May 1995 arXiv papers — page 8

R. B. Stinchcombe, E. D. Moore, S. L. A. de Queiroz

Analytic phenomenological scaling is carried out for the random field Ising model in general dimensions using a bar geometry. Domain wall configurations and their decorated profiles and associated wandering and other exponents $(ζ,γ,δ,μ)$ are obtained by free energy minimization. Scaling between different bar widths provides the renormalization group (RG) tr

E. D. Moore, R. B. Stinchcombe, S. L. A. de Queiroz

A scaling description is obtained for the $d$--dimensional random field Ising model from domains in a bar geometry. Wall roughening removes the marginality of the $d=2$ case, giving the $T=0$ correlation length $ξ\sim \exp\left(A h^{-γ}\right)$ in $d=2$, and for $d=2+ε$ power law behaviour with $ν= 2/εγ$, $h^\star \sim ε^{1/γ}$. Here, $γ= 2,4/3$ (lattice, co

V. Loreto, G. Paladin, A. Vulpiani

We introduce a measure of complexity in terms of the average number of bits per time unit necessary to specify the sequence generated by the system. In random dynamical system, this indicator coincides with the rate K of divergence of nearby trajectories evolving under two different noise realizations. The meaning of K is discussed in the context of the info

Serguei B. Isakov

We give two formulations of exclusion statistics (ES) using a variable number of bosonic or fermionic single-particle states which depend on the number of particles in the system. Associated bosonic and fermionic ES parameters are introduced and are discussed for FQHE quasiparticles, anyons in the lowest Landau level and for the Calogero-Sutherland model. In

Nathan Argaman

The Kubo formula for the conductance of a mesoscopic system is analyzed semiclassically, yielding simple expressions for both weak localization and universal conductance fluctuations. In contrast to earlier work which dealt with times shorter than $O(\log \hbar^{-1})$, here longer times are taken to give the dominant contributions. For such long times, many

Owen Rambow, K. Vijay-Shanker, David Weir

DTG are designed to share some of the advantages of TAG while overcoming some of its limitations. DTG involve two composition operations called subsertion and sister-adjunction. The most distinctive feature of DTG is that, unlike TAG, there is complete uniformity in the way that the two DTG operations relate lexical items: subsertion always corresponds to co

Oliver Bauer, Ronnie Mainieri

We review the convergence of chaotic integrals computed by Monte Carlo simulation, the trace method, dynamical zeta function, and Fredholm determinant on a simple one-dimensional example: the parabola repeller. There is a dramatic difference in convergence between these approaches. The convergence of the Monte Carlo method follows an inverse power law, where

P. M. Gade, Chaitali Basu

Recently it has been found that different physical systems driven by identical random noise behave exactly identical after a long time. It is also suggested that this is an outcome of finite precision in numerical experiments. Here we show that the origin of the non-chaotic behavior lies in the structural instability of the attractor of these systems which c

J. Frieman, C. Hill, A. Stebbins, I. Waga

We explore the cosmological implications of an ultra-light pseudo-Nambu-Goldstone boson. With global spontaneous symmetry breaking scale $f \simeq 10^{18}$ GeV and explicit breaking scale comparable to MSW neutrino masses, $M \sim 10^{-3}$ eV, such a field, which acquires a mass $m_ϕ\sim M^2/f \sim H_0$, would have become dynamical at recent epochs and curre

M. J. Balbes, R. N. Boyd, G. Steigman, D. Thomas

We explore the Gnedin-Ostriker suggestion that a post-Big-Bang photodissociation process may modify the primordial abundances of the light elements. We consider several specific models and discuss the general features that are necessary (but not necessarily sufficient) to make the model work. We find that with any significant processing, the final D and $^3$

J. I. Collar, F. T. Avignone

Nuclear recoil cascades induced by Cold Dark Matter (CDM) elastic scattering can produce the ejection of target atoms from solid surfaces. We calculate the yield and energy distribution of these sputtered atoms in a variety of materials. These parameters would suffer a large diurnal modulation induced by the rotation of the Earth and its motion through the g

Dirk H. Rischke, Yaris Puersuen, Joachim A. Maruhn, Horst Stoecker

It is shown that in ideal relativistic hydrodynamics a phase transition from hadron to quark and gluon degrees of freedom in the nuclear matter equation of state leads to a minimum in the excitation function of the transverse collective flow.

Boris Blok, Thomas Mannel

Assuming so called global duality we argue that it is very likely that local duality needed to obtain results for the hadronic width of heavy meson decays within the $1/m_Q$ expansion holds. Hence, if the discrepancy between experiment and the theory concerning charm counting, the semileptonic branching fraction and the lifetimes of $b$ hadrons persist, it m

J. I. Collar, F. T. Avignone

Recoiling nuclei from Cold Dark Matter (CDM) elastic scattering interactions with the constituent elements of some minerals may produce etchable damage tracks in the crystal structure. Present calculations show that in muscovite mica, CDM tracks from recoiling potassium atoms could be readily distinguished from others due to alpha-decays in the uranium and t

J. R. Forshaw, M. H. Seymour

The unique nature of the photon can be investigated in hitherto unexplored kinematic regions at LEP2. We discuss the theoretical significance of deep inelastic measurements and present a prescription that allows a theoretically and experimentally sensible separation of the so-called `anomalous' and `hadronic' components of the target photon. We perfo

U. Kerres, G. Mack, G. Palma

We propose a two-step procedure to study the order of phase transitions at finite temperature in electroweak theory and in simplified models thereof. In a first step a coarse grained free energy is computed by perturbative methods. It is obtained in the form of a 3-dimensional perfect lattice action by a block spin transformation. It has finite temperature d

Pawel Moskalik

Until very recently the physical mechanism driving oscillations in $\beta$~Cep and other early type stars has been a mystery. The breakthrough came with the publication of new OPAL and OP opacity data. Model calculations with the new opacities have demonstrated that the pulsations are driven by the familiar $\kappa$-mechanism, acting in the metal opacity bum

Toshiaki KANEKO, Nobuya NAKAZAWA

An automatic system to calculate two loop weak corrections to muon anomalous magnetic moment is discussed. Diagrams are classified into eight types, according to their topology. Adopting Civitanovi\'c-Kinoshita representation of Feynman amplitude and using the topological property, the renormalization is performed consistently by n-dimensional regularization

E. Elizalde, S. Leseduarte, S. D. Odintsov, Yu. I. Shil'nov

A number of 2d and 3d four-fermion models which are renormalizable ---in the $1/N$ expansion--- in a maximally symmetric constant curvature space, are investigated. To this purpose, a powerful method for the exact study of spinor heat kernels and propagators on maximally symmetric spaces is reviewed. The renormalized effective potential is found for any valu

H. Jeong, B. Kahng, D. Kim

We analyze the anisotropic Kardar-Parisi-Zhang equation in general substrate dimensions $d'$ with spatially correlated noise, $\langle\tilde η({\bf{k}},ω)\rangle=0$ and $\langle\tilde η({\bf{k}},ω) \tilde η({\bf{k}}',ω')\rangle$ $=2D(k)δ^{d'}({\bf{k}}+{\bf{k}}')δ(ω+ω')$ where $D(k)=D_0+D_ρk^{-2ρ}$, using the dynamic renormalization gr

A. Kazarnovski-Krol

This paper is devoted to homological treatment of Harish-Chandra decomposition for zonal spherical functions of type $A_n$.

V. R. Galakhov, E. Z. Kurmaev, V. M. Cherkashenko, Yu. M. Yarmoshenko

The full set of high-energy spectroscopy measurements including X-ray photoelectron valence band spectra and soft X-ray emission valence band spectra of both components of FeSi (Fe K_beta_5, Fe L_alpha, Si K_beta_1,3 and Si L_2,3) are performed and compared with the results of ab-initio band structure calculations using the linearized muffin-tin orbital meth

M. T. Grisaru, M. E. Wehlau

Starting with the prepotential description of two-dimensional $(2,2)$ supergravity we use local supersymmetry transformations to go to light-cone gauge. We discuss properties of the theory in this gauge and derive Ward identities for correlation functions defined with respect to the induced supergravity action.

M. Berkooz

We suggest a dual to an $SU(2k)$ Susy gauge theory containing an antisymmetric tensor, $\nf$ fundamentals and $\nfb$ anti-fundamentals. This is done by expanding the theory into an equivalent description with two gauge groups and then performing known duality tranformations on each gauge group separately. Chiral operators, mass perturbations and flat directi

Bernard Derrida, Vincent Hakim, Vincent Pasquier

In the zero temperature Glauber dynamics of the ferromagnetic Ising or $q$-state Potts model, the size of domains is known to grow like $t^{1/2}$. Recent simulations have shown that the fraction $r(q,t)$ of spins which have never flipped up to time $t$ decays like a power law $r(q,t) \sim t^{-θ(q)}$ with a non-trivial dependence of the exponent $θ(q)$ on $q$

V. V. Nesterenko, A. Feoli, G. Scarpetta

The equations of motion for a Lagrangian ${\cal L}(k_1)$, depending on the curvature $k_1$ of the particle worldline, embedded in a space--time of constant curvature, are considered and reformulated in terms of the principal curvatures. It is shown that for arbitrary Lagrangian function ${\cal L}(k_1)$ the general solution of the motion equations can be obta

Ralf Kerschner

The existence of inequivalent representations in quantum field theory with {\it finitely} many degrees of freedom is shown. Their properties are exemplified and analysed for concrete and simple models. In particular the relations to Bogoliubov--Valatin quasi-particles, to thermo field dynamics, and to $q$--deformed quantum theories are put foreward. The ther

C. Ahn, W. M. Koo

A supersymmetric extension of the color Calogero-Sutherland model is considered based on the Yangian $Y(gl(n|m))$. The algebraic structure of the model is discussed in some details. We show that the commuting conserved quantities can be generated from the super-quantum determinant, thus establishing the integrability of the model. In addition, rational limit

M. Shifman

Some recent developments in the heavy quark theory are briefly reviewed. The main emphasis is put on interrelation between HQET and OPE. The notion of duality and deviations from duality are discussed in detail.

J. Clua, J. A. Grifols

We explore systematically, in a general two Higgs doublet model, the possibility, that bound systems of scalar bosons do exist. We find a wide region of parameter space in the scalar potential for which S-wave bound states of Higgs bosons do indeed exist. On the contrary we show that the Minimal Supersimmetric Standard Model does not admit such bound systems

Lincoln Wolfenstein

The existence of $D^0-\overline{D^0}$ mixing at a detectable level requires new physics, which effectively yields a $Δc = 2$ superweak interaction. In general this interaction may involve significant CP violation. For small values of the mixing it may be much easier to detect the CP-violating part of the mixing than the CP-conserving part.

R. Fiore, L. L. Jenkovszky, F. Paccanoni

Diffractive deep inelastic events with a large rapidity gap are analyzed by using a Regge model for the pomeron flux and a gluonic content for the pomeron. Contrary to the expectations, the simplest assumption for the pomeron trajectory gives the best agreement with the data on the ratio of diffractive to the total number of events. In this case the main pro

Lynne H. Orr, T. Stelzer, W. J. Stirling

Understanding the pattern of gluon radiation in $t \bar t$ production processes is important for making an accurate determination of the top mass from the measurement of its decay products. In a recent paper we showed that the exact matrix element and parton shower (HERWIG) calculations gave very different results for the distribution of gluon jets in $t \ba

Mohan Narayan, M. V. N. Murthy, G. Rajasekaran, S. Uma Sankar

We analyze the solar and the atmospheric neutrino problems in the context of three flavour neutrino oscillations. We assume a mass hierarchy in the vacuum mass eigenvalues $μ_3^2 \gg μ_2^2 \geq μ_1^2$, but make no approximation regarding the magnitudes of the mixing angles. We find that there are small but continuous bands in the parameter space where the co

S. Fajfer

The decays $K^{+} \rightarrow π^{+} e^{+} e^{-}$, $K_{S} \rightarrow π^{0} e^{+} e^{-}$ and $K_{L} \rightarrow π^{0} e^{+} e^{-}$ are reinvestigated within the framework of chiral perturbation theory. The counterterms induced by strong, electromagnetic and weak interactions are determined assuming the resonance exchange. The weak deformation model, the facto

V. A. Saleev, N. P. Zotov

Processes of heavy quark photoproduction at HERA energies and beyond are investigated using the semihard ($k_{\bot}$ factorization) approach. Virtuality and longitudinal polarization of gluons in the photon - gluon subprocess as well as the saturation effects in the gluon distribution function at small $x$ have been taken into account. The total cross sectio

O. V. TARASOV

An algorithm for obtaining the Taylor coefficients of an expansion of Feynman diagrams is proposed. It is based on recurrence relations which can be applied to the propagator as well as to the vertex diagrams. As an application, several coefficients of the Taylor series expansion for the two-loop propagator and two-loop non-planar vertex diagrams are calcula

R. Friedberg, T. D. Lee, Y. Pang, H. C. Ren

We expand the gauge field in terms of a suitably constructed complete set of Bloch wave functions, each labeled by a band designation $\,n\,$ and a wave number $\,\vec K\,$ restricted to the Brillouin zone. A noncompact formulation of lattice QCD (or QED) can be derived by restricting the expansion only to the $\,0^{th}$-band ($\,n = 0\,$) functions, which a

F. Antonuccio, S. Dalley

We briefly review the 1+1-dimensional SU(N) gauge theory minimally coupled to an adjoint scalar, based upon a dimensional reduction of 2+1-dimensional pure gauge theory, which approximates the dynamics of the transversely polarized gluon. The lightest glueball states are investigated non-perturbatively using light-front quantisation in the large-N limit a la

F. M. Paiva, Anzhong Wang

The Geometry of planar domain walls is studied. It is argued that the planar walls indeed have plane symmetry. In the Minkowski coordinates the walls are mapped into revolution paraboloids.

M. Koehler

For an analogon of the free Wess-Zumino model on Ricci flat spacetimes, the relation between a conserved `supercurrent' and the point-separated improved energy momentum tensor is investigated and a similar relation as on Minkowski space is established. The expectation value of the latter in any globally Hadamard product state is found to be a priori fini

Takeshi FUKUYAMA, Kiyoshi Kamimura, Songju YU

We discuss an analytic proof of a conjecture (Nakamura) that solutions of Toda molecule equation give those of Ernst equation giving Tomimatsu-Sato solutions of Einstein equation. Using Pfaffian identities it is shown for Weyl solutions completely and for generic cases partially.

R. Koberle, A. Lima-Santos

We solve for the spectrum of quantum spin chains based on representations of the Temperley-Lieb algebra associated with the quantum groups ${\cal U}_q(X_n } for $X_n = A_1,B_n,C_n$ and $D_n$. We employ a generalization of the coordinate Bethe-Ansatz developed previously for the deformed biquadratic spin one chain. As expected, all these models have equivalen

M. P. Nightingale, E. Granato, J. M. Kosterlitz

We use extensive Monte Carlo transfer matrix calculations on infinite strips of widths $L$ up to 30 lattice spacing and a finite-size scaling analysis to obtain critical exponents and conformal anomaly number $c$ for the two-dimensional $XY$-Ising model. This model is expected to describe the critical behavior of a class of systems with simultaneous $U(1)$ a

Igor F. Herbut, Zlatko Tesanovic

We consider a disordered two-dimensional electronic system in the limit of high magnetic field at the metal-insulator transition. Density of states close to the Fermi level acquires a divergent correction to the lowest order in electron-electron interaction and shows a new power-law dependence on the energy, with the power given by the anomalous diffusion ex

Francisco Dominguez-Adame

We theoretically study electronic states in graded-gap junctions of IV-VI compounds with band inversion. Using a two-band model within the ${\bf k}\cdot{\bf p}$ approximation and assuming that the gap and the gap centre present linear profiles, we demonstrate the existence of a set of localized states along the growth direction with a discrete energy spectru

S. Jain

The relaxational behaviour of the bond-diluted two-dimensional Ising model below the percolation threshold is studied using Monte Carlo techniques. The non-equilibrium decay of the magnetization,M(t), and the relaxation of the equilibrium spin-spin autocorrelation function, C(t), are monitored. The behaviour of both C(t) and M(t) is found to satisfy the Kohl

Martin Holthaus, Gerald H. Ristow, Daniel W. Hone

An ac field, tuned exactly to resonance with the Stark ladder in an ideal tight binding lattice under strong dc bias, counteracts Wannier-Stark localization and leads to the emergence of extended Floquet states. If there is random disorder, these states localize. The localization lengths depend non-monotonically on the ac field amplitude and become essential

Jong C. Park

Traditional approaches to quantifier scope typically need stipulation to exclude readings that are unavailable to human understanders. This paper shows that quantifier scope phenomena can be precisely characterized by a semantic representation constrained by surface constituency, if the distinction between referential and quantificational NPs is properly obs

Thorsten Brants, Christer Samuelsson

Experiments were carried out comparing the Swedish Teleman and the English Susanne corpora using an HMM-based and a novel reductionistic statistical part-of-speech tagger. They indicate that tagging the Teleman corpus is the more difficult task, and that the performance of the two different taggers is comparable.

Dennis Zaritsky

I discuss observations of magnitude residuals from the B-band Tully-Fisher relationship, B-V color, chemical abundance gradients, and asymmetries in the H I and stellar disks of nearby spiral galaxies within the context of a model in which small satellites or H I clouds are accreted onto the outer disks of spiral galaxies. Correlations between the various ob

Wolfgang Brandner, Jerome Bouvier, Eva K. Grebel, Eric Tessier

Using adaptive optics at the ESO 3.6m telescope, we obtained diffraction limited JHK-images of the region around the Herbig AeBe star NX Pup. We clearly resolved the close companion (sep. 0.128") to NX Pup -- originally discovered by HST -- and measured its JHK magnitudes. A third object at a separation of 7.0" from NX Pup was identified as a classic

Veikko Saar, Erik Tago, Jaan Einasto, Maret Einasto

We have developed a parameter-independent method to detect local maxima of the two-point correlation function. By applying it to two samples of rich Abell clusters of galaxies with redshift limits z<0.08 and z<0.12 we detect three maxima centered at 150 Mpc, 300 Mpc and 430 Mpc with confidence levels 80% and higher. This sequence of fluctuations has an avera

A. C. Fabian, C. S. Crawford

A ROSAT HRI image of the hyperluminous infrared galaxy IRAS P09104+4109 shows extended X-ray emission peaked around the central galaxy in a profile characteristic of a cooling flow. The inferred soft X-ray luminosity is comparable to that detected with ASCA. The ASCA spectrum is well fit by a cooling flow spectrum, indicating a mass cooling rate of about 100

I. V. Artemova, G. S. Bisnovatiy-Kogan, G. Bjornsson, I. D. Novikov

We present here the solution for accretion disk structure, which describes continuously the transition between optically thick and optically thin disk regions. We show that the disk structure equations without advection, used here, give two branches of solutions which do not intersect for $L<L_{b}\lesssim 0.6 L_{\rm Edd}$ for $α=1.0$ and $M_{BH}=10^8 M_\odot

S. Borgani, M. Plionis, P. Coles, L. Moscardini

We present simulations of the cluster distribution in several dark matter models, using an optimized version of the truncated Zel&#39;dovich approximation (TZA). We compare them with N-body cluster simulations and find that the TZA provides a very accurate description of the cluster distribution as long as fluctuations on the cluster mass scale are in the mi

Victor Vassiliev

The monodromy action in the homology of level sets of Morse functions on stratified singular analytic varieties is studied. The local variation operators in both the standard and the intersection homology groups defined by the loops around the critical values of such functions are reduced to similar operators in the homology groups of the transversal slices

Stanley J. Brodsky, Felix Schlumpf

We calculate the electromagnetic and axial nuclear moments of the deuteron and triton as a function of their radius using a relativistic two-nucleon and three-nucleon model formulated on the light-cone. The results also provide an estimate of the nuclear binding corrections to helicity-dependent deep inelastic scattering sum rules. At large nucleon radius, t

T. Inagaki, S. Mukaigawa, T. Muta

We consider the theory of four-fermion interactions with N-component fermions in de Sitter space. It is found that the effective potential for a composite operator in the theory is calculable in the leading order of the 1/N expansion. The resulting effective potential is analyzed by varying both the four-fermion coupling constant and the curvature of the spa

Enrico Cappellaro, John I. Danziger, Massimo Turatto

We report on the optical recovery of SN~1986E 7.1 and 7.9 years after explosion. The spectra are dominated by broad H$α$ and [O~I] $λλ$6300,6364 emission lines with a minor contribution from [Ca~II] $λλ$7291,7324 and, possibly, [Fe~II] $λ$7155. Compared with the spectra of the other recovered SNII, SN1986E shows strong H$α$ luminosity similar to SN~1979C but

J. FUJIMOTO, Y. SHIMIZU, K. KATO, T. KANEKO

Extending the method successful for one-loop integrals, the computation of two-loop diagrams with general internal masses is discussed. For the two-loop vertex of non-planar type, as an example, we show a calculation related to \(Z^0\rightarrow t \bar t\) vertex.

C. D. Batista, F. Lema, A. A. Aligia

We consider a chain described by a next-nearest-neighbor hopping combined with a nearest-neighbor spin flip. In two dimensions this three-body term arises from a mapping of the three-band Hubbard model for CuO$_2$ planes to a generalized $t-J$ model and for large O-O hopping favors resonance-valence-bond superconductivity of predominantly $d$-wave symmetry.

Horst Mueller, Brian D. Serot

A relativistic mean-field model of nuclear matter with arbitrary proton fraction is studied at finite temperature. An analysis is performed of the liquid-gas phase transition in a system with two conserved charges (baryon number and isospin) using the stability conditions on the free energy, the conservation laws, and Gibbs&#39; criteria for phase equilibriu

Steve Gelbart

These are Notes prepared for nine lectures given at the Mathematical Sciences Research Institute, MSRI, Berkeley during the period January--March 1995. It is a pleasant duty to record here my gratitude to MSRI, and its staff, for making possible this 1994--95 Special Year in Automorphic Forms, and for providing such a setting for work. The purpose of these N

Tomasz Dubejko

It has been shown that univalent circle packings filling in the complex plane $\bold C$ are unique up to similarities of $\bold C$. Here we prove that bounded degree branched circle packings properly covering $\bold C$ are uniquely determined, up to similarities of $\bold C$, by their branch sets. In particular, when branch sets of the packings considered ar

Philip C. Argyres, Michael R. Douglas

We show that four-dimensional N=2 supersymmetric SU(n) gauge theory for n>2 necessarily contains vacua with mutually non-local massless dyons, using only analyticity of the effective action and the weak coupling limit of the moduli space of vacua. A specific example is the Z_3 point in the exact solution for SU(3), and we study its effective Lagrangian. We p

A. A. Bytsenko, G. Cognola, L. Vanzo, S. Zerbini

The heat-kernel expansion and $ζ$-regularization techniques for quantum field theory and extended objects on curved space-times are reviewed. In particular, ultrastatic space-times with spatial section consisting in manifold with constant curvature are discussed in detail. Several mathematical results, relevant to physical applications are presented, includi

Daniele Guido, Roberto Longo

We prove the equality between the statistics phase and the conformal univalence for a superselection sector with finite index in Conformal Quantum Field Theory on $S^1$. A relevant point is the description of the PCT symmetry and the construction of the global conjugate charge.

Masao Jinzenji

We calculate correlation functions of topological sigma model (A-model) on Calabi-Yau hypersurfaces in $CP^{N-1}$ using torus action method. We also obtain path-integral represention of free energy of the theory coupled to gravity.

Roberto Zucchini

In this paper, a novel method is presented for the study of the dependence of the functional determinant of the Laplace operator associated to a subbundle $F$ of a hermitian holomorphic vector bundle $E$ over a Riemann surface $Σ$ on the hermitian structure $(h,H)$ of $E$. The generalized Weyl anomaly of the effective action is computed and found to be expre

Emilio N. M. Cirillo, Enzo Olivieri

We study metastability and nucleation for the Blume-Capel model: a ferromagnetic nearest neighbour two-dimensional lattice system with spin variables taking values in -1,0,+1. We consider large but finite volume, small fixed magnetic field h and chemical potential &#34;lambda&#34; in the limit of zero temperature; we analyze the first excursion from the meta

Shyamoli Chaudhuri, G. Hockney, Joseph D. Lykken

The existence of maximally supersymmetric solutions to heterotic string theory that are not toroidal compactifications of the ten-dimensional superstring is established. We construct an exact fermionic realization of an N=1 supersymmetric string theory in D=8 with non-simply-laced gauge group Sp(20). Toroidal compactification to six and four dimensions gives

K. Intriligator

We present evidence for new, non-trivial RG fixed points with dual magnetic descriptions in $N=1$ supersymmetric $SP(N_c)$ and $SO(N_c)$ gauge theories. The $SP(N_c)$ case involves matter $X$ in the antisymmetric tensor representation and $N_f$ flavors of quarks $Q$ in the fundamental representation. The $SO(N_c)$ case involves matter $X$ in the symmetric te

Mikhail Alexandrov

All possible action functionals on the space of surfaces in ${\bf R}^4$ that depend only on first and second derivatives of the functions, entering the equation of the surface, and satisfy the condition of invariance with respect to rigid motions are described.

E. J. Chun, Anjan S. Joshipura, A. Yu. Smirnov

We suggest that a singlet fermion $S$ exists beyond the standard see-saw structure. It mixes with light neutrinos via interactions with the right-handed neutrino components, so that $\n_e \to S$ conversion solves the solar neutrino problem. Supersymmetry endowed with R-symmetry is shown to give a natural framework for existence, mass scale and mixing ($\sin^

E. Accomando, M. Iori, M. Mattioli

The supersymmetric left-right models suggest a production of doubly charged Higgs particles. Still there is no evidence for the existence and only some lower limits for their mass are present from the Z decay. Here we investigate the possibility of observing the doubly electronic Higgs decay assuming a M{H--}=50 Gev and M{H--}=100 Gev.The ZEUS detector

F. Hussain, A. N. Ivanov, N. I. Troitskaya

We apply the infinite mass effective theory, when a heavy quark mass tends to infinity, and Chiral perturbation theory at the quark level, based on the extended Nambu -- Jona -- Lasinio model with linear realization of chiral $U(3)\times U(3)$ symmetry, to calculate the form factors of the $D^{\,+}_{\,s}\toϕ~μ^+~ν_{\,μ}$ decay up to the first order in curren

Zhi-zhong Xing

Within the standard electroweak model we carry out an instructive analysis of the effect of $K^{0}-\bar{K}^{0}$ mixing on $CP$ asymmetries in some weak decay modes of $D^{\pm}$ and $\stackrel{(-)}{B}$$^{0}_{d}$ mesons. We point out that a clean signal of $CP$ violation with magnitude of 2Re($ε$) $\approx 3.3\times 10^{-3}$ can manifest in the semileptonic de

Ansgar Denner, Stefan Dittmaier, Georg Weiglein

The application of the background-field method to the electroweak Standard Model is reviewed and further explored. Special emphasis is put on questions of gauge invariance and gauge-parameter (in-)dependence. Owing to the gauge invariance of the background-field effective action, the vertex functions obey simple Ward identities which imply important properti

Yongseok Oh, Byung-Yoon Park

We calculate the magnetic moments of heavy baryons in the Skyrme model in the limit of infinite heavy quark mass. We show that the Skyrme model yields the same limit as the nonrelativistic quark model when heavy vector mesons are treated properly. The essential role of the magnetic moment coupling terms in the electromagnetic interactions of heavy mesons is

A. R. Levi, J. Polonyi

In this article we analyze the vacuum structure of pure SU(2) Yang-Mills using non-perturbative techniques. Monte Carlo simulations are performed for the lattice gauge theory with external sources to obtain the effective potential. Evidence from the lattice gauge theory indicating the presence of the unstable mode in the effective potential is reported.

Adriano di Giacomo

The condensation of monopoles (dual superconductivity) of QCD vacuum is reviewed. Direct evidence is produced that the system, in the confined phase, is a dual superconductor.

Fermilab E665 Collaboration

Nuclear shadowing is observed in the per-nucleon cross-sections of positive muons on carbon, calcium and lead as compared to deuterium. The data were taken by Fermilab experiment E665 using inelastically scattered muons of mean incident momentum 470 GeV/c. Cross-section ratios are presented in the kinematic region 0.0001 < XBj <0.56 and 0.1 < Q**2 < 80 GeVc.

Jacob D. Bekenstein, V. F. Mukhanov

We develop the idea that, in quantum gravity where the horizon fluctuates, a black hole should have a discrete mass spectrum with concomitant line emission. Simple arguments fix the spacing of the lines, which should be broad but unblended. Assuming uniformity of the matrix elements for quantum transitions between near levels, we work out the probabilities f

J. Anandan

The determination of the quantum state of a single system by protective observation is used to justify operationally a formulation of quantum theory on the quantum state space (projective Hilbert space) $\cal P$. Protective observation is extended to a more general quantum theory in which the Schrodinger evolution is generalized so that it preserves the symp

J. A. Marck

It is shown how the use of the Kerr-Schild coordinate system can greatly simplify the formulation of the geodesic equation of the Schwarzschild solution. An application of this formulation to the numerical computation of the aspect of a non-rotating black hole is presented. The generalization to the case of the Kerr solution is presented too.

R. Matveyev

We prove that any two smooth h-cobordant simply-connected 4-manifolds can be obtained by taking two manifolds with boundary, one of which is contractible, and gluing them along the boundary via two different attaching maps.

Muriel Ney-Nifle, Marc Gabay

We study the thermal fluctuations of anisotropic order parameters (OP) in layered superconductors. In particular, for copper oxides and a d-wave OP, we present some experimental consequences of fluctuations in the direction normal to the layers. It is shown that the c-axis penetration depth $λ_c$ can have a &#34;disorder-like&#34; quadratic temperature depen

Umberto Marini Bettolo Marconi, Federico Corberi

We study the time evolution of an N-component model of bicontinuous microemulsions based on a time dependent Ginzburg-Landau equation quenched from an high temperature uncorrelated state to the low temperature phases. The behavior of the dynamical structure factor $\tilde C(k,t)$ is obtained, in each phase, in the framework of the large-$N$ limit with both c

Dong Lai

The recent claim that in a strong magnetic field hydrogenlike gas (e.g., excitons in certain semiconductors, neutron star surface layers) becomes superfluid is refuted. Molecules form by strong covalent bond along the magnetic field axis, which prohibits Bose-Einstein condensation.

Diane J. Litman, Rebecca J. Passonneau

We predict discourse segment boundaries from linguistic features of utterances, using a corpus of spoken narratives as data. We present two methods for developing segmentation algorithms from training data: hand tuning and machine learning. When multiple types of features are used, results approach human performance on an independent test set (both methods),

Bernard Jones

Few, if any, current NLP systems make any significant use of punctuation. Intuitively, a treatment of punctuation seems necessary to the analysis and production of text. Whilst this has been suggested in the fields of discourse structure, it is still unclear whether punctuation can help in the syntactic field. This investigation attempts to answer this quest

B. Srinivas, Aravind Joshi

In this paper we present some novel applications of Explanation-Based Learning (EBL) technique to parsing Lexicalized Tree-Adjoining grammars. The novel aspects are (a) immediate generalization of parses in the training set, (b) generalization over recursive structures and (c) representation of generalized parses as Finite State Transducers. A highly impover

A. Bonasera, V. Latora, A. Rapisarda

We calculate the Lyapunov exponents in a classical molecular dynamics framework. The system is composed of few hundreds particles interacting either through Yukawa (Nuclear) or Slater-Kirkwood (Atomic) forces. The forces are chosen to give an Equation of State that resembles the nuclear and the atomic $^4He$ Equation Of State respectively near the critical p

E. Aurell, G. Boffetta, A. Crisanti, G. Paladin

In chaotic dynamical systems, an infinitesimal perturbation is exponentially amplified at a time-rate given by the inverse of the maximum Lyapunov exponent $λ$. In fully developed turbulence, $λ$ grows as a power of the Reynolds number. This result could seem in contrast with phenomenological arguments suggesting that, as a consequence of `physical&#39; pert

Tsafrir Kolatt

The one-point probability distribution function (pdf) is computed for the $25\hmpc$-smoothed density field of rich clusters of galaxies in the Abell/\aco\ catalogs. The observed pdf is compared to the pdf s drawn similarly from mock catalogs of clusters in cosmological simulations of Gaussian and several non-Gaussian initial conditions. Several statistics al

I. Aretxaga, B. J. Boyle, R. J. Terlevich

Based on an R-band imaging survey of 6 high redshift (z~2) and high luminosity (M<-28mag) QSOs, we report the detection of extensions in two radio-quiet and one radio-loud QSO. The extensions are most likely due to the host galaxies of these QSOs, with luminosities of at least 3-7 per cent of the QSO luminosity. The most likely values for the luminosity of t

Thierry Contini, Emmanuel Davoust, Suzanne Considere

We report the discovery of emission from Wolf-Rayet stars in a giant HII region 4.5 arcsec South of the nucleus of the IRAS barred spiral galaxy Mrk 712. The ratio of WNL to OV stars, estimated from the luminosity of the HeII 4686 line, is 0.2. By comparison with starburst and stellar evolution models, we find that this high value is only compatible with a v

P. T. Zycki, S. Collin-Souffrin, B. Czerny

We discuss a model for the central region of radio-quiet AGN in which coronal accretion is the source of energy for X-ray emission. We start from the Haardt & Maraschi model but supplement it with pressure balance condition, two possibilities of the angular momentum transfer and three models of the disc-corona transition. We employ the alpha-description of v

Stefan Dittmaier, Carsten Grosse-Knetter

We integrate out the Higgs boson in the electroweak standard model at one loop and construct a low-energy effective Lagrangian assuming that the Higgs mass is much larger than the gauge-boson masses. Instead of applying diagrammatical techniques, we integrate out the Higgs boson directly in the path integral, which turns out to be much simpler. By using the