November 1993 arXiv papers — page 3

G. Amelino-Camelia

The nature of the Abelian Higgs Model phase transition is investigated. A variational approximation is used in the evaluation of the relevant finite temperature effective potential. Some of the results presented are valid not only in the Abelian Higgs Model, but also in more complex theories.

M. Bowick, M. Falcioni, G. Harris, E. Marinari

We simulate single and multiple Ising models coupled to 2-d gravity using both the Swendsen-Wang and Wolff algorithms to update the spins. We study the integrated autocorrelation time and find that there is considerable critical slowing down, particularly in the magnetization. We argue that this is primarily due to the local nature of the dynamical triangula

O. A. Borisenko, V. K. Petrov, G. M. Zinovjev

The general conditions for the Chern-Simons action to be induced as a nonuniversal contribution of fermionic determinant are formulated in the finite temperature lattice QCD. The dependence of the corresponding action coefficient on nonuniversal parameters (chemical potentials, vacuum features, etc. ) is explored. Special attention is paid to the role of $A_

Colin J. Morningstar

Progress in the improvement program in nonrelativistic lattice QCD is outlined. The leading radiative corrections to the heavy-quark mass renormalization, energy shift, and two important kinetic coupling coefficients are presented. The reliability of tadpole-improved perturbation theory in determining the energy shift and mass renormalization is demonstrated

Ulli Wolff

We report about our ongoing computation of running coupling constants in asymptotically free theories using the recursive finite size scaling technique. The latest results for the SU(3) Yang-Mills theory are presented.

Antonio Gonzalez-Arroyo, Jeroen Snippe, Pierre van Baal

We present results related to the search of SU(2) instantons on a geometry $[0,L]^3\times [0,T]$ obtained using over-improved cooling with fixed boundary conditions. We also introduce a criterion for finding a sphaleron at the top of the energy barrier of the instanton path.

Efrat Shimshoni, S. L. Sondhi

We study the Coulomb drag between two spatially separated electron systems in a strong magnetic field, one of which exhibits the quantum Hall effect. At a fixed temperature, the drag mimics the behavior of $σ_{xx}$ in the quantum Hall system, in that it is sharply peaked near the transitions between neighboring plateaux. We assess the impact of critical fluc

Richard Rozanski, Michael Rowan-Robinson

Use of the brightest stars in galaxies as a distance indicator and claims that the method supports the `short' distance scale are examined. Data from several different observational programmes are brought together for the first time with a procedure for the careful accounting of errors. The true uncertainties of the method are found to be much larger tha

O. Lahav, K. B. Fisher, Y. Hoffman, C. A. Scharf

The analysis of whole-sky galaxy surveys commonly suffers from the problems of shot-noise and incomplete sky coverage (e.g. at the Zone of Avoidance). The orthogonal set of spherical harmonics is utilized here to expand the observed galaxy distribution. We show that in the framework of Bayesian statistics and Gaussian random fields the $4 π$ harmonics can be

C. J. Pethick, Vesteinn Thorsson

We demonstrate that band-structure effects suppress bremsstrahlung of neutrino pairs by electrons in the crusts of neutron stars at temperatures of the order of $5\times 10^9 \,{\rm K}$ and below. Taking this into account, together with the fact that recent work indicates that the masses of neutron star crusts are considerably smaller than previously estimat

J. A. Peacock, S. J. Dodds

We describe an attempt to reconstruct the initial conditions for the formation of cosmological large-scale structure. The power spectrum of the primordial fluctuations is affected by bias, nonlinear evolution and redshift-space distortions, but we show how these effects can be corrected for analytically. Using eight independent datasets, we obtain excellent

D. Munshi, A. A. Starobinsky

Nonlinear approximation methods such as the Zeldovich approximation, and more recently the frozen flow and linear potential approximations, are sometimes used to simulate nonlinear gravitational instability in the expanding Universe. We investigate the relative accuracy of these approximations by comparing them with the exact solution using second order pert

S. Bauer, V. Pidstrigatch

We consider the spin polynomial invariants for bundles with c_2=2 and c_1 = K_S + 2nk a rational mutiple of the canonical divisor on a Dolgacev surface. It is shown that the chamber structure can be controlled so that the polynomials give diffeomorphism invariants of Dolgachev surfaces of the form q_S(n) = a(n)Q^2 + b(n)Qk^2 + c(n)k^4. The two leading coeffi

P. Jain, D. W. McKay

We describe a simple mechanism to break electroweak symmetry dynamically as well as to generate a large fermion mass hierarchy. The mechanism is displayed within the framework of a simple left-right symmetric model. The model has exact horizontal symmetry which is broken dynamically giving rise to the mixing angles as well as to the fermion masses. The light

Johan Linde, Håkan Snellman

We discuss the magnetic moments of the baryons allowing for flavor symmetry breaking in the quark magnetic moments. We show that there is a correlation between isospin symmetry breaking and data for the nucleon spin structure obtained from deep inelastic scattering. For small values of the isospin symmetry breaking, of the order of $5\%$, the magnetic moment

O. Aharony, S. Yankielowicz, A. N. Schellekens

Some errors in section 4 are corrected. No change in the results.

Fred Cooper, Harvey Shepard

We study the class of shallow water equations of Camassa and Holm derived from the Lagrangian: $ L= \int \left( \frac{1}{2} (φ_{xxx}-φ_{x} )φ_{t} - {1 \over 2} {(φ_{x})^{3}} - {1 \over 2}φ_{x}(φ_{xx})^{2} - {1 \over 2} κφ_{x}^{2} \right) dx, $

V. Hnizdo, C. R. Gould

A time-reversal-violating spin-correlation coefficient in the total cross section for polarized neutrons incident on a tensor rank-2 polarized target is calculated by assuming a time-reversal-noninvariant, parity-conserving ``five-fold" interaction in the neutron-nucleus optical potential. Results are presented for the system $n + {^{165}{\rm Ho}}$ for n

S. V. Mashkevich, G. M. Zinovjev

We consider a simplified model of particles with effectively distance dependent statistics, that is particles coupled to a gauge field the Lagrangian of which contains the Chern-Simons term. We analyze the low-lying states of the two-particle system and show that under certain conditions they can exhibit negative compressibility, hinting on a possible à la v

A. A. Balinsky

We present the method for finding of the nonlinear Poisson-Lie groups structures on the vector spaces and for their quantization. For arbitrary central extension of Lie algebra explicit formulas of quantization are proposed.

A. A. Balinsky, A. I. Balinsky

The generalized form of the Kac formula for Verma modules associated with linear brackets of hydrodynamics type is proposed. Second cohomology groups of the generalized Virasoro algebras are calculated. Connection of the central extensions with the problem of quntization of hydrodynamics brackets is demonstrated.

Cenalo Vaz, Louis Witten

We describe a classical configuration of conformal matter forming a naked singularity and discuss its subsequent Hawking evaporation within the context of two dimensional dilaton gravity. The one loop analysis is credible for a large mass naked singularity and suggests the existence of a weak cosmological censorship that would cause it to explode into radiat

Pavel Etingof

In this paper the quantum integrals of the Hamiltonian of the quantum many-body problem with the interaction potential K/sinh^2(x) (Sutherland operator) are constructed as images of higher Casimirs of the Lie algebra gl(N) under a certain homomorphism from the center of U(gl(N)) to the algebra of differential operators in N variables. A similar construction

Philip C. Argyres, S. -H. Henry Tye

The spin-4/3 fractional superstring is characterized by a world-sheet chiral algebra involving spin-4/3 currents. The discussion of the tree-level scattering amplitudes of this theory presented in hepth/9310131 is expanded to include amplitudes containing two twisted-sector states. These amplitudes are shown to satisfy spurious state decoupling. The restrict

Michael R. Douglas

Following some motivating comments on large N two-dimensional Yang-Mills theory, we discuss techniques for large N group representation theory, using quantum mechanics on the group manifold U(N), its equivalence to a quasirelativistic two-dimensional free fermion theory, and bosonization. As applications, we compute the free energy for two-dimensional Yang-M

E. Martinec

Notes of the author's talk at Cargese, May 19,1993. The calculation of the string field commutator is simplified by relating it to the short proper time, semiclassical string path integral.

Hitoshi Sato

We construct the Poincare polynomials for Landau-Ginzburg orbifolds with projection operators.Using them we show that special types of dualities including Poincare duality are realized under certain conditions. When Calabi-Yau interpretation exists, two simple formulae for Hodge numbers $h^{2,1}$ and $h^{1,1}$ are obtained.

Jay Watson

It is shown how the Mandelstam constraints for an $SU(2)$ pure lattice gauge theory with $3{\cal N}$ physical degrees of freedom may be solved completely in terms of $3{\cal N}$ Wilson and Polyakov loop variables and ${\cal N}-1$ gauge invariant discrete +/-1 variables, thus enabling a manifestly gauge invariant formulation of the theory.

I. I. Bigi, N. G. Uraltsev

There is a recent claim by Guralnik and Manohar \cite{GM} to have established a rigorous lower bound on $\bar Λ$, the asymptotic difference between the mass of a heavy flavour {\em hadron} and that of the heavy flavour {\em quark}. We point out the flaw in their reasoning and discuss the underlying physical problem. An explicit counterexample to the GM bound

Michael S. Chanowitz, William Kilgore

We exhibit a complementary relationship between resonant $WZ$ and nonresonant $W^+W^+$ scattering in a chiral Lagrangian model of the electroweak symmetry breaking sector with a dominant ``$ρ$'' meson. We use the model to estimate the minimum luminosity for the LHC to ensure a ``no-lose'' capability to observe the symmetry breaking sector.

Mohammad R. Ahmady, Dongsheng Liu

We estimate the non-leptonic B decays $B \rightarrow (ψ,ψ^\prime , χ_{1c})+K^i$, where $K^i$ are various K-meson resonances. We use the model of Isgur, Wise, Scora and Grinstein in the context of heavy quark effective theory, to calculate the hadronic matrix elements. Our estimates show that a substantial fraction of $B \rightarrow X_s ψ$ results in higher r

G. Amelino-Camelia, So-Young Pi

In order to investigate the nature of the phase transition, we study the finite temperature effective potential for the $λΦ^4$ theory in the Hartree-Fock approximation, which sums up all the daisy and superdaisy diagrams.

J. G. K"orner, A. Pilaftsis, M. M. Tung

The analytic expressions for the production cross sections of polarized bottom and top quarks in $e^+e^-$ annihilation are explicitly derived at the one-loop order of strong interactions. Chirality-violating mass effects will reduce the longitudinal spin polarization for the light quark pairs by an amount of $3\%$, when one properly considers the massless li

Boris Blok, Michael Shifman

The problem of the hierarchy of lifetimes of charmed hadrons is reviewed. The QCD-based theory of preasymptotic effects in inclusive weak decays dating back to the beginning of the eighties is now entering its mature phase. Combining recent and old results we argue that the observed hierarchy reflects most intimate features of the hadronic structure. The pro

R. Baier, S. Peigné, D. Schiff

We calculate the production rate of soft real photons from a hot quark -- gluon plasma using Braaten -- Pisarski's perturbative resummation method. To leading order in the QCD coupling constant $g$ we find a logarithmically divergent result for photon energies of order $gT$, where $T$ is the plasma temperature. This divergent behaviour is due to unscreen

J. Perez-Mercader

We discuss a natural notion of entropy in quantum field theory and apply it to asymptotically free theories in their perturbative regimes. We then specialize to QCD and find that quark flavor states can be described as entropy--ordered states of QCD, and that the masses for the $s\bar{s}$--state, charm, $c\bar{c}$--state, bottom and $b\bar{b}$--state can all

Guey-Lin Lin, Thomas Mannel

The semileptonic decay $Λ_c \to Λ\ell ν$ is considered in the framework of heavy quark effective theory beyond the leading order in the $1/m_c$ expansion. According to our estimate the polarization variable will receive only very small corrections such that $α_{Λ_c} \le -0.95$.

C. Best, A. Schaefer

We use Daubechies' orthonormal compact wavelets as a variational basis for the $XY$ model in two and three dimensions. Assuming that the fluctuations of the wavelet coefficients are Gaussian and uncorrelated, minimization of the free energy yields the fluctuation strength of wavelet coefficients at different scales, from which observables can be computed

C. B. Lang, T. Neuhaus

We study the deconfinement phase transition of compact $U(1)$ pure lattice gauge theory with the Wilson action on {\em closed topology} lattices. In contrast to studies of compact QED on {\em hypercubic lattices with periodic boundary conditions}, we find no metastability signal at the phase transition on the lattices with the topology of a sphere. Thus the

S. K. Yip

Recently the identification of 3He-A with the axial state has been questioned. It is suggested that the A-phase can actually be in the axiplanar state. We point out in the present paper that experiments in a film geometry may be useful to distinguish the above two possibilities. In particular a second order phase transition between an axial and an axiplanar

Gerd Schön, A. D. Zaikin

Single electron tunneling into small superconducting islands is sensitive to the gap energy of the excitations created in the process and, hence, depends on the electron number parity. At low temperature the properties of the system are 2e-periodic in the applied gate voltage, turning e-periodic at higher temperature. We evaluate the tunneling rates and dete

F. Bernardeau, T. P. Singh, B. Banerjee, S. M. Chitre

Two quasi-linear approximations, the frozen flow approximation (FFA) and the frozen potential approximation (FPA), have been proposed recently for studying the evolution of a collisionless self-gravitating fluid. In the FFA it is assumed that the velocity field remains unchanged from its value obtained from the linear theory whereas in FPA the same approxima

David Gershon

We derive a charged black hole solution in four dimensions described by $SL(2,R)\times SU(2)\times U(1)/U(1)^2$ WZW coset model. Using the algebraic Hamiltonian method we calculate the corresponding solution that is exact to all orders in ${1\over k}$. It is shown that unlike the 2D black hole, the singularity remains also in the exact solution, and moreover

Boris Khesin, Ilya Zakharevich

The Lie algebra of pseudodifferential symbols on the circle has a nontrivial central extension (by the ``logarithmic'' 2-cocycle) generalizing the Virasoro algebra. The corresponding extended subalgebra of integral operators generates the Lie group of classical symbols of all real (or complex) degrees. It turns out that this group has a natural Poiss

Hitoshi Murayama, Hiroshi Suzuki, T. Yanagida, Jun'ichi Yokoyama

We propose a Kähler potential in supergravity which successfully accommodates chaotic inflation. This model can have a large gravitino mass without giving a large mass to squarks and sleptons, and thus is free from both the gravitino problem and entropy crisis. In this model baryogenesis takes place naturally, identifying the inflaton with a right-handed sne

Matthias Neubert

We present a QCD-based approach to the endpoint region of the lepton spectrum in $\bar B\to X_u\,\ell\,\barν$ decays. We introduce a genuinely nonperturbative form factor, the shape function, which describes the fall-off of the spectrum close to the endpoint. The moments of this function are related to forward scattering matrix elements of local, higher-dime

R. Jackiw, notes by G. Amelino-Camelia

Techniques of zero-temperature field theory that have found application in the analysis of field theory at finite temperature are revisited. Specifically, several of the results that are discussed are relevant to the study of symmetry-changing phase transitions and high temperature QCD, which today are among the most actively investigated problems in finite

R. Rapp, J. Wambach

Based on a recent meson-exchange model for the vacuum $ππ$ interaction we compute selfconsistently the in-medium $ππ$ scattering amplitude and pion selfenergy in a hot $πNΔ$ gas. The contributions to the pion selfenergy are calculated from the $ππ$ T-matrix as well as from p-wave interaction with nucleons and thermally abundant $Δ$'s. Results are present

E. V. Gorbar, S. V. Mashkevich

It is shown that in the P,T-invariant model with the mixed Chern-Simons term the interaction of charge carriers leads to effective changing of their statistics, which depends on distance between them. In particular, in the limit of large distances fermions effectively turn into bosons.

Alexander Turbiner, Gerhard Post

Families of operator identities appeared as a consequence of an existence of finite-dimensional representation of (super) Lie algebras of first-order differential operators and $q$-deformed (quantum) algebras of first-order finite-difference operators are presented. It is shown that those identities can be rewritten in terms of creation/annihilation operator

F. J. Yndurain

A detailed evaluation is presented of production of heavy fermions (particularly ttbar quarks) by a vector current, in the region around threshold. This includes bound states as well as the region above threshold, to the same degree of accuracy; in both cases radiative and nonperturbative corrections are included. The contribution of this region to the vacuu

Michael A. Doncheski, Sean Fleming, Michelangelo L. Mangano

We present the preliminary results of a calculation of the fragmentation contribution to charmonium production at large transverse momentum in $p\bar{p}$ colliders. The fragmentation of gluons and charm quarks is the dominant direct production mechanism for sufficiently large $p_{\perp}$. We find that for both $J/ψ$ and $ψ'$ production fragmentation domi

R. Kenna, C. B. Lang

The scaling behaviour of the edge of the Lee--Yang zeroes in the four dimensional Ising model is analyzed. This model is believed to belong to the same universality class as the $ϕ^4_4$ model which plays a central role in relativistic quantum field theory. While in the thermodynamic limit the scaling of the Yang--Lee edge is not modified by multiplicative lo

D. K. K. Lee, J. T. Chalker

A single model is presented which represents both of the two apparently unrelated localisation problems of the title. The phase diagram of this model is examined using scaling ideas and numerical simulations. It is argued that the localisation length in a spin-degenerate Landau level diverges at two distinct energies, with the same critical behaviour as in a

J. M. Deutsch

Linear systems with many degrees of freedom containing multiplicative and additive noise are considered. The steady state probability distribution for equations of this kind is examined. With multiplicative white noise it is shown that under some symmetry conditions, the probability distribution of a single component has power law tails, with the exponent in

Jeffrey B. Weiss

Structures such as waves, jets, and vortices have a dramatic impact on the transport properties of a flow. Passive tracer transport in incompressible two-dimensional flows is described by Hamiltonian dynamics, and, for idealized structures, the system is typically integrable. When such structures are perturbed, chaotic trajectories can result which can signi

J. M. Deutsch

Systems described by equations involving both multiplicative and additive noise are common in nature. Examples include convection of a passive scalar field, polymersin turbulent flow, and noise in dye lasers. In this paper the one component version of this problem is studied. The steady state probability distribution is classified into two different types of

N. Z. Akopov, E. M. Madounts, A. B. Nersesian, G. K. Savvidy

We suggest fast algorithm for the matrix generator of pseudorandom numbers based on Kolmogorov-Anosov K systems which has been proposed earlier. This algorithm reduces $N^{2}$ operation of the matrix generator to $NlnN$ and essentially reduces the generation time. It also clarifies the algebraic structure of this type of K system generators.

Joao P. Nunes, Howard J. Schnitzer

A cutoff version of the $λϕ^4$ O(N) model is considered to leading order in 1/N with particular attention to the effective potential, which is surprisingly rich in structure. With suitable restriction on a background classical field, one finds a phenomenologically viable model with spontaneously broken symmetry, a potential bounded below, and amplitudes free

Max Tegmark, Emory Bunn, Wayne Hu

A formalism is presented that allows cosmological experiments to be tested for consistency, and allows a simple frequentist interpretation of the resulting significance levels. As an example of an application, this formalism is used to place constraints on bulk flows of galaxies using the results of the microwave background anisotropy experiments COBE and SP

R. Mélin, B. Douçot, P. Butaud

Using the adiabatic switching of interactions, we establish a condition for the existence of electronic quasiparticles in a Luttinger liquid. It involves a characteristic interaction strength proportional to the inverse square root of the system length. An investigation of the exact energy level separation probability distribution shows that this interaction

W. Kalau, N. A. Papadopoulos, J. Plass, J. -M. Warzecha

We discuss the differential algebras used in Connes' approach to Yang-Mills theories with spontaneous symmetry breaking. These differential algebras generated by algebras of the form functions $\otimes$ matrix are shown to be skew tensorproducts of differential forms with a specific matrix algebra. For that we derive a general formula for differential al

F. Bonechi, Enrico Celeghini, R. Giachetti, C. M. Pereña

The concept of universal T matrix, recently introduced by Fronsdal and Galindo in the framework of quantum groups, is here discussed as a generalization of the exponential mapping. New examples related to inhomogeneous quantum groups of physical interest are developed, the duality calculations are explicitly presented and it is found that in some cases the u

Wenbin Zhang, Jorge Vinals

A two dimensional model is introduced to study pattern formation, secondary instabilities and the transition to spatiotemporal chaos (weak turbulence) in parametric surface waves. The stability of a periodic standing wave state above onset is studied against Eckhaus, zig-zag and transverse amplitude modulations (TAM) as a function of the control parameter $\

R. Wuensch, K. Goeke, Th. Meissner

We consider a two-flavor Nambu \& Jona-Lasinio model in Hartree approximation involving scalar-isoscalar and pseudoscalar-isovector quark-quark interactions. Average meson fields are defined by minimizing the effective Euklidean action. The fermionic part of the action, which contains the full Dirac sea, is regularized within Schwinger's proper-time sche

D. C. Zheng, L. Zamick, M. Fayache

It is shown that when higher-shell admixtures are included for systems with two valence particles or holes, there are effects which are quite different from those for one-valence-nucleon systems. For example, for nuclei with one valence particle or hole, there is no first-order correction for the magnetic dipole moment or the Gamow-Teller transition amplitud

M. J. Duff, Ramzi R. Khuri, Ruben Minasian, Joachim Rahmfeld

We present solutions of the low-energy four-dimensional heterotic string corresponding to $p$-branes with $p=0,1,2$, which are characterized by a mass per unit $p$-volume, ${\cal M}_{p+1}$, and topological ``magnetic'' charge, $g_{p+1}$. In the extremal limit, $\sqrt{2} κ{\cal M}_{p+1} = g_{p+1}$, they reduce to the recently discovered non-singular s

Jacek Szmigielski

Exploiting the formulation of the Self Dual Yang-Mills equations as a Riemann-Hilbert factorization problem, we present a theory of pulling back soliton hierarchies to the Self Dual Yang-Mills equations. We show that for each map $ \C^4 \to \C^{\infty } $ satisfying a simple system of linear equations formulated below one can pull back the (generalized) Drin

P. Maslanka

Abstr.: The classical r-matrix implied by the quantum k-Poincare algebra of Lukierski,Nowicki and Ruegg is used to generate a Poisson structure on the ISL(2,C) group. A quantum deformation of the ISL(2,C) group ( on the Hopf algebra level ) is obtained by a trivial quantization.

I. Jack, D. R. T. Jones, J. Panvel

The two-dimensional supersymmetric $\s$-model on a Kähler manifold has a non-vanishing $\b$-function at four loops, but the $\b$-function at five loops can be made to vanish by a specific choice of renormalisation scheme. We investigate whether this phenomenon persists at six loops, and conclude that it does not; there is a non-vanishing six-loop $\b$-functi

E. Quattrini, F. Ravanini, R. Tateo

A large class of Thermodynamic Bethe Ansatz equations governing the Renormalization Group evolution of the Casimir energy of the vacuum on the cylinder for an integrable two-dimensional field theory, can often be encoded on a tensor product of two graphs. We demonstrate here that in this case the two graphs can only be of $ADE$ type. We also give strong nume

C. D. Fosco, R. C. Trinchero

We study the realisation of global symmetries in a polynomial formulation of the non-linear sigma-model. We show that there are global symmetries whose corresponding Noether currents are the topological currents in the usual formulation. The usual Noether currents associated with the internal symmetry group are reproduced, but part of them become non-local i

A. P. Isaev, P. N. Pyatov

We consider the possible covariant external algebra structures for Cartan's 1-forms on GL_q(N) and SL_q(N). We base upon the following natural postulates: 1. the invariant 1-forms realize an adjoint representation of quantum group; 2. all monomials of these forms possess the unique ordering. For the obtained external algebras we define the exterior deriv

H. -T. Sato

We find a quantum group structure in two-dimensional motions of a nonrelativistic electron in a uniform magnetic field and in a periodic potential. The representation basis of the quantum algebra is composed of wavefunctions of the system. The quantum group symmetry commutes with the Hamiltonian and is relevant to the Landau level degeneracy. The deformation

D. L. Bennett H. B. Nielsen

In developing a model for predicting the nonabelian gauge coupling constants we argue for the phenomenological validity of a ``principle of multiple point criticality''. This is supplemented with the assumption of an ``(grand) anti-unified'' gauge group $SMG^{N_{gen.}}\sim U(1)^{N_{gen.}}\times SU(2)^{N_{gen.}}\times SU(3)^{N_{gen.}}$ that, a

Thomas Appelquist, John Terning

An extended technicolor model is constructed. Quark and lepton masses, spontaneous CP violation, and precision electroweak measurements are discussed. Dynamical symmetry breaking is analyzed using the concept of the BIG MAC.

G. D'Ambrosio, N. Paver

We discuss the time dependent interferences between $K_L$ and $K_S$ in the decays in $3π$ and $ππγ$, to be studied at interferometry machines such as the $ϕ$-factory and LEAR. We emphasize the possibilities and the advantages of using interferences, in comparison with width measurements, to obtain information both on $CP$ conserving and $CP$ violating amplit

C. W. Kim, J. A. Lee

Motivated by the indication that both the Solar and the atmospheric neutrino puzzles may simultaneously be solved by (vacuum as well as matter-induced resonant) oscillations of two generations of neutrinos with large mixing, we have analyzed the data on the Solar and atmospheric neutrinos assuming that all {\it three} neutrinos are maximally mixed. It is sho

Eduardo de Rafael

The contributions to the muon anomalous magnetic moment from hadronic vacuum polarization and from hadronic light-by-light scattering are reexamined within the frame work of chiral perturbation theory; the $1/N_c$-expansion; and the extended Nambu Jona-Lasinio model of low-energy QCD.

Rajesh R. Parwani

Consideration of some perturbatively calculated gauge-invariant expectation values of local noncomposite operators in pure Yang-Mills theory indicates that those expectation values which are not dimension specific, and which are well defined near $D=4$ dimensions, have some {\it finite} limit as the evaluated expression is naively extrapolated from $D=4$ to

Ugo Aglietti

The effective theory for heavy quarks has additional symmetries with respect to QCD, which relate charm and beauty hadron masses. Assuming the spectrum of charmed particles, we predicted in a previous work the masses of some beauty particles. The predictions of the Lambda_b mass, M(Lambda_b)=5630 MeV, and of the B_s mass, M(B_s)=5379 MeV, are in agreement wi

H. Gausterer, C. B. Lang

We study the phase structure of the massive one flavour lattice Schwinger model on the basis of the finite size scaling behaviour of the partition function zeroes. At $β= 0$ we observe and discuss a possible discrepancy with results obtained by a different method.

Khalil M. Bitar, R. Edwards, Steven Gottlieb, U. M. Heller

We have extended our previous study of the lattice QCD spectrum with 2 flavors of staggered dynamical quarks at $6/g^2=5.6$ and $am_q=0.025$ and 0.01 to larger lattices, with better statistics and with additional sources for the propagators. The additional sources allowed us to estimate the $Δ$ mass and to measure the masses of all mesons whose operators are

G. K. Savvidy, K. G. Savvidy

We classify different theories of self-intersecting random surfaces assigning special weights to intersections. When self-intersection coupling constant $κ$ tends to zero, then the surface can freely inetrsect and it is completely self-avoiding when $κ$ tends to infinity. Equivalent spin systems for this general case were constructed. In two-dimension the sy

P. Cea, L. Cosmai

We investigate the dynamics of three-dimensional lattice gauge theories by means of an external Abelian magnetic field. For the SU(2) lattice gauge theory we find evidence of the unstable modes.

P. Cea, L. Cosmai

We investigate the dual superconductor model of color confinement in SU(2) lattice gauge theory. We find that the transverse distribution of the longitudinal chromoelectric field between static quarks displays the dual Meissner effect. We also give evidence that the problem of color confinement could be approached in the framework of the 't~Hooft's A

Yigal Meir

A generalized $ν=2/3$ state, which unifies the edge-state pictures of MacDonald and of Beenakker is presented and studied in detail. Using an exact relation between correlation functions of this state and those of the Laughlin $ν=1/3$ wave function, the correlation functions of the $ν=2/3$ state are determined via a classical Monte Carlo calculation, for sys

L. S. Levitov, G. B. Lesovik

We study excess noise in a quantum conductor in the presence of constant voltage and alternating external field. Due to a two particle interference effect caused by Fermi correlations the noise is sensitive to the phase of the time dependent transmission amplitude. We compute spectral density and show that at T=0 the noise has singular dependence on the {\rm

Gabor Vattay

We show that the eigenvalues of the first order partial differential equation derived by quasi-classical approximation of the Schrödinger equation can be computed from the trace of a classical operator. The derived trace formula is different from the Gutzwiller trace formula.

Edward L. Wright

Abbreviated abstract of an invited talk at the International Cosmic Ray Conference in Calgary, July 1993: The results from the COBE satellite are in close agreement with the predictions of the standard hot Big Bang model, suggesting that the Universe was once hot, dense and isothermal, giving a background radiation spectrum that is close to a perfect blackbo

A. Babul, D. Weinberg, A. Dekel, J. Ostriker

We challenge a widely accepted assumption of observational cosmology: that successful reconstruction of observed galaxy density fields from measured galaxy velocity fields (or vice versa), using the methods of gravitational instability theory, implies that the observed large-scale structures and large-scale flows were produced by the action of gravity. This

Viacheslav V. Nikulin

We prove the following main result: Let X be a Fano 3-fold with terminal Q-factorial singularities and X does not have a small extremal ray and a face of Kodaira dimension 1 or 2 for Mori polyhedron of X. Then the Picard number ρ(X) < 8.

Kaupo Palo

Recently it has been argued, that Poincaré supersymmetric field theories admit an underlying loop space hamiltonian (symplectic) structure. Here shall establish this at the level of a general $N=1$ supermultiplet. In particular, we advocate the use of a superloop space and explain the necessity of using nonconventional auxiliary fields. As an example we cons

Shahn Majid

We show that every Lie algebra or superLie algebra has a canonical braiding on it, and that in terms of this its enveloping algebra appears as a flat space with braided-commuting coordinate functions. This also gives a new point of view about $q$-Minkowski space which arises in a similar way as the enveloping algebra of the braided Lie algebra $gl_{2,q}$. Ou

F. Hussain, G. Thompson, J. G. Koerner

We present a general construction of the spin content of the Bethe-Salpeter amplitudes (covariant wave functions) for heavy hadrons with arbitrary orbital excitations, using representations of the Lorentz group. These wave functions incorporate the symmetries manifest in the heavy quark limit. In the baryonic sector we clearly differentiate between the $\Lam

Philippe Jetzer

It has been shown by Paczyński that gravitational microlensing is a useful method to detect brown dwarfs in the dark halo of our galaxy. At present several experiments are carried out to monitor several million stars in the Large Magellanic Cloud with the aim to find such microlensing events. Here I discuss the possibility to use as targets stars in the Andr

Philippe Jetzer

It has been shown by Paczyński that gravitational microlensing is potentially a useful method for detecting the dark constituents of the halo of our galaxy, if their mass lies in the approximate domain $10^{-6} < M/M_{\odot} < 10^{-1}$. Microlensing observations now under way monito several millions of stars in the Large Magellanic Cloud and in the Galactic

Philippe Jetzer

It has been shown by Paczyński that gravitational microlensing is potentially a useful method for detecting the dark constituents of the halo of our galaxy, if their mass lies in the approximate domain $10^{-6}<M/M_\odot<10^{-1}$. Microlensing observations now im progress monitor several millions of stars in the Large Magellanic Cloud and in the Galactic Bul

Kiyoshi Ezawa

Two canonical formulations of the Einstein gravity in 2+1 dimensions, namely, the ADM formalism and the Chern-Simons gravity, are investigated in the case of nonvanishing cosmological constant. General arguments for reducing phase spaces of the two formalisms are given when spatial hypersurface is compact. In particular when the space has the topology of a s

A. J. Niemi, P. Pasanen

We study the infrared limit of two dimensional QCD, with massless dynamical Dirac fermions that are in the fundamental representation of the gauge group. We find that the theory reduces to a spin generalization of the Calogero model with an additional magnetic coupling which is of the Pauli type.