October 1995 arXiv papers — page 8

Selman Akbulut

These are yet another lecture notes on Seiberg-Witten invariants, where no claim of originality is made, they contain a discussion of some related results from the recent literature.

Dinesh Nehete, Vaishali Shah, D. G. Kanhere

The ground state geometries of some small clusters have been obtained via ab initio molecular dynamical simulations by employing density based energy functionals. The approximate kinetic energy functionals that have been employed are the standard Thomas-Fermi $(T_{TF})$ along with the Weizsacker correction $T_W$ and a combination $F(N_e)T_{TF} + T_W$. It is

S. Kumano

We propose to measure valence-quark shadowing by observing charged pion productions in electron-nucleus scattering at HERA. Studies of shadowing phenomena in the valence-quark distribution could be useful in discriminating among various models, which produce similar results in the $F_2$ shadowing.

Zhenbo Qin, Yongbin Ruan

Results in the preliminary version have been strengthed. In addition, Batyrev's conjectural formula for quantum cohomology of projective bundles associated to direct sum of line bundles over $\Pee^n$ is partially verified.

Michael Yampolsky

We use the methods developed with M. Lyubich for proving complex bounds for real quadratics to extend E. De Faria's complex a priori bounds to all critical circle maps with an irrational rotation number. The contracting property for renormalizations of critical circle maps follows. In the Appendix we give an application of the complex bounds for proving

G. Aldazabal, L. E. Ibanez, A. Font, F. Quevedo

We report on a search for $N=2$ heterotic strings that are dual candidates of type II compactifications on Calabi-Yau threefolds described as $K3$ fibrations. We find many new heterotic duals by using standard orbifold techniques. The associated type II compactifications fall into chains in which the proposed duals are heterotic compactifications related one

S. F. Hewson

We discuss the non-abelian duality procedure for groups which do not act freely. As an example we consider Taub-NUT space, which has the local isometry group $SU(2) \otimes U(1)$. We dualise over the entire symmetry group as well as the subgroups $SO(3)$ and $U(1)$, presenting unusual new solutions to low energy string theory. The solutions obtained highligh

Thomas G. Rizzo

We consider the production of a pair of like-sign charged Higgs bosons in $e^-e^-$ collisions at the NLC within the context of several electroweak models with extended symmetry breaking sectors. We find that the rate for this process, which proceeds through $W^-W^-$ fusion, is a very sensitive probe of the nature of these extended Higgs sectors and that the

Raj Gandhi, Chris Quigg, M. H. Reno, Ina Sarcevic

In light of recent measurements of the nucleon structure function in the small-$x$ deep-inelastic regime at HERA and the consequently improved theoretical understanding of the quark distributions in this range of parton fractional momentum, we present new results for the neutrino-nucleon cross section at ultra high energies, up to $ E_ν \sim 10^{21}$ eV. The

A. Khodjamirian, R. Rückl

We present results for the $B \rightarrow π$ and $D\rightarrow π$ form factors derived from QCD sum rules on the light-cone. Our predictions are compared with experiment and used to extract the quark mixing parameter $|V_{ub}|$ from a recent CLEO measurement of $B \ra πl^+ ν$. Furthermore, we discuss the factorization approximation for exclusive nonleptonic

R. Vogt

We discuss the renormalization and factorization scale dependence of charm and bottom production both at fixed-target energies and at present and future colliders. We investigate whether distributions calculable at leading order can be extrapolated to next-to-leading order by a constant multiplicative factor.

V. A. Bednyakov, H. V. Klapdor-Kleingrothaus, S. G. Kovalenko

We consider the neutralino as a dominant Dark Matter particle in the galactic halo and investigate some general issues of direct Dark Matter searches via elastic neutralino-nucleus scattering. On the basis of conventional assumptions about the nuclear and nucleon structure we analyse constraints on SUSY model parameter space accessible by the direct Dark Mat

M. M. Block, A. R. White, B. Margolis

Utilizing the most recent experimental data, we reanalyze high energy \pbar p and pp data, using the asymptotic amplitude analysis, under the assumption that we have reached `asymptopia'. This analysis gives strong evidence for a $\log \,(s/s_0)$ dependence at {\em current} energies and {\em not} $\log^2 (s/s_0)$, and also demonstrates that odderons are

M. Mohazzab, M. M. Sheikh Jabbari, H. Salehi

We show that particle production during the expansion of bubbles of true vacuum in the sea of false vacuum is possible and calculate the resulting rate. As a result the nucleated bubbles cannot expand due to the transfer of false vacuum energy to the created particles inside the bubbles. Therefore all the inflationary models dealing with the nucleation and e

Jian-Sheng Wang

We review the background of the cluster algorithms in Monte Carlo simulation of statistical physics problems. One of the first such successful algorithm was developed by Swendsen and Wang eight years ago. In contrast to the local algorithms, cluster algorithms update dynamical variables in a global fashion. Therefore, large changes are made in a single step.

K. S. Cheng, Z. G. Dai

This paper argues that conversion of neutron stars to strange stars as an origin of cosmological stars in the binaries with low-mass companions. Our model may provide an explanation why the binary millisecond pulsars seem to have same low magnetic fields.

Indranil Biswas, Pablo Gastesi, Suresh Govindarajan

In this paper we study the relation between parabolic Higgs bundles and irreducible representations of the fundamental group of punctured Riemann surfaces established by Simpson. We generalize a result of Hitchin, identifying those parabolic Higgs bundles that correspond to Fuchsian representations. We also study the Higgs bundles that give representations w

Kimball A. Milton

In the final few years of his life, Julian Schwinger proposed that the ``dynamical Casimir effect'' might provide the driving force behind the puzzling phenomenon of sonoluminescence. Motivated by that exciting suggestion, I have computed the static Casimir energy of a spherical cavity in an otherwise uniform material with dielectric constant $\epsilon$ and

Martin M. Block

The ``normal'' analysis of $\pbar p$ and $pp$ elastic scattering uses a `spinless' Coulomb amplitude, \ie a Rutherford amplitude ($2\sqrtπα/t$) multiplied by a Coulomb form factor $G^2(t)$, an {\em ansatz} that pretends that the nucleon does not have any magnetic scattering. In this note, we investigate the role of the anomalous magnetic moment o

David Branch, W. Romanishin, E. Baron

Statistical connections between the properties of Type Ia supernovae (SNe Ia) and the B--V colors of their parent galaxies are established. Compared to SNe Ia in blue galaxies [B-V$\la$0.75], SNe Ia in redder galaxies have (1) a wider dispersion in the blueshifts of their Si II $λ$6355 absorption features, ten days after maximum light; (2) more rapidly decli

Yael Karshon

We classify the periodic Hamiltonian flows on compact four dimensional symplectic manifolds up to isomorphism of Hamiltonian S^1 spaces. Additionally, we show that all these spaces are Kaehler, that every such space is obtained from a simple model by a sequence of symplectic blowups, and that if the fixed points are isolated then the space is a toric variety

Olivier Piguet, Silvio Paolo Sorella

The antighost equation valid for usual gauge theories in the Landau gauge, is generalized to the case of $N=1$ supersymmetric gauge theories in a supersymmetric version of the Landau gauge. This equation, which expresses the nonrenormalization of the Faddeev-Popov ghost field, plays an important role in the proof of the nonrenormalization theorems for the ch

Xerxes Tata

We present a pedagogical, but by no means complete, review of weak scale supersymmetry phenomenology. After a general introduction to the new particles that must be present in any supersymmetric framework, we describe how to write down their interactions with one another as well as with the particles of the Standard Model. We then elucidate the assumptions u

Joaquim Gomis, Steven Weinberg

We raise the issue whether gauge theories, that are not renormalizable in the usual power-counting sense, are nevertheless renormalizable in the modern sense that all divergences can be cancelled by renormalization of the infinite number of terms in the bare action. We find that a theory is renormalizable in this sense if the {\em a priori} constraints that

Fan Wang, Jia-lun Ping, T. Goldman

The fractional parentage expansion method is extended from $SU(2)_{f}$ nonrelativistic to $SU(3)_{f}$ and relativistic dibaryon calculations. A transformation table between physical bases and symmetry bases for the $SU(3)_{f}$ dibaryon is provided. A program package has been written for dibaryon calculation based on the fractional parentage expansion method.

Cheng-Zhang Wang, Rici Yu, Henry Krakauer

The pressure dependence of the Born effective charge, dielectric constant and zone-center LO and TO phonons have been determined for $3C$-SiC by a linear response method based on the linearized augmented plane wave calculations within the local density approximation. The Born effective charges are found to increase nearly linearly with decreasing volume down

Ruth Gornet

The subject of this paper is the relationship among the marked length spectrum, the length spectrum, the Laplace spectrum on functions, and the Laplace spectrum on forms on Riemannian nilmanifolds. In particular, we show that for a large class of three-step nilmanifolds, if a pair of nilmanifolds in this class has the same marked length spectrum, they necess

J. E. Hetrick, Y. Hosotani, S. Iso

The Schwinger model (QED_2) with N flavors of massive fermions on a circle of circumference L, or equivalently at finite temperature T, is reduced to a quantum mechanical system of N-1 degrees of freedom. With degenerate fermion masses (m) the chiral condensate develops a cusp singularity at $θ=\pm π$ in the limit L -> $\infty$ or T -> 0, which is removed by

Yuri M. Malyuta, Nikolay N. Aksenov

Distler-Kachru models which yield three generations of chiral fermions with gauge group SO(10) are found. These models have mirror partners.

Ernest Ma

If the b and c quarks mix with new heavy quarks of weak isospin I_3 = -1 and 0 respectively, then the Z -> b b(bar) (c c(bar)) rate is necessarily greater (smaller) than that of the standard model. This may be the reason for the R_b excess and R_c deficit observed at LEP. A possible consequence of this scenario is the prospective discovery of a new quark x w

Toru Goto, Takeshi Nihei, Yasuhiro Okada

\bb mixing and a CP violation parameter in \kk mixing $ε_K$ are studied in the minimal supergravity model. We solve the one-loop renormalization group equations for the minimal supersymmetric standard model (MSSM) parameters numerically in order to determine the masses and mixings of the supersymmetric particles, while all off-diagonal (generation mixing) el

Yu. B. Yufryakov

Model-independent features of hybrid states with heavy quarks and adiabatic approximation for such systems are discussed.These general arguments are applied to the QCD-based constituent gluon model.The leading- order Hamiltonian is derived from the general formalism. The masses of heavy quarks hybrids, including charmonium hybrid states,are calculated. We pr

H. Markum, W. Sakuler, S. Thurner

We analyze the relation between instantons and abelian projected monopoles in both phases of pure QCD by calculating local correlation functions between topological charge densities and monopole densities. On an $8^{3} \times 4$ lattice, it turns out that topological quantities are correlated approximately two lattice spacings. The monopole-instanton correla

C. Christou, A. Di Giacomo, H. Panagopoulos, E. Vicari

We analyze the properties of a class of improved lattice topological charge density operators, constructed by a smearing-like procedure. By optimizing the choice of the parameters introduced in their definition, we find operators having (i) a better statistical behavior as estimators of the topological charge density on the lattice, i.e. less noisy; (ii) a m

Gérard Clément

We generate from the static charged BTZ black hole a family of spinning charged solutions to the Einstein-Maxwell equations in 2+1 dimensions. These solutions go over, in a suitable limit, to self-dual spinning charged solutions, which are horizonless and regular, with logarithmically divergent mass and spin. To cure this divergence, we add a topological Che

P. V. Moniz

The issue concerning the existence of wormhole states in locally supersymmetric minisuperspace models with matter is addressed. Wormhole states are apparently absent in models obtained from the more general theory of N=1 supergravity with supermatter. A Hartle-Hawking type solution can be found, even though some terms (which are scalar field dependent) canno

P. H. Diamond, A. V. Gruzinov

The theory of passive scalar transport in two dimensional turbulent fluids is generalized to the case of 2D MHD. Invariance of the cross correlation of scalar concentration and magnetic potential produces a novel contribution to the concentration flux. This pinch effect is proportional to the mean potential gradient, and is shown to drastically reduce transp

A. H. MacDonald, H. A. Fertig, Luis Brey

We report on a microscopic theory of the Skyrmion states which occur in the quantum Hall regime. The theory is based on the identification of Skyrmion states in this system with zero-energy eigenstates of a hard-core model Hamiltonian. We find that for $N_ϕ$ orbital states in a Landau level, a set of Skyrmions states with orbital degeneracy $N_ϕ-K$ and spin

Jorge Kurchan, Laurent Laloux

We describe a non-Arrhenius mechanism for slowing down of dynamics that is inherent to the high dimensionality of the phase space. We show that such a mechanism is at work both in a family of mean-field spin-glass models without any domain structure and in the case of ferromagnetic domain growth. The marginality of spin-glass dynamics, as well as the existen

P. Czerner, U. Ritschel

We study the short-time dynamics of systems that develop ``quasi long-range order'' after a quench to the Kosterlitz-Thouless phase. With the working hypothesis that the ``universal short-time behavior'', previously found in Ising-like systems, also occurs in the Kosterlitz-Thouless phase, we explore the scaling behavior of thermodynamic vari

U. Ritschel, H. W. Diehl

We study how the finite-sized n-component model A with periodic boundary conditions relaxes near its bulk critical point from an initial nonequilibrium state with short-range correlations. Particular attention is paid to the universal long-time traces that the initial condition leaves. An approach based on renormalization-group improved perturbation theory i

Jukka A. Ketoja, Indubala I. Satija

We study the phase diagram of an electron on a square lattice in a transverse magnetic field. Using a renormalization scheme, we show that the inequality of the two next-nearest neighbor couplings destroys the fat critical regime above the bicritical line and replaces it with another reentrant extended phase. Furthermore, the universal strange attractor desc

Yu. G. Makhlin, G. E. Volovik

Fermions localized within vortex cores can form one-dimensional Fermi liquids. The nonzero density of states in these Fermi-liquids can lead to instability of the symmetric structure of the vortex core. We consider a symmetry breaking which is obtained due to spontaneous admixture of the spin-triplet p-wave component of the order parameter in conventional s-

Bianca L. Cerchiai, Peter Schupp

The correct Hamiltonian for an extended Hubbard model with quantum group symmetry as introduced by A. Montorsi and M. Rasetti is derived for a D-dimensional lattice. It is shown that the superconducting SUq(2) holds as a true quantum symmetry only for D = 1 and that terms of higher order in the fermionic operators in addition to phonons are required for a qu

Turab Lookman, Yanan Wu, Francis Alexander, Shiyi Chen

Using a Langevin description of spinodal decomposition in fluids, we examine domain growth in the diffusive, viscous and inertial regimes. In the framework of this model, numerical results corroborate earlier theoretical predictions based on scaling arguments and dimensional analysis.

Kazuo Hida

The ground state of the square lattice bilayer quantum antiferromagnet with nearest and next-nearest neighbour intralayer interaction is studied by means of the modified spin wave method. For weak interlayer coupling, the ground state is found to be always magnetically ordered while the quantum disordered phase appear for large enough interlayer coupling. Th

Kazuo Hida

The ground state and low lying excitation of the spin 1/2 Heisenberg ladder with antiferromagnetic leg ($J$) and ferromagnetic rung ($-λJ, λ>0$) interaction is studied by means of the density matrix renormalization group method. It is found that the state remains in the Haldane phase even for small $λ\sim 0.02$ suggesting the continuous transition to the gap

Kiyomi Okamoto

I analytically study the plateau of the magnetization curve at $M/M_{\rm S} = 1/3$ (where $M_{\rm S}$ is the saturation magnetization) of the one-dimensional $S=1/2$ trimerized Heisenberg spin system with ferromagnetic ($J_{\rm F}$)-ferromagnetic ($J_{\rm F}$)-antiferromagnetic ($J_{\rm A}$) interactions at $T=0$. I use the bosonization technique for the fer

Kiyomi Okamoto, Kiyohide Nomura

We comment on the recent work of Alcaraz and Malvezzi [1995 {\it J. Phys. A: Math. Gen.} {\bf 19} 1521] for the critical properties of the $S=1/2$ $XXZ$ chain in staggered magnetic field. The method of determining the phase boundary from the finite-size numerical data is also discussed.

Michael Brenner, Detlef Lohse, David Oxtoby, Todd Dupont

A gas bubble trapped in water by an oscillating acoustic field is expected to either shrink or grow on a diffusive timescale, depending on the forcing strength and the bubble size. At high ambient gas concentration this has long been observed in experiments. However, recent sonoluminescence experiments show that in certain circumstances when the ambient gas

Julyan H. E. Cartwright, Mario Feingold, Oreste Piro

We introduce and study the first model of an experimentally realizable three-dimensional time-dependent nonturbulent fluid flow to display the phenomenon of global diffusion of passive-scalar particles at arbitrarily small values of the nonintegrable perturbation. This type of chaotic advection, termed {\it resonance-induced diffusion\/}, is generic for a la

Robert G. Crittenden, Neil Turok

In models with a cosmological constant, a significant component of the large scale cosmic microwave background (CMB) anisotropy is produced at rather low redshifts, z < 1. In these models, the gravitational potential perturbations begin to evolve at late times. Photons passing through these time varying potentials aquire frequency shifts, an effect first not

E. Baron, P. H. Hauschildt, D. Branch, R. P. Kirshner

We present optical spectra of the Type Ic supernova 1994I in M51 and preliminary non-LTE analysis of the spectra. Our models are not inconsistent with the explosions of C+O cores of massive stars. While we find no direct evidence for helium in the optical spectra, our models cannot rule out small amounts of helium. More than 0.1~\msol\ of helium seems unlike

Albert A. Zijlstra, Cecile Loup, L. B. F. M. Waters, P. A. Whitelock

We have carried out an infrared search for obscured AGB stars in the Magellanic Clouds. The survey uncovered a number of obscured AGB stars as well as some supergiants with infrared excess. We present photometry of the sources and discuss the colour diagrams and bolometric luminosities. Most of the AGB stars are luminous, often close to the classical limit o

J. W. Moffat, I. Yu. Sokolov

The analytical structure of the difference between the static vacuum solution in the nonsymmetric gravitational theory (NGT) and the Schwarzschild solution of Einstein&#39;s gravitational theory (EGT) is studied. It is proved that a smooth matching of the solutions does not exist in the range $0 < r \leq 2M$, for any non-zero values of the parameters $M$ and

Ludmil Katzarkov

In this paper we prove that the universal cover of a smooth projective variety with nilpotent fundamental group is holomorphically convex.

Donald Marolf

The phase space reduction of Schwarzschild black holes by Thiemann and Kastrup and by Kuchař is reexamined from a different perspective on gauge freedom. This perspective introduces additional gauge transformations which correspond to asymptotically nontrivial diffeomorphisms. Various subtleties concerning variational principles for asymptotically flat syste

Chiu Liu, Qian Niu

We present a comprehensive investigation of nonequilibrium effects and self heating in single electron transfer devices based primarily on the Coulomb blockade effect. During an electron trapping process, a hot electron may be deposited in a quantum dot or metal island, with an extra energy usually on the order of the Coulomb charging energy, which is much h

H. Grosse, C. Klimcik, P. Presnajder

In the framework of noncommutative geometry we describe spinor fields with nonvanishing winding number on a truncated (fuzzy) sphere. The corresponding field theory actions conserve all basic symmetries of the standard commutative version (space isometries and global chiral symmetry), but due to the noncommutativity of the space the fields are regularized an

Yu. S. Kalashnikova, A. V. Nefediev

We extend the model for QCD string with quarks to consider the Mercedes Benz string configuration describing the three-quark baryon. Under the assumption of adiabatic separation of quark and string junction motion we formulate and solve the classical equation of motion for the junction.We dare to quantize the motion of the junction, and discuss the impact of

F. Leyvraz, D. Ullmo

A compound tunneling mechanism from one integrable region to another mediated by a delocalized state in an intermediate chaotic region of phase space was recently introduced to explain peculiar features of tunneling in certain two-dimensional systems. This mechanism is known as chaos-assisted tunneling. We study its consequences for the distribution of the l

L O&#39;C Drury, P Duffy, J G Kirk

The limits imposed on diffusive shock acceleration by upstream ion-neutral Alfven wave damping, and by ionisation and Coulomb losses of low energy particles, are calculated. Analytic solutions are given for the steady upstream wave excitation problem with ion-neutral damping and the resulting escaping upstream flux calculated. The time dependent problem is d

Sang-Ok Hahn, Phillial Oh, Myung-Ho Kim

We investigate classical integrable spins defined on the reduced phase spaces of coadjoint orbits of $G= SU(N)$ and study quantum mechanics of them. After discussions on a complete set of commuting functions on each orbit and construction of integrable spin models on the flag manifolds, we quantize a concrete example of integrable spins on SU(3) flag manifol

Yu. N. Bespalov

Let $A$ be a Hopf algebra in a braided category $\cal C$. Crossed modules over $A$ are introduced and studied as objects with both module and comodule structures satisfying a compatibility condition. The category $\DY{\cal C}^A_A$ of crossed modules is braided and is a concrete realization of a known general construction of a double or center of a monoidal c

Yuri Bespalov

Fully braided analog of Faddeev-Reshetikhin-Takhtajan construction of quasitriangular bialgebra $A(X,R)$ is proposed. For given pairing $C$ factor-algebra $A(X,R;C)$ is a dual quantum braided group. Corresponding inhomogeneous quantum group is obtained as a result of generalized bosonization. Construction of first order bicovariant differential calculus is p

J. Parramore, H. -C. Jean, J. Piekarewicz

We investigate the light and heavy meson spectra in the context of the instantaneous approximation to the Bethe-Salpeter equation (Salpeter&#39;s equation). We use a static kernel consisting of a one-gluon-exchange component and a confining contribution. Salpeter&#39;s equation is known to be formally equivalent to a random-phase-approximation equation; as s

R. Machleidt, F. Sammarruca, Y. Song

We calculate the triton binding energy with a non-local NN potential that fits the world NN data below 350 MeV with the almost perfect $χ^2$/datum of 1.03. The non-locality is derived from relativistic meson field theory. The result obtained in a 34-channel, charge-dependent Faddeev calculation is 8.00 MeV, which is 0.4 MeV above the predictions by local NN

B. S. Pudliner, A. Smerzi, J. Carlson, V. R. Pandharipande

The J$^π$=0$^+$ ground state of a drop of 8 neutrons and the lowest 1/2$^-$ and 3/2$^-$ states of 7-neutron drops, all in an external well, are computed accurately with variational and Green&#39;s function Monte Carlo methods for a Hamiltonian containing the Argonne $v_{18}$ two-nucleon and Urbana IX three-nucleon potentials. These states are also calculated

John H. Schwarz

A proposed duality between type IIB superstring theory on R^9 X S^1 and a conjectured 11D fundamental theory (``M theory&#39;&#39;) on R^9 X T^2 is investigated. Simple heuristic reasoning leads to a consistent picture relating the various p-branes and their tensions in each theory. Identifying the M theory on R^{10} X S^1 with type IIA superstring theory on

M. Alvarez

A calculation of the Aharonov-Bohm wave function is presented. The result is a series of confluent hypergeometric functions which is finite at the forward direction.

Silvia Penati, Andrea Refolli, Daniela Zanon

We study the quantum integrability of nonsimply--laced affine Toda theories defined on the half--plane and explicitly construct the first nontrivial higher--spin charges in specific examples. We find that, in contradistinction to the classical case, addition of total derivative terms to the &#34;bulk&#34; current plays a relevant role for the quantum boundar

Haru-Tada Sato

We show the OPE formulae for three types of deformed super-Virasoro algebras: Chaichian-Presnajder&#39;s deformation, Belov-Chaltikhian&#39;s one and its modified version. Fundamental (anti-)commutation relations toward a ghost realization of deformed super-Virasoro algebra are also discussed.

R. Brustein, M. Gasperini, M. Giovannini, G. Veneziano

A spectrum of relic stochastic gravitational radiation, strongly tilted towards high frequencies, and characterized by two basic parameters is shown to emerge in a class of string theory models. We estimate the required sensitivity for detection of the predicted gravitational radiation and show that a region of our parameter space is within reach for some of

K. Behrndt

We are discussing the $S$ \& $T$ duality for special class of heterotic string configurations. This class of solutions includes various types of black hole solutions and Taub-NUT geometries. It allows a self-dual point for both dualities which corresponds to massless configurations. As string state this point corresponds to $N_R=1/2$ and $N_L=0$. The string/

I. Antoniadis, S. Ferrara, E. Gava, K. S. Narain

We review the derivation and the basic properties of the perturbative prepotential in N=2 compactifications of the heterotic superstring. We discuss the structure of the perturbative monodromy group and the embedding of rigidly supersymmetric monodromies associated with enhanced gauge groups, at both perturbative and non-perturbative level.

Claudio Lucchesi

I present a criterion for all-order finiteness in $N=1$ SYM theories. The structure of the supercurrent anomaly, the Callan-Symanzik equation and the supersymmetric non-renormalization theorem for chiral anomalies are the essential ingredients of the proof.

Ryuji Kemmoku, Satoru Saito

The Moyal quantization is described as a discretization of the classical phase space by using difference analogue of vector fields. Difference analogue of Lie brackets plays the role of Heisenberg commutators.

R. Alkofer, C. D. Roberts

The form factor for the anomalous process $γπ^* \to ππ$, $F^{3π}(s,t,u)$, is calculated as a phenomenological application of the QCD Dyson-Schwinger equations. The chiral-limit value dictated by the electromagnetic, anomalous chiral Ward identity, $F^{3π}(0,0,0)= e N_c/(12π^2 f_π^3)$, is reproduced, {\it independent} of the details of the modelling of the gl

B. R. Webber

The following aspects of hadronic final states in deep inelastic lepton scattering are reviewed: measuring $alpha_s$ from multi-jet production rates and event shapes; alternative jet algorithms for DIS; power-suppressed corrections to event shapes; comparing jet fragmentation in $e^+e^-$ annihilation and DIS; final states in the BFKL and CCFM formulations of

T. R. Taylor

This is a review of basic ideas and mechanisms encountered in the supersymmetry breaking problem at the global level, in supergravity models, and in superstring theory.

Hai-Yang Cheng

The U(1) Goldberger-Treiman (GT) relation for the axial charge $g_A^0$ is reexamined. It is stressed that the isosinglet GT relation in terms of the $η_0$ holds irrespective of the quark masses and the axial anomaly. We pointed out that the identification of the $η_0-N$ and $\dk-N$coupling terms with the quark and gluon spin components respectively in a prot

Jisuke Kubo, Myriam Mondragon, Mark Olechowski, George Zoupanos

The consequences of Gauge-Yukawa Unification (GYU) in supersymmetric unified models on low energy physics are analyzed. We find that the observed top-bottom mass hierarchy can be explained by supersymmetric GYU and different models can be experimentally distinguished if the top quark mass does not exceed the value $\sim 185$ GeV.

Tao Huang, Chuan-Wang Luo

SU(3) flavor dependence of the leading and subleading parameters appeared in the heavy quark expansion of the heavy-light mesons are systematically analyzed by using QCD sum rules.

J. Sexton, A. Vaccarino, D. Weingarten

We compute from lattice QCD in the valence (quenched) approximation the partial decay widths of the lightest scalar glueball to pairs of pseudoscalar quark-antiquark states. These predictions and values obtained earlier for the scalar glueball&#39;s mass are in good agreement with the observed properties of $f_J(1710)$ and inconsistent with all other observe

W. Beirl, A. Hauke, P. Homolka, B. Krishnan

We examine the phase structure of pure Regge gravity in four dimensions and compare our Monte Carlo results with $Z_2$-link Regge-theory as well as with another formulation of lattice gravity derived from group theoretical considerations. Within all three models we find an extension of the well-defined phase to negative gravitational coupling and a new phase

K. Kajantie, M. Laine, K. Rummukainen, M. Shaposhnikov

We study on the lattice the 3d SU(2)+Higgs model, which is an effective theory of a large class of 4d high temperature gauge theories. Using the exact constant physics curve, continuum ($V\to\infty, a\to 0$) results for the properties of the phase transition (critical temperature, latent heat, interface tension) are given. The 3-loop correction to the effect

Daniel M. Kaplan

Some recent results from the Fermilab fixed-target experiment E789 on production of charm, charmonium, and beauty are summarized and compared to model predictions. The data indicate that heavy-quark and quarkonium production are not yet entirely understood. The largest discrepancy concerns the rate of $ψ^\prime$ production, which is a factor $\approx$25 abov

V. Korepin, A. Its, A. Waldron

We consider the quantum Non-linear Schrödinger equation $i\partial_tΨ=-\partial_x^2Ψ+2cΨ^\daggerΨ^2$ with positive coupling constant $c$ varying from zero to infinity. We study quantum correlation functions of this model using the determinant representation of these correlation functions. We consider the case of a finite density ground state and evaluate, us

Sungkit Yip

This paper considers the conductance through a dirty junction between a normal conductor and a superconductor with an insulating barrier. It is shown that for large barrier resistances there is a relative enhancement of the conductance near zero voltage, whereas for low barrier resistance this anomaly appears at finite voltage.

Kun Yang, R. N. Bhatt

We report results of a numerical study of non-interacting electrons moving in a random potential in two dimensions in the presence of a weak perpendicular magnetic field. We study the topological properties of the electronic eigenstates within a tight binding model. We find that in the weak magnetic field or strong randomness limit, extended states float up

G. E. Volovik, Tanmay Vachaspati

We describe certain aspects of ${}^3He$ and compare them to related aspects of the standard electroweak model of particle physics. We note various similarities in the order parameter structure, defect structure, interactions with fermions and anomalies in the two systems. Many issues in the condensed matter literature that are often confusing to the particle

Rajiv R. P. Singh

We calculate the excitation spectra for the one-$d$ Heisenberg-Ising antiferromagnets by expansions around the Ising limit. For $S=1/2$, the calculated expansion coefficients for the spinon-spectra agree term by term with the solution of Johnson and McCoy. For $S=1$, the solitons become gapless before the Heisenberg limit is reached, signalling a transition

Tom Schork

We consider a magnetic impurity which interacts by hybridization with a system of weakly correlated electrons and determine the energy of the ground state by means of an 1/N_f expansion. The correlations among the conduction electrons are described by a Hubbard Hamiltonian and are treated to lowest order in the interaction strength. We find that their effect

Anton Bovier, J. -M. Ghez

Schrödinger operators with potentials generated by primitive substitutions are simple models for one dimensional quasi-crystals. We review recent results on their spectral properties. These include in particular an algorithmically verifiable sufficient condition for their spectrum to be singular continuous and supported on a Cantor set of zero Lebesgue measu

E. Eisenriegler, U. Ritschel

Mesoscopic particles immersed in a critical fluid experience long-range Casimir forces due to critical fluctuations. Using field theoretical methods, we investigate the Casimir interaction between two spherical particles and between a single particle and a planar boundary of the fluid. We exploit the conformal symmetry at the critical point to map both cases

A. A. Odintsov

We investigate uniform one-dimensional arrays of small Josephson junctions ($E_J \ll E_C$, $E_C = (2e)^2/2C$) with a realistic Coulomb interaction $U(x) = E_C λ\exp( - |x|/λ)$ (here $λ\gg 1$ is the screening length in units of the lattice constant of the array). At low energies this system can be described in terms of interacting Bose particles (extra single

E. Granato, M. R. Baldan, S. C. Ying

A two-dimensional \underline{Frenkel-Kontorova model} under a steady external force is used to study the nonlinear sliding friction between flat macroscopic surfaces with a lubricant layer in between. The nonequilibrium properties of the model are simulated by a Brownian molecular dynamics and results are obtained as a function of temperature and a microscop

U. Ritschel, P. Czerner

We study the time evolution of classical spin systems with purely relaxational dynamics, quenched from T >> T_c to the critical point, in the semi-infinite geometry. Shortly after the quench, like in the bulk, a nonequilibrium regime governed by universal power laws is also found near the surface. We show for `ordinary&#39; and `special&#39; transitions that

B. S. Helmkamp, D. A. Browne

We study how the interaction with an external incoherent environment induces a crossover from quantum to classical behavior for a particle whose classical motion is chaotic. Posing the problem in the semiclassical regime, we find that noise produced by the bath coupling rather than dissipation is primarily responsible for the dephasing that results in the ``

R. Benzi, L. Biferale, S. Ciliberto, M. V. Struglia

In this paper we report numerical and experimental results on the scaling properties of the velocity turbulent fields in several flows. The limits of a new form of scaling, named Extended Self Similarity(ESS), are discussed. We show that, when a mean shear is absent, the self scaling exponents are universal and they do not depend on the specific flow (3D hom