July 1993 arXiv papers — page 4

Z. Burda, K. Zalewski, R. Peschanski, J. Wosiek

Finite size scaling is shown to work very well for the block variables used in intermittency studies on a 2-d Ising lattice. The intermittency exponents so derived exhibit the expected relations to the magnetic critical exponent of the model. Email contact: pesch@amoco.saclay.cea.fr

X. Shi, D. N. Schramm, B. D. Fields

We discuss in detail the effect of neutrino oscillations in Big Bang nucleosynthesis, between active and sterile neutrinos, as well as between active and active neutrinos. We calculate the constraints on mixings between active and sterile neutrinos from the present observation of the primordial helium abundance and discuss the potential implications on vario

F. C. Alcaraz, D. Arnaudon, V. Rittenberg, M. Scheunert

We consider an extension of the (t-U) Hubbard model taking into account new interactions between the numbers of up and down electrons. We confine ourselves to a one-dimensional open chain with L sites (4^L states) and derive the effective Hamiltonian in the strong repulsion (large U) regime. This Hamiltonian acts on 3^L states. We show that the spectrum of t

A. Y. Shiekh

A scalar field theory is investigated within the context of orthodox quantum gravity.

Paolo Rossi, Ettore Vicari

Lattice $SU(N)\times SU(N)$ chiral models are analyzed by strong and weak coupling expansions and by numerical simulations. $12^{th}$ order strong coupling series for the free and internal energy are obtained for all $N\geq 6$. Three loop contributions to the internal energy and to the lattice $β$-function are evaluated for all $N$ and non-universal correcti

B. Harms, Y. Leblanc

Two types of semiclassical calculations have been used to study quantum effects in black hole backgrounds, the WKB and the mean field approaches. In this work we systematically reconstruct the logical implications of both methods on quantum black hole physics and provide the link between these two approaches. Our conclusions completely support our previous f

T. D. Palev, N. I. Stoilova

We present three groups of noncanonical quantum oscillators. The position and the momentum operators of each of the groups generate basic Lie superalgebras, namely $sl(1/3)$, $osp(1/6)$ and $osp(3/2)$. The $sl(1/3)$-oscillators have finite energy spectrum and finite-dimensions. The $osp(1/6)$-oscillators are related to the para-Bose statistictics. The intern

Paul Fendley, Ken Intriligator

We show how to obtain the ultraviolet central charge from the exact S-matrix for a wide variety of models with a $U(1)$ symmetry. This is done by coupling the $U(1)$ current $J$ to a background field. In an $N$=2 superconformal theory with $J$ the fermion number current, the OPE of $J$ with itself and hence the free energy are proportional to $c$. By deformi

Y. Brihaye, P. Kosinski

We investigate the conditions under which systems of two differential eigenvalue equations are quasi exactly solvable. These systems reveal a rich set of algebraic structures. Some of them are explicitely described. An exemple of quasi exactly system is studied which provides a direct counterpart of the Lamé equation.

R. Sollacher

The introduction and quantization of a center-of-mass coordinate is demonstrated for the one-soliton sector of nonlinear field theories in (1+1) dimensions. The present approach strongly emphazises the gauge and BRST-symmetry aspects of collective coordinate quantization. A gauge is presented which is independent of any approximation scheme and which allows

F. A. Smirnov

We continue study of the connection of classical limit of integrable asymptotically free field theory to the finite-gap solutions of classical integrable equations. In the limit the momenta of particles turn into the moduli of Riemann surfaces while their isotopic structure is related to the period lattices. In this paper we explain that the classical limit

G. Azuelos, A. Djouadi

We discuss the production of heavy leptons at a future high--energy $e^+e^-$ linear collider with a center of mass energy of 500 GeV. Signals and backgrounds are analyzed for their single production in association with ordinary leptons. [Talk given by A.D. at the second Workshop on "Physics and Experiments with Linear e+e- Colliders", Waikoloa, Hawai

G. A. Ladinsky, C. --P. Yuan

We describe how to probe new physics through large CP violation effects and non--standard Z-t-t couplings via the scattering process e^-e^+ -> t tbar. [Talk presented at the Workshop on Physics and Experiments with Linear $e^+e^-$ Colliders, Waikoloa, Hawaii, 26-30 April 1993.]

Patrick J. O'Donnell, Utpal Sarkar

We study baryogenesis through lepton number violation in left-right symmetric models. In these models the lepton number and CP violating interactions of the triplet higgs scalars can give rise to lepton number asymmetry through non-equilibrium decays of the $SU(2)_L$ triplet higgs and the right handed neutrinos. This in turn generates baryon asymmetry during

T. Altherr

This is intended to be a very basic introduction and short (and of course incomplete) overview of thermal field theory. In the first part, I introduce the thermal propagator at a very simple level and give the Feynman rules using the time-path contour method. In the second part, I give examples of these rules in scalar theory and discuss the origin of the th

Stephen P. Martin

In the minimal supersymmetric standard model, the existence of R-parity is not required for the internal consistency of the theory and might therefore be regarded as ad hoc. I catalog some simple conditions which are sufficient to guarantee that R-parity survives as an unbroken gauged discrete subgroup of the continuous gauge symmetry in certain extensions o

H. -C. Cheng, M. S. Gill, L. J. Hall

In grand unified theories the flavor mixing angles of leptons are related to those of quarks. In this paper we study SO(10) theories with a precise group theoretic relation at the GUT scale for mixing between the heaviest two generations: $\thetuto = κ\abs{\vcbo}$. A comprehensive operator search yields all possible cases where $κ$ is a group theory Clebsch.

N. Dadhich, R. Tikekar, L. K. Patel

In 1990 Senovilla$^1$ obtained an interestisng cosmological solution of Einstein's equations that was free of the big-bang singularity. It represented an inhomogeneous and anisotropic cylindrical model filled with disordered radiation, ${\bf ρ= 3p}$. The model was valid for ${\bf t \rightarrow - \infty }$ to ${\bf t \rightarrow \infty}$ having all physic

Jian Ping Lu

The morphology of Bucky onions is investigated by {\it ab initio} calculations using Yang's new $O(N)$ method. It is found that for large single shell fullerenes with $I_h$ symmetry, the spherical morphology has the lower energy than that of polyhedrons. The formation energy per atom follows a simple scaling law. Including an estimate of inter-shell van

G. A. Drukier

Model surface brightness profiles based on Fokker-Planck simulations have been used to assess the high resolution surface brightness profile of the globular cluster NGC 6397 of Lauzeral et al. (1992). The profile is well fitted by the model in the maximum-expansion phase of a gravothermal oscillation with a core radius of 0.06 pc (6''), but an unreso

Geza Gyuk, Michael S. Turner

We have modified the standard code for primordial nucleosynthesis to include the effect of finite nucleon mass on the weak-interaction rates as calculated by Seckel \cite{seckel}. We find a small, systematic increase in the $^4$He yield, $ΔY \simeq 0.0057\,Y$, which is insensitive to the value of the baryon-to-photon ratio $η$ and slightly larger than Seckel

Bohdan Paczynski, James E. Rhoads

The rapid time variability of gamma-ray bursts implies the sources are very compact, and the peak luminosities are so high that some matter must be ejected at ultra-relativistic speeds. The very large Lorentz factors of the bulk flow are also indicated by the very broad and hard spectra. It is natural to expect that when the relativistic ejecta interact with

R. A. Richardson, O. Pla, Franco Nori

From a very simple description of vortices and pinning centers and without using any electrodynamical assumptions, we obtain nonlinear density profiles of vortices in type-II dirty superconductors that result from raising or lowering an external magnetic field. The results confirm a modified Bean model description of these systems, and in particular, follow

Chopin Soo, Lay Nam Chang

Superspace parametrized by gauge potentials instead of metric three-geometries is discussed in the context of the Ashtekar variables. Among other things, an "internal clock" for the full theory can be identified. Gauge-fixing conditions which lead to the natural geometrical separation of physical from gauge modes are derived with the use of the metri

R. D. Amado, Bin Shao, Niels R. Walet

We examine the derivation of the spin-orbit force from the Skyrme model. We find substantial agreement with phenomenological potentials. We show that a systematic and simultaneous treatment of all components of the kinetic energy introduces a minus sign relative to previous calculations for the iso-spin independent part of the interaction. We also explain th

Younggi Lee, In-Mook Kim

We study the crossover behavoir on restricted surface depostions.

Christoph M. A. Scheich

We discuss discrete symmetries in several string compactification schemes. The same constraints on the light spectra as for Gepner models \cite{rosss} are found in various cases for non-$R$ symmetries. The analogous constraints for $R$ symmetries are also established.Therefore it seems natural to conjecture that they always apply.

Sven Sandow, Gunter Schuetz

We study analytically a model where particles with a hard-core repulsion diffuse on a finite one-dimensional lattice with space-dependent, asymmetric hopping rates. The system dynamics are given by the \mbox{U$_{q}$[SU(2)]}-symmetric Hamiltonian of a generalized anisotropic Heisenberg antiferromagnet. Exploiting this symmetry we derive exact expressions for

Alberto Saa

We study the gravitational interaction involving the dilaton and the anti-symmetrical $B_{μν}$ fields that arises in the low-energy limit of string theory. It is shown that such interaction can be derived from a geometrical action principle, with the scalar of curvature of a non-Riemannian, but {\em metric-compatible}, connection as the lagrangian, and with

G. V. Grigoriyn, R. P. Grigoryan

The pseudoclassical hamiltonian and action of the $D=2n$ dimensional Dirac particle with anomalous magnetic moment interacting with the external electromagnetic field is found. The Bargmann-Michel-Telegdi equation of motion for the Pauli-Lubanski vector is deduced. The canonical quantization of $D=2n$ dimensional Dirac spinning particle with anomalous magnet

Arthur Hebecker

A complete calculation of the finite temperature effective potential for the abelian Higgs model to the order $e^4,λ^2$ is presented and the result is expressed in terms of physical parameters defined at zero temperature. The absence of a linear term is verified explicitly to the given order and proven to survive to all orders. The first order phase transiti

Sanjaye Ramgoolam

We write down all orders large $N$ expansions for the dimensions of irreducible representations of $O(N)$ and $Sp(N)$. We interpret all the terms in these expansions as symmetry factors for singular worldsheet configurations, involving collapsed crosscaps and tubes. We use it to complete the interpretation of two dimensional Yang Mills Theories with these ga

W. E. Ormand, D. J. Dean, C. W. Johnson, G. H. Lang

We apply the auxiliary-field Monte Carlo approach to the nuclear shell model in the 1s-0d configuration space. The Hamiltonian was chosen to have isovector pairing and isoscalar multipole-multipole interactions, and the calculations were performed within the fixed-particle, canonical ensemble. The results demonstrate the feasibility of the method for $N\neq

L. Satpathy, P. K. Sahu, V. S. Uma Maheswari

The mass formulae for finite lumps of strange quark matter with $u$, $d$ and $s$ quarks, and non-strange quark matter consisting of $u$ and $d$ quarks are derived in a non-relativistic potential model. The finite-size effects comprising the surface, curvature and even, the Gauss curvature were consistently obtained, which shows a converging trend. It is foun

Bin Shao, Niels R. Walet, R. D. Amado

The kinetic energy of the Skyrmion-Skyrmion system is calculated in the product ansatz. The energy is expanded in a set of rotationally invariant quadratic functions of translational and iso-rotational velocities in the product ansatz and all inertial parameters are evaluated. Most of the iso-spin dependent parameters are small at separations larger than 1 f

Pavlos Protopapas, Abraham Klein, Niels R. Walet

We reexamine the long-standing problem of the microscopic derivation of a particle-core coupling model. We base our research on the Klein-Kerman approach, as amended by Dönau and Frauendorf. We describe the formalism to calculate energy spectra and transition strengths in some detail. We apply our formalism to the rotational nuclei $^{155,157}$Gd, where rece

M. B. Barbaro, A. De Pace, T. W. Donnelly, A. Molinari

Parity-violating quasielastic electron scattering is studied within the context of the relativistic Fermi gas and its extensions to include the effects of pionic correlations and meson-exchange currents. The work builds on previous studies using the same model; here the part of the parity-violating asymmetry that contains axial-vector hadronic currents is de

Hans J. Haubold, Arak Mathai Mathai

This article gives an brief outline of the applications of generalized special functions such as generalized hypergeometric functions, G-functions and H-functions into the general area of nuclear energy generation and reaction rate theory such as the energy generation in a simple stellar model and nuclear reaction rates in non-resonant and resonant as well a

Hitoshi Nishino

We show that recently formulated four-dimensional self-dual supersymmetric Yang-Mills theory, which is consistent background for open $~N=2$~ superstring, generates two-dimensional $~N=(1,1),~\, N=(1,0) $~ and $~N=(2,0)$~ supersymmetric gauged Wess-Zumino-Novikov-Witten $~\s\-$models on coset manifolds $~G/H$, after appropriate dimensional reductions. This i

B. Sathiapalan

Some issues in the loop variable renormalization group approach to gauge invariant equations for the free fields of the open string are discussed. It had been shown in an earlier paper that this leads to a simple form of the gauge transformation law. We discuss in some detail some of the curious features encountered there. The theory looks a little like a ma

S. Deser, J. McCarthy, Alan R. Steif

We obtain the high energy, small angle, 2-particle gravitational scattering amplitudes in topologically massive gravity (TMG) and its two non-dynamical constituents, Einstein and Chern--Simons gravity. We use 't Hooft's approach, formally equivalent to a leading order eikonal approximation: one of the particles is taken to scatter through the classic

B. K. Chung, Soonkeon Nam, Q-Han Park, H. J. Shin

Exact solutions of conformal turbulence restricted on a upper half plane are obtained. We show that the inertial range of homogeneous and isotropic turbulence with constant enstrophy flux develops in a distant region from the boundary. Thus in the presence of an anisotropic boundary, these exact solutions of turbulence generalize Kolmogorov's solution consis

S. Pakuliak

The annihilation poles for the form factors in XXZ model are studied using vertex operators introduced in \cite{DFJMN}. An annihilation pole is the property of form factors according to which the residue of the $2n$-particle form factor in such a pole can be expressed through linear combination of the $2n-2$-particle form factors. To prove this property we u

H. Simma

We study the application of the classical equations of motion (EOM) within the framework of an effective low-energy Lagrangian treated at the loop level. Gauge-fixing and ghost terms, which enter naturally in the EOM, are found to lead to no physical effects --- neither through operator mixing nor in matrix elements. Beyond first order in the effective inter

Graham G. Ross, Christoph M. A. Scheich

Compactified string theories give rise to discrete symmetries which are essential if they are to provide a realistic low energy theory. We find that in a class of four dimensional string theories these symmetries are constrained by similar conditions to those discrete anomaly cancellation conditions found in the case the discrete symmetry is a residue of a s

J. H. Kühn

Semileptonic decays of polarised $τ$ leptons are investigated. Predictions for the rate, based on CVC and chiral Lagrangians, are contrasted with experiments. Predictions for the angular distributions of three meson final states are given. Emphasis is put on studies in electron-positron annihilation where the neutrino escapes detection and the $τ$ restframe

J. H. Kühn

The status of top quark searches will be briefly reviewed. Theoretical predictions for the top quark decay rate are presented including QCD and electroweak radiative corrections. The possibilities for quarkonium searches at an hadron collider will be discussed. The perspectives for top production at an electron positron collider will be described in detail w

J. H. Kühn

The momenta of $τ$ decay products in the reaction $e^+e^-\toτ^+τ^-$ do not constrain the $τ$ direction unambiguously. It is shown how the measurement of tracks of hadrons from semileptonic $τ$ decays, in particular their relative impact parameters, allows to resolve this ambiguity.

Enrico Nardi

The constraints on the mixing angles of the standard fermions with new heavy particles that can appear in many extensions of the electroweak theory are reviewed. Some emphasis is put in distinguishing the effects of a mixing with new states which transform in a non-canonical way with respect to $SU(2)\times U(1)$ (left-handed singlets or right-handed doublet

M. Klomfass

Investigating the cutoff dependence of the Higgs mass triviality bound, the $ϕ^4$ theory is formulated on an $F_4$ lattice which preserves Lorentz invariance to a higher degree than the commonly used hypercubic lattice. I solve this model non-perturbatively by evaluating the high temperature expansion through 13th order following the approach of Lüscher and

David Garfinkle, G. Comer Duncan

We study the collapse of a circular loop of cosmic string. The gravitational field of the string is treated using the weak field approximation. The gravitational radiation from the loop is evaluated numerically. The memtric of the loop near the point of collapse is found analytically.

Kristin Schleich, Donald M. Witt

This paper examines the issues involved with concretely implementing a sum over conifolds in the formulation of Euclidean sums over histories for gravity. The first step in precisely formulating any sum over topological spaces is that one must have an algorithmically implementable method of generating a list of all spaces in the set to be summed over. This r

Ulvi Yurtsever

The mathematical formalism for linear quantum field theory on curved spacetime depends in an essential way on the assumption of global hyperbolicity. Physically, what lie at the foundation of any formalism for quantization in curved spacetime are the canonical commutation relations, imposed on the field operators evaluated at a global Cauchy surface. In the

Ulvi Yurtsever

The research effort reported in this paper is directed, in a broad sense, towards understanding the small-scale structure of spacetime. The fundamental question that guides our discussion is ``what is the physical content of spacetime topology?" In classical physics, if spacetime, $(X, τ)$, has sufficiently regular topology, and if sufficiently many fiel

Fong Liu

The phase transition kinetics of Ising gauge models are investigated. Despite the absence of a local order parameter, relevant topological excitations that control the ordering kinetics can be identified. Dynamical scaling holds in the approach to equilibrium, and the growth of typical length scale is characteristic of a new universality class with $L(t)\sim

A. Klümper, A. Schadschneider, J. Zittartz

We have found the exact groundstate for a large class of antiferromagnetic spin-1 models with nearest-neighbour interactions on a linear chain. All groundstate properties can be calculated. The groundstate is determined as a matrix product of individual site states and has the properties of the Haldane scenario.

H. Jeong, B. Kahng, D. Kim

We introduce a novel three dimensional Toom model on bcc lattice, and study its physical properties. In low-noise limit, the model leads to an effective solid-on-solid-type model, which exhibits a stationary interface via depositions and evaporations with avalanche process. We find that the model is described by the Edwards-Wilkinson equation for unbiased ca

L. Satpathy, P. K. Sahu, V. S. Uma Maheswari

The mass formulae for finite lumps of strange quark matter with $u$, $d$ and $s$ quarks, and non-strange quark matter consisting of $u$ and $d$ quarks are derived in a non-relativistic potential model. The finite-size effects comprising the surface, curvature and even, the Gauss curvature were consistently obtained, which shows a converging trend. It is foun

Karl Glazebrook, J. A. Peacock, C. A. Collins, L. Miller

We present results from a large area (552\,\sqamin) imaging $K$-band survey to a 5$σ$ limit of $K\simeq 17.3$. We have optical-infrared colours of almost all the objects in the sample. Star-galaxy discrimination is performed and the results used to derive the infrared star and galaxy counts. $K$-band ``no-evolution'' galaxy-count models are construct

Robert Friedman

This paper is the second in a series of three devoted to the smooth classification of simply connected elliptic surfaces. In this paper, we study the case where one of the multiple fibers has even multiplicity, and describe the moduli space of stable rank two vector bundles with the appropriate first Chern class needed to calculate Donaldson polynomials. The

Robert Friedman

This paper is the first in a series of three devoted to the smooth classification of simply connected elliptic surfaces. The method is to compute some coefficients of Donaldson polynomials of $SO(3)$ invariants whose second Stiefel-Whitney class is transverse to the unique primitive class $κ$ such that a positive multiple of $κ$ is the class of a general fib

Derek B. Leinweber, Thomas D. Cohen

Two-pion induced self-energy contributions to the $ρ$-meson mass are examined in relation to the quenched approximation of QCD, where the physics associated with two-pion intermediate states has been excluded from vector-isovector correlation functions. Corrections to quenched QCD calculations of the $ρ$-meson mass are estimated to be small at the order of a

D. Dumm, F. Pisano, V. Pleitez

We consider flavor changing neutral current effects coming from the $Z'$ exchange in 3-3-1 models. We show that the mass of this extra neutral vector boson may be less than 2 TeV and discuss the problem of quark family discrimination.

V. Van der Sluys, J. Ryckebusch, M. Waroquier

The response functions for the unpolarized $(e,e'p)$ and polarized $(\vec{e},e'p)$ reaction are calculated for medium-heavy nuclei under quasifree conditions. The formalism presented here incorporates two-body currents related to meson-exchange and the $Δ(1232)$ excitation. The final-state interaction of the outgoing nucleon with the residual nucleus

Mike A. Clayton

The existence of the invariant measure in nonlocal regularized actions is discussed. It is shown that the measure for nonlocally regularized QED, as presented in\cite{Moff-Wood}, exists to all orders, and is precisely what is required to maintain gauge invariance at one loop and guarantees perturbative unitarity. We also demonstrate how the given procedure b

Ashoke Sen, Barton Zwiebach

We give a complete proof of local background independence of the classical master action for closed strings by constructing explicitly, for any two nearby conformal theories in a CFT theory space, a symplectic diffeomorphism between their state spaces mapping the corresponding non-polynomial string actions into each other. We uncover a new family of string v

B. Sakita

We construct a $W_{\infty}$ gauge field theory of electrons in the lowest Landau level. For this purpose we introduce an external gauge potential $\cal A $ such that its $W_{\infty}$ gauge transformations cancel against the gauge transformation of the electron field. We then show that the electromagnetic interactions of electrons in the lowest Landau level a

D. Espriu, J. Matias

Chiral lagrangians describing the interactions of Goldstone bosons in a theory possessing spontaneous symmetry breaking are effective, non-renormalizable field theories in four dimensions. Yet, in a momentum expansion one is able to extract definite, testable predictions from perturbation theory. These techniques have yielded in recent years a wealth of info

G. V. Grigoryan, R. P. Grigoryan

The canonical quantization of $D=2n$ dimensional Dirac spinning particle in the external electromagnetic field is carried out in the gauge which allows to describe simultaneously particles and antiparticles (massive and massless) already at the classical level. Pseudoclassical Foldy-Wouthuysen transformation is used to obtain canonical (Newton-Wigner) coordi

A. C. Mattingly, P. M. Stevenson

The new result for the third-order QCD corrections to R_{e^+e^-}, unlike the old, incorrect result, is nicely compatible with the principle-of-minimal-sensitivity optimization method. Moreover, it leads to infrared fixed-point behaviour: the optimized couplant, alpha_s/pi, for R(e+e-) does not diverge at low energies, but "freezes" to a value 0.26 be

Pankaj Jain, Alan J. Sommerer, Douglas W. McKay, J. R. Spence

The coupled Bethe--Salpeter bound state equations for a $Q\bar Q$ system, where $Q=(U,D)$ is a degenerate, fourth generation, super--heavy quark doublet, are solved in several ladder approximation models. The exchanges of gluon, Higgs and Goldstone modes in the standard model are calculated in the ultra--heavy quark limit where weak $γ, W^\pm$ and $Z^0$ cont

John F. Donoghue, Eugene Golowich

Although the weak nonleptonic amplitudes of the Standard Model are notoriously difficult to calculate, we have produced a modified weak matrix element which can be analyzed using reliable methods. This hypothetical nonleptonic matrix element is expressible in terms of the isovector vector and axialvector spectral functions $ρ_{\rm V}(s)$ and $ρ_{\rm A}(s)$,

John F. Donoghue, Eugene Golowich

We present an analysis of four sum rules, each based on chiral symmetry and containing the difference $ρ_{\rm V}(s) - ρ_{\rm A}(s)$ of isovector vector and axialvector spectral functions. Experimental data from tau lepton decay and electron-positron scattering identify the spectral functions over a limited kinematic domain. We summarize the status of the exi

F. E. Close, A. Wambach

We show how both the spectroscopy of heavy-light hadrons and the slope of the Isgur-Wise function can be simultaneously fitted when Heavy Quark Effective Theory is matched onto dynamical quark models, including careful treatment of wigner rotations. Working consistently to order $\vec{v}^2$ and using the parameters from hadron spectroscopy as input, we deter

M. S. Berger

We have performed a complete one-loop calculation of $γγ\rightarrow ZZ$ in the Standard Model, including both gauge bosons and fermions in the loop. We confirm the large irreducible continuum background from the $W$-boson loop found by Jikia. We have included the photon-photon luminosity, and find that the continuum background of transverse $Z$ boson pairs p

K. Langfeld, F. Schm"user, H. Reinhardt

Non-trivial $ϕ^{4}$-theory is studied in a renormalisation group invariant approach inside a box consisting of rectangular plates and where the scalar modes satisfy periodic boundary conditions at the plates. It is found that the Casimir energy exponentially approaches the infinite volume limit, the decay rate given by the scalar condensate. It therefore ess

Tadashi Kon

We investigate the charged scalar lepton production processes $γγ\to{\widetilde{\ell}}^{+}{\widetilde{\ell}}^{-}$ at high energy $γγ$ colliders in the framework of the minimal supersymmetric standard model (MSSM). Here the high energy $γ$ beams are obtained by the backward Compton scattering of the laser flush by the electron in the basic linear TeV $ee$ col

Stephen Godfrey, K. Andrew Peterson

We studied single $W$ boson production in high energy $eγ$ collisions and the sensitivity of various observables to the $WWγ$ vertex. We included gauge boson decay to final state fermions and all contributions to the same final state. The contributions of the non-resonant diagrams and their interference with the resonant gauge boson production diagrams give

J. Kiskis, P. Vranas

The behavior of the adjoint Wilson line in finite-temperature, $SU(2)$, lattice gauge theory is discussed. The expectation value of the line and the associated excess free energy reveal the response of the finite-temperature gauge field to the presence of an adjoint source. The value of the adjoint line at the critical point of the deconfining phase transiti

C. J. Griffin, T. D. Kieu

Random-lattice fermions have been shown to be free of the doubling problem if there are no interactions or interactions of a non-gauge nature. However, gauge interactions impose stringent constraints as expressed by the Ward-Takahashi identities which could revive the free-field suppressed doubler modes in loop diagrams. After introducing a formulation for f

Kristin Schleich, Donald M. Witt

This paper proposes to generalize the histories included in Euclidean functional integrals from manifolds to a more general set of compact topological spaces. This new set of spaces, called conifolds, includes nonmanifold stationary points that arise naturally in a semiclasssical evaluation of such integrals; additionally, it can be proven that sequences of

F. Dalfovo

A density functional theory is used to predict the binding energy of atomic and molecular impurities (Ne, Ar, Kr, Xe, Li, Na, K, Rb, Cs, and SF$_6$) in the center of $^4$He clusters, in the limit of zero temperature and for zero angular momentum states. The size dependence of the binding energy, from small clusters to the bulk liquid limit, is investigated.

Sabrina Oppo, Vincenzo Fiorentini, Matthias Scheffler

We present first-principles studies of the adsorption of Sb and Ag on clean and Sb-covered Ag (111). For Sb, the {\it substitutional} adsorption site is found to be greatly favored with respect to on-surface fcc sites and to subsurface sites, so that a segregating surface alloy layer is formed. Adsorbed silver adatoms are more strongly bound on clean Ag(111)

A. Pelizzola, A. Stella

We analyze in some detail a recently proposed transfer matrix mean field approximation which yields the exact critical point for several two dimensional nearest neighbor Ising models. For the square lattice model we show explicitly that this approximation yields not only the exact critical point, but also the exact boundary magnetization of a semi--infinite

R. F. Peletier, S. P. Willner

We present new magnitudes derived from 1.65 micron images for 23 galaxies in the Ursa Major cluster. Magnitudes now exist for all but one spiral meeting our criteria for cluster membership and having HI velocity width greater than 187 km/s and inclination greater than 45 deg. These spirals fit a Tully-Fisher relation with dispersion in intrinsic magnitudes (

Michael Stone

This paper is incorrect, and has been withdrawn by the author.

Rudolf A. Römer, Bill Sutherland

In this paper, we continue our investigation of a one-dimensional, two-component, quantum many-body system in which like particles interact with a pair potential $s(s+1)/{\rm sinh}^{2}(r)$, while unlike particles interact with a pair potential $-s(s+1)/{\rm cosh}^{2}(r)$. For an equal number of particles of the two components, the ground state for $s>0$ corr

Peter Kostaedt, Mario Liu

A rigorous hydrodynamic theory of the A-B transition is presented. All dissipative processes are considered. At low interface velocities, those occurring on hydrodynamic length scales, not considered hitherto, are most probably the dominant ones.

B. Blok, L. Koyrakh, M. Shifman, A. I. Vainshtein

Several references added, typos corrected.

K. J. Eskola, Xin-Nian Wang

The space and time evolution of initial parton production in ultrarelativistic heavy ion collisions is investigated within the framework of perturbative QCD which includes both initial and final state radiations. Uncertainty principle is used to relate the life time of a radiating parton to its virtuality and momentum. The interaction time of each hard or se

J. A. de Azcárraga, Demosthenes Ellinas

A method for obtaining complex analytic realizations for a class of deformed algebras based on their respective deformation mappings and their ordinary coherent states is introduced. Explicit results of such realizations are provided for the cases of the $q$-oscillators ($q$-Weyl-Heisenberg algebra) and for the $su_{q}(2)$ and $su_{q}(1,1)$ algebras and thei

Hyuk-jae Lee

By dimensional reduction, Einstein-Hermitian equations of n + 1 dimensional closed Kahler manifolds lead to vortex equations of n dimensional closed Kahler manifolds. A Yang-Mills-Higgs functional to unitary bundles over closed Kahler manifolds has topological invariance by adding the additional terms which have ghost fields. Henceforth we achieve the matter

Hyuk-jae Lee

The structure of topological quantum field theories on the compact Kahler manifold is interpreted. The BRST transformations of fields are derived from universal bundle and the observables are found from the second Chern class of universal bundle.

Kenichiro Aoki

We derive the boson--fermion bound state equation in a two dimensional gauge theory in the large--$\nc$ limit. We analyze the properties of this equation and in particular, find that the mass trajectory is linear with respect to the bound state level for the higher mass states.

M. L. Stong, K. Hagiwara

We study possible deviations from the Standard Model in the reaction $e^+e^- \to Zϕ$, where $ϕ$ denotes a spinless neutral boson. We show how the $Z$ decay angular correlation can be used to extract detailed information on the $ϕ$ couplings, such as the parity of $ϕ$, radiatively induced form factor effects and possible CP violation in the scalar sector.

Patrick J. O'Donnell, Utpal Sarkar

We consider the three lepton decay modes of the proton within the proton decay interpretation of the atmospheric neutrino anomaly. We construct higher dimensional operators in the framework of the standard model. The operators which allow the particularly interesting decay mode are of dimension 10 involving $SU(2)_L$ non-singlet higgs. We show how these oper

Mark Hindmarsh, R. J. Rivers

We construct a new coarse-grained effective potential which enables us to estimate the probabilities of thermal fluctuations above an arbitrary threshold at different length scales.

R. Alemany, J. J. Gomez-Cadenas, M. C. Gonzalez-Garcia, J. W. F. Valle

We discuss the potential of $τ$-charm and B factories for the search of new physics through the study of rare $τ$ decays. We consider decays that involve the violation of lepton flavour conservation. Such decays bear a close relationship to the physics of neutrino mass and the properties of the lepton sector of the electroweak theory.

Frank Close

I discuss the special opportunities that a Tau-Charm Factory offers for identifying gluonic excitations, hybrid charmonium and other exotic hadronic states. (Invited talk at TCF Workshop, Marbella, 1-6June)

S. M. Troshin, N. E. Tyurin

We consider consequences of violation of the black disk limit possibly revealed by the new CDF measurements of the total, elastic and diffractive cross--sections.