November 1994 arXiv papers — page 7

V. Mull, K. Holinde

A model for the nucleon-antinucleon interaction is presented which is based on meson-baryon dynamics. The elastic part is the $G$-parity transform of the Bonn $NN$ potential. Annihilation into two mesons is described in terms of microscopic baryon-exchange processes including all possible combinations of $π,η,ρ,ω,a_0,f_0,a_1,f_1,a_2,f_2,K,K^*$. The remaining

A. Babichenko

Kink-kink S-matrix for integrable vector perturbed $WD_{n}^{(k)}$ minimal models is constructed from the Boltzmann weights of $A_{2n-1}^{(2)}$ RSOS model and checked in two limit cases $k=1$ and $k\rightarrow \infty$

A. Corral, C. J. Perez, A. Diaz-Guilera, A. Arenas

We introduce two coupled map lattice models with nonconservative interactions and a continuous nonlinear driving. Depending on both the degree of conservation and the convexity of the driving we find different behaviors, ranging from self-organized criticality, in the sense that the distribution of events (avalanches) obeys a power law, to a macroscopic sync

J. Hisano, T. Moroi, K. Tobe, T. Yanagida

In the minimum supersymmetric SU(5) GUT, we derive the upper limit on the mass of the color-triplet Higgs multiplets as $\mhc\leq 2.4\times 10^{16}~\GEV$ (90 \% C.L.) taking all possible corrections into account in a renormalization group analysis. If the above upper limit is compared with a limit on $\mhc$ from the negative search for the proton decay; $\mh

T. Asaka, Ken-ichi Hikasa

We calculate four-fermion decays of a Higgs boson via $WW$ and/or $ZZ$ intermediate states for Higgs masses below $m_W$. We examine models with a doubly-charged Higgs boson $H^{++}$ and show that the four-fermion decay is the dominant mode for a wide range of parameter space. Existing searches for $H^{++}$ in $Z$ decays have not looked for this mode. We also

H. Lu, C. N. Pope

We study the $N=2$ string with a real structure on the $(2,2)$ spacetime, using BRST methods. Several new features emerge. In the diagonal basis, the operator $\exp(λ\int^z J^{\rm tot})$, which is associated with the moduli for the $U(1)$ gauge field on the world-sheet, is local and it relates the physical operators in the NS and R sectors. However, the pict

C. B. Dover, A. Gal, J. M. Richard

We refute a recent claim by Nazaruk that the limits placed on the free--space neutron--antineutron oscillation time $τ_{n\bar n}$ can be improved by many orders of magnitude with respect to the estimate $τ_{n\bar n}>2(T_0/Γ)^{1/2}$, where $T_0$ is a measured limit on the annihilation lifetime of a nucleus and $Γ\sim 100$ MeV is a typical antineutron-nucleus

D. Troltenier, C. Bahri, J. P. Draayer

The pseudo-SU(3) model is extended to explicitly include the spin and proton-neutron degrees of freedom. A general formalism for evaluating matrix elements of one-body and two-body tensor operators within this framework is presented. The pairing interaction, which couples different irreducible representations of SU(3), is expressed in terms of pseudo-space t

Yuri Gurevich, Saharon Shelah

The main result of this paper is a probabilistic construction of finite rigid structures. It yields a finitely axiomatizable class of finite rigid structures where no L^omega_{infty, omega} formula with counting quantifiers defines a linear order.

Yuri Gurevich, Neil Immerman, Saharon Shelah

Gregory McColm conjectured that positive elementary inductions are bounded in a class K of finite structures if every (FO + LFP) formula is equivalent to a first-order formula in K. Here (FO + LFP) is the extension of first-order logic with the least fixed point operator. We disprove the conjecture. Our main results are two model-theoretic constructions, one

Alan H. Mekler, Saharon Shelah, Otmar Spinas

We partially prove a conjecture from [MkSh:366] which says that the spectrum of almost free, essentially free, non-free algebras in a variety is either empty or consists of the class of all successor cardinals.

Wei-ping Li, Zhenbo Qin

We prove an existence result for stable vector bundles with arbitrary rank on an algebraic surface, and determine the birational structure of certain moduli space of stable bundles on a rational ruled surface.

L. H. Ford, N. F. Svaiter

Using the effective potential, we study the one-loop renormalization of a massive self-interacting scalar field at finite temperature in flat manifolds with one or more compactified spatial dimensions. We prove that, owing to the compactification and finite temperature, the renormalized physical parameters of the theory (mass and coupling constant) acquire t

Rajamani Narayanan, Herbert Neuberger

Path integration over Euclidean chiral fermions is replaced by the quantum mechanics of an auxiliary system of non--interacting fermions. Our construction avoids the no--go theorem and faithfully maintains all the known important features of chiral fermions, including the violation of some perturbative conservation laws by gauge field configurations of non--

J. L. Vazquez-Bello

This letter studies the Sp(2) covariant quantisation of gauge theories. The geometrical interpretation of gauge theories in terms of quasi principal fibre bundles $Q(M_S, G_S)$ is reviewed. It is then described the Sp(2) algebra of ordinary Yang-Mills theory. A consistent formulation of covariant lagrangian quantisation for general gauge theories based on Sp

B. Abdesselam, D. Arnaudon, A. Chakrabarti

Representations of $SO(5)_{q}$ can be constructed on bases such that either the Chevalley triplet $(e_{1},\;f_{1},\;h_{1})$ or $(e_{2},\;f_{2},\;h_{2})$ has the standard $SU(2)_{q}$ matrix elements. The other triplet in each cases has a more complicated action. The $q$-deformation of such representations present striking differences. In one case a {\bf non-m

J. Navarro-Salas, M. Navarro, C. F. Talavera

We carry out a parallel study of the covariant phase space and the conservation laws of local symmetries in two-dimensional dilaton gravity. Our analysis is based on the fact that the Lagrangian can be brought to a form that vanishes on-shell giving rise to a well-defined covariant potential for the symplectic current. We explicitly compute the symplectic st

V. A. Tsokur, Yu. M. Zinoviev

In this paper we consider the problem of spontaneous supersymmetry breaking in $N=4$ supergravity interacting with vector multiplets. We start with the ordinary version of such model with the scalar field geometry $SU(1,1)/U(1)\otimes SO(6,m)/SO(6)\otimes SO(m)$. Then we construct a dual version of this theory with the same scalar field geometry, which corre

Edward Witten

Recent developments in the understanding of $N=2$ supersymmetric Yang-Mills theory in four dimensions suggest a new point of view about Donaldson theory of four manifolds: instead of defining four-manifold invariants by counting $SU(2)$ instantons, one can define equivalent four-manifold invariants by counting solutions of a non-linear equation with an abeli

Peter Cho, Mark B. Wise

We investigate the implications of spin symmetry for heavy quarkonia production and decay. We first compare spin symmetry predictions for charmonia and bottomonia radiative transitions with data and find they agree quite well. We next use spin symmetry along with nonrelativistic QCD power counting to determine the leading order alignment of P and D-wave orth

K. Martins, D. Blaschke, E. Quack

A diagrammatic approach to quark exchange processes in meson-meson scattering is applied to the case of inelastic reactions of the type $(Q\barQ)+(q\barq)\rightarrow (Q\barq) + (q\barQ)$, where $Q$ and $q$ refer to heavy and light quarks, respectively. This string-flip process is discussed as a microscopic mechanism for charmonium dissociation (absorption) i

Ulf-G. Meißner

In these lectures, the status of baryon chiral perturbation theory is reviewed. Particular emphasis is put on the two--flavor sector and the physics related to electromagnetic probes. I discuss in some detail the structure of the effective Lagrangian at next--to--leading order, the meaning of low--energy theorems in Compton scattering and pion photoproductio

E. Kh. Akhmedov, A. Lanza, S. T. Petcov

The results of all currently operating solar neutrino experiments are analyzed in the framework of the resonant neutrino spin--flavor precession scenario including the effects of neutrino mixing. Nine different profiles of the solar magnetic field are used in the calculations. It is shown that the available experimental data can be accounted for within the c

Leo Karkkainen, K. Rummukainen

Expansions of the Wilson determinant in lattice QCD with quarks produce gauge action terms which shift the coupling constant of the fundamental representation plaquette action and induce an adjoint representation plaquette action. We study the magnitude of these induced couplings with two flavors of Wilson fermions. We utilize a microcanonical demon method,

R. Sommer

The present status of lattice calculations of $f_D$, $f_B$ and some mass splittings are discussed. When one includes the uncertainties due to discretization errors, the results do not yet have a sufficient precision to be relevant to phenomenological applications. There are, however, good prospects of cutting down the uncertainties by a factor of 2 or more s

B. S. Sathyaprakash

Gravitational waves from inspiralling binaries are expected to be detected using a data analysis technique known as {\it matched filtering.} This technique is applicable whenever the form of the signal is known accurately. Though we know the form of the signal precisely, we will not know {\it a priori} its parameters. Hence it is essential to filter the raw

Janna Levin

A gravity-driven inflation is shown to arise from a simple higher dimensional universe. In vacuum, the shear of $n>1$ contracting dimensions is able to inflate the remaining three spatial dimensions. Said another way, the expansion of the 3-volume is accelerated by the contraction of the $n$-volume. Upon dimensional reduction, the theory is equivalent to a f

N. Deruelle, D. Langlois

We clarify the links between a recently developped long wavelength iteration scheme of Einstein's equations, the Belinski Khalatnikov Lifchitz (BKL) general solution near a singularity and the antinewtonian scheme of Tomita's. We determine the regimes when the long wavelength or antinewtonian scheme is directly applicable and show how it can otherwis

S. Massar

The semi-classical back reaction to black hole evaporation (wherein the renormalized energy momentum tensor is taken as source of Einstein's equations) is analyzed in detail. It is proven that the mass of a Schwarzshild black hole decreases according to Hawking's law $dM/dt = - C/ M^2$ where $C$ is a constant of order one and that the particles are e

Roumen Borissov

In the paper we discuss the process of regularization of the Hamiltonian constraint in the Ashtekar approach to quantizing gravity. We show in detail the calculation of the action of the regulated Hamiltonian constraint on Wilson loops. An important issue considered in the paper is the closure of the constraint algebra. The main result we obtain is that the

Somendra M. Bhattacharjee, Sutapa Mukherji

We show that the amplitude of the finite size correction term for the $n$th moment of the partition function, for randomly interacting directed polymers, diverges (on the high temperature side) as $(n_c - n)^{-r}$, as a critical moment $n_c$ is approached. The exponent $r$ is independent of temperature but does depend on the effective dimensionality. There i

Harold U. Baranger, Pier A. Mello

We investigate the effects of phase-breaking events on electronic transport through ballistic chaotic cavities. We simulate phase-breaking by a fictitious lead connecting the cavity to a phase-randomizing reservoir and introduce a statistical description for the total scattering matrix, including the additional lead. For strong phase-breaking, the average an

Shelly L. Shumway, Andrew S. Clarke, Hannes Jónsson

We simulate the compression of a two-component Lennard-Jones liquid at a variety of constant temperatures using a molecular dynamics algorithm in an isobaric-isothermal ensemble. The viscosity of the liquid increases with pressure, undergoing a broadened transition into a structurally arrested, amorphous state. This transition, like the more familiar one ind

J. F. Babb, A. Dalgarno

The formation of $\mbox{O}_2$ by radiative association and by inverse predissociation of ground state oxygen atoms is studied using quantum-mechanical methods. Cross sections, emission spectra, and rate coefficients are presented and compared with prior experimental and theoretical results. At temperatures below 1000~K radiative association occurs by approac

Piero Olla

A simplified Lagrangean closure for the Navier-Stokes equation is used to study the production of intermittency in the inertial range of three dimensional turbulence. This is done using localized wavepackets following the fluid rather than a standard Fourier basis. In this formulation, the equation for the energy transfer acquires a noise term coming from th

Nicolas Pavloff

We consider two and three-dimensional quantum billiards with discrete symmetries. We derive the first terms of the Weyl expansion for the level density projected onto the irreducible representations of the symmetry group. As an illustration the method is applied to the icosahedral billiard. The paper was published in J. Phys. A /27/ (1994) 4317-4323

Nicholas B. Tufillaro

Solutions in terms of Elliptic Functions are provided for SAM in the integrable case where the mass ration equals three. My last SAM paper (I promise). To appear in The American Journal of Physics.

Ramesh Narayan, Insu Yi

We consider axisymmetric viscous accretion flows where a fraction f of the viscously dissipated energy is advected with the accreting gas as stored entropy and a fraction 1-f is radiated. When f is small (i.e. very little advection), our solutions resemble standard thin disks in many respects except that they have a hot tenuous corona above. In the opposite

M. Tosi

Standard models for the chemical evolution of the Galaxy are reviewed with particular emphasis on the history of the abundance gradients in the disk. The effects on the disk structure and metallicity of gas accretion are discussed, showing that a significant fraction of the current disk mass has been accreted in the last Gyrs and that the chemical abundances

Frits Eulderink, Garrelt Mellema

We present a numerical method to solve the equations of general relativistic hydrodynamics in a given external gravitational field. The method is based on a generalization of Roe's approximate Riemann solver for the non relativistic Euler equations in Cartesian coordinates. The new method is applied to a set of standard test problems for general relativi

I. A. Trifalenkov

Early-type galaxies from CfA catalogue were assotiated with IRAS FSC sources. In given sample IR and optical properties were used to obtain some classification of these objects. The existance of significant classes can be evidence of presence one main type of the dust in each galaxy. Physical interpretation of obtained classes was discussed. The dust mass in

Victor V. Batyrev, Yuri Tschinkel

We investigate the analytic properties of the zeta-function associated with heights on equivariant compactifications of anisotropic tori over number fields. This allows to verify conjectures about the distribution of rational points of bounded height.

C. Ciliberto, A. Lopez, R. Miranda

Let $S_{g}$ be a general prime K3 surface in $P^g$ of genus $g \geq 3$ or a general double cover of $P^2$ ramified along a sextic curve for $g = 2$ and $S = S_{i,g}$ its {\it i}-th Veronese embedding. In this article we compute the corank of the Gaussian map $Φ:\bigwedge^2 H^0(S,O_S(1)) \to H^0(S,Ω_S^1(2))$ for $i \geq 2, g \geq 2$ and $i=1, g \geq 17$. The

Mikhail Voloshin

It is argued that the quark mass difference $m_b-m_c$ can be extracted with a high accuracy from experimental data on ratia of moments of lepton energy spectrum in semileptonic decays of $B$ mesons. Theoretical expressions for the moments are presented, which include perturbative as well as non-perturbative corrections.

Erich Poppitz, Lisa Randall

paper is withdrawn - the model lacks a stable ground state

Lyndon Alvero, Harry Contopanagos

Using a recent calculation of the perturbative hard part for dilepton production that sums large threshold corrections to all orders in perturbative QCD, we compute the corresponding cross sections. The hard part has been evaluated using principal value resummation and contains all singular momentum-dependent corrections. We also include a resummation of lar

J. G. Russo, A. A. Tseytlin

We consider a simple model describing a closed bosonic string in a constant magnetic field. Exact conformal invariance demands also the presence of a non-trivial metric and antisymmetric tensor (induced by the magnetic field). The model is invariant under target space duality in a compact Kaluza-Klein direction introduced to couple the magnetic field. Like o

Abraham Loeb, Daniel J. Eisenstein

Groups and clusters of galaxies hosting a quasar can be found through the detection of Lyman-alpha absorption lines beyond the quasar redshift. The effect occurs whenever the distortion to the redshift distribution of Lyman-alpha clouds induced by the cluster potential extends beyond the proximity effect of the quasar. Based on CDM cosmological models for th

York-Peng Yao

We perform a $1/m_b$ and $1/m_t$ expansion of the Cabibbo-Kobayashi- Maskawa mixing matrix. Data suggest that the dominant parts of the Yukawa couplings are factorizable into sets of numbers $\vert r>$, $\vert s>$, and $\vert s'>$, associated, respectively, with the left-handed doublets, the right-handed up singlets, and the right- handed down singlets.

Carlos O. Lousto

We study first order fluctuations of a relativistic membrane in the curved background of a black hole. The zeroth-order solution corresponds to a spherical membrane tightly covering the event horizon. We obtain a massive Klein-Gordon equation for the fluctuations of the membrane's radial coordinate on the 2+1 dimensional world-volume. We finally suggest

G. Albertini, V. E. Korepin, A. Schadschneider

We consider the limit of strong Coulomb attraction for generalized Hubbard models with $η$-symmetry. In this limit these models are equivalent to the ferromagnetic spin-1/2 Heisenberg quantum spin chain. In order to study the behaviour of the superconducting phase in the electronic model under perturbations which break the $η$-symmetry we investigate the gro

E. J. Chun

The generalized Higgs mass term $NH_1H_2$ of the supersymmetric standard model is used to implement the Peccei-Quinn Symmetry to solve the strong-CP problem. Then supersymmetry breaking can generate the Higgs mass parameter $μ$ of order $m_{3/2}$ through soft-breaking parameters. This kind of extension contains extra light fields of the axion supermultiplet

Jeffrey A. Harvey

I discuss some current thoughts on how low-energy measurements and consistency constrain theories at high energies with emphasis on string theory. I also discuss some recent work on the dynamics of supersymmetric gauge theories.

J. Bernabéu, G. A. González-Sprinberg, M. Tung, J. Vidal

We calculate the prediction for the anomalous weak-magnetic form factor of the tau lepton at $q^2=M_Z^2$ within the Standard Model. With all particles on-shell, this is a electroweak gauge invariant quantity. Its value is $a_τ^w (M_Z^2)= - \;(2.10 + 0.61\, i) \times 10^{-6}$. We show that the transverse and normal components of the single-tau polarization of

Gabriel Lopes Cardoso, Dieter Lüst

In this letter we discuss the relation of four-dimensional, $N=2$ supersymmetric string backgrounds to integrable models. In particular we show that non-Kählerian gravitational backgrounds with one $U(1)$ isometry plus non-trivial antisymmetric tensor and dilaton fields arise as the solutions of the Liouville equation or, for the case of vanishing central ch

H. C. Rosu

I present an elementary essay on some issues related to nonrelativistic quantum mechanics, which is written in the spirit of extreme simplicity, making it an easy-to-read paper. Moreover, one can find a useful collection of ideas and opinions expressed by many well-known authors in this vast research field

V. Matveev, R. Shrock

We investigate complex-temperature singularities in the Ising model on the triangular lattice. Extending an earlier analysis of the low-temperature series expansions for the (zero-field) susceptibility $\barχ$ by Guttmann \cite{g75} to include the use of differential approximants, we obtain further evidence in support of his conclusion that the exponent desc

S. Flach

We consider time-periodic nonlinear localized excitations (NLEs) on one-dimensional translationally invariant Hamiltonian lattices with arbitrary finite interaction range and arbitrary finite number of degrees of freedom per unit cell. We analyse a mapping of the Fourier coefficients of the NLE solution. NLEs correspond to homoclinic points in the phase spac

Wolfgang Bauer, William Friedman

We show that the critical exponents of nuclear multi-fragmentation have not been determined conclusively yet.

Jorge G. Hirsch, O. Castaños, P. O. Hess, Osvaldo Civitarese

The double beta decay of $^{100}Mo$ to the ground state and excited states of $^{100}Ru$ is analysed in the context of the pseudo SU(3) scheme. The results of this deformed limit are compared with the vibrational one based on the QRPA formalism. Consistency between the deformed limit and the experimental information is found for various $ββ$ transitions, alt

Markus Hofmann, Raffaele Mattiello, Heinz Sorge, Horst Stoecker

We predict the formation of highly dense baryon-rich resonance matter in Au+Au collisions at AGS energies. The final pion yields show observable signs for resonance matter. The Delta(1232) resonance is predicted to be the dominant source for pions of small transverse momenta. Rescattering effects -- consecutive excitation and deexcitation of Deltas -- lead t

B. Kohler, P. Ruggerone, S. Wilke, M. Scheffler

Using helium atom scattering Hulpke and L"udecke recently observed a giant phonon anomaly for the hydrogen covered W(110) and Mo(110) surfaces. An explanation which is able to account for this and other experiments is still lacking. Below we present density-functional theory calculations of the atomic and electronic structure of the clean and hydrogen-co

A. A. Migdal

Treating the QCD Wilson loop as amplitude for the propagation of the first quantized particle we develop the second quantization of the same propagation. The operator of the particle position $\hat{\cal X}_μ$ (the endpoint of the "open string") is introduced as a limit of the large $N$ Hermitean matrix. We then derive the set of equations for the exp

Nguyen Anh Ky, N. Stoilova

The construction approach proposed in the previous paper Ref. 1 allows us there and in the present paper to construct at generic deformation parameter $q$ all finite--dimensional representations of the quantum Lie superalgebra $U_{q}[gl(2/2)]$. The finite--dimensional $U_{q}[gl(2/2)]$-modules $W^{q}$ constructed in Ref. 1 are either irreducible or indecompos

V. A. Tsokur, Yu. M. Zinoviev

In this paper we investigate the problem of spontaneous supersymmetry breaking without a cosmological term in $N=3$ supergravity with matter vector multiplets, scalar fields geometry being $SU(3,m)/SU(3)\otimes SU(m)\otimes U(1)$. At first, we consider the case of minimal coupling with different possible gaugings (compact as well as non-compact). Then we sho

Hermann Hessling

A physical system is in local equilibrium if it cannot be distinguished from a global equilibrium by ``infinitesimally localized measurements''. This should be a natural characterization of local equilibrium, but the problem is to give a precise meaning to the qualitative phrase ``infinitesimally localized measurements''. A solution is sugges

E. Bergshoeff, M. Vasiliev

We construct new realizations of the Virasoro algebra inspired by the Calogero model. The Virasoro algebra we find acts as a kind of spectrum-generating algebra of the Calogero model. We furthermore present the superextension of these results and introduce a class of higher-spin extensions of the Virasoro algebra which are of the $W_\infty$ - type.

S. Y. Choi, J. S. Shim, H. S. Song

We investigate all the four-body graviton interaction processes: $gX\rightarrow γX$, $gX\rightarrow gX$, and $gg\rightarrow gg$ with $X$ as an elementary particle of spin less than two in the context of linearized gravity except the spin-3/2 case. We show explicitly that gravitational gauge invariance and Lorentz invariance cause every four-body graviton sca

S. James Gates,, Lubna Rana

Utilizing (4,0) superfields, we discuss aspects of supersymmetric sigma models and the ADHM construction of instantons a' la Witten.

M. Yu. Kuchiev

Gravity can arise in a conventional non-Abelian gauge theory in which a specific phenomenon takes place. Suppose there is a condensation of polarized instantons and antiinstantons in the vacuum state. Then the excitations of the gauge field in the classical approximation are described through the variables of Riemann geometry satisfying the Einstein equation

Suzhou Huang, Marcello Lissia

We introduce the running coupling constant of QCD in the high temperature phase, $\tilde{g}^2(T)$, through a renormalization scheme where the dimensional reduction is optimal at the one-loop level. We then calculate the relevant scale parameter, $Λ_T$, which characterizes the running of $\tilde{g}^2(T)$ with $T$, using the background field method in the stat

A. Deandrea

The BESS model consists of an effective lagrangian parametrization with dynamical symmetry breaking, describing scalar, vector and axial-vector bound states in a rather general framework. After a brief description of the model and its generalizations, predictions for physics at future accelerators are given both for LHC and e+e- machines. Contribution to the

F. J. Botella, Joao P. Silva

Within the framework of theories where both scalars and fermions are present, we develop a systematic prescription for the construction of CP-violating quantities that are invariant under basis transformations of those matter fields. In theories with Spontaneous Symmetry Breaking, the analysis involves the vevs' transformation properties under a scalar b

V. Bernard, N. Kaiser, Ulf-G. Meißner

We investigate threshold pion photoproduction in the framework of heavy baryon chiral perturbation theory. We give the expansion of the electric dipole amplitude $E_{0+}$ to three orders in $μ$, the ratio of the pion to nucleon mass, and show that it is slowly converging. We argue that this observable is not a good testing ground for the chiral dynamics of Q

F. Buccella, M. Lusignoli, G. Miele, A. Pugliese

A previous analysis of two-body Cabibbo allowed nonleptonic decays of $D^0$ mesons and of Cabibbo allowed and first-forbidden decays of $D^+$ and $D_s^+$ has been adjourned using more recent experimental data and extended to the Cabibbo forbidden decays of $D^0$. Annihilation and W-exchange contributions as well as final state interaction effects (assumed to

Johan Bijnens, Joaquim Prades, Eduardo de Rafael

We study the value of the light quark masses combination $m_u+m_d$ in QCD using both Finite Energy Sum Rules and Laplace Sum Rules. We have performed a detailed analysis of both the perturbative QCD and the hadronic parametrization inputs needed in these Sum Rules. As main result, we obtain $m_u\left(1~{\rm GeV}^2\right) + m_d \left(1~{\rm GeV}^2\right) = \l

Pierre Chiappetta

The idea of a strongly interacting sector as responsible for the electroweak symmetry breaking is tested through an effective lagrangian description, called the BESS model, constructed on the standing point of custodial symmetry and gauge invariance, without specifing any dynamical scheme.

Arjun Berera

A model example is given of how properties of the hadronic light-cone wave function are revealed in a particular high energy process. The meson wave function is derived in scalar quark QCD. We apply it to compute the form of the cross section for lossless diffractive jet-production, an upcoming possiblity at HERA.

Dmitri V. Vassilevich

Some recent results show that the covariant path integral and the integral over physical degrees of freedom give contradicting results on curved background and on manifolds with boundaries. This looks like a conflict between unitarity and covariance. We argue that this effect is due to the use of non-covariant measure on the space of physical degrees of free

J. R. L. de Almeida, S. Coutinho

In this work a short overview of the development of spin glass theories, mainly long and short range Ising models, are presented.

J. Bellissard, A. van Elst, H. Schulz-Baldes

We give an overview of the Integer Quantum Hall Effect. We propose a mathematical framework using Non-Commutative Geometry as defined by A. Connes. Within this framework, it is proved that the Hall conductivity is quantized and that plateaux occur when the Fermi energy varies in a region of localized states.

Gerrit Rentier

Unbounded dependencies are often modelled by ``traces'' (and ``gap threading'') in unification-based grammars. Pollard and Sag, however, suggest an analysis of extraction based on lexical rules, which excludes the notion of traces (P&S 1994, Chapter 9). In parsing, it suggests a trade of indeterminism for lexical ambiguity. This paper provide

James K. Wiggs, Hannes Jonsson

We have developed a flexible hybrid decomposition parallel implementation of the first-principles molecular dynamics algorithm of Car and Parrinello. The code allows the problem to be decomposed either spatially, over the electronic orbitals, or any combination of the two. Performance statistics for 32, 64, 128 and 512 Si atom runs on the Touchstone Delta an

J. Bricmont, A. Kupiainen

In this review paper, we explain how to apply Renormalization Group ideas to the analysis of the long-time asymptotics of solutions of partial differential equations. We illustrate the method on several examples of nonlinear parabolic equations. We discuss many applications, including the stability of profiles and fronts in the Ginzburg-Landau equation, anom

Z. MEI, A. J. ROBERTS

Long waves in rivers, estuaries and floods are described by the St Venant and Boussinesq equations in classical fluid dynamics. Based on the widely used $k$-$ε$ model for turbulence, we use the techniques of centre manifold theory to show how these classical models can be derived from a unified approach to low-dimensional modelling. The model may be refined

Sang-Yoon Kim

We numerically reexamine the scaling behavior of period doublings in four-dimensional volume-preserving maps in order to resolve a discrepancy between numerical results on scaling of the coupling parameter and the approximate renormalization results reported by Mao and Greene [Phys. Rev. A {\bf 35}, 3911 (1987)]. In order to see the fine structure of period

P. D. Morley, Ivan Schmidt

A platelet collapse model of starquakes is introduced. It displays self-organized criticality with a robust power-law behavior. The simulations indicate a near-constant exponent, whenever scaling is present.

Jeremiah P. Ostriker, Lori M. Lubin, Lars Hernquist

If the large-scale galaxy distribution is filamentary, as suggested by some observations and recent hydrodynamical simulations, then lengthwise views of filaments will apparently produce compact groups (CGs) that are in reality stretched out along the line of sight. This possibility has been advocated recently by Hernquist, Katz \& Weinberg (1994). Here, we

J. P. Beaulieu, R. Ferlet, Ph. Grison, A. Vidal-Madjar

Low resolution spectroscopy, and UBVRI photometry, have been obtained for the two EROS microlensing candidates. Radial velocities indicate that both stars are members of the Large Magellanic Cloud. The spectrum and the colours of EROS1, the first candidate, reveal that it is a moderately reddened main-sequence B star with H emission lines. The presence of H

C. Borgs, J. T. Chayes

We consider the covariance matrix $G^{mn}(x-y)$ of the d-dimensional q-states Potts model, rewriting it in terms of the connectivity, the finite-cluster connectivity and the infinite-cluster covariance in the random cluster repre- sentation of Fortuin and Kasteleyn. In any of the $q$ ordered phases, we show that the matrix $G^{mn}(x-y)$ has one tivial eigenv

M. Martellini, A. Sagnotti, M. Zeni

In Yang-Mills theory massless point sources lead naturally to shock-wave configurations. Their magnetic counterparts endow the vacuum of the four-dimensional compact abelian model with a Coulomb-gas behaviour whose physical implications are briefly discussed. (Contribution to ``Quark Confinement and the Hadron Spectrum'', Como 20-24 June 1994. Revise

S. A. Gurvitz, A. S. Rinat

The response of a nucleus composed of nucleons and confined quarks is calculated in a non-relativistic cluster model and is shown to be a convolution of responses of, respectively, a nucleus with interacting point-nucleons and of a nucleon composed of quarks. We further show that the apparent off-shell energy in the expression for the nucleon structure funct

G. Sardanashvily

The fibre bundle formulation of gauge theory is generally accepted. The jet manifold machinery completes this formulation and provides the adequate mathematical description of dynamics of fields represented by sections of fibre bundles. Theory of differential operators, Lagrangian and Hamiltonian formalisms on bundles have utilized widely the language of jet

Andrzej Czarnecki, Marek Jezabek, Johann H. Kuhn

Analytical calculation is presented of the QCD radiative corrections to the rate of the process $b\to cτ\barν_τ$ and to the $τ$ lepton longitudinal polarization in $τ\barν_τ$ rest frame. The results are given in the form of one dimensional infrared finite integrals over the invariant mass of the leptons. We argue that this form may be optimal for phenomelogi

Neil J. Cornish, Janna J. Levin

Recently, it has been claimed that the back reaction of vacuum polarization on a black hole spacetime naturally regularizes infinities in the black hole entropy. We examine the back reaction calculation and find no such short-distance cut-off,in contradiction with these recent claims. Moreover, the intuitive expectation that the perturbative calculation brea

Nikos Berdenis, Ganpathy Murthy

A numerical renormalization group technique recently developed by one of us is used to analyse the Coulomb pseudopotential (${μ^*}$) in ${{\rm C}_{60}}$ for a variety of bare potentials. We find a large reduction in ${μ^*}$ due to intraball screening alone, leading to an interesting non-monotonic dependence of ${μ^*}$ on the bare interaction strength. We fin

L. Stella, E. Arlandi, G. Tagliaferri, G. L. Israel

This paper summarises two recently developed techniques in power spectral analysis and their application to a sample of X-ray light curves of accreting collapsed objects in active galactic nuclei and X-ray binaries. The first technique is designed to carry out detailed model fitting of continuum power spectrum components arising from noise variability by usi

D. Nanopoulos

The different steps that led us to the discovery of {\em no-scale supergravity} are discussed from a very personal point of view. No-scale supergravity has been heralded as the most promising effective theory that describes physics below the Planck scale. In its string-derived form it holds the potential for a Dynamical Determination Of Everything (DDOE). (I

Nicholas B. Tufillaro

Template and prunning front are calculated for an experimental chaotic time series from a mechanical string experiment. An empirical synchronized model is also created for the data set. To appear in Physical Review E.

Nicholas B. Tufillaro

To appear in Physical Review E. Contains some analysis of experimental (mechanical) string data.