March 1995 arXiv papers — page 3

Philip Pearle, Euan Squires

We interpret the probability rule of the CSL collapse theory to mean that the scalar field which causes collapse is the grvitational curvature scalar with two sources, the expectation value of the mass density and a white noise fluctuating source. We examine two models of the fluctuating source, monopole fluctuations and dipole fluctuations, and show that th

Daniel Altschuler

We show that the number of homomorphisms from a knot group to a finite group $G$ cannot be a Vassiliev invariant, unless it is constant on the set of $(2,2p+1)$ torus knots. In several cases, such as when $G$ is a dihedral or symmetric group, this implies that the number of homomorphisms is not a Vassiliev invariant.

S. S. Mao, J. R. de Bruyn, S. W. Morris

We have measured the stability boundary for steady electrically-driven convective flow in thin, freely suspended films of Smectic-A liquid crystal. The thinness and layered structure of the films supress two- and three-dimensional instabilities of the convection pattern. As the voltage applied across the film, or the length of the film, is varied, convective

A. A. Usmani

Using a three-baryon $ΛNN$ potential having a spin-independent dispersive and a two-pion exchange components, realistic variational Monte Carlo calculations have been performed for the $Λ$-seperation energy for $^{5}_Λ$He. A relationship between strengths associated with both pieces of $ΛNN$ force giving exact experimental $Λ$-seperation energy has been obta

Masatoshi Noumi, Tetsuya Sugitani

A class of quantum analogues of compact symmetric spaces of classical type is introduced by means of constant solutions to the reflection equations. Their zonal spherical functions are discussed in connection with $q$-orthogonal polynomials.

Masatoshi Noumi

Quantum analogues of the homogeneous spaces $\GL(n)/\SO(n)$ and $\GL(2n)/\Sp(2n)$ are introduced. The zonal spherical functions on these quantum homogeneous spaces are represented by Macdonald's symmetric polynomials $P_{\ld}=P_{\ld}(x_1,\cdots,x_n;q,t)$ with $t=q^{1 \over 2}$ or $t=q^2$.

Gernot Akemann

The loop equation for the complex one-matrix model with a multi-cut structure is derived and solved in the planar limit. An iterative scheme for higher genus contributions to the free energy and the multi-loop correlators is presented for the two-cut model, where explicit results are given up to and including genus two. The double-scaling limit is analyzed a

E. Celeghini, M. Rasetti, G. Vitiello

Second quantization is revisited and creation and annihilation operators are shown to be related, on the same footing both to the algebra ${\it h}(1)$, ${\underline {and}}$ to the superalgebra ${\it osp}(1|2)$ that are shown to be both compatible with Bose ${\underline {and}}$ Fermi statistics. The two algebras are completely equivalent in the one-mode secto

P. Pasti, D. Sorokin, M. Tonin

We consider a generalization of a duality symmetric model proposed by Schwarz and Sen. It is based on enlarging the model with a dynamical vector field being a time-like component of a local Lorentz frame. This allows one to preserve the manifest Lorentz invariance of the model in flat space--time. The presence of this field is regarded as a relic of gravita

Pietro Menotti, Pier Paolo Peirano

By regularizing the singularities appearing in the two dimensional Regge calculus by means of a segment of a sphere or pseudo-sphere and then taking the regulator to zero, we obtain a simple formula for the gauge volume which appears in the functional integral. Such a formula is an analytic function of the opening of the conic singularity in the interval fro

T. Ackermann, J. Tolksdorf

In this letter we show how the action functional of the standard model and of gravity can be derived from a specific Dirac operator. Far from being exotic this particular Dirac operator turns out to be structurally determined by the Yukawa coupling term. The main feature of our approach is that it naturally unifies the action of the standard model with gravi

G. Amelino-Camelia, O. Pisanti, L. Rosa

The implications on neutrino physics and on the dynamical generation of the baryonic asymmetry of a class of $SO(10)$ non-supersymmetric models are discussed.

G. Amelino-Camelia

Two recently proposed approaches to the study of the electroweak phase transition are discussed.

Jin Dai, J. F. Gunion, R. Vega

We demonstrate that the detection of the SM and MSSM Higgs bosons will be possible at the LHC via $t\anti t b\anti b$ and $b\anti b b\anti b$ final state, provided $b$-tagging can be performed with good efficiency and purity.

M. H. Friedman, Y. Srivastava, A. Widom

We consider Fermions in a constant and uniform external $SU(2)$ magnetic field. We find that the results for the energy levels depend on the choice of gauge potential. Choosing a Landau type gauge potential yields his results. On the other hand in another gauge potential, one obtains a different continuous eigenvalue spectrum.

Paul H. Frampton, B. Charles Rasco

We consider the production of a 300GeV dilepton in very intense 4GeV electron scattering off of a lead target. The production cross-section and angular distribution of the resulting muons are calculated. There occur several such events per year, and their detection is rendered feasible by measurement of $e^+μ^-μ^-$ angular correlations.

I. M. DREMIN, A. V. LEONIDOV

The properties of QCD vacuum and the confinement of quarks and gluons certainly influence the multiparticle production processes. Some phenomenological attempts of the consideration of related collective effects and the possibilities of their experimental detection are briefly discussed in this review. We consider in particular the correlation characteristic

Andrzej Czarnecki

A method of computing two-loop fermionic contributions to the width of a heavy quark is described. An analytical formula for this effect in the limit of mass of the quark much larger than the decay products is obtained for the first time. The result confirms previous numerical studies.

A. Dabelstein

The results of a complete one-loop calculation for the fermionic decay width h^0, H^0, A^0 -> f bar(f) of the neutral MSSM Higgs bosons are presented and the dominant light Higgs decay channel h^0 -> b bar(b) is discussed in detail. The enhancement of the partial decay width h^0 -> b bar(b) compared to the standard Higgs decay is shown for pseudoscalar masse

A. Denner, S. Dittmaier, R. Schuster

The cross-section for $γγ\to W^+ W^-$ with arbitrary polarized photons and W bosons is calculated within the electroweak Standard Model including the complete virtual and soft-photonic ${\cal O}(α)$ corrections. We present a detailed numerical discussion of the complete radiative corrections and an analytical investigation of the leading corrections. It turn

H. Holtmann, N. N. Nikolaev, A. Szczurek, J. Speth

The excitation of the proton into undetected multiparticle states (double diffraction dissociation) is an important background to single diffractive deep-inelastic processes $ep \rightarrow e'p'ρ^{0}, ~e'p'J/Ψ, ~e'p'X$ at HERA. We present estimates of the admixture of the double diffraction dissociation events in all diffractive event

Stefan Dittmaier, Carsten Grosse-Knetter

We integrate out the Higgs boson in the electroweak standard model at one loop, assuming that it is very heavy. We construct a low-energy effective Lagrangian, which parametrizes the one-loop effects of the heavy Higgs boson at O(M_H^0). Instead of applying conventional diagrammatical techniques, we integrate out the Higgs boson directly in the path integral

Tereza Mendes, Alan D. Sokal

We study the dynamic critical behavior of the multi-grid Monte Carlo (MGMC) algorithm with piecewise-constant interpolation and a W-cycle, applied to the one-dimensional $O(4)$-symmetric nonlinear $σ$-model [= $SU(2)$ principal chiral model], on lattices from $L=128$ to $L=16384$. Our data for the integrated autocorrelation time $τ_{int,{\cal M}^2}$ are well

MOGAMI, Tsuguo

It is proven that the partition function of 3-dimensional simplicial gravity has an exponential upper bound with the following assumption: any three dimensional sphere $S^3$ is constructed by repeated identification of neighboring links and neighboring triangles in the boundary of a simplicial 3-ball. This assumption is weaker than the one proposed by other

ZEUS Collaboration

This paper reports the cross section measurements for the process ep $\rightarrow$ e~\jpsi~p for $Q^2 < 4$ GeV$^2$ at $\sqrt s = 296$ GeV, based on an integrated luminosity of about 0.5~pb$^{-1}$, using the ZEUS detector. The \jpsi~was detected in its $\rm e^{+}e^{-}$ and $\rm μ^{+}μ^{-}$ decay modes. The photoproduction cross section was measured to be $52^

ZEUS Collaboration

Inclusive transverse momentum spectra of charged particles in photoproduction events in the laboratory pseudorapidity range $-1.2<η<1.4$ have been measured up to $p_{T}=8\GeV $ using the ZEUS detector. Diffractive and non--diffractive reactions have been selected with an average $γp$ centre of mass (c.m.) energy of $\langle W \rangle = 180\GeV$. For diffract

Vivek Iyer, Robert M. Wald

The entropy of stationary black holes has recently been calculated by a number of different approaches. Here we compare the Noether charge approach (defined for any diffeomorphism invariant Lagrangian theory) with various Euclidean methods, specifically, (i) the microcanonical ensemble approach of Brown and York, (ii) the closely related approach of Bañados,

R. Loll

We review and systematize recent attempts to canonically quantize general relativity in 2+1 dimensions, defined on space-times $\R\timesΣ^g$, where $Σ^g$ is a compact Riemann surface of genus $g$. The emphasis is on quantizations of the classical connection formulation, which use Wilson loops as their basic observables, but also results from the ADM formulat

Nathalie Deruelle, V. F. Mukhanov

We derive the matching conditions for cosmological perturbations in a Friedmann Universe where the equation of state undergoes a sharp jump, for instance as a result of a phase transition. The physics of the transition which is needed to follow the fate of the perturbations is clarified. We dissipate misleading statements made recently in the literature conc

Juan Garcia-Bellido, David Wands

Quantum fluctuations of scalar fields during inflation could determine the very large-scale structure of the universe. In the case of general scalar-tensor gravity theories these fluctuations lead to the diffusion of fundamental constants like the Planck mass and the effective Brans--Dicke parameter, $ω$. In the particular case of Brans--Dicke gravity, where

G. N. Parfionov, R. R. Zapatrin

The new approach to quantize the gravity based on the notion of differential algebra is suggested. It is shown that the differential geometry of this object can not be described in terms of points. The spatialization procedure giving rise to points by loosing a part of the entire structure is discussed. The counterpart of the traditional objects of different

A. V. Andreev, B. L. Altshuler

Using a nonperturbative approach we examine the large frequency asymptotics of the two-point level density correlator in weakly disordered metallic grains. This allows us to study the behavior of the two-level structure factor close to the Heisenberg time. We find that the singularities (present for random matrix ensembles) are washed out in a grain with a f

J. E. Furneaux, S. V. Kravchenko, Whitney Mason, G. E. Bowker

We report experimental studies of disorder-induced transitions between quantum-Hall, metallic, and insulating states in a very dilute two-dimensional electron system in silicon at a magnetic field corresponding to Landau level filling factor $ν=1$. At low disorder, the lowest extended state at $ν=1$ is below the Fermi energy so that the system is in the quan

E. Abraham, I. M. Barbour, P. H. Cullen, E. G. Klepfish

A finite size scaling is applied to the Yang-Lee zeros of the grand canonical partition function for the 2-D Hubbard model in the complex chemical potential plane. The logarithmic scaling of the imaginary part of the zeros with the system size indicates a singular dependence of the carrier density on the chemical potential. Our analysis points to a second-or

Kun Yang, A. H. MacDonald

We report on a Hartree-Fock approximation study of the meron pseudospin-texture excitations of the broken-symmetry incompressible ground states of double-layer quantum Hall states at $ν=1$. We have obtained results for meron core energies and core sizes. We use these to estimate the charge gap which determines the activation energy for dissipation in the qua

U. E. H. Laheld, F. B. Pedersen, P. C. Hemmer

Quantum size effects for an exciton attached to a spherical quantum dot are calculated by a variational approach. The band line-ups are assumed to be type-II with finite offsets. The dependence of the exciton binding energy upon the dot radius and the offsets is studied for different sets of electron and hole effective masses.

O. Derzhko, R. Levitskii, O. Chernyavskii

A gas of atoms some of which are in excited electronic state is under consideration. Since the lifetime of an excited state is to great extent larger than the time required for establishing the equilibrium over translational degrees of freedom the system possesses equilibrium properties. They are determined essentially by many-particle resonance interactions

L. W. Molenkamp, K. Flensberg, M. Kemerink

The charging energy of a quantum dot is measured through the effect of its potential on the conductance of a second dot. This technique allows a measurement of the scaling of the dot&#39;s charging energy with the conductance of the tunnel barriers leading to the dot. We find that the charging energy scales quadratically with the reflection probability of th

Lev Mikheev

A crossover from $d$ to $d-1$, and then back to $d$-dimensional critical behavior is argued to be a generic feature characterizing ordering in a $d$-dimensional superlattice composed of atomically {\em thick} films of two ferromagnets. The crossover leads to anomalous changes in the amplitudes of critical singularities. In $d=3$ Heisenberg and $XY$ superlatt

Tabish Qureshi

Dynamics of a dissipative two-level system is studied using quantum relaxation theory. This calculation for the first time goes beyond the commonly used dilute bounce gas approximation (DBGA), even for strong damping. The new results obtained here deviate from the DBGA results at low temperatures, however, the DBGA form is recovered at high temperatures. The

E. Diez, A. Sanchez, F. Dominguez-Adame

We introduce a solvable model of a nonlinear double-barrier structure, described by a generalized effective-mass equation with a nonlinear coupling term. This model is interesting in its own right for possible new applications, as well as to help understand the combined effect of spatial correlations and nonlinearity on disordered systems. Although we specif

B. Kaulakys, G. Vilutis

We investigate a microwave ionization of highly excited atom in a low frequency field and show that such a process may be studied on the bases of map for the electron energy change during the period of the electron motion between two subsequent passages at aphelion. Simple approximate criterion results to the threshold field for transition to chaotic behavio

Benjamin T. Dehner, Steven D. Kawaler

Seismological observations with the Whole Earth Telescope (WET) allow the determination of the subsurface compositional structure of white dwarf stars. The hot DO PG 1159 has a helium surface layer with a mass of 0.001 Msun, while the cooler DB white dwarf GD 358 has a much thinner surface helium layer of 10^-6 Msun. These results imply that either there is

J. P. Beaulieu

We present Fourier analysis at 490\,nm for 87 Cepheid light curves in the bar of the Large Magellanic Cloud. The photometry has be obtained through the EROS project whose main purpose is the search for baryonic dark matter in the Galactic halo. The very high quality of the photometry and the good phase coverage enable us to obtain accurate Fourier decomposit

V. Testa, F. R. Ferraro, E. Brocato, V. Castellani

Deep CCD photometry down to V=24.5 is presented for the old Magellanic Globular cluster NGC 2257. The main result cna be summarized as follows: i) the RGB Bump has been detected at V=18.7+-0.1, and is compatible with determination of this feature in GGCs; ii) NGC 2257 seems to be 2-3 Gyrs younger than a typical GGC; iii) the helium abundance has been estimat

Stella Seitz, Peter Schneider

Gravitational light deflection can distort the images of distant sources by its tidal effects. The population of faint blue galaxies is at sufficiently high redshift so that their images are distorted near foreground clusters, with giant luminous arcs being the most spectacular evidence for this effect. Much weaker distortions, however, can observationally b

L. Gardiner, M. Noguchi

An extensive set of N-body simulations has been carried out on the gravitational interaction of the Small Magellanic Cloud (SMC) with the Galaxy and the Large Magellanic Cloud (LMC). The SMC is assumed to have been a barred galaxy with a disc-to-halo mass ratio of unity before interaction and modelled by a large number of self-gravitating particles, whereas

Martin Pikaart

We define a partition of ${\overline{M}_g^n}$ and show that the cohomology of ${\overline{M}_g^n}$ in a given degree admits a filtration whose respective quotients are isomorphic to the shifted cohomology groups of the parts if $g$ is sufficiently large. This implies that the map $H^k({\overline{M}_g^n}) \ra H^k(M_g^n)$ is onto and that the Hodge structure o

Bruce Hunt

We introduce one of the most beautiful algebraic varieties known, a quintic hypersurface in projective five-space, which is invariant under the action of the Weyl group of $E_6$. This variety is intricately related with many other moduli problems, some of which are: marked hyperelliptic curves of genus two, Picard curves of genus four with a $\sqrt{-3}$-leve

Piljin Yi

We consider quantum fields around uniformly accelerated black holes. At a particular value of the acceleration, the Bogolubov transformation which would be responsible for the late-time Hawking radiation, is found to be trivial. When this happens, Hawking&#39;s thermal radiation, Doppler-shifted or not, is absent to the asymptotic inertial observers despite

Halina Abramowicz, Leonid Frankfurt, Mark Strikman

Coherence phenomena, the increase with energy of coherence length and the non-universality of parton structure of the effective Pomeron are explained. New hard phenomena directly calculable in QCD such as diffractive electroproduction of states with $M^2\ll Q^2$ and the color transparency phenomenon as well as new options to measure the light-cone wave funct

Kyungsik Kang, Jihn E. Kim, Pyungwon Ko

We suggest a simple modification of the maximal mixing scenario (with $S_3$ permutation symmetry) for three light neutrinos. Our neutrino mass matrix has smaller permutation symmetry $S_{2}$ ($ν_μ \leftrightarrow ν_{e}$), and is consistent with all neutrino experiments except the $^{37}$Cl experiment. The resulting mass eigenvalues for three neutrinos are $m

K. Intriligator, N. Seiberg

We study supersymmetric $SO(N_c)$ gauge theories with $N_f$ flavors of quarks in the vector representation. Among the phenomena we find are dynamically generated superpotentials with physically inequivalent branches, smooth moduli spaces of vacua, confinement and oblique confinement, confinement without chiral symmetry breaking, massless composites (glueball

Boyu Hou, Kangjie Shi, Yanshen Wang, Wenli Yang

Boundary operators and boundary states in $SU(2)$-invariant Thirring model are considered from the point of view of bosonization and oscillator realizations of bulk and boundary Zamolodchikov-Faddeev algebras.

Shinji HAMAMOTO

A canonical formalism for higher-derivative theories is presented on the basis of Dirac&#39;s method for constrained systems. It is shown that this formalism shares a path integral expression with Ostrogradski&#39;s canonical formalism.

Alexandre D. ~Dolgov, Georg G. ~Raffelt

The absence of dispersion effects of the SN~1987A neutrino pulse has been used to constrain novel long-range forces between neutrinos and galactic baryonic or non-baryonic matter. If these forces are mediated by vector bosons, screening effects by the cosmic neutrino background invalidate the SN~1987A limits and other related arguments.

H. Aihara, T. Barklow, U. Baur, J. Busenitz

We discuss the direct measurement of the trilinear vector boson couplings in present and future collider experiments. The major goals of such experiments will be the confirmation of the Standard Model (SM) predictions and the search for signals of new physics. We review our current theoretical understanding of anomalous trilinear gauge boson self-interaction

G. Sigl, K. Jedamzik, D. N. Schramm, V. S. Berezinsky

We consider the production of $^3$He and $^2$H by $^4$He photodisintegration initiated by non-thermal energy releases during early cosmic epochs. We find that this process cannot be the predominant source of primordial $^2$H since it would result in anomalously high $^3$He/D ratios in conflict with standard chemical evolution assumptions. We apply this fact

J. J. Dalcanton, D. N. Spergel, F J Summers

The formation of low surface brightness galaxies is an unavoidable prediction of any hierarchical clustering scenario. In these models, low surface brightness galaxies form at late times from small initial overdensities, and make up most of the faint end of the galaxy luminosity function. Because there are tremendous observational biases against finding low

Miles Reid

Following Akizuki, I construct a Noetherian local integral domain C_M whose normalisation (integral closure) is not finite over C_M. My proof follows closely Akizuki&#39;s ingenious calculations.

Roberto Silvotti

In this note we generalize and prove a recent conjecture of Varchenko concerning the number of critical points of a (multivalued) meromorphic function $ϕ$ on an algebraic manifold. Under certain conditions, this number turns out to coincide with the Euler characteristic (up to a sign) of the complement of the divisor of $ϕ$. A few variants of this basic situ

Denis V. Juriev

The classical and quantum dynamics of the noncanonically coupled oscillators is considered. It is shown that though the classical dynamics is well--defined for both harmonic and anharmonic oscillators, the quantum one is well--defined in the harmonic case, admits a hidden (super)Hamiltonian formulation, and thus, preserves the initial operator relations, whe

J. C. Walpe, B. F. Davis, S. Naguleswaran, W. Reviol

Lifetimes for the lowest three transitions in the nucleus $^{120}$Xe have been measured using the Recoil Distance Technique. Our data indicate that the lifetime for the $2_{1}^{+} \to 0_{1}^{+}$ transition is more than a factor of two lower than the previously adopted value and is in keeping with more recent measurements performed on this nucleus. The theore

Reinhold W. Gebert, Takeo Inami, Shun&#39;ya Mizoguchi

We show that the Painlevé test is useful not only for probing (non-)integrability but also for finding the values of spins of conserved currents (W currents) in Toda field theories (TFTs). In the case of the TFTs based on simple Lie algebras the locations of resonances are shown to give precisely the spins of conserved W currents. We apply this test to TFTs

H. J. Weber, X. Song, M. Kirchbach

The spin and flavor fractions of constituent quarks in the proton are obtained from their chiral fluctuations involving Goldstone bosons. SU(3) flavor symmetry breaking suggested by the mass difference between the strange and up, down quarks is included, and this improves the agreement with the data markedly.

A. P. Kobushkin, A. I. Syamtomov, L. Ya. Glozman

Microscopical approach to a deuteron breakup at high and intermediate energies is proposed. We show that the quark exchange effects, resulting from the full asymmetry of the $6q$-deuteron wave function with respect to the pair permutations of quark variables, strongly affect the proton momentum distribution in the deuteron, as well as the polarization observ

K. Philippides, A. Sirlin

The vacuum--polarization contributions of ${\cal O}(b^{n-1} \al_s^n)$ to the relation between the pole--mass $M$ of a quark and the \MS parameter $\mh (M)$ are evaluated by a straightforward method. They are found to approximate very well the exact answer, known through ${\cal O}(\al_s^2)$, thus providing a simple physical interpretation. Results are also gi

M. Bocquet, S. Bonazzola, E. Gourgoulhon, J. Novak

We present the first numerical solutions of the coupled Einstein-Maxwell equations describing rapidly rotating neutron stars endowed with a magnetic field. These solutions are fully relativistic and self-consistent, all the effects of the electromagnetic field on the star&#39;s equilibrium (Lorentz force, spacetime curvature generated by the electromagnetic

Arul Lakshminarayan

The quantum baker&#39;s map is the quantization of a simple classically chaotic system, and has many generic features that have been studied over the last few years. While there exists a semiclassical theory of this map, a more rigorous study of the same revealed some unexpected features which indicated that correction terms of the order of log(h) had to be

Kimberly C. B. New, G. Chanmugam, Warren W. Johnson, Joel E. Tohline

Laboratory searches for the detection of gravitational waves have focused on the detection of burst signals emitted during a supernova explosion, but have not resulted in any confirmed detections. An alternative approach has been to search for continuous wave (CW) gravitational radiation from the Crab pulsar. In this paper, we examine the possibility of dete

Ryoji Enomoto

In 1989, an air-borne experiments (VEGA experiment) aiming at the detection of a few 10 GeV $γ$-ray were carried out. In these experiments, nine point-source candidates along the Galactic plane were reported. In these candidates, the five of five highest significance candidates positionally coincide with the EGRET galactic plane sources.

D. L. Welch, C. Alcock, D. P. Bennett, K. H. Cook

In the past few years, the Magellanic Clouds have been the targets for several major variable star surveys. The results of these surveys are now becoming available and it is clear that a Renaissance in LMC and SMC variable star research will result. In this review, I will describe the results of such surveys and review the questions that are likely to be ans

A. P. Balachandran, G. Bimonte, G. Marmo, A. Simoni

The role of topology in elementary quantum physics is discussed in detail. It is argued that attributes of classical spatial topology emerge from properties of state vectors with suitably smooth time evolution. Equivalently, they emerge from considerations on the domain of the quantum Hamiltonian, this domain being often specified by boundary conditions in e

Kenneth Lane, Estia Eichten

We construct a prototype of topcolor--assisted technicolor in which, although both top and bottom quarks acquire some mass from extended technicolor, strong $U(1)$ couplings of technifermions are isospin symmetric and all gauge anomalies vanish. There is a mechanism for mixing between the light and heavy generations and there need be no very light pseudo--Go

E. N. Antonov

We obtain a generalization of the Low theorem for non-Abelian boson emission in collision of scalar and gauge vector particles and its extension to high energy collisions for small transverse momenta of produced particles. We demonstrate that in the case of particles with spin the direct extension the Low formula to high energy is in contradiction with the c

Avinash Dhar, Gautam Mandal, Spenta R. Wadia

We derive the $σ$-model tachyon $β$-function equation of 2-dimensional string theory, in the background of flat space and linear dilaton, working entirely within the $c=1$ matrix model. The tachyon $β$-function equation is satisfied by a \underbar{nonlocal} and \underbar{nonlinear} combination of the (massless) scalar field of the matrix model. We discuss th

A. Ritz, R. Delbourgo

The subject of low energy photon-photon scattering is considered in arbitrary dimensional space-time and the interaction is widened to include scattering events involving an arbitrary number of photons. The effective interaction Lagrangian for these processes in QED has been determined in a manifestly invariant form. This generalisation resolves the structur

Z. Lalak, A. Niemeyer, H. P. Nilles

The status of the gaugino condensation as the source of supersymmetry breaking is reexamined. It is argued that one cannot have stable minima with broken supersymmetry in models where the dilaton is coupled only linearly to the gaugino condensate. We show that the problems of the gaugino condensate mechanism can be solved by considering nonstandard gauge kin

A. A. Bolokhov, A. N. Manashov, M. V. Polyakov, V. V. Vereshagin

Using the method of asymptotic sum rules we estimated the size of $O(m_s p_π^4)$ and $O(m_s^2 p_π^2)$ corrections to $πK$ scattering amplitude in large $N_c$ limit. These corrections arise from the sixth order effective chiral lagrangian (EChL). Our method enables us to estimate the corresponding terms of the sixth order EChL in leading order of $1/N_c$ expa

Michael R. Douglas, Stephen H. Shenker

We study the physics of the Seiberg-Witten and Argyres-Faraggi-Klemm-Lerche-Theisen-Yankielowicz solutions of $D=4$, $\mathcal{N}=2$ and $\mathcal{N}=1$ $SU(N)$ supersymmetric gauge theory. The $\mathcal{N}=1$ theory is confining and its effective Lagrangian is a spontaneously broken $U(1)^{N-1}$ abelian gauge theory. We identify some features of its physics

A. Barenco, D. Deutsch, A. Ekert, R. Jozsa

Quantum logic gates provide fundamental examples of conditional quantum dynamics. They could form the building blocks of general quantum information processing systems which have recently been shown to have many interesting non--classical properties. We describe a simple quantum logic gate, the quantum controlled--NOT, and analyse some of its applications. W

G. N. Parfionov, R. R. Zapatrin

The non-commutative algebraic analog of the moduli of vector and covector fields is built. The structure of moduli of derivations of non-commutative algebras are studied. The canonical coupling is introduced and the conditions for appropriate moduli to be reflexive are obtained.

S. Misicu

In the frame of the algebraic Riemann Rotational Model one computes the longitudinal, transverse and toroidal multipoles corresponding to the excitations of low-lying levels in the ground state band of several even-even nuclei by inelastic electron scattering (e,e&#39;). Related to these transitions a new quantity, which accounts for the deviations from the

Warren G. Anderson, Nemanja Kaloper

We derive several new solutions in three-dimensional stringy gravity. The solutions are obtained with the help of string duality transformations. They represent stationary configurations with horizons, and are surrounded by (quasi) topologically massive Abelian gauge hair, in addition to the dilaton and the Kalb-Ramond axion. Our analysis suggests that there

Maximilian Kreuzer, Christoph Schweigert

We show that the numbers of generations and anti-generations of a (2,2) string compactification with diagonal internal theory can be expressed in terms of certain specifications of the elliptic genus of the untwisted internal theory which can be computed from the Poincare polynomial. To establish this result we show that there are no cancellations of positiv

W. Siegel

We introduce the Liouville mode into the Green-Schwarz superstring. Like massive supersymmetry without central charges, there is no kappa symmetry. However, the second-class constraints (and corresponding Wess-Zumino term) remain, and can be solved by (twisted) chiral superspace in dimensions D=4 and 6. The matter conformal anomaly is c = 4-D < 1. It thus ca

Per Elmfors

The free propagator for the scalar $λϕ^4$--theory is calculated exactly up to the second derivative of a background field. Using this propagator I compute the one--loop effective action, which then contains all powers of the field but with at most two derivatives acting on each field. The standard derivative expansion, which only has a finite number of deriv

L. Accardi, Y. G. Lu, I. Volovich

A procedure of bosonization of Fermions in an arbitrary dimension is suggested. It is shown that a quadratic expression in the fermionic fields after rescaling time $t\to t/λ^2$ and performing the limit $λ\to0$ (stochastic limit), gives rise to a bosonic operator satisfying the boson canonical commutation relations. This stochastic bosonization of Fermions i

V. B. Kuznetsov, M. F. Jorgensen, P. L. Christiansen

New boundary conditions for integrable nonlinear lattices of the XXX type, such as the Heisenberg chain and the Toda lattice are presented. These integrable extensions are formulated in terms of a generic XXX Heisenberg magnet interacting with two additional spins at each end of the chain. The construction uses the most general rank 1 ansatz for the 2x2 L-op

Jean-François Roussel

The first chapters introduce briefly conformal theories, Moore and Seiberg polynomial equations and Gervais-Neveu quantization of Liouville theory. The next chapters present the original results of this thesis. First, the algebra of the chiral components is completely elucidated, both in the Bloch wave and in the Quantum Group basis. Then, in the strong coup

J. Gomis, J. Herrero, K. Kamimura

We comment on relations between the linear W_{2,4}^{linear} algebra and non-linear W(2,4)$ algebra appearing in a Sp(4) particle mechanics model by using Lax equations. The appearance of the non-local V_{2,2} algebra is also studied.

Katsushi Ito, Seiji Terashima

We study the BRST-cohomology in the quantum hamiltonian reduction of affine Lie algebras of non-simply laced type. We obtain the free field realization of the $W{\bf g}$-algebra for $\bg=B_{2}$, $B_{3}$, $C_{3}$ and $G_{2}$. The $WC_{3}$ algebra is shown to be equal to the $WB_{3}$ algebra at the quantum level by duality transformation.

L. Chao, Q. P. Liu

We consider the classical \w42 algebra from the integrable system viewpoint. The integrable evolution equations associated with the \w42 algebra are constructed and the Miura maps , consequently modifications, are presented. Modifying the Miura maps, we give a free field realization the classical \w42 algebra. We also construct the Toda type integrable syste

J. Ellis, N. E. Mavromatos, D. V. Nanopoulos

We describe a scenario for inflation in the framework of non-critical string theory, which does not employ an inflaton field. There is an exponential expansion of the volume of the Universe, induced by enormous entropy production in the early stages of cosmological evolution. This is associated with the loss of information carried by global string modes that

O. J. P. Eboli, M. B. Magro, P. G. Mercadante, S. F. Novaes

We study the constraints on the vertices $W^+W^- Zγ$, $W^+W^-γγ$, and $ZZγγ$ that can be obtained from triple-gauge-boson production at the next generation of linear $e^+e^-$ colliders operating in the $γγ$ mode. We analyze the processes $γγ\to W^+W^-V$ ($V=Z$, or $γ$) and show that these reactions increase the potential of $e^+e^-$ machines to search for an

A. Datta, M. Guchait, M. Drees, .

Relatively light sneutrinos, which are experimentally allowed, may significantly affect the currently popular search strategies for supersymmetric particles by decaying dominantly into an invisible channel. In certain cases the second lightest neutralino may also decay invisibly leading to two extra carriers of missing energy -- in addition to the lightest s

W. Haxton

The solar neutrino problem has persisted for almost three decades. Recent results from Kamiokande, SAGE, and GALLEX indicate a pattern of neutrino fluxes that is very difficult to reconcile with plausible variations in standard solar models. This situation is reviewed and suggested particle physics solutions are discussed. A summary is given of the important

Edward Shuryak

In recent years, significant progress was reached in understanding of vacuum and hadronic structure. We review recent works on the {\it point-to-point correlation functions}, comparing those obtained from phenomenology, ``instanton liquid&#34; models and on the lattice. The second topic is physics of chiral symmetry restoration, which may lead to observable

J. Ellis

The Standard Model is the answer to questions 1 and 2, as established by LEP. Supersymmetry is doubtless the answer to question 3, as may well be established by the LHC.

Jose Wudka

The applications of effective lagrangians to the determination of the effects of physics beyond the Standard Model are briefly described. Emphasis is given to those effective operators which generate the largest deviations form the Standard Model; some applications are described. of the paper (or other short description) [Talk given at &#34;Beyond the Standa