional-theory total-energy and linear-response calculations through the use of a localized, symmetrized basis set of ``lattice Wannier functions.&#39;&#39; Preliminary results of Monte Carlo simulations for this system show a first-order cu

Armando Antillón, Joaquín Escalona, Gabriel Germán, Manuel Torres

We study a non-Abelian Chern-Simons gauge theory in $ 2+ 1$ dimensions with the inclusion of an anomalous magnetic interaction. For a particular relation between the Chern-Simons (CS) mass and the anomalous magnetic coupling the equations for the gauge fields reduce from second- to first order differential equations of the pure CS type. We derive the Bogomol

F. T. Brandt, J. Frenkel

Following a remark advanced by Feynman,we study the connection between the form of the nonlinear vertices involving gauge particles and the Abelian gauge invariance of physical tree amplitudes. We show that this requirement, together with some natural assumptions, fixes uniquely the structure of the Yang-Mills theory. However, the constraints imposed by the

Michael Creutz

I discuss the global structure of the strongly interacting gauge theory of quarks and gluons as a function of the quark masses and the CP violating parameter $θ$. I concentrate on whether a first order phase transition occurs at $θ=π.$ I show why this is expected when multiple flavors have a small degenerate mass. This transition can be removed by sufficient

Ph. Brax

The long-time large-distance behaviour of free decaying two dimensional turbulence is studied. Stochastic solutions of the Navier-Stokes equation are explicitly shown to follow renormalisation group trajectories. It is proven that solutions of the Navier-Stokes equation asymptotically converge to fixed points which are conformal field theories. A particular

Tze-Dan Chung, Jen-Chi Lee

A general formula for the discrete states (Neveu-Schwarz sector) in $N=1$ $2D$ super-Liouville theory is written down in the world-sheet supersymmetric form. We then derive a set of gauge states at the discrete momenta. These discrete gauge states are shown to carry the $w_\infty$ charges and serve as the symmetry parameters in the old covariant quantization

P. C. Argyres, M. R. Plesser, A. Shapere

We present an explicit non-perturbative solution of N=2 supersymmetric SU(N_c) gauge theory with N_f \le 2N_c flavors generalizing results of Seiberg and Witten for N_c=2.

N. G. Deshpande, G. Eilam, Xiao-Gang He, J. Trampetic

We study the energy distribution of $ϕ$ in pure penguin induced $B\rightarrow X_s ϕ$ taking into account the fermi motion of b inside $B$ meson for $b\rightarrow sϕ$ and also modification due to gluon bremsstrahlung process $b\rightarrow sϕg$. We find that the contribution to $B\rightarrow X_sϕ$ from $b\rightarrow sϕg$ is less than 3\%. This study provides a

K. S. Babu, Jogesh C. Pati, Frank Wilczek

We show how two different scales for oscillations between $e$ and $μ$ neutrinos, characterized by different mixing angles and effective mass scales, can arise in a simple and theoretically attractive framework. One scale characterizes direct oscillations, which can accommodate the MSW approach to the solar neutrino problem, whereas the other can be considere

Matteo Cacciari

The phenomenology of heavy quarkonia production in hadron collisions is reviewed. The theoretical predictions are compared to data. Commonly used production models are shown to fail in explaining all the experimental findings. The shortcomings of these models are analysed and possible improvements are discussed.

R. Foot, R. R. Volkas

We show how the use of a see-saw mechanism based on a $3 \times 3$ neutrino mass matrix texture can considerably simplify Higgs sectors for quark-lepton symmetric models (and for Standard Model extensions generally). The main theory we discuss also incorporates a previously considered scenario whereby the charged lepton of a particular generation is necessar

W. Franzki, C. Frick, J. Jersak, X. Q. Luo

The chiral phase transition induced by a charged scalar field is investigated numerically in a lattice fermion-gauge-scalar model with U(1) gauge symmetry, proposed recently as a model for dynamical fermion mass generation. For very strong gauge coupling the transition is of second order and its scaling properties are very similar to those of the Nambu--Jona

ZEUS Collaboration

This paper presents measurements of \k\ and \lam\ production in neutral current, deep inelastic scattering of 26.7 GeV electrons and 820 GeV protons in the kinematic range $ 10 < Q^{2} < 640 $ GeV$^2$, $0.0003 < x < 0.01$, and $y > 0.04$. Average multiplicities for \k\ and \lam\ production are determined for transverse momenta \ \ptr\ $> 0.5 $ GeV and pseudo

Alexander Vilenkin

Eternally inflating universes can contain large thermalized regions with different values of the constants of Nature and with different density fluctuation spectra. To find the probability for a `typical&#39; observer to detect a certain set of constants, or a certain fluctuation spectrum, one needs to compare the volumes occupied by different types of regio

Anthony Zee

We study Hamiltonians consisting of a deterministic term plus a random term. Using a daigrammatic approach and introducing the concept of &#34;gluon connectedness,&#34; we calculate the density of energy levels for a wide class of probability distributions governing the random term, thus generalizing a result obtained recently by Brézin, Hikami, and Zee. The

P. Schmitteckert, P. Schwab, U. Eckern

Using the Quantum Inverse Scattering Method we construct an integrable Heisenberg-XXZ-model, or equivalently a model for spinless fermions with nearest-neighbour interaction, with defects. Each defect involves three sites with a fine tuning between nearest-neighbour and next-nearest-neighbour terms. We investigate the finite size corrections to the ground st

Chetan Nayak, Frank Wilczek

By carefully considering a family of wave functions for Skyrmions in simple quantum Hall states, whose members are labelled by a non-negative integer and which properly generalizes the traditional Laughlin quasiparticle, we argue that the spin of this particle has a fractional part related in a universal fashion to the properties of the bulk state, and propo

Th. Jolicoeur

I study phase transitions occuring in noncollinear magnets by means of a self-consistent screening approximation. The Ginzburg-Landau theory involves two N-component vector fields with two independent quartic couplings allowing a symmetry-breaking scheme which is SO(N)times SO(2) broken down to SO(N-2)times SO(2)_diag. I find that there is a second-order pha

I. Safi, H. J. Schulz

Transport through a one--dimensional wire of interacting electrons connected to semi--infinite leads is investigated using a bosonization approach. An incident electron is transmitted as a sequence of partial charges. The dc conductance is found to be entirely determined by the properties of the leads. The dynamic nonlocal conductivity is rigorously expresse

M. Hettler, K. Ziegler

A grand canonical system of non-interacting fermions on a square lattice is considered at zero temperature. Three different phases exist: an empty lattice, a completely filled lattice and a liquid phase which interpolates between the other two phases. The Fermi statistics can be changed into a Bose statistics by coupling a statistical gauge field to the ferm

W. Hubner, K. H. Bennemann

We extend our previous study of the polarization dependence of the nonlinear optical response to the case of magnetic surfaces and buried magnetic interfaces. We calculate for the longitudinal and polar configuration the nonlinear magneto-optical Kerr rotation angle. In particular, we show which tensor elements of the susceptibilities are involved in the enh

A. Dobry, A. Greco, S. Koval, J. Riera

We study by exact diagonalization the two-dimensional t-J-Holstein model near quarter filling by retaining only few phonon modes in momentum space. This truncation allows us to incorporate the full dynamics of the retained phonon modes. The behavior of the kinetic energy, the charge structure factor and other physical quantities, show the presence of a trans

Nicolas Pavloff, Charles Schmit

We study diffractive effects in two dimensional polygonal billiards. We derive an analytical trace formula accounting for the role of non-classical diffractive orbits in the quantum spectrum. As an illustration the method is applied to a triangular billiard.

Dave Syer

We show how to develop an expansion of nearly oblate systems in terms of a set of potential-density pairs. A harmonic (multipole) structure is imposed on the potential set at infinity, and the density can be made everywhere regular. We concentrate on a set whose zeroth order functions describe the perfect oblate spheroid of de Zeeuw (1985). This set is not b

D. Grupe, K. Beuermann, K. Mannheim, N. Bade

We report optical, soft X-ray, and UV observations of the peculiar Seyfert galaxy IC 3599 using data obtained with ROSAT and IUE. Most remarkably, we discovered a rapid decrease of the X-ray flux by a factor of about 100 within one year and a more gradual decrease thereafter. The X-ray spectrum of IC 3599 was soft at flux maximum and became even softer as th

Francesco Sylos Labini, Luciano Pietronero

Galaxies and clusters distributions show two major properties: (i) the positions of galaxies and clusters are characterized by a power law distribution indicating properties with respect to their positions. (ii) The distribution of masses is also characterized by a power law corresponding to self similarity of different nature. These two properties are natur

Alberto Manrique, Eduard Salvador-Sole

This is the first paper of a series of two devoted to develop a practical method to describe the growth history of bound virialized objects in the gravitational instability scenario without resorting to $N$-body simulations. Here we present the basic tool of this method, ``the confluent system formalism&#39;&#39;, which allows us to follow the filtering evol

Eli Waxman

We discuss a scenario in which the highest energy cosmic rays (CR&#39;s) and cosmological $γ$-ray bursts (GRB&#39;s) have a common origin. This scenario is consistent with the observed CR flux above $10^{20}\text{eV}$, provided that each burst produces similar energies in $γ$-rays and in CR&#39;s above $10^{20}\text{eV}$. Protons may be accelerated by Fermi&

Eric Poisson

A particle of mass $\mu$ moves on a circular orbit around a nonrotating black hole of mass $M$. Under the assumption $\mu \ll M$ the gravitational waves emitted by such a binary system can be calculated exactly numerically using black-hole perturbation theory. If, further, the particle is slowly moving, then the waves can be calculated approximately analytic

Jonathan Engel, Paul H. Frampton, Roxanne P. Springer

Using effective Lagrangians, we argue that any time-reversal-violating but parity-conserving effects are too small to be observed in flavor-conserving nuclear processes without dramatic improvement in experimental accuracy. In the process we discuss other arguments that have appeared in the literature.

Hai Ren

We study the WZW model based on the centrally extended 2D de Sitter algebra. We obtain the spacetime metric and its explicitly conformally flat expression. The symmetries of the spacetime are found by identifying the Killing vectors with the group generators. The energy-momentum tensor obtained from the affine-Sugawara construction agrees with that from the