December 1992 arXiv papers — page 4

N. G. Uraltsev

Inclusive and exclusive decays of heavy flavours look quite different from a theoretical viewpoint. We argue that inclusive decays can be treated quantitatively and report on the calculation of the perturbative corrections to the Final State Interaction phases in connection to their impact on effects of CP violation.

A. C. Mattingly, P. M. Stevenson

We discuss the use of the optimization procedure based on the Principle of Minimal Sensitivity to the third-order calculation of {\mbox{${R_{e^+e^-}}$}}. The effective coupling constant remains finite allowing us to apply the Poggio-Quinn-Weinberg smearing method down to energies below 1 GeV, where we find good agreement between theory and experiment. The co

J. L. Goity

The electromagnetic contribution to the isomultiplet mass splittings of heavy mesons is reanalyzed within the framework of the heavy mass expansion. It is shown that the leading term in the expansion is given to a good approximation by the elastic term. $1/m_{Q}$-corrections can only be estimated, the main source of uncertainty now being inelastic contributi

P. Hernandez, F. J. Vegas

Low energy effects of generic extensions of the Standard Model can be comprehensively parametrized in terms of higher dimensional effective operators. After the success of all the recent precission tests on the Standard Model, we argue that any sensible description of these extensions at the Z-scale must be stable under higher order quantum corrections. The

Leandros Perivolaropoulos

We use the analytical model recently introduced in Ref. \cite{lp92}, to investigate the statistics of temperature fluctuations on the cosmic microwave background (CMB), induced by topological defects. The cases of cosmic strings and textures are studied. We derive analytically the characteristic function of the probability distribution for ${δT}\over T$ and

Didier Poilblanc, Timothy Ziman, H. J. Schulz, Elbio Dagotto

A finite size scaling analysis of the spectral function and of the optical conductivity of a single hole moving in an antiferromagnetic background is performed. It is shown that both the low energy quasiparticle peak and the broad higher energy structure are robust with increasing cluster size from $4\times 4$ to $\sqrt{26}\times\sqrt{26}$ sites. In the absc

Jose Riera, Elbio Dagotto

A simple variation of the Lanczos method is discussed. The new technique is based on a systematic reduction of the size of the Hilbert space of the model under consideration. As an example, the two dimensional ${\rm t-J_z}$ model of strongly correlated electrons is studied. Accurate results for the ground state energy can be obtained on clusters of up to 50

Elbio Dagotto, Jose Riera

Superconducting correlations in the two dimensional ${\rm t-J}$ model at zero temperature are evaluated using numerical techniques. At the fermionic density $\langle n \rangle \sim 1/2$, strong signals of $\dx2y2$ superconductivity were observed in the ground state. These conclusions are based on a study of static pairing correlations, the Meissner effect, f

Y. Meir, N. S. Wingreen, P. A. Lee

NEC technical report 92-079-2-0077-1.

U. -J. Wiese, H. -P. Ying

We perform numerical simulations of the 2-d antiferromagnetic quantum Heisenberg model using an efficient cluster algorithm. Comparing the finite size and finite temperature effects of various quantities with recent results from chiral perturbation theory we are able to determine the low energy parameters of the system very precisely. We find $e_0 = - 0.6693

David Cai, A. R. Bishop, Angel Sanchez

It is shown that there are two different regimes for the damped sine-Gordon chain driven by the spatio-temporal periodic force $Γsin(ωt - k_{n} x)$ with a flat initial condition. For $Γ_{c}(n)$ to a translating {\em 2-breather} excitation from a state locked to the driver. For $ω< k_{n}$, the excitations of the system are the locked states with the phase vel

Heino Falcke, Peter L. Biermann, Wolfgang J. Duschl, Peter G. Mezger

Recent observations of Sgr A* give strong constraints for possible models of the physical nature of Sgr A* and suggest the presence of a massive black~hole with M<2 10^6 M_sun surrounded by an accretion disk which we estimate to radiate at a luminosity of <7 10^5 L_sun. We therefore calculate the appearance of a standard accretion disk around a Kerr hole in

P. E. L. Rakow

The existence of the monopole condensation transition reported by Kocic et al. in non-compact, quenched QED is tested. No phase transition is found. This shows that divergence of the `monopole susceptibility&#39; introduced by Hands and Wensley is not a reliable indicator of second order phase transitions. In view of these results I discuss claims that the c

I. I. Bigi, B. Blok, M. Shifman, N. G. Uraltsev

A selfconsistent treatment of nonperturbative effects in inclusive nonleptonic and semileptonic decays of beauty and charm hadrons is presented. It is illustrated by calculating semileptonic branching ratios, lifetime ratios, radiative decay rates and the lepton spectra in semileptonic decays.

Mikhail Lyubich

The Milnor problem on one-dimensional attractors is solved for S-unimodal maps with a non-degenerate critical point c. It provides us with a complete understanding of the possible limit behavior for Lebesgue almost every point. This theorem follows from a geometric study of the critical set $ω(c)$ of a &#34;non-renormalizable&#34; map. It is proven that the

HoSeong La

Time-dependent domain wall solutions with infinitesimal thickness are obtained in the theory of a scalar field coupled to gravity with the dilaton, i.e. the Jordan-Brans-Dicke gravity. The value of the dilaton is determined in terms of the Brans-Dicke parameter $ω$. In particular, the solutions exist for any $ω>0$ and as $ω\to\infty$ we obtain new solutions

E. Langmann, G. W. Semenoff

Using the hamiltonian framework, we analyze the Gribov problem for U(N) and SU(N) gauge theories on a cylinder (= (1+1) dimensional spacetime with compact space S^1). The space of gauge orbits is found to be an orbifold. We show by explicit construction that a proper treatment of the Gribov ambiguity leads to a highly non-trivial structure of all physical st

P. Huet, K. Kajantie, R. G. Leigh, B. -H. Liu

Assuming that the electroweak and QCD phase transitions are first order, upon supercooling, bubbles of the new phase appear. These bubbles grow to macroscopic sizes compared to the natural scales associated with the Compton wavelengths of particle excitations. They propagate by burning the old phase into the new phase at the surface of the bubble. We study t

A. Matsuo

The $q$-vertex operators of Frenkel and Reshetikhin are studied by means of a $q$-deformation of the Wakimoto module for the quantum affine algebra $U_q(\widehat{\sl}_2)$ at an arbitrary level $k\ne 0,-2$. A Fock module version of the $q$-deformed primary field of spin $j$ is introduced, as well as the screening operators which (anti-)commute with the action

Kazuhiro Kimura

A boson representation of the quantum affine algebra $U_q(\widehat{\sl}_2)$ is realized based on the Wakimoto construction. We discuss relations with the other boson representations.

E. Bergshoeff, R. Percacci, E. Sezgin, K. S. Stelle

We consider, for $p$ odd, a $p$--brane coupled to a $(p+1)$th rank background antisymmetric tensor field and to background Yang-Mills (YM) fields {\it via} a Wess-Zumino term. We obtain the generators of antisymmetric tensor and Yang-Mills gauge transformations acting on $p$--brane wavefunctionals (functions on `$p$-loop space&#39;). The Yang-Mills generator

Elizabeth Jenkins, Michael Luke, Aneesh V. Manohar, M. J. Savage

Nonanalytic $m_q^{1/2}$ and $m_q\ln m_q$ chiral corrections to the baryon magnetic moments are computed. The calculation includes contributions from both intermediate octet and decuplet baryon states. Unlike the one-loop contributions to the baryon axial currents and masses, the contribution from decuplet intermediate states does not partially cancel that fr

Thomas D. Cohen, Derek B. Leinweber

Diagrammatic methods and Large $N_c$ QCD are used to argue that the nucleon as calculated in quenched QCD contains physics which can be ascribed to the pion cloud of the nucleon. In particular, it is argued that the physics corresponding to one-pion loops in chiral perturbation theory are included in the quenched approximation.

David Kastor, Jennie Traschen

We present simple, analytic solutions to the Einstein-Maxwell equation, which describe an arbitrary number of charged black holes in a spacetime with positive cosmological constant $Λ$. In the limit $Λ=0$, these solutions reduce to the well known Majumdar-Papapetrou (MP) solutions. Like the MP solutions, each black hole in a $Λ>0$ solution has charge $Q$ equ

Richard Gass, Louis Witten

We argue that the collapse of a non-rotating object into a black hole has not been proved to be dynamically stable. There are unstable modes and one should explore whether they may be excited. This paper is withdrawn for revisions and clarification

Amnon Neeman

Let $G$ be a connected, reductive algeraic group whose Dynkin diagram contains no components of type $G_2,$ $F_4,$ $E_6,$ $E_7$ or $E_8.$ That is, all the components are of classical type. Suppose $X$ is an affine variety, and suppose $G$ acts freely on $X.$ Then $X$ and $X/G$ are stably birationally equivalent.

Gilles Pisier

Let $H,K$ be Hilbert spaces. Let $E \subset B(H)$ and $F \subset B(K)$ be operator spaces in the sense of [1,2]. We study the operators $u : E \to F$ which admit a factorization $E \to OH \to F$ with completely bounded maps through the operator Hilbert space $OH$ which we have introduced and studied in a recent note. We give a characterization of these opera

Gilles Pisier

In Banach space theory, the ``local theory&#39;&#39; refers to the collection of finite dimensional methods and ideas which are used to study infinite dimensional spaces (see e.g. [P4,TJ]). It is natural to try to develop an analogous theory in the recently developed category of operator spaces [BP,B1-2,BS,ER1-7,Ru]. The object of this paper is to start such

Gilles Pisier

We continue an investigation started in a preceding paper. We discuss the classical results of Carleson connecting Carleson measures with the $\d$-equation in a slightly more abstract framework than usual. We also consider a more recent result of Peter Jones which shows the existence of a solution of the $\d$-equation, which satisfies simultaneously a good $

Alexander Koldobsky

Let $E$ be a real Banach space. For $x,y \in E,$ we follow R.James in saying that $x$ is orthogonal to $y$ if $\|x+αy\|\geq \|x\|$ for every $α\in R$. We prove that every operator from $E$ into itself preserving orthogonality is an isometry multiplied by a constant.

V. A. Kazakov

We discuss basic features and new developments in recently proposed induced gauge theory solvable in any number of dimensions in the limit of infinite number of colours. Its geometrical (string) picture is clarified, using planar graph expansion of the corresponding matrix model. New analytical approach is proposed for this theory which is based on its equiv

C. Bachas

The production of o(1/g^2) particles in a weakly-coupled theory is believed to be non-perturbatively suppressed. I comment on the prospects of (a) establishing this rigorously, and (b) estimating the effect to exponential accuracy semiclassically, by discussing two closely-related problems: the large-order behaviour of few-point Green functions, and induced

A. Sedrakyan

A three dimensional string model is analyzed in the strong coupling regime. The contribution of surfaces with different topology to the partition function is essential. A set of corresponding models is discovered. Their critical indices, which depend on two integers (m,n), are calculated analyticaly. The critical indices of the three dimensioal Ising model s

Krzysztof Kowalski

A new method of determining Bäcklund transformations for nonlinear partial differential equations of the evolution type is introduced. Using the Hilbert space approach the problem of finding Bäcklund transformations is brought down to the solution of an abstract equation in Hilbert space.

E. A. Bergshoeff, R. Kallosh, T. Ortin

We present plane-wave-type solutions of the lowest order superstring effective action which have unbroken space-time supersymmetries. They describe dilaton, axion and gauge fields in a stringy generalization of the Brinkmann metric. Some conspiracy between the metric and the axion field is required. We show that there exists a special class of these solution

Jizhi Wu, Shinichi Urano, Richard Arnowitt

A detailed analysis on the rare $τ$ decay {\it via} $\taumue$ and $\taumus$ in the string models with $\e6$ symmetry is reported. It is found that $Γ(\taumue)\sim(6-7)Γ(\taumus)$ and these rates are in general about 1000 times less than that of $Γ(μ\rightarrow eγ)$. It is also found that the out-going muon in $\taumue$ is almost 100\% right-handed polarized

K. Charchula, J. Gajewski

A detailed numerical study of radiative corrections in the low $Q^2$ region at the HERA $ep$ collider was performed. The specific case of the total photoproduction cross section measurement was taken as an example. Two different programs, TERAD91 and HERACLES4.2, were used to get an estimation of the size of radiative effects. It was found that radiative cor

K. S. Babu, S. M. Barr

We show how in a class of models Peccei--Quinn symmetry can be realized as an automatic consequence of a gauged $U(1)$ family symmetry. These models provide a solution to the strong CP problem either via a massless $u$--quark or via the DFSZ invisible axion. The local family symmetry protects against potentially large corrections to $\overlineθ $ induced by

Hisao Nakanishi, Muhammad Sahimi, Michelle C. Robertson, Charles C. Sammis

We investigate a recent suggestion that the spatial distribution of earthquake hypocenters makes a fractal set with a structure and fractal dimensionality close to those of the backbone of critical percolation clusters, by analyzing four different sets of data for the hypocenter distributions and calculating the dynamical properties of the geometrical distri

J. G. Korner, D. Pirjol, K. Schilcher

Minor (mainly numerical) corrections.

Patrick Huet

Presented at the 1992 Meeting of the DPF, Fermilab. The electroweak phase transition is reviewed in light of some recent developments. Emphasis is on the issue whether the transition is first or second order and its possible role in the generation of the baryon asymmetry of the universe.

Hidenori Sonoda

We study the operator product expansion of two non-interacting chiral currents in the presence of external gauge fields in four dimensional euclidean space. We obtain the operator singularity in terms of the beta function of the free energy density and a connection on the space of external gauge fields, by imposing the consistency between the variational for

A L Matacz, A C Ottewill, P C W Davies

We discuss the Starobinskii-Unruh process for the Kerr black hole. We show how this effect is related to the theory of squeezed states. We then consider a simple model for a highly relativistic rotating star and show that the Starobinskii-Unruh effect is absent.

R. De Pietri, L. Lusanna, M. Pauri

A generalization of Newtonian gravitation theory is obtained by a suitable limiting procedure from the ADM action of general relativity coupled to a mass-point. Three particular theories are discussed and it is found that two of them are invariant under an extended Galilei gauge group.

Mirjam Cvetič, Stephen Griffies, Harald H. Soleng

Non-extreme walls (bubbles with two insides) and ultra-extreme walls (bubbles of false vacuum decay) are discussed. Their respective energy densities are higher and lower than that of the corresponding extreme (supersymmetric), planar domain wall. These singularity free space-times exhibit non-trivial causal structure analogous to certain non-extreme black h

Ramzi R. Khuri

In recent work, Dabholkar {\it et al.} constructed static ``cosmic string&#34; solutions of the low-energy supergravity equations of the heterotic string, and conjectured that these solitons are actually exterior solutions for infinitely long fundamental strings. In this paper we provide compelling dynamical evidence to support this conjecture by computing t

S. N. Solodukhin

We consider the topological theory of Witten type for gauge differential p-forms. It is shown that some topological invariants such as linking numbers appear under quantization of this theory. The non-abelian generalization of the model is discussed.

Avinash Dhar, Gautam Mandal, Spenta R. Wadia

We describe a real-time classical solution of $c=1$ string field theory written in terms of the phase space density, $u(p,q,t)$, of the equivalent fermion theory. The solution corresponds to tunnelling of a single fermion above the filled fermi sea and leads to amplitudes that go as $\exp(- C/ \gst)$. We discuss how one can use this technique to describe non

Ramzi R. Khuri

We compute the metric on moduli space for the Dabholkar-Harvey string soliton in $D=4$ to lowest nontrivial order in the string tension. The metric is found to be flat, which implies trivial scattering of the solitons. This result is consistent with an earlier test-string calculation of the leading order dynamical force and a computation of the Veneziano amp

A. Kovner, B. Rosenstein

We present a picture of confinement based on representation of quarks as pointlike topological defects. The topological charge carried by quarks and confined in hadrons is explicitly constructed in terms of Yang - Mills variables. In 2+1 dimensions we are able to construct a local complex scalar field $V(x)$, in terms of whichthe topological charge is $Q=-\f

Edward Hsu, David Kutasov

We use matrix model results to investigate the Sine-Gordon model coupled to two dimensional gravity. For relevant (in the RG sense) potentials, we show that the $c=1$ string, which appears in the ultraviolet limit of this model, flows to a set of decoupled $c=0$ (pure gravity) models in the infrared. The torus partition sum, which was argued previously to co

Charles Nash, Denjoe O&#39; Connor

We obtain explicit expressions for the determinants of the Laplacians on zero and one forms for an infinite class of three dimensional lens spaces $L(p,q)$. These expressions can be combined to obtain the Ray-Singer torsion of these lens spaces. As a consequence we obtain an infinite class of formulae for the Riemann zeta function $ζ(3)$. The value of these

G. Ferretti, Z. Yang

Polyakov has suggested that two dimensional turbulence might be described by a minimal model of conformal field theory. However, there are many minimal models satisfying the same physical inputs as Polyakov&#39;s solution (p,q)=(2,21). Dynamical magnetic fields and passive scalars pose different physical requirements. For large magnetic Reynolds number other

David A. Lowe

Polyakov recently showed how to use conformal field theory to describe two-dimensional turbulence. Here we construct an infinite hierarchy of solutions, both for the constant enstrophy flux cascade, and the constant energy flux cascade. We conclude with some speculations concerning the stability and physical meaning of these solutions.

Beth Basista, Peter Suranyi

A Hamiltonian effective potential (the logarithm of the square of the wave functional) is defined and calculated at the tree and one loop levels in a $ϕ^4$ scalar field theory. The loop expansion for eigenfunctionals is equivalent to the combination of WKB expansion and an expansion around constant field configurations. The results are compared with those ob

M. J. Musolf, T. W. Donnelly

Contributions from physics beyond the Standard Model, strange quarks in the nucleon, and nuclear structure effects to the left-right asymmetry measured in parity-violating (PV) electron scattering from $\nuc{12}{C}$ and the proton are discussed. It is shown how lack of knowledge of the distribution of strange quarks in the nucleon, as well as theoretical unc

Stephen Sharpe

I give a brief overview of the status of lattice QCD, concentrating on topics relevant to phenomenology. I discuss the calculation of the light quark spectrum, the lattice prediction of $α_\MS(M_Z)$, and the calculation of $f_B$.

P. G. Silvestrov

Constrained Instanton and Baryon Number Non--Conservation at High Energies, P.G.Silvestrov, BUDKERINP 92--92. The total cross-section for baryon number violating processes at high energies is usually parametrized as $σ_{total}\propto\exp(\frac{4π}α F(\varepsilon))$, where $\varepsilon =\sqrt{s}/E_0 , \,\, E_0 = \sqrt{6} πm_w/α$. In the present paper the thir

Ornella Pantano, Antonio Riotto

We study the dynamics of the quark-hadron transition for a scenario in which the Universe is matter dominated and a large amount of entropy is generated by decaying particles of mass 1--10 TeV, as suggested by a large class of superstring--inspired models. We estimate the nucleation rate and compute the mean separation between baryon fluctuations generated d

Carl H. Brans, Duane Randall

We review recent developments in differential topology with special concern for their possible significance to physical theories, especially general relativity. In particular we are concerned here with the discovery of the existence of non-standard (``fake&#39;&#39; or ``exotic&#39;&#39;) differentiable structures on topologically simple manifolds such as $S

Thorsten Poeschel

We report on density waves in granular material, investigated both experimentally and numerically. When granular material falls through a long narrow pipe one observes recurrent clogging. The kinetic energy of the falling particles increases up to a characteristic threshold corresponding to the onset of recurrent clogging and density waves of no definite wav

T. Filk, M. Marcu, B. Scheffold

We present results of a high precision Monte Carlo simulation of dynamically triangulated random surfaces (up to $\approx$ 34,000 triangles) coupled to one scalar field ($c=1$). The mean square extent has been measured for different actions to test the universality of the leading term as a function of the size of the surfaces. Furthermore, the integrated 2-p

Ken Yee

A ``3D&#39;&#39; Mathematica@-generated picture of monopoles and Dirac strings in $D=2+1$ compact QED is given. In the Villain approximation, the monopole part of the partition function factorizes from the Dirac string part, which generates the photon propagator. Numerical experiments in exact compact QED confirm this result: photon mass pole $M_γ$, original

V. F. Dmitriev

The excitation of a $Δ$-isobar in a finite nucleus in charge--exchange ($^3\!$He,t) reaction is discussed in terms of a nuclear response function. The medium effects modifying a $Δ$- and a pion propagation were considered for a finite size nucleus. The Glauber approach has been used for distortion of a $^3\!$He and a triton in the initial and the final state

Sy D. Friedman

Let k be a definable L-cardinal. Then there is a set of reals X, class-generic over L, such that L(X) and L have the same cardinals, X has size k in L(X) and some pi-1-2 formula defines X in all set-generic extensions of L(X). Two corollaries, both assuming the consistency of an inaccessible: It is consistent for the Perfect Set Property to hold for boldface

Sy D. Friedman

The purpose of this article is to indicate how a reformulation of Jensen&#39;s $Σ^*$ theory (developed for the study of core models) can be used to provide a more satisfactory treatment of uniformization, hulls and Skolem functions for the $J_α$&#39;s. Then we use this approach to fine structure to formulate a principle intended to capture the combinatorial

Mauro Carfora, Maurizio Martellini, Annalisa Marzuoli

We propose a model which represents a four-dimensional version of Ponzano and Regge&#39;s three-dimensional euclidean quantum gravity. In particular we show that the exponential of the euclidean Einstein-Regge action for a $4d$-discretized block is given, in the semiclassical limit, by a gaussian integral of a suitable $12j$-symbol. Possible developments of

H. Lu, B. E. W. Nilsson, C. N. Pope, K. S. Stelle

We investigate the spectrum of physical states in the $W_3$ string theory, up to level 2 for a multi-scalar string, and up to level 4 for the two-scalar string. The (open) $W_3$ string has a photon as its only massless state. By using screening charges to study the null physical states in the two-scalar $W_3$ string, we are able to learn about the gauge symm

Peter West

A spectrum generating algebra is constructed and used to find all the physical states of the $W_3$ string with standard ghost number. These states are shown to have positive norm and their partition function is found to involve the Ising model characters corresponding to the weights 0 and 1/16. The theory is found to be modular invariant if , in addition, on

Gregory Falkovich, Amihay Hanany

A set of different conformal solutions corresponding to a constant flux of squared vorticity is considered. Requiring constant fluxes of all inviscid vorticity invariants (higher powers of the vorticity), we come to the conclusion that the general turbulence spectrum should be given by Kraichnan&#39;s expression $E(k)\propto k\sp{-3}$. This spectrum, in part

Leonardo Castellani

The inhomogeneous quantum groups $IGL_q(n)$ are obtained by means of a particular projection of $GL_q(n+1)$. The bicovariant differential calculus on $GL_q(n)$ is likewise projected into a consistent bicovariant calculus on $IGL_q(n)$. Applying the same method to $GL_q(n,\Cb)$ leads to a bicovariant calculus for the complex inhomogeneous quantum groups $IGL_

B. A. Harris, G. C. Joshi

Recent developments in quantum gravity suggest that wormholes may influence the observed values of the constants of nature. The Euclidean formulation of quantum gravity predicts that wormholes induce a probability distribution in the space of possible fundamental constants. This distribution may computed by evaluating the functional integral about the statio

M. I. Dobroliubov, I. I. Kogan, G. W. Semenoff, N. Weiss

We examine some properties of the filled Wilson loop observables in the Kazakov-Migdal model of induced QCD. We show that they have a natural interpretation in a modification of the original model in which the $Z_N$ gauge symmetry is broken explicitly by a Wilson kinetic term for the gauge fields. We argue that there are two large N limits of this theory, on

Y. Matsuo

We made a careful study of Polyakov&#39;s Diofantian equations for 2D turbulence and found several additional CFTs which meet his criterion. This fact implies that we need further conditions for CFT in order to determine the exponent of the energy spectrum function.

Jonathan A. Bagger

In this talk we survey the SSC and LHC signals and backgrounds for the physics of electroweak symmetry breaking. We study the process $pp \rightarrow WWX$ and compute the rate for the ``gold-plated&#39;&#39; signals $W^\pm \rightarrow \ell^\pm ν$ and $Z \rightarrow \ell^+\ell^-$ $(\ell = e,μ)$ for a wide variety of models. We use a forward jet tag and centra

John C. Collins, Leonid Frankfurt, Mark Strikman

Diffractive scattering involves exchange of a Pomeron to make a rapidity gap. It is normally assumed that to get a hard scattering in diffraction, one may treat the Pomeron as an ordinary particle, which has distributions of gluons and quarks. We show that this is not so: When we use perturbative QCD, there is a breakdown of the factorization theorem. The wh

Sergio Ferrara, Antonio Masiero, Massimo Porrati

We perform a model-independent analysis of the spontaneously broken phase of an $SU(2)\times U(1)$ supersymmetric gauge theory, by using a non-linear parametrization of the Goldstone sector of the theory. The non-linear variables correspond to an $SL(2,C)$ superfield matrix in terms of which a non-linear Lagrangian can be constructed, and the pattern of supe

J. Letessier, A. Tounsi, U. Heinz, J. Sollfrank

A constraint between thermal fireball parameters arises from the requirement that the balance of strangeness in a fireball is (nearly) zero. We study the impact of this constraint on (multi-)strange (anti-)baryon multiplicities and compare the hadron gas and quark-gluon plasma predictions. We explore the relation between the entropy content and particle mult

B. E. Hanlon, G. C. Joshi

By combining the generalized exterior algebra of forms over a noncommutative algebra with the gauging of discrete directions and the associated Higgs fields, we consider the construction of the bosonic sector of left-right symmetric models of the form $SU(2)_{L}\otimes SU(2)_{R}\otimes U(1)$. We see that within this formalism maximal use can be made of the g

Kei-ichi Kondo, Masaharu Tanabashi, Koichi Yamawaki

Based on the Cornwall-Jackiw-Tomboulis effective potential, we extensively study nonperturbative renormalization of the gauged Nambu-Jona-Lasinio model in the ladder approximation with standing gauge coupling. Although the pure Nambu-Jona-Lasinio model is not renormalizable, presence of the gauge interaction makes it possible that the theory is renormalized

V. P. Gudkov, X. -G. He, B. McKellar

The CP-odd nucleon potential for different models of CP violation in the one meson exchange approximation is studied. It is shown that the main contribution is due to the $π$-meson exchange which leads to a simple one parameter CP-odd nucleon potential.

M. Caselle, A. D&#39;Adda, S. Panzeri

Recently Kazakov and Migdal proposed a new approach to the large $N$ limit of SU(N) gauge theories which could hopefully describe the asymptotically free fixed point of QCD in 4 dimensions. In this contribution we review the exact solution of their model in the case of a $d=1$ compactified lattice and its connection with the partition function of the vortex-

Sean A. Hayward

The global structure of 2-dimensional dilaton gravity is studied, attending in particular to black holes and singularities. A gravitational energy is defined and shown to be positive at spatial singularities and negative at temporal singularities. Trapped points are defined, and it is shown that spatial singularities are trapped and temporal singularities ar

H. U. Baranger, R. A. Jalabert, A. D. Stone

We demonstrate the existence of an interference contribution to the average magnetoconductance, G(B), of ballistic cavities and use it to test the semiclassical theory of quantum billiards. G(B) is qualitatively different for chaotic and regular cavities, an effect explained semiclassically by the differing classical distribution of areas. The magnitude of G

Carl M. Bender, Stephen Pinsky, Brett Van de Sande

We study spontaneous symmetry breaking in phi^4_(1+1) using the light-front formulation of the field theory. Since the physical vacuum is always the same as the perturbative vacuum in light-front field theory the fields must develop a vacuum expectation value through the zero-mode components of the field. We solve the nonlinear operator equation for the zero

D. Senechal

The $O(3)$ nonlinear $σ$ model is studied in the disordered phase, using the techniques of the effective action and finite temperature field theory. The nonlinear constraint is implemented through a Lagrange multiplier. The finite temperature effective potential for this multiplier is calculated at one loop. The existence of a nontrivial minimum for this pot

L. Alvarez-Gaume, M. A. Vazquez-Mozo

These lectures present a general critical assessment of various frameworks for quantum gravity, with particular emphasis on string theory. The topics discussed cover field-theoretical approaches to quantum gravity, anomalies, bosonic and fermionic string theories, as well as some aspects of string phenomenology and black hole physics.

Jean-Pierre Demailly, Laszlo Lempert, Bernard Shiffman

It is shown that every holomorphic map $f$ from a Runge domain $Ω$ of an affine algebraic variety $S$ into a projective algebraic manifold $X$ is a uniform limit of Nash algebraic maps $f_ν$ defined over an exhausting sequence of relatively compact open sets $Ω_ν$ in $Ω$. A relative version is also given: If there is an algebraic subvariety $A$ (not necessar

Andreas Cap, Peter W. Michor, Hermann Schichl

In this paper we show that in the case of noncommutative two-tori one gets in a natural way simple structures which have analogous formal properties as Hopf algebra structures but with a deformed multiplication on the tensor product.

C. Pinheiro, G. O. Pires

The spin-projector operators for symmetric rank-2 tensors are reassessed in connection with the issue of topologically massive gravity. The original proposal by Barnes and Rivers is generalised to account for D-dimensional Einstein gravity and 3-dimensional Chern-Simons massive gravitation.

P. P. Kulish, R. Sasaki

The reflection equations (RE) are a consistent extension of the Yang-Baxter equations (YBE) with an addition of one element, the so-called reflection matrix or $K$-matrix. For example, they describe the conditions for factorizable scattering on a half line just like the YBE give the conditions for factorizable scattering on an entire line. The YBE were gener

David B. Fairlie, Jan Govaerts

The Universal Field Equations, recently constructed as examples of higher dimensional dynamical systems which admit an infinity of inequivalent Lagrangians are shown to be linearised by a Legendre transformation. This establishes the conjecture that these equations describe integrable systems. While this construction is implicit in general, there exists a la

H. Dorn, H. -J. Otto

We discuss various aspects of the calculation of correlation functions in conformal theories coupled to quantized 2-dimensional gravity. The main emphasis lies on the construction of a continuation in the number of insertions of the cosmological constant operator for $arbitrary$ dimension of the target space. Following closely our paper \cite{DO2} we add a m

Robert Marnelius

It is shown that the BRST charge $Q$ for any gauge model with a Lie algebra symmetry may be decomposed as $$Q=\del+\del^†, \del^2=\del^{†2}=0, [\del, \del^†]_+=0$$ provided dynamical Lagrange multipliers are used but without introducing other matter variables in $\del$ than the gauge generators in $Q$. Furthermore, $\del$ is shown to have the form $\del=c^{†

Haruhiko Terao

Quantization of the pure $1+1$ dimensional dilaton gravity is examined in the light-cone gauge. It is found that the total action including ghosts generates a $c=0$ free conformal field theory without modification of the classical action, which is required in the conformal gauge. We also study semiclassical equations of the dilaton gravity coupled to $N$ sca

Andrzej Sitarz

The main aim of this work is to present the interpretation of the Ising type models as a kind of field theory in the framework of noncommutative geometry. We present the method and construct sample models of field theory on discrete spaces using the introduced tools of discrete geometry. We write the action for few models, then we compare them with various m

Craig A. Tracy, Harold Widom

Scaling level-spacing distribution functions in the ``bulk of the spectrum&#39;&#39; in random matrix models of $N\times N$ hermitian matrices and then going to the limit $N\to\infty$, leads to the Fredholm determinant of the sine kernel $\sinπ(x-y)/π(x-y)$. Similarly a scaling limit at the ``edge of the spectrum&#39;&#39; leads to the Airy kernel $[{\rm Ai}

F. Cooper, J. M. Eisenberg, Y. Kluger, E. Mottola

We study pair production from a strong electric field in boost-invariant coordinates as a simple model for the central rapidity region of a heavy-ion collision. We derive and solve the renormalized equations for the time evolution of the mean electric field and current of the produced particles, when the field is taken to be a function only of the fluid prop

C. L. Y. Lee

This paper considers the implications of the heavy quark and chiral symmetries for the semi-leptonic decay $B \rightarrow D^* X \ell \bar ν_\ell$. The general kinematic analysis for decays of the form {\sl pseudoscalar meson $\rightarrow$ vector meson $+$ pseudoscalar meson $+$ lepton $+$ anti-lepton} is presented. This formalism is applied to the above excl

John N. Bahcall, H. A. Bethe

None of the 1000 solar models in a full Monte Carlo simulation is consistent with the results of the chlorine or the Kamiokande experiments. Even if the solar models are forced artifically to have a \b8 neutrino flux in agreeement with the Kamiokande experiment, none of the fudged models agrees with the chlorine observations. The GALLEX and SAGE experiments,