January 1993 arXiv papers — page 3

Jacob D. Bekenstein

Hawking's radiance, even as computed without account of backreaction, departs from blackbody form due to the mode dependence of the barrier penetration factor. Thus the radiation is not the maximal entropy radiation for given energy. By comparing estimates of the actual entropy emission rate with the maximal entropy rate for the given power, and using st

Paul Langacker

The implications of the deficit of solar neutrinos are discussed. If all of the experiments are taken literally the relative suppressions render an astrophysical explanation unlikely. Allowing MSW conversions, the data simultaneously determine the temperature of the core of the sun to within five percent. The implications of the atmospheric $ν_μ/ν_e$ ratio a

H. K. Lee, M. A. Nowak, Mannque Rho, I. Zahed

We show how generic nonabelian gauge fields can be induced in baryons when a hierarchy of fast degrees of freedom is integrated out. We identify them with nonabelian Berry potentials and discuss their role in transmuting quantum numbers in bag and soliton models of baryons. The resulting baryonic spectra for both light and heavy quark systems are generic and

P. Colangelo, F. De Fazio, G. Nardulli

We evaluate the non leptonic decays $B \to D^* ππ$ and $B \to D^* ρπ$ in the limit of infinitely heavy quarks, assuming the dominance of intermediate positive parity charmed resonances. We find that the branching ratios are of the order $10^(-3)$.

Balram Rai, Goran Senjanovic

It is well known that the spontaneous breaking of discrete symmetries may lead to conflict with big-bang cosmology. This is due to formation of domain walls which give unacceptable contribution to the energy density of the universe. On the other hand it is expected that gravity breaks global symmetries explicitly. In this work we propose that this could prov

J. F. Wheater, P. W. Stephenson

We investigate the crumpling transition on crystalline random surfaces with extrinsic curvature on lattices up to $64^2$. Our data are consistent with a second order phase transition and we find correlation length critical exponent $ν=0.89\pm 0.07$. The specific heat exponent, $α=0.2\pm 0.15$, is in much better agreement with hyperscaling than hitherto. The

A. M. Green, C. Michael, J. E. Paton, M. E. Sainio

Energies of four-quark systems have been extracted in a quenched SU(2) lattice Monte Carlo calculation for two different geometries, rectangular and colinear, with $β=2.4$ and lattice size $16^3\times 32$. Also, by going to a lattice $24^3\times 32$ and to $β=2.5$, the effect of the finite lattice size and scaling are checked. An attempt is made to understan

Colin J. Morningstar

The heavy quark self-energy in nonrelativistic lattice QCD is calculated to $O(α_s)$ in perturbation theory. An action which includes all spin-independent relativistic corrections to order $v^2$, where $v$ is the typical heavy quark velocity, and all spin-dependent corrections to order $v^4$ is used. The standard Wilson action and an improved multi-plaquette

J. H. Yoon

We propose a 4-dimensional Kaluza-Klein approach to general relativity in the (2,2)-splitting of space-time using the double null gauge. The associated Lagrangian is equivalent to the Einstein-Hilbert Lagrangian, since it yields the same field equations as the E-H Lagrangian does. It is describable as a (1+1)-dimensional Yang-Mills type gauge theory coupled

G. Date, M. Krishna, M. V. N. Murthy

The spectrum of anyons confined in harmonic oscillator potential shows both linear and nonlinear dependence on the statistical parameter. While the existence of exact linear solutions have been shown analytically, the nonlinear dependence has been arrived at by numerical and/or perturbative methods. We develop a method which shows the possibility of nonlinea

G. Date, M. V. N. Murthy

In this paper we show that (a) all the known exact solutions of the problem of N-anyons in oscillator potential precisely arise from the collective degrees of freedom, (b) the system is pseudo-integrable ala Richens and Berry. We conclude that the exact solutions are trivial thermodynamically as well as dynamically.

A. H. MacDonald, S. -R. Eric Yang, M. D. Johnson

In this article we discuss the ground state of a parabolically confined quantum dots in the limit of very strong magnetic fields where the electron system is completely spin-polarized and all electrons are in the lowest Landau level. Without electron-electron interactions the ground state is a single Slater determinant corresponding to a droplet centered on

Peter L. Biermann

I develop a theory to account for the cosmic ray spectrum. The essential assumption is that, due to fast convective motions, the free mean path perpendicular to the magnetic field is independent of energy and has the scale of the thickness of the shocked layer. I use the basic concept, that the energetic Cosmic Ray particles are accelerated in a Supernova sh

R. Penrose, R. D. Sorkin, E. Woolgar

A positive mass theorem for General Relativity Theory is proved. The proof is 4-dimensional in nature, and relies completely on arguments pertaining to causal structure, the basic idea being that positive energy-density focuses null geodesics, and correspondingly retards them, whereas a negative total mass would advance them. Because it is not concerned with

James D. E. Grant

(One typo corrected and one incorrect statement removed. Extra details on conserved quantities and symmetry algebras added).

David Seibert

I estimate the degree of local chemical equilibration for $π$, $ρ$ and $ω$ mesons in ultra--relativistic nuclear collisions. The $π$ and $ρ$ mesons remain near chemical equilibrium in all cases, while the $ω$ meson density is typically 30--50\% higher than the equilibrium value for O+Ag collisions at $\sqrt{s}=20$ GeV. If chemical reactions are turned off, t

M. Campanelli, C. O. Lousto

We study a three-parameters family of solutions of the Brans-Dicke field equations. They are static and spherically symmetric. We find the range of parameters for which this solution represents a black hole different from the Schwarzschild one. We find a subfamily of solutions which agrees with experiments and observations in the solar system. We discuss som

Jacek Miekisz

We give a strong evidence that noncrystalline materials such as quasicrystals or incommensurate solids are not exceptions but rather are generic in some regions of a phase space. We show this by constructing classical lattice-gas models with translation-invariant, finite-range interactions and with a unique quasiperiodic ground state which is stable against

J. Gonzalez, M. A. Martin-Delgado

We propose an approach to statistical systems on lattices with sphere-like topology. Focusing on the Ising model, we consider the thermodynamic limit along a sequence of lattices which preserve the {\em fixed} large scale geometry. The hypothesis of scaling appears to hold at criticality, pointing at a sensible definition of the continuum limit of the model

Haye Hinrichsen, Vladimir Rittenberg

We show in two simple examples that for one-dimensional quantum chains with quantum group symmetries, the correlation functions of local operators are, in general, infrared divergent. If one considers, however, correlation functions invariant under the quantum group, the divergences cancel out.

M. Tonin

In this talk new formulations of the Green--Schwarz heterotic strings in $D$ dimensions that involve commuting spinors, are reviewed. These models are invariant under $n$--extended, world sheet supersymmetry as well as under $N=1$, target space supersymmetry where $n\leq D-2$ and $D=3,4,6,10$. The world sheet supersymmetry replaces $n$ components (and provid

Makoto Sakamoto

We study string theory on orbifolds in the presence of an antisymmetric constant background field in detail and discuss some of new aspects of the theory. It is pointed out that the term with the antisymmetric background field can be regarded as a topological term like a Chern-Simons term or a Wess-Zumino term. Detailed analysis in the operator formalism sho

Feng Yu

An infinite number of free field realizations of the universal nonlinear $\hat{W}_{\infty}^{(N)}$ ($\hat{W}_{1+\infty}^{(N)}$) algebras, which are identical to the KP Hamiltonian structures, are obtained in terms of $p$ plus $q$ scalars of different signatures with $p-q=N$. They are generalizations of the Miura transformation, and naturally give rise to the

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

We consider the implications of the recent results of SAGE and GALLEX experiments for the solution of the solar neutrino problem in the framework of the resonant neutrino spin-flavor precession scenario. It is shown that this scenario is consistent with all the existing solar neutrino data including the gallium results. The quality of the fit of the data dep

F. K. Diakonos, O. Korakianitis, C. G. Papadopoulos, C. Philippides

The reaction $pp \to W \ +\ γ +\ jet \ +\ X$ is considered at centre-of-mass energies $\sqrt{s} = 16$ and $40\;\tev$, including anomalous three-gauge-boson couplings $κ$ and $λ$. The possibility of obtaining limits on these quantities by comparison with the standard model is investigated. The radiation zero properties of the subprocess matrix elements are st

Massimo Porrati

I show that the gravitational scattering amplitudes of a spin-5/2 field with mass $m\ll M_{Pl}$ violate tree-level unitarity at energies $\sqrt{s}\approx\sqrt{mM_{Pl}}$ if the coupling to gravity is minimal. Unitarity up to energies $\sqrt{s}\approx M_{Pl}$ is restored by adding a suitable non-minimal term, which gives rise to interactions violating the (str

Erik Westerberg, T. H. Hansson

We discuss the quantum mechanics of particles of arbitrary statistics on an infinite cylinder with and without a magnetic field perpendicular to the surface. In the presence of a magnetic field, the translational symmetry along the cylinder is broken down to a discrete one by the Aharonov-Bohm effect. For interacting fermions in a strong field we get an effe

Jacek Miekisz

A classical lattice gas model with translation-invariant finite range competing interactions, for which there does not exist an equivalent translation-invariant finite range nonfrustrated potential, is constructed. The construction uses the structure of nonperiodic ground state configurations of the model. In fact, the model does not have any periodic ground

P. Mészáros, P. Laguna, M. J. Rees

We calculate both analytically and numerically the evolution of a highly relativistic fireball through the stages of free expansion and coasting, and determine the dependence of the thermodynamic and radiation variables in the comoving and laboratory frames. Magnetic fields may have been important in the original impulsive event. We discuss their effect on t

R. Capuzzo-Dolcetta

Dynamical friction due to field stars and tidal disruption caused by a central nucleus are crucial in determining the evolution of the globular cluster system in an elliptical galaxy. In this paper I examine the possibility that some of galactic nuclei have been formed by frictionally decayied globular clusters moving in a triaxial potential. The initial rap

R. Gregory, R. Laflamme

We investigate the evolution of small perturbations around black strings and branes which are low energy solutions of string theory. For simplicity we focus attention on the zero charge case and show that there are unstable modes for a range of time frequency and wavelength in the extra $10-D$ dimensions. These perturbations can be stabililized if the extra

James B. Hartle

Measurement is a fundamental notion in the usual approximate quantum mechanics of measured subsystems. Probabilities are predicted for the outcomes of measurements. State vectors evolve unitarily in between measurements and by reduction of the state vector at measurements. Probabilities are computed by summing the squares of amplitudes over alternatives whic

David Seibert

Requirements for correlation measurements in high--multiplicity events are discussed. Attention is focussed on detection of so--called hot spots, two--particle rapidity correlations, two--particle momentum correlations (for quantum interferometry) and higher--order correlations. The signal--to--noise ratio may become large in the high--multiplicity limit, al

I. Bars, K. Sfetsos

We present an effective quantum action for the gauged WZW model $G_{-k}/H_{-k}$. It is conjectured that it is valid to all orders of the central extension $(-k)$ on the basis that it reproduces the exact spacetime geometry of the zero modes that was previously derived in the algebraic Hamiltonian formalism. Besides the metric and dilaton, the new results tha

R. Kedem, T. R. Klassen, B. M. McCoy, E. Melzer

We present sum representations for all characters of the unitary Virasoro minimal models. They can be viewed as fermionic companions of the Rocha-Caridi sum representations, the latter related to the (bosonic) Feigin-Fuchs-Felder construction. We also give fermionic representations for certain characters of the general $(G^{(1)})_k \times (G^{(1)})_l \over (

John Harnad, Craig A. Tracy, Harold Widom

The level spacing distributions in the Gaussian Unitary Ensemble, both in the ``bulk of the spectrum,'' given by the Fredholm determinant of the operator with the sine kernel ${\sin π(x-y) \over π(x-y)}$ and on the ``edge of the spectrum,'' given by the Airy kernel ${\rm{Ai}(x) \rm{Ai}'(y) - \rm{Ai}(y) \rm{Ai}'(x) \over (x-y)}$, are d

Murat Gunaydin

We study the conformal groups of Jordan algebras along the lines suggested by Kantor. They provide a natural generalization of the concept of conformal transformations that leave 2-angles invariant to spaces where "p-angles" can be defined. We give an oscillator realization of the generalized conformal groups of Jordan algebras and Jordan triple syst

Murat Gunaydin

As shown by Witten the N=1 supersymmetric gauged WZW model based on a group G has an extended N=2 supersymmetry if the gauged subgroup H is so chosen that G/H is Kahler. We extend Witten's result and prove that the N=1 supersymmetric gauged WZW models over G X U(1) are actually invariant under N=4 superconformal transformations if the gauged subgroup H i

Boris Feigin, Edward Frenkel

We prove that the dimensions of coinvariants of certain nilpotent subalgebras of the Virasoro algebra do not change under deformation in the case of irreducible representations of (2,2r+1) minimal models. We derive a combinatorial description of these representations and the Gordon identities from this result.

Andrzej Czarnecki, Sacha Davidson

We present an analytic formula for the $O(α_s)$ corrections to the decay $t\to H^+b$ for nonzero $m_H$ and $m_b$. The Equivalence Theorem is used to relate these corrections to those for the process $t\to W^+b$. Contrary to previously published results we find that the effect of the $b$ quark mass is negligible for a wide range of $m_t$, $m_H$ and $\tan β$.

Jean-Paul BLAIZOT, Edmond IANCU

We show that longwavelength excitations of the quark-gluon plasma are described by simple kinetic equations which represent the exact equations of motion at leading order in $g$. Properties of the so-called ``hard thermal loops'', i.e. the dominant contributions to amplitudes with soft external lines, find in this approach a natural explanation. In p

Antonio Riotto

We investigate an extension of the Singlet Majoron Model in which the breaking of dilatation symmetry by the mass parameters of the scalar potential is removed by means of a dilaton field. Starting from the one-loop renormalization group improved potential, we discuss the ground state of the theory. The flat direction in the classical potential is lifted by

V. Singh, D. A. Browne, R. W. Haymaker

We calculate the electric flux and magnetic monopole current distribution in the presence of a static quark-antiquark pair for SU(2) lattice gauge theory in the maximal Abelian gauge. The current distribution confines the flux in a dual Abrikosov vortex whose core size is comparable to the flux penetration depth. The observed structure is described by a dual

R. Ben-Av, G. Bhanot

We describe a method to study the rate at which modes decorrelate in numerical simulations. We study the XY model updated with the Metropolis and Wolff dynamics respectively and compute the rate at which each eigenvector of the dynamics decorrelates. Our method allows us to identify the decorrelation time for each mode separately. We find that the autocorrel

Dingping Li

We construct the hierarchical wave function of the spin-singlet fractional quantum Hall effect, which turns out to satisfy Fock cyclic condition. The spin-statistics relation of the quasi-particles in the spin-singlet fractional quantum Hall effect is also discussed. Then we use particle-hole conjugation to check the wave function.

Peter Ossadnik, Jysoo Lee

Using both analytic and numerical methods, we study the radial growth probability distribution $P(r,M)$ for large scale off lattice diffusion limited aggregation (DLA) clusters. If the form of $P(r,M)$ is a Gaussian, we show analytically that the width $ξ(M)$ of the distribution {\it can not} scale as the radius of gyration $R_G$ of the cluster. We generate

R. Mayle, D. N. Schramm, M. S. Turner, J. Wilson

The Livermore Supernova Explosion Code was used to calculate the effect of a massive Dirac neutrino on neutrino emission from SN 1987A in a fully self-consistent manner. Spin-flip interactions lead to the copious emission of sterile, right-handed neutrinos and cool the core faster than the observed neutrino emission time for Dirac masses exceeding about 3$\,

Edward Witten

This is a study of the Landau-Ginzburg/Calabi-Yau correspondence, and related matters, using linear sigma models.

V. Pleitez, M. D. Tonasse

We consider an $SU(3)_L\otimes U(1)_N$ model for the electroweak interactions which includes extra charged leptons which do not mix with the known leptons. These new leptons couple to $Z^0$ only through vector currents. We consider constraints on the mass of one of these leptons coming from the $Z^0$-width and from the muon $(g-2)$ factor. The last one is le

Paul S. Aspinwall, Brian R. Greene, David R. Morrison

We use mirror symmetry to establish the first concrete arena of spacetime topology change in string theory. In particular, we establish that the {\it quantum theories} based on certain nonlinear sigma models with topologically distinct target spaces can be smoothly connected even though classically a physical singularity would be encountered. We accomplish t

M. A. Alberg, E. M. Henley, L. Wilets, P. D. Kunz

A quark model which includes both scalar and vector contributions to the reaction mechanism is used in a DWBA calculation of total and differential cross-sections, polarizations, and spin correlation coefficients for the reaction $\bar p p \rightarrow \bar ΛΛ$ at laboratory momenta from threshold to 1.92 GeV/c. The free parameters of the calculation include

Oleg Mokhov

In this paper we consider symplectic and Hamiltonian structures of systems generated by actions of sigma-model type and show that these systems are naturally connected with specific symplectic geometry on loop spaces of Riemannian and (pseudo)Riemannian manifolds.

Doron Gepner, Jurgen Fuchs

Braiding matrices in rational conformal field theory are considered. The braiding matrices for any two block four point function are computed, in general, using the holomorphic properties of the blocks and the holomorphic properties of rational conformal field theory. The braidings of $SU(N)_k$ with the fundamental are evaluated and are used as examples. Sol

Samir D. Mathur

We study the real time formalism of non-equilibrium many-body theory, in a first quantised language. We argue that on quantising the relativistic scalar particle in spacetime with Minkowski signature, we should study both propagations $e^{i(p^2-m^2)\tilde λ}$ and $e^{-i(p^2-m^2)\tilde λ}$ on the particle world line. The path integral needs regulation at the

Ansar Fayyazuddin

In this paper I discuss how the component structure of anyon wave functions arises in theories with non-relativistic matter coupled to a Chern-Simons gauge field on the torus. It is shown that there exists a singular gauge transformation which brings the Hamiltonian to free form. The gauge transformation removes a degree of freedom from the Hamiltonian. This

L. Frappat, E. Ragoucy, P. Sorba

In the same way the folding of the Dynkin diagram of A_{2n} (resp. A_{2n-1}) produces the B_n (resp. C_n) Dynkin diagram, the symmetry algebra W of a Toda model based on B_n (resp. C_n) can be seen as resulting from the folding of a W-algebra based on A_{2n} (resp. A_{2n-1}). More generally, W algebras related to the B-C-D algebra series can appear from W al

Matthias Staudacher

We write down and solve a closed set of Schwinger-Dyson equations for the two-matrix model in the large $N$ limit. Our elementary method yields exact solutions for correlation functions involving angular degrees of freedom whose calculation was impossible with previously known techniques. The result sustains the hope that more complicated matrix models impor

Kyungsik Kang, Alan R. White

We suggest that the sextet color condensation model is not only the simplest and most attractive scheme to modify the standard model but also may already have some ``experimental" support. The crucial test may be to observe a short-- lived axion--like $η_6$ of mass around 60 GeV/$c^2$ that can produce high energy photon pairs diffractively at hadron coll

Felix Schlumpf

We demonstrate that a relativistic constituent-quark model can give nucleon form factors in agreement with data for both low and high momentum transfer. The relativistic features of the model and the specific form of the wave function are essential for the result.

J. T. Peltoniemi, J. W. F. Valle

We show that certain models for neutrino masses that lead to the MSW explanation of the solar neutrino data and/or the hot dark matter component in the universe can also naturally allow for the successful generation of the cosmological baryon asymmetry at the electroweak scale. This follows either because the experimental Higgs boson mass limit is weakened d

K. Langfeld, H. Reinhardt

Field strength formulated Yang-Mills theory is confronted with the traditional formulation in terms of gauge fields. It is shown that both formulations yield the same semiclassics, in particular the same instanton physics. However, at the tree level the field strength approach is superior because it already includes a good deal of of quantum fluctuations of

M. Gasperini, M. Giovannini

We estimate the entropy associated to a background of squeezed cosmic gravitons, and we argue that the process of cosmological pair production from the vacuum may explain the large amount of entropy of our present universe.

Gary T. Horowitz

If string theory describes nature, then charged black holes are not described by the Reissner-Nordstrom solution. This solution must be modified to include a massive dilaton. In the limit of vanishing dilaton mass, the new solution can be found by a generalization of the Harrison transformation for the Einstein-Maxwell equations. These two solution generatin

Tsvi Piran, Amotz Shemi, Ramesh Narayan

We examine analytically and numerically the evolution of a relativistic fireball. We show that, after an early rearrangement phase, most of the matter and energy in the fireball is concentrated within a narrow shell. The shell propagates at nearly the speed of light, with a frozen radial profile and according to a simple set of scaling laws. The spectrum of

Pablo Sisterna, Hector Vucetich

According to recent reports there is an excess correlation and an apparent regularity in the galaxy one-dimensional polar distribution with a characteristic scale of 128 $h^{-1}$ Mpc. This aparent spatial periodicity can be naturally explained by a time oscillation of the gravitational constant $G$. On the other hand, periodic growth features of bivalve and

Colin Wilkin

It is shown that the striking energy variation in the $p\, d \rightarrow \mbox{$^{\, 3}{\rm He}$}\, η$ cross section near threshold is probably due to a final state interaction associated with a large (complex) $η-\mbox{$^{3}{\rm He}$}$ scattering length. The consequences of this hypothesis are studied for the production of the meson in the $η-\mbox{$^{4}{\r

Chihong Chou, V. P. Nair, A. Polychronakos

Using the appropriate representation of the Poincare group and a definition of minimal coupling, we discuss some aspects of the electromagnetic interactions of charged anyons. In a nonrelativistic expansion, we derive a Schrodinger-type equation for the anyon wave function which includes spin-magnetic field and spin-orbit couplings. In particular, the gyroma

Mario Bergeron, David Eliezer, Gordon Semenoff

We find an explicit solution of the Schrödinger equation for a Chern-Simons theory coupled to charged particles on a Riemann surface, when the coefficient of the Chern-Simons term is a rational number (rather than an integer) and where the total charge is zero. We find that the wave functions carry a projective representation of the group of large gauge tran

Ramzi R. Khuri

In recent work a multimonopole solution of heterotic string theory was obtained. The monopoles are noted to be stable, in contrast with analogous solutions of Einstein-Maxwell or Yang-Mills-dilaton theory. The existence of this and other classes of stable solitonic solutions in string theory thus provides a possible test for low-energy string theory as disti

E. C. Marino

We study the electrodynamics of generic charged particles (bosons, fermions, relativistic or not) constrained to move on an infinite plane. An effective gauge theory in 2+1 dimensional spacetime which describes the real electromagnetic interaction of this particles is obtained. The relationship between this effective theory with the Chern-Simons theory is ex

I. Antoniadis, T. R. Taylor

We report on the recent progress in computing the effective supergravity action from superstring scattering amplitudes beyond the tree approximation. We discuss the moduli-dependent string loop corrections to gauge, gravitational and Yukawa couplings.

K. Zarembo

The spatially inhomogeneous large $N$ solutions to Kazakov--Migdal model are analyzed. The set of nonlinear differential equations is derived in the continuum limit. In one dimensional case these equations has a natural interpretation in terms of the dynamics of a Fermi gas. The multidimensional case seems to be inconsistent because of its instability relate

C. Imbimbo

We consider the quantum-mechanical algebra of observables generated by canonical quantization of $SL(2,R)$ Chern-Simons theory with rational charge on a space manifold with torus topology. We produce modular representations generalizing the representations associated to the $SU(2)$ WZW models and we exhibit the explicit polynomial representations of the corr

Gregory Falkovich, Amihay Hanany

A critical analysis of the conformal approach to the theory of 2d turbulence is delivered. It is shown, in particular, that conformal minimal models cannot give a general turbulent solution, which should provide for constant fluxes of all vorticity integrals of motion.

M. J. Musolf, M. Burkardt

Intrinsic strangeness contributions to low-energy strange quark matrix elements of the nucleon are modelled using kaon loops and meson-nucleon vertex functions taken from nucleon-nucleon and nucleon-hyperon scattering. A comparison with pion loop contributions to the nucleon electromagnetic (EM) form factors indicates the presence of significant SU(3)-breaki

J. -M. Frère, L. Houart, J. M. Moreno, J. Orloff

Fermions scattering off first-order phase transition bubbles, in the framework of $SU(2)_L\otimes SU(2)_R\otimes U(1)$ models, may generate the Baryon Asymmetry of the Universe (BAU), either at the $LR$-symmetry-breaking scale, or at the weak scale. In the latter case, the baryon asymmetry of the Universe is related to CP violation in the $K_0$--$\bar K_0$ s

H. Reinhardt, K. Langfeld, L. v. Smekal

It is shown that the field strength formulated Yang-Mills theory yields the same semiclassics as the standard formulation in terms of the gauge potential. This concerns the classical instanton solutions as well as the quantum fluctuations around the instanton.

J. M. P. Carmelo, A. H. Castro Neto

The conformal invariant character of $ν$-multicomponent integrable systems (with $ν$ branches of gapless excitations) is described from the point of view of the response to curvature of the two-dimensional space. The $ν\timesν$ elements of the dressed charge matrix are shown to be transition matrix elements of the zero ($μ=0$) components of the diagonal gene

Olle Heinonen, Walter Kohn

We discuss the effects of surfaces on bulk plasma oscillations in a metallic film of thickness $L$. The leading corrections to the plasma frequencies due to the surfaces are proportional to $L^{-1}$. dispersion relation of bulk modes, $ω=ω_p[1+α(q^2/k_F^2)] $, where the allowed $q$-values are $q^{(n)}=(nπ/\overline L)$, $\overline L\equiv L-2d_b$, and $d_b$

Y. Meir, O. Entin-Wohlman

Random matrix theory of the transition strengths is applied to transport in the strongly localized regime. The crossover distribution function between the different ensembles is derived and used to predict quantitatively the {\sl universal} magnetoconductance curves in the absence and in the presence of spin-orbit scattering. These predictions are confirmed

P. Fazekas, Hae-Young Kee

It has been suggested recently by Gan, Coleman, and Andrei that studying the underscreened Kondo problem may help to understand the nature of magnetism in heavy fermion systems. Motivated by Doniach's work on the S=1/2 Kondo necklace, we introduce the underscreened Kondo necklace models with S>1/2. The underscreened Kondo necklace is the simplest lattice

Domingos H. U. Marchetti

An alternative to Plemelj - Smithies formulas for the p -regularized quantities $d^{(p)}(K)$ and $D^{(p)}(K)$ is presented which generalizes previous expressions with $p=1$ due to Grothendieck and Fredholm. It is also presented global upper bounds for these quantities. In particular we prove that $$ |d^{(p)}(K)| \le e^{κ\n K \n_p^p} $$ holds with $κ= κ(p) \l

Ronnie Mainieri

A cycle expansion for the Lyapunov exponent of a product of random matrices is derived. The formula is non-perturbative and numerically effective, which allows the Lyapunov exponent to be computed to high accuracy. In particular, the free energy and the heat capacity are computed for the one-dimensional Ising model with quenched disorder. The formula is deri

A. Abbasabadi, David Bowser-Chao, Duane A. Dicus, Wayne W. Repko

We study the effects of a strongly interacting Higgs sector on the amplitudes for $γ\,γ\rightarrow W_L^+\,W_L^-, Z_L^{\,0}\,Z_L^{\,0}$ by unitarizing the $W_L^+\,W_L^-, Z_L^{\,0}\,Z_L^{\,0}, γ\,γ$ system using the $K$--matrix technique. Unitarization produces substantial corrections to the cross sections for gauge boson pair production by photon fusion when

V. O. Rivelles

We present a topological version of two dimensional dilaton supergravity. It is obtained by gauging an extension of the super-Poincaré algebra in two space-time dimensions. This algebra is obtained by an unconventional contraction of the super de Sitter algebra. Besides the generators of the super de Sitter algebra it has one more fermionic generator and two

A. Soni, R. M. Xu

Since decays to four leptons is widely considered a promising way to search for the Higgs particle, we show how the same final state can also be used to search for signals of CP nonconservation. Energy asymmetries and triple correlations are related to parameters in the underlying CP violating effective interaction at the $H^0$-$W$-$W$ and $H^0$-$Z$-$Z$ vert

Jorge Pullin

These notes summarize the lectures delivered in the V Mexican School of Particle Physics, at the University of Guanajuato. We give a survey of the application of Ashtekar's variables to the quantization of General Relativity in four dimensions with special emphasis on the application of techniques of analytic knot theory to the loop representation. We di

Yoshiaki Tanii, Masakazu Yamashita

Physical states of two-dimensional topological gauge theories are studied using the BRST formalism in the light-cone gauge. All physical states are obtained for the abelian theory. There are an infinite number of physical states with different ghost numbers. Simple examples of physical states in a non-abelian theory are also given.

Yoshiaki Ohkuwa

We confirm that the diagonal elements of the Gell-Mann and Hartle's decoherence decoherence functional are equal to the relative frequencies of the results of many identical experiments, when a set of alternative histories decoheres. We consider both cases of the pure and mixed initial states.

F. Delduc, E. Ivanov

We construct $N=4$ supersymmetric KdV equation as a hamiltonian flow on the $N=4\;SU(2)$ super Virasoro algebra. The $N=4$ KdV superfield, the hamiltonian and the related Poisson structure are concisely formulated in $1D \;N=4$ harmonic superspace. The most general hamiltonian is shown to necessarily involve $SU(2)$ breaking parameters which are combined in

H. J. Schulz

A one--dimensional gas of electrons interacting with long--range Coulomb forces ($V(r) \approx 1/r$) is investigated. The excitation spectrum consists of separate collective charge and spin modes, with the charge excitation energies in agreement with RPA calculations. For arbitrarily weak Coulomb repulsion density correlations at wavevector $4k_F$ decay extr

Jan Bartelski, Stanislaw Tatur

We discuss the influence of glueball coupling to nucleons on the weak axial-vector coupling constants including singlet channel. We consider a possibility of introduction of constituent gluon contribution to the proton spin. The estimated value for this quantity seems to be rather small.

C. Schwiebert

The correspondence between the braid group on a solid torus of arbitrary genus and the algebra of Yang-Baxter and reflection equation operators is shown. A representation of this braid group in terms of $R$-matrices is given. The characteristic equation of the reflection equation matrix is considered as an additional skein relation. This could lead to an int

Miao Li

The field content of the two dimensional string theory consists of the dynamical tachyon field and some nonpropagating fields which consist in the topological sector of this theory. We propose in this paper to study this topological sector as a spacetime gauge theory with a simple centrally extended $w_\infty$ algebra. This $w_\infty$ algebra appears in both

Jeffrey Anderson, Markus A. Luty

We show that the leading $SU(3)$-breaking corrections to the $ΔS = 1$ $f_1$ vector form factors of hyperons are $O(m_s)$ and $O(m_s^{3/2})$, and are expected to be $\sim 20$--$30\%$ by dimensional analysis. This is consistent with the Ademollo--Gatto theorem, in a sense that we explain. We compute the $O(m_s)$ corrections and a subset of the $O(m_s^{3/2})$ c

Ole Warnaar, Bernard Nienhuis

An equivalence between generalised restricted solid-on-solid (RSOS) models, associated with sets of graphs, and multi-colour loop models is established. As an application we consider solvable loop models and in this way obtain new solvable families of critical RSOS models. These families can all be classified by the Dynkin diagrams of the simply-laced Lie al

Chung-I Tan

By using lessons learned from modern string studies, we show how interesting non-perturbative features of QCD can be learned from future heavy ion collisions even if the deconfinement density is not reached.

David Seibert, Kevin Haglin, Charles Gale

We show how to determine the ratio of the transverse velocity of a source to the velocity of emitted particles, using split-bin correlation functions. The technique is to measure $S_2$ and $S_2^{\phi}$, subtract the contributions from the single-particle distribution, and take the ratio as the bin size goes to zero. We demonstrate the technique for two cases

Laurent Lellouch, Lisa Randall, Eric Sather

H.~Yamamoto has proposed employing $B$ mesons produced in conjunction with a single charged pion at an $Υ$ resonance for studies of CP violation in the neutral $B$ meson system at a symmetric $e^+$-$e^-$ collider. The sign of the charged pion would tag the neutral $B$ meson. We estimate this branching ratio, employing the heavy meson chiral effective field t

Dimitris Kominis, R. Sekhar Chivukula

We examine perturbatively the two-Higgs-doublet extension of the \SM\ in the context of the suspected triviality of theories with fundamental scalars. Requiring the model to define a consistent effective theory for scales below a cutoff of $2π$ times the largest mass of the problem, as motivated by lattice investigations of the one-Higgs-doublet model, we ob