April 1995 arXiv papers — page 9

C. Lu, D. Marlow, C. Mindas, E. Prebys

The DIRC (Detection of Internally Reflected Cerenkov light) is a new type of ring imaging Cerenkov detector, which detects images from Cerenkov light produced in precisely machined quartz bars. The Cerenkov images are transported along several meters of bar to the edge of the detector where they are proximity focussed unto an array of conventional photomulti

Dieter Maison

The aim of the present letter is to explain the `critical behaviour' observed in numerical studies of spherically symmetric gravitational collaps of a perfect fluid. A simple expression results for the critical index $γ$ of the black hole mass considered as an order parameter. $γ$ turns out to vary strongly with the parameter $k$ of the assumed equation

G. Esposito, A. Yu. Kamenshchik, I. V. Mishakov, G. Pollifrone

This paper studies the quantization of the electromagnetic field on a flat Euclidean background with boundaries. One-loop scaling factors are evaluated for the one-boundary and two-boundary backgrounds. The mode-by-mode analysis of Faddeev-Popov quantum amplitudes is performed by using zeta-function regularization, and is compared with the space-time covaria

Guillermo A. Mena Marugan

We carry out the canonical quantization of the Levi-Cività family of static and cylindrical solutions. The reduced phase space of this family of metrics is proved to coincide with that corresponding to the Kasner model, including the associated symplectic structures, except for that the respective domains of definition of one of the phase space variables are

S. Q. Shen, X. C. Xie

In this paper, we discuss physical consequences of pseudospin SU(2) symmetry breaking in the negative-U Hubbard model at half-filling. If pseudospin symmetry is spontaneously broken while its unique subgroup U(1) remains invariant, it will lead to the charge density wave (CDW) ground state. Furthermore, if the U(1) symmetry is also broken, the ground state w

G. Uhrig, D. Vollhardt

The Drude weight $D$ and the dc-conductivity $σ_{dc} (T)$ of strongly correlated electrons are investigated theoretically. Analytic results are derived for the homogeneous phase of the Hubbard model in $d = \infty$ dimensions, and for spinless fermions in this limit with $1/d$-corrections systematically included to lowest order. It is found that $σ_{dc}(T)$

Juan J. Mazo, Fernando Falo, Luis M. Floría

This paper considers a Josephson Junction array with the geometry of a ladder and anisotropy in the Josephson couplings. The ground state problem for the ladder corresponds to the one for the one-dimensional chiral XY model in a two-fold anisotropy field, which allows of a rigorous characterization of the ground state phase diagram and the relevant elementar

S. Hikami, A. Zee

We study the one-point and two-point Green's functions in a complex random matrix model to sub-leading orders in the large N limit. We take this complex matrix models as a model for the two-state scattering problem, as applied to spin dependent scattering of impurities in quantum Hall fluids. The density of state shows a singularity at the band center du

Marilyn Walker, Steve Whittaker

Conversation between two people is usually of mixed-initiative, with control over the conversation being transferred from one person to another. We apply a set of rules for the transfer of control to 4 sets of dialogues consisting of a total of 1862 turns. The application of the control rules lets us derive domain-independent discourse structures. The derive

Steve Whittaker, Phil Stenton

We conducted an empirical analysis into the relation between control and discourse structure. We applied control criteria to four dialogues and identified 3 levels of discourse structure. We investigated the mechanism for changing control between these structures and found that utterance type and not cue words predicted shifts of control. Participants used c

Philippe Blache, Nabil Hathout

This paper proposes an evaluation of the adequacy of the constraint logic programming paradigm for natural language processing. Theoretical aspects of this question have been discussed in several works. We adopt here a pragmatic point of view and our argumentation relies on concrete solutions. Using actual contraints (in the CLP sense) is neither easy nor di

Mario Salerno

A general method to construct basis functions for fermionic systems which account for the $SU(2)$ symmetry and for the translational invariance of the Hamiltonian is presented. The method does not depend on the dimensionality of the system and it appears as a natural generalization of the Bethe Ansatz to the case of non integrable systems. As an example we p

R. A. Malaney, G. D. Starkman, L. Widrow

We investigate a new hybrid-model universe containing two types of dark matter, one ``warm'' and the other ``hot''. The hot component is an ordinary light neutrino with mass $\sim 25h^2$~eV while the warm component is a sterile neutrino with mass $\sim 700h^2$~eV. The two types of dark matter arise entirely within the neutrino sector and do n

L. Pietronero, F. Sylos Labini

The basic hypothesis of a post-Copernican Cosmological theory is that {\em all the points} of the Universe have to be essentially equivalent: this hypothesis is required in order to avoid any privileged {\em observer}. This assumption has been implemented by Einstein in the so-called Cosmological Principles (CP): {\em all the positions} in the Universe have

F. Sylos Labini, L. Pietronero

Two main features of the observable distribution of visible matter are the space correlations of galaxy positions and the mass function of galaxies. As discussed in Pietronero and Sylos Labini on this issue ([1], see also [2],[3]), the concept of multifractal (MF) distribution (including the masses) naturally unifies these two properties. Hence with the know

Paul Goudfrooij, Teije de Jong

The presence of dust in elliptical galaxies has recently been shown to be quite common. Deep optical multi-colour CCD imaging has revealed the presence of dust lanes and patches, and the technique of co-adding IRAS survey scans has led to many detections of elliptical galaxies. The optical and far-infrared surveys reported similar detection rates of dust, wh

Dongsu Ryu, Garry L. Brown, Jeremiah P. Ostriker, Abraham Loeb

The properties of axisymmetric accretion flows of cold adiabatic gas with zero total energy in the vicinity of a Newtonian point mass are characterized by a single dimensionless parameter, the thickness of incoming flow. In the limit of thin accretion flows with vanishing thickness, we show that the governing equations become self-similar, involving no free

M. G. Olsson, S. Veseli, K. Williams

We adapt a general method to solve both the full and reduced Salpeter equations and systematically explore the conditions under which these two equations give equivalent results in meson dynamics. The effects of constituent mass, angular momentum state, type of interaction, and the nature of confinement are all considered in an effort to clearly delineate th

Xavier Artru, John Collins

The azimuthal distribution of pairs of particles in a jet is sensitive to the transverse polarization of the quark initiating the jet, but with a sensitivity that involves a nonperturbative analyzing power. We show in detail how to measure the analyzing power from 4-hadron correlations in $e^+ e^- \to 2 \ {\rm jets}$. We explain the combinations of particle

G. Moretto, G. R. LemaitreT. Bactivelane, M. Wang, M. Ferrari

We investigate the aspherization of an active mirror for correcting third and fifth-order aberrations. We use a stainless steel AISI 420 mirror with a controlled pressure load, two series of 12-punctual radial positions of force application distributed symmetrically in two concentric rings around the mirror. We obtain the wavefronts for Cv1, Sph3, Coma3, Ast

Hoi-Kwong Lo

We prove a theorem for coding mixed-state quantum signals. For a class of coding schemes, the von Neumann entropy $S$ of the density operator describing an ensemble of mixed quantum signal states is shown to be equal to the number of spin-$1/2$ systems necessary to represent the signal faithfully. This generalizes previous works on coding pure quantum signal

Ted Jacobson

The Einstein equation is derived from the proportionality of entropy and horizon area together with the fundamental relation $δQ=TdS$ connecting heat, entropy, and temperature. The key idea is to demand that this relation hold for all the local Rindler causal horizons through each spacetime point, with $δQ$ and $T$ interpreted as the energy flux and Unruh te

Gabriele Ferretti

The large N limit of the hermitian matrix model in three and four Euclidean space-time dimensions is studied with the help of the approximate Renormalization Group recursion formula. The planar graphs contributing to wave function, mass and coupling constant renormalization are identified and summed in this approximation. In four dimensions the model fails t

Alan R. Steif

We show how the supersymmetric properties of three dimensional black holes can be obtained algebraically. The black hole solutions are constructed as quotients of the supergroup $OSp(1|\,2;R)$ by a discrete subgroup of its isometry supergroup. The generators of the action of the isometry supergroup which commute with these identifications are found. These yi

Robin G. Stuart

The top-quark, $W$ and $Z^0$ bosons have widths that are a sizable fraction of their masses and will be produced copiously at upcoming accelerators. Yet S-matrix theory cannot treat unstable particles as external states. Dealing with complete matrix elements involving their decay products complicates calculations considerably and is unnecessary in many pract

Tetsuyuki Ochiai

We analyze multi-instanton sector in two dimensional U(N) Yang-Mills theory on a sphere. We obtain a contour intregrals representation of the multi-instanton amplitude and find ``neutral'' configurations of the even number instantons are dominant in the large N limit. Using this representation, we calculate 1,2,3,4 bodies interactions and the free en

Andrey V. Chubukov

We consider a two-dimensional Fermi liquid in the vicinity of a spin-density-wave transition to a phase with commensurate antiferromagnetic long-range order. We assume that near the transition, the Fermi surface is large and crosses the magnetic Brillouin zone boundary. We show that under these conditions, the self-energy corrections to the dynamical spin su

E. K. Sklyanin

The review is based on the author's papers since 1985 in which a new approach to the separation of variables (\SoV) has being developed. It is argued that \SoV, understood generally enough, could be the most universal tool to solve integrable models of the classical and quantum mechanics. It is shown that the standard construction of the action-angle var

Henry P. Stapp

Norbert Wiener and J.B.S. Haldane suggested during the early thirties that the profound changes in our conception of matter entailed by quantum theory opens the way for our thoughts, and other experiential or mind-like qualities, to play a role in nature that is causally interactive and effective, rather than purely epiphenomenal, as required by classical me

Richard J. Hughes, D. M. Alde, P. Dyer, G. G. Luther

Quantum cryptography is a new method for secret communications offering the ultimate security assurance of the inviolability of a Law of Nature. In this paper we shall describe the theory of quantum cryptography, its potential relevance and the development of a prototype system at Los Alamos, which utilises the phenomenon of single-photon interference to per

Dmitri V. Vassilevich

In the example of $R^2+T^2$ gravity on the unit two dimensional disk we demonstrate that in the presence of an independent spin connection it is possible to define local gauge invariant boundary conditions even on boundaries which are not totally geodesic. One-loop partition function and the corresponding heat kernel are calculated.

J. M. F. Labastida, M. Mariño

We present a non-abelian generalization of Witten monopole equations and we analyze the associated moduli problem, which can be regarded as a generalization of Donaldson theory. The moduli space of solutions for SU(2) monopoles on Kähler manifolds is discussed. We also construct, using the Mathai-Quillen formalism, the topological quantum field theory corres

J. E. Paschalis, P. I. Porfyriadis

The two-flavor Wess-Zumino model coupled to electromagnetism is treated as a constraint system using the Faddeev-Jackiw method. Expanding into series of powers of the pion fields and keeping terms up to second and third order we obtain Coulomb- gauge Lagrangeans containing non-local terms.

M. R-Monteiro, I. Roditi, L. M. C. S. Rodrigues, S. Sciuto

We study the relationship among the XXZ Heisenberg model and three models obtained from it by various transformations. In particular, we emphasize the role of a non trivial central element $t^Z$ in the underlying algebra and its relationship with the twisted boundary conditions, $S^{\pm}_{N+1}=t^{\pm N}S^{\pm}_1$.

A. L. Larsen, N. Sánchez

Recent results on classical and quantum strings in a variety of black hole and cosmological spacetimes, in various dimensions, are presented. The curved backgrounds under consideration include the $2+1$ black hole anti de Sitter spacetime and its dual, the black string, the ordinary $D\geq 4$ black holes with or without a cosmological constant, the de Sitter

Bernard de Wit, Vadim Kaplunovsky, Jan Louis, Dieter Luest

We study the low-energy effective Lagrangian of $N=2$ heterotic string vacua at the classical and quantum level. The couplings of the vector multiplets are uniquely determined at the tree level, while the loop corrections are severely constrained by the exact discrete symmetries of the string vacuum. We evaluate the general transformation law of the perturba

R. B. Zhang, B. L. Wang, A. L. Carey, J. McCarthy

A topological quantum field theory is introduced which reproduces the Seiberg-Witten invariants of four-manifolds. Dimensional reduction of this topological field theory leads to a new one in three dimensions. Its partition function yields a three-manifold invariant, which can be regarded as the Seiberg-Witten version of Casson's invariant. A Geometrical

F. del Aguila, M. Zrałek

We study CP violation in the lepton sector in extended models with right-handed neutrinos, without and with left-right symmetry, and with arbitrary mass terms. We find the conditions which must be satisfied by the neutrino and charged lepton mass matrices for CP conservation. These constraints, which are independent of the choice of weak basis, are proven to

Yu. L. Dokshitzer, B. R. Webber

We compute power corrections to hadronic event shapes in $e^+e^-$ annihilation, assuming an infrared regular behaviour of the effective coupling $α_s$. With the integral of $α_s$ over the infrared region as the only non-perturbative parameter, also measured in heavy quark physics, we can account for the empirical features of $1/Q$ corrections to the mean val

Kuninori Horikawa, Ken Sasaki

We examine the magnetic field dependence of the muonium($μ^+ e^-$) - antimuonium($μ^- e^+$) conversion in the models which accommodate the dilepton gauge bosons. The effective Hamiltonian for the conversion due to dileptons turns out to be in the $(V-A)\times(V+A)$ form and, in consequence, the conversion probability is rather insensitive to the strength of

G. Martinelli, M. Neubert, C. T. Sachrajda

We study the structure of renormalons in the Heavy Quark Effective Theory, by expanding the heavy quark propagator in powers of $1/m_Q$. We demonstrate that the way in which renormalons appear depends on the regularisation scheme used to define the effective theory. In order to investigate the relation between ultraviolet renormalons and power divergences of

M. Cvetic, S. Godfrey

The discovery potential and diagnostic abilities of proposed future colliders for new heavy neutral ($Z'$) and charged ($W'$) gauge bosons are summarized. Typical bounds achievable on $M_{Z',W'}$ at the TEVATRON, DI-TEVATRON, LHC, 500 GeV NLC, and 1 TeV NLC are $\sim$1~TeV, $\sim$2~TeV, $\sim$4~TeV, 1--3~TeV, and 2--6~TeV, respectively. For $

P. Levai, X. N. Wang

Strangeness production was investigated during the equilibration of a gluon dominated parton plasma produced at RHIC and LHC energies. The time evolution of parton densities are followed by a set of rate equations in a 1-dimensional expanding system. The strangeness production will depend on the initial chemical equilibration level and in our case the parton

Hanqing Zheng

Using a four fermion interaction Lagrangian, we demonstrate that the spontaneous breaking of vector symmetries requires the existence of a light (comparing with the heavy fermion mass) scalar particle and the low energy effective theory (the $σ$ model) obtained after integrating out heavy fermion degrees of freedom is asymptotically a renormalizable one. Whe

Danny Birmingham

We study the ground state wave function for a universe which is topologically a lens space within the Regge calculus approach. By restricting the four dimensional simplicial complex to be a cone over the boundary lens space, described by a single internal edge length, and a single boundary edge length, one can analyze in detail the analytic properties of the

S. Alexander Ridgway, Erick J. Weinberg

The static black hole solutions to the Einstein-Maxwell equations are all spherically symmetric, as are many of the recently discovered black hole solutions in theories of gravity coupled to other forms of matter. However, counterexamples demonstrating that static black holes need not be spherically symmetric exist in theories, such as the standard electrowe

Bai-Ling Wang

A systematic description of the Wess-Zumino-Witten model is presented. The symplectic method plays the major role in this paper and also gives the relationship between the WZW model and the Chern-Simons model. The quantum theory is obtained to give the projective representation of the Loop group. The Gauss constraints for the connection whose curvature is on

R. Eder, Y. Ohta, S. Maekawa

We present an exact diagonalization study of bilayer clusters of t-J model. Our results indicate a crossover between two markedly different regimes which occurs when the ratio J_perp/J between inter-layer and intra-layer exchange constants increases: for small J_perp/J the data suggest the development of 3D antiferromagnetic correlations without appreciable

Fernando Jiménez, Germán Sierra

Fokker-Planck equations have been applied in the past to field theory topics such as the stochastic quantization and the stabilization of bottomless action theories. In this paper we give another application of the FP-techniques in a way appropriate to the study of the ground state, the excited states and the critical behaviour of quantum lattice Hamiltonian

M. Fabrizio, Alexander O. Gogolin

We discuss the properties of interacting electrons on a finite chain with open boundary conditions. We extend the Haldane Luttinger liquid description to these systems and study how the presence of the boundaries modifies various correlation functions. In view of possible experimental applications to quantum wires, we analyse how tunneling measurements can r

D. Z. Liu, X. C. Xie, Q. Niu

We study the localization properties in the transition from a two-dimensional electron gas at zero magnetic field into an integer quantum Hall (QH) liquid. By carrying out a direct calculation of the localization length for a finite size sample using a transfer matrix technique, we systematically investigate the field and disorder dependences of the metal-in

L. B. Ioffe, A. J. Millis

We argue that strongly correlated two dimensional electrons form a spin liquid in some regimes of density and temperature and give the theory of the magnetic properties of this spin liquid using the representation in terms of femions interacting with a gauge field. This state is characterized by anomalous power law spin correlations and discuss the implicati

Walt Detmar Meurers, Guido Minnen

We describe a compiler which translates a set of HPSG lexical rules and their interaction into definite relations used to constrain lexical entries. The compiler ensures automatic transfer of properties unchanged by a lexical rule. Thus an operational semantics for the full lexical rule mechanism as used in HPSG linguistics is provided. Program transformatio

Peter A. Heeman, Graeme Hirst

This paper presents a computational model of how conversational participants collaborate in order to make a referring action successful. The model is based on the view of language as goal-directed behavior. We propose that the content of a referring expression can be accounted for by the planning paradigm. Not only does this approach allow the processes of b

Thorsten Pöschel, Werner Ebeling, Helge Rosé

We propose a new method for the calculation of the statistical properties, as e.g. the entropy, of unknown generators of symbolic sequences. The probability distribution $p(k)$ of the elements $k$ of a population can be approximated by the frequencies $f(k)$ of a sample provided the sample is long enough so that each element $k$ occurs many times. Our method

Charles A. Meegan, Dieter H. Hartmann, J. J. Brainerd, Michael S. Briggs

The demonstration of repeated gamma-ray bursts from an individual source would severely constrain burst source models. Recent reports (Quashnock and Lamb 1993; Wang and Lingenfelter 1993) of evidence for repetition in the first BATSE burst catalog have generated renewed interest in this issue. Here, we analyze the angular distribution of 585 bursts of the se

Eli Waxman, Jordi Miralda-Escudé

Observations of gravitational lensing indicate that the mass distribution in clusters of galaxies (where most of the mass is dark matter) is highly peaked towards the center, while X-ray observations imply that the gas is more extended. The additional fact that the gas is cooling in the center has often led one to expect that the gas temperature should be lo

S. A. Stanford, P. R. M. Eisenhardt, Mark Dickinson

Wide-field optical and near--IR ($JHK$) imaging is presented for two rich galaxy clusters: Abell~370 at $z=0.374$ and Abell~851 (Cl0939+47) at $z=0.407$. Galaxy catalogs selected from the near--IR images are 90\% complete to approximately 1.5 mag below $K^\ast$ resulting in samples with $\sim$100 probable member galaxies per cluster in the central $\sim$2 Mp

Sandra Savaglio, John Webb

We have re--examined the chemical composition of \lya clouds using the composite--cloud technique, in which each \lya line in a spectrum is shifted to its rest frame wavelength and all rest frame spectra are co--added to form an `averaged' \lya cloud spectrum. We illustrate how various estimates of the spectrum and redshift evolution of the background io

S. Ettori, L. Guzzo, M. Tarenghi

We present the data from an extensive, moderately deep (b_J = 19.5) spectroscopic survey of $\sim 600$ galaxies within four regions of sky located near the South Galactic Pole. About 75% of the measured galaxies are in a 3deg x 1.5deg region dominated by the rich cluster Klemola 44 (Abell 4038). The other three smaller areas cover about 1 square degree each.

S. L'vovsky

Generalizing a classical lemma of Castelnuovo, we characterize rational normal curves (resp. linearly normal elliptic curves) as curves $C\subset \PP^n$ such that the number of linearly independent hypersurfaces $Z\supset C$ of given degree~$m$ is maximal (resp. next to maximal).

Kunihiko Kaneko, Tetsuya Yomo

A novel theory for cell differentiation is proposed, based on simulations with interacting artificial cells which have metabolic networks within, and divide into two when the final product is accumulated. Results of simulations with coupled chemical networks and division process lead to the following scenario of the differentiation: Up to some numbers of cel

Jeeva Anandan

The duality found by Aharonov and Casher for topological phases in the electromagnetic field is generalized to an arbitrary linear interaction. This provides a heuristic principle for obtaining a new solution of the field equations from a known solution. This is applied to the general relativistic Sagnac phase shift due to the gravitational field in the inte

Giuseppe Bertin, Thomas Toniazzo

A simple spherically-symmetric, steady-state, cooling-flow description with gas loss (following Sarazin \& Ashe 1989), within galaxy models constrained by radially extended stellar dynamical data, is shown to provide generally reasonable fits to the existing data on X-ray emission profiles and temperatures for a set of bright elliptical galaxies in Virgo and

Suresh Govindarajan

Recently, certain higher dimensional complex manifolds were obtained in [hep-th/9412078] by associating a higher dimensional uniformisation to the generalised Teichmüller spaces of Hitchin. The extra dimensions are provided by the ``times'' of the generalised KdV hierarchy. In this paper, we complete the proof that these manifolds provide the analog

P. Coleman, L. Ioffe, A. M. Tsvelik

We reformulate the two-channel Kondo model to explicitly remove the unscattered charge degrees of freedom. This procedure permits us to move the non-Fermi liquid fixed point to infinite coupling where we can apply a perturbative strong-coupling expansion. The fixed point Hamiltonian involves a three-body Majorana zero mode whose scattering effects give rise

David Elworthy

An experiment designed to explore the relationship between tagging accuracy and the nature of the tagset is described, using corpora in English, French and Swedish. In particular, the question of internal versus external criteria for tagset design is considered, with the general conclusion that external (linguistic) criteria should be followed. Some problems

Francis Wolinski, Frantz Vichot, Bruno Dillet

This paper shows first the problems raised by proper names in natural language processing. Second, it introduces the knowledge representation structure we use based on conceptual graphs. Then it explains the techniques which are used to process known and unknown proper names. At last, it gives the performance of the system and the further works we intend to

Jacek Dziarmaga

We point out that nontrivial quantumstatistics of vortices in planar superfluid systems has its origin in the Schrodinger equation rather then the Chern-Simons term. Vortices in superfluid helium films are not anyons because helium films are compressible. Quantum Hall effect layers admit vortices with nontrivial statistical interactions thanks to their incom

Myung-Ho Kim, Phillial Oh

We construct integrable models on flag manifold by using the symplectic structure explicitly given in the Bruhat coordinatization of flag manifold. They are non-commutative integrable and some of the conserved quantities are given by the Casimir invariants. We quantize the systems using the coherent state path integral technique and find the exact expression

J. E. Nelson, T. Regge

The abstract quantum algebra of observables for 2+1 gravity is analysed in the limit of small cosmological constant. The algebra splits into two sets with an explicit phase space representation;~one set consists of $6g-6$ {\it commuting} elements which form a basis for an algebraic manifold defined by the trace and rank identities;~the other set consists of

S. James Gates, V. G. J. Rodgers

We construct an explicit and manifestly (1,0) heterotic sigma-model where the background fields are those of 10D, N=IIB supergravity.

Victor Tapia

For time-dependent systems the wavefunction depends explicitly on time and it is not a pure state of the Hamiltonian. We construct operators for which the above wavefunction is a pure state. The method is based on the introduction of conserved quantities $Q$ and the pure states are defined by ${\hat Q}ψ=qψ$. The conserved quantities are constructed using par

Reinhard Häring

All rational semisimple braided tensor categories are representation categories of weak quasi Hopf algebras. To proof this result we construct for any given category of this kind a weak quasi tensor functor to the category of finite dimensional vector spaces. This allows to reconstruct a weak quasi Hopf algebra with the given category as its representation c

Cristina Blancafort

In this paper we give an effective characterization of Hilbert functions and polynomials of standard algebras over an Artinian equicharacteristic local ring; the cohomological properties of such algebras are also studied. We describe algorithms to check the admissibility of a given function or polynomial as a Hilbert function or polynomial, and to produce a

I. A. Shovkovy

De Witt--Seeley--Gilkey coefficients are calculated for the most general minimal differential fourth--order operator on Riemannian space of an arbitrary dimension.

F. Franke, T. Woehrmann

Within the Minimal Supersymmetric Standard Model (MSSM), we study the production of the neutral scalar and pseudoscalar as well as the charged Higgs bosons together with fermions or sfermions in deep inelastic $ep$ scattering at $\sqrt{s}=1.6$ TeV. We focus on the parameter space where a Higgs particle is likely to be invisible at LEP2 and LHC. Although we c

A. Djouadi

We discuss the production of new matter particles that are predicted by many extensions of the Standard Model, at future high--energy pp, eP and $e^+e^-$ linear colliders. We focus on the case of exotic, excited and di--fermions. Talk given at "Beyond the Standard Model IV", Lake Tahoe, Ca., December 1994.

A. Djouadi, J. Ng, T. G. Rizzo

We analyze the manifestations of new matter particles predicted by models of new physics beyond the Standard Model, at present and future high--energy colliders. We consider both the production of these new particles and some of their indirect signatures at $pp$ and $eP$ colliders as well as TeV $\ee$ colliders with their $\ee, e γ, γγ$ and $e^- e^-$ modes.

S. Dawson, G. Valencia

We describe CP violating observables in resonant $W^\pm$ and $W^\pm$ plus one jet production at the Tevatron. We present simple examples of CP violating effective operators, consistent with the symmetries of the Standard Model, which would give rise to these observables. We find that CP violating effects coming from new physics at the $TeV$ scale could in pr

E. Papageorgiu

Motivated by the possibility that new (gauge) symmetries which are broken at the grand- (string-) unification scale give rise to texture zeros in the fermion mass matrices which are at the origin of the hierarchy of masses and mixings we explore the effect of such zeros on the neutrino spectrum of SUSY-GUT models. We find that the quadratic-seesaw spectrum o

Jorge Ananias Neto

We choose three different coupling constants for a particular higher-derivative term in the Skyrme model that allows the total Lagrangian to converge in a binomial, geometric and a logarithmic form. Improved numerical results are obtained.

Ian Hinchliffe

A review is given of the theoretical expectations of the self couplings of gauge bosons and of the present experimental information on the couplings. The possibilities for future measurements are also discussed.

J. Edsjo

The flux of neutrino-induced muons at the surface of the Earth is calculated from injection of neutralino annihilation products in the core of the Sun and the Earth. An improved treatment of neutrino propagation through the Sun is performed and the results are presented in an easy-to-use parameterization. For an explicit supersymmetric model, an observable n

Dima Bardin, Arnd Leike, Tord Riemann

Predictions for Higgs production with processes of the type $e^+ e^- \rightarrow μ{\bar μ}\;b\bar b $ at LEP~2 and the NLC are calculated. Short analytical formulae describe the double differential distribution in the invariant masses of the $μ\bar μ$ and $b \bar{b}$ pairs. The total cross section may be got with two numerical integrations. The various Higgs

T. S. Biro, P. Levai, J. Zimanyi

Hadron multiplicities --- especially for strange particles --- are calculated in the framework of the algebraic coalescence rehadronization model (ALCOR), which counts for redistribution of quarks into hadrons for relativistic heavy-ion collisions. The influence of Bjorken flow on the final hadronic composition are incorporated in the model. A comparison is

Marco Genovese

A study of the effects of the anomalous evolution due to mesonic degrees of freedom on singlet structure functions is presented. Possible phenomenological applications are discussed.

B. Machet

The scalar composite representations of the electroweak symmetry group of the Standard Model are exhibited in the case of two generations of quarks. The link between `strong' and `electroweak' eigenstates is investigated, showing that the quark content commonly attributed to pseudoscalar mesons needs to be modified. After doing so, the mechanism supp

K. Funakubo, A. Kakuto, S. Otsuki, K. Takenaga

By treating CP-violating interaction of the electroweak bubble wall as a perturbative term, chiral charge flux through the bubble wall is estimated. It is found that the absolute value of the flux $F_Q$ has a sharp peak at $m_0 \sim a \sim T$ with $F_Q/(u T^3) \sim 10^{-3}\, (Q_L-Q_R)\,Δθ$. Here $m_0$ is the fermion mass, $1/a$ is the wall thickness, $T$ is

THE NEW MUON COLLABORATION, M. Arneodo, A. Arvidson, B. Badelek

We present the structure function ratios F2(Li)/F2(D) and F2(C)/F2(D) measured in deep inelastic muon-nucleus scattering at a nominal incident muon energy of 200 GeV. The kinematic range 0.0001 < x < 0.7 and 0.01< Q^2 < 70 GeV^2 is covered. For values of $x$ less than $0.002$ both ratios indicate saturation of shadowing at values compatible with photoabsorpt

I. Ispolatov, P. L. Krapivsky, S. Redner

We study the kinetics of two-species annihilation, A+B--->0, when all particles undergo strictly biased motion in the same direction and with an excluded volume repulsion between same species particles. It was recently shown that the density in this system decays as t^{-1/3}, compared to t^{-1/4} density decay in A+B--->0 with isotropic diffusion and either

O. Entin-Wohlman, A. G. Aronov, Y. Levinson, Y. Imry

The Hall conductivity and resistivity of strongly localized electrons at low temperatures and at small magnetic fields are obtained. It is found that the results depend on whether the conductivity or the resistivity tensors are averaged to obtain the macroscopic Hall resistivity. In the second case the Hall resistivity always {\it diverges} exponentially as

Anton Bovier, Véronique Gayrard

We prove a large deviation principle for the finite dimensional marginals of the Gibbs distribution of the macroscopic `overlap&#39;-parameters in the Hopfield model in the case where the number of random patterns, $M$, as a function of the system size $N$ satisfies $\limsup M(N)/N=0$. In this case the rate function (or free energy as a function of the overl

M. Fannes, B. Nachtergaele, R. F. Werner

We consider actions of quantum groups on lattice spin systems. We show that if an action of a quantum group respects the local structure of a lattice system, it has to be an ordinary group. Even allowing weakly delocalized (quasi-local) tails of the action, we find that there are no actions of a properly quantum group commuting with lattice translations. The

S. Richter, R. F. Werner

We define a class of dynamical maps on the quasi-local algebra of a quantum spin system, which are quantum analogues of probabilistic cellular automata. We develop criteria for such a system to be ergodic, i.e., to possess a unique invariant state. Intuitively, ergodicity obtains if the local transition operators exhibit sufficiently large disorder. The ergo

M. Yu. Kuchiev, O. P. Sushkov

We demonstrate that in the strong coupling limit (the superconducting gap $Δ$ is as large as the chemical potential $μ$), which is relevant to the high-$T_c$ superconductivity, the correlation corrections to the gap and critical temperature are about 10\% of the corresponding mean field approximation values. For the weak coupling ($Δ\ll μ$) the correlation c

Krzysztof Gawedzki, Antti Kupiainen

The present note contains the text of lectures discussing the problem of universality in fully developed turbulence. After a brief description of Kolmogorov&#39;s 1941 scaling theory of turbulence and a comparison between the statistical approach to turbulence and field theory, we discuss a simple model of turbulent advection which is exactly soluble but who

Lawrence M. Krauss, Michael S. Turner

A diverse set of observations now compellingly suggest that Universe possesses a nonzero cosmological constant. In the context of quantum-field theory a cosmological constant corresponds to the energy density of the vacuum, and the wanted value for the cosmological constant corresponds to a very tiny vacuum energy density. We discuss future observational tes

Abraham Loeb, Dimitar Sasselov

The standard light curve of a microlensing event provides only two constraints on the six unknown parameters of the lens. We show that narrow-band photometry during a microlensing event of a giant star can in addition determine the angular radius of the Einstein ring and the proper motion of the lens. This possibility results from the fact that the extended

Edmund Bertschinger

This is a set of lecture notes basd on the lectures on cosmological dynamics given by E. Bertschinger at Les Houches in August 1993. The contents include elementary mechanics in cosmology, Eulerian and Lagrangian fluid dynamics, hot dark matter, and relativistic cosmological perturbation theory. To typeset the notes one must first obtain the style files and