August 1996 arXiv papers — page 4

Agustin Nieto

A hierarchy of effective field theories is used to separate the contributions from different momentum scales and to calculate the free energy of QCD at high temperature in powers of the coupling constant up to order $g^5$. The behavior of the perturbative series will also be discussed.

R. Baier, M. Dirks, O. Kober

Chiral theories of constituent quarks interacting with bosons and photons at high temperatures are studied. In the expected chirally symmetric phase effective electromagnetic anomalous couplings for e.g. $πσ\to γγ, ~ γ\to πππσ, $ etc., are derived by applying functional methods.

D. de Florian, C. Garcia Canal, R. Sassot

We compute the ratio between the direct and the resolved photon components of single jet and dijet production in $ep$ collisions for the kinematical range covered by the most recent ZEUS data. We analyse the phenomenological consequences of different models for the structure of virtual photons in these observables and compare them with the available data. We

M. Peter

Top quark pair production close to threshold at a next linear collider is discussed, with special focus on the influence of rescattering corrections. Numerical results are shown for the differential cross-section, i.e. the momentum distribution and the forward backward asymmetry, and for moments of the angular distribution of leptons arising from the semilep

V. V. Kiselev

The decay constant for the vector state of $3S$-level in the heavy $(\bar b c)$-quarkonium is evaluated in the framework of sum rules for the mesonic currents. A scaling relation for the constants of vector quarkonia with different quark contents is derived. The numerical estime gives $Γ(B_c^{*+}(3S)\to B^+D^0)=90 \pm 35$ MeV.

Yubing Luo

Expanding upon the arguments of Sharpe, we explicitly implement the Symanzik improvement program demonstrating the absence of order $a$ terms in the staggered fermion action. We propose a general program to improve fermion operators to remove $O(a)$ corrections from their matrix elements, and demonstrate this program for the examples of matrix elements of fe

Andreas S. Kronfeld

Relativistic corrections communicate the binding energy of a bound state to its kinetic mass. This mechanism is reviewed and used to explain anomalous results of Collins, Edwards, Heller, and Sloan (hep-lat/9512026), which compared rest and kinetic masses of heavy-light mesons and quarkonia.

A. Patrascioiu, E. Seiler

We comment on the recent paper by Alles et al (hep-lat/9608002)

Y. Kikukawa, S. Miyazaki

We examine the vacuum overlap formula for the two-dimensional SU(2) Wess-Zumino term in lattice regularization. Perturbatively it reproduces the Wess-Zumino term correctly in the continuum limit and yields the IR fixed point in the beta function of the chiral model. Nonperturbatively it shows a sharp Gaussian distribution for the SU(2) chiral field configura

T. Aoyama, Y. Kikukawa

We calculate the complex phase of chiral determinant by the vacuum overlap formula with configurations of two-dimensional U(1) gauge field fixed in Landau and Laplacian gauge. The complex phase fluctuates over the Gribov copies, which appear in the process of Landau gauge fixing and contain vortex-like singularities. In the Laplacian gauge, the fluctuation c

Robert Adair, Grigor Atoyan, Basem Barakat, Milind V. Diwan

We have examined the physics and the experimental feasibility at the AGS of various kaon decay processes in which the polarization of a muon in the final state is measured. Valuable information on CP violation, the CKM matrix or new physics can be obtained with these measurements and therefore they are well motivated. In particular, models of non-standard CP

Ho Jung Paik

The construction of a massive (~ 40 ton) spherical antennas for gravitational wave astronomy has been proposed by a number of groups worldwide. Summed over all five quadrupole modes, the sphere has a direction-independent cross section, permitting full-sky coverage. Combined with its enhanced sensitivity due to its multi-nature and increased mass, sphereical

Lior M. Burko

We critically examine the Roberts homothetic solution for the spherically symmetric Einstein-scalar field equations in double null coordinates, and show that the Roberts solution indeed solves the field equations only for one non-trivial case. We generalize this solution and discuss its relations with other known exact solutions.

Bjørn Jensen, Harald H. Soleng

We find an anisotropic, non-supersymmetric generalization of the extreme supersymmetric domain walls of simple non-dilatonic supergravity theory. As opposed to the isotropic non- and ultra-extreme domain walls, the anisotropic non-extreme wall has the \emph{same} spatial topology as the extreme wall. The solution has naked singularities which vanish in the e

B. Shapiro

For a given real generic curve $\ga: S^1\to \Bbb {RP}^n$ let $D_\ga$ denote the ruled hypersurface in $\Bbb {RP}^n$ consisting of all osculating subspaces to $\ga$ of codimension 2. A curve $\ga: S^1\to \Bbb {RP}^n$ is called convex if the total number of its intersection points (counted with multiplicities) with any hyperplane in $\Bbb {RP}^n$ does not exce

Sudip Chakravarty

The dimensional crossover in a spin-$S$ nearest neighbor Heisenberg antiferromagnet is discussed as it is tuned from a two-dimensional square lattice, of lattice spacing $a$, towards a spin chain by varying the width $L_y$ of a semi-infinite strip $L_x\times L_y$. For integer spins and arbitrary $L_y$, and for half integer spins with $L_y/a$ an arbitrary eve

W. -S. Zeng, O. Jepsen, V. Heine

Recent experimental results on two hcp phases of barium under high pressure show interesting variation of the lattice parameters. They are here interpreted in terms of electronic structure calculation by using the LMTO method and generalized pseudopotential theory (GPT) with a NFE-TBB approach. In phase II the dramatic drop in c/a is an instability analogous

K. A. Kikoin, M. N. Kiselev, A. S. Mishchenko

The mechanism explaining the key role of AFM correlations in formation of the heavy fermion state is offered. It is shown that in the case of $(T^*-T_N)/T_N << 1$ the critical spin fluctuations transform the mean-field second-order transition to RVB state into the crossover from high-temperature paramagnetic behavior of localized spins to strongly correlated

Massimiliano Capezzali, Daniel Ariosa, Hans Beck

The partition function of the Hubbard model with local attraction and long range Coulomb repulsion between electrons is written as a functional integral with an action $A$ involving a pairing field $Δ$ and a local potential $V$. After integration over $V$ and over fluctuations in $|Δ|^{2}$, the final form of $A$ involves a Josephson coupling between the loca

N. Shibata, T. Nishino, K. Ueda, C. Ishii

The density-matrix renormalization-group method is applied to the one-dimensional Kondo-lattice model with the Coulomb interaction between the conduction electrons. The spin and charge gaps are calculated as a function of the exchange constant $J$ and the Coulomb interaction $U_c$. It is shown that both the spin and charge gaps increase with increasing $J$ a

E. Brézin, S. Hikami

In the theory of disordered systems the spectral form factor $S(τ)$, the Fourier transform of the two-level correlation function with respect to the difference of energies, is linear for $τ<τ_c$ and constant for $τ>τ_c$. Near zero and near $τ_c$ its exhibits oscillations which have been discussed in several recent papers. In the problems of mesoscopic fluctu

R. Aurich, A. Bäcker, F. Steiner

The mode-fluctuation distribution $P(W)$ is studied for chaotic as well as for non-chaotic quantum billiards. This statistic is discussed in the broader framework of the $E(k,L)$ functions being the probability of finding $k$ energy levels in a randomly chosen interval of length $L$, and the distribution of $n(L)$, where $n(L)$ is the number of levels in suc

Mark Hillery, Leonard Mlodinow

Theories which have been used to describe the quantized electromagnetic field interacting with a nonlinear dielectric medium are either phenomenological or derived by quantizing the macroscopic Maxwell equations. Here we take a different approach and derive a Hamiltonian describing interacting fields from one which contains both field and matter degrees of f

Q. Daniel Wang, Taisheng Ye

We measured the extragalactic 0.7 keV X-ray background by observing the X-ray shadow of a neutral gas cloud in the Magellanic Bridge region. Two \rosat PSPC observations of total 104~ks were complemented by a detailed H I mapping of the cloud with both the Parkes 64~m telescope and the Australia Telescope Compact Array. From the detected anti-correlation bet

K. Nandra, R. F. Mushotzky, T. Yaqoob, I. M. George

We present strong evidence for variability of the flux of the iron K$α$ emission line in the Seyfert 1 galaxy, NGC 3516. Two ASCA observations, separated by $\sim 1$~yr, showed a marked decrease in continuum flux by $\sim 60$~per cent. The flux in the broad, iron K$α$ line decreased by the same factor in this time period, with no evidence for changes in the

K. Nandra, I. M. George, R. F. Mushotzky, T. J. Turner

We present the first in a series of papers describing the X-ray properties of a sample of 18 Seyfert 1 galaxies, using data obtained by \asca. The imaging data reveal a number of serendipitous hard X-ray sources in some source fields, but none contribute significantly to the hard X-ray flux of the AGN. All but one of the Seyferts show evidence for variabilit

M. Kiraga, B. Paczynski, K. Z. Stanek

We have reanalyzed the OGLE $V$ and $I$ photometry of $\sim 500,000$ stars in Baade&#39;s Window, and we confirm the extinction map published by Stanek (1996). However, we find that the interpretation of the OGLE color--magnitude diagram for the disk stars proposed by Paczyński et al. (1994) was incorrect: the dominant disk population in Baade&#39;s Window i

J. Pérez-Mercader

The Universe that we know is populated by structures made up of aggregated matter that organizes into a variety of objects; these range from stars to larger objects, such as galaxies or star clusters, composed by stars, gas and dust in gravitational interaction. We show that observations support the existence of a composite (two--exponent) power law relating

M. D. Still

The emission lines found in the majority of cataclysmic variables are generally used as tracers of accretion flows which dominate the light at optical wavelengths. It has been suggested from previous observations that the eclipsing nova-like variable PG0859+415 shows individualistic orbital characteristics which are inconsistent with canonical models of stel

H. J. A. Röttgering, G. K. Miley

The study of high-$z$ radio galaxies (HZRGs) has matured considerably during the last decade. Large numbers of $z>2$ radio galaxies have been found and have been studied in considerable detail. In this review we will address the importance of the VLT for studies of samples of distant radio galaxies. We shall first briefly discuss the importance of radio gala

Herbert Kanarek

Given an arrangement of hyperplanes in $¶^n$, possibly with non-normal crossings, we give a vanishing lemma for the cohomology of the sheaf of $q$-forms with logarithmic poles along our arrangement. We give a basis for the ideal $\cal J$ of relations for the Orlik-Solomon&#39;s algebra. Under certain genericity conditions it was shown by H.~Esnault, V.~Schec

Eleny Ionel

We prove recursive formulas for $τ_d$, the number of degree $d$ elliptic curves with fixed j-invariant in P^n. We use analysis to relate the classical invariant $τ_d$ to the genus one perturbed invariant $RT_{1,d}$ defined recently by Ruan and Tian (the later invariant can be computed inductively). By considering a sequence of perturbations converging to zer

H. Arfaei, M. M. Sheikh Jabbari

We use rotation of one D-brane with respect to the other to reveal the hidden structure of D-branes in type-II theories. This is done by calculation of the interaction amplitude for two different parallel and angled branes. The analysis of strings with different boundary conditions at the ends is also given. The stable configuration for two similar branes oc

Junichiro Makino, Piet Hut

We present cross sections and reaction rates for merging to occur during encounters of equal-mass spherical galaxies. As an application, we determine the rate of galaxy merging in clusters of galaxies. We present results for two types of Plummer models (a full and a truncated one), two King models and the Hernquist model. Cross sections are determined on the

A. N. Leznov, A. S. Sorin

The formalism of integrable mappings is applied to the problem of constructing hierarchies of $(1+2)$ dimensional integrable systems in the $(2|2)$ superspace. We find new supersymmetric integrable mappings and corresponding to them new hierarchies of integrable systems which, at the reduction to the $(1|2)$ superspace, possess $N=2$ supersymmetry. The gener

Tomohide Terasoma

A constructible sheaf corresponding to Gel&#39;fand Zelevinski hypergeometric functions on a torus is called hypergeometric sheaf. We consider Hodge and Tate conjectrue for hypergeomtric sheaves. Hodge conjecture is formulated in terms of variation of Hodge strucure and Tate conjecture is done for l-adic sheaves on an open set of torus. We prove Hodge and Ta

Jeremy S. Heyl, Lars Hernquist

We calculate the reaction cross-sections for the fusion of hydrogen and deuterium in strong magnetic fields as are believed to exist in the atmospheres of neutron stars. We find that in the presence of a strong magnetic field ($B \gsim 10^{12}$G), the reaction rates are many orders of magnitude higher than in the unmagnetized case. The fusion of both protons

A. Marshakov

One of the perspectives in modern quantum field and string theory is related with the attempts to go beyond the perturbation theory. It turns out that a key principle in the formulation of all known non-perturbative results is {\it integrability}, i.e. arising of the structures of completely integrable systems. I discuss several important steps in this direc

P. V. Pobylitsa, M. V. Polyakov

At large N_c the nucleon can be viewed as a soliton of the effective chiral lagrangian. This picture of nucleons allows a consistent nonperturbative calculation of the leading-twist parton distributions at a low normalization point. We derive general formulae for the transverse spin quark distribution h_1(x) in the chiral quark-soliton model. We present nume

A. Bochkarev, Ph. de Forcrand

The correlator of heavy-quark currents is calculated in quenched Lattice QCD on a $16^3 \times 32$-lattice for $β= { 6, 6.3 }$. The renormalized charmed quark mass is extracted from the short-distance part of that correlator: $m_c^{\overline{MS}}(m_c) = 1.22(5) GeV$. We study the sensitivity of our data to the strong coupling constant.

JLQCD Collaboration, S. Aoki, M. Fukugita, S. Hashimoto

We present new results of our ongoing project toward a precision determination of the kaon $B$ parameter with the Kogut-Susskind quark action in quenched QCD. New results taken at $β$=6.4 and $β=5.7$ suggest that an apparently linear $a$ dependence of $B_K$ previously observed for $β=5.85-6.2$ arises from a change of curvature from convex to concave as the l

F. Lesage, H. Saleur

We show how to analytically determine for $g\leq 1/2$ the &#34;Friedel oscillations&#34; of charge density by a single impurity in a 1D Luttinger liquid of spinless electrons.

Z. Kuncic, A. Celotti, M. J. Rees

The primary radiation generated in the central continuum-forming region of Active Galactic Nuclei can be reprocessed by very dense, small-scale clouds that are optically-thin to Thomson scattering. In spite of the extreme conditions expected to prevail in this innermost, central environment, the radiative clouds can survive and maintain cool temperatures rel

Toshio Tsuchiya, Naoteru Gouda, Tetsuro Konishi

This is the third paper of the series of our studies of the one-dimensional self-gravitating many-body systems. In this paper, we thus study the transition phenomena after the first transition from a quasiequilibrium. We found that irrespective of the initial conditions, the system wanders between many states which yield the same properties of the quasiequil

Junichiro Makino

We investigated the evolution of the black hole binary formed by the merging of two galaxies each containing a central massive black hole. Our main goal here is to determine if the black hole binary can merge through the hardening by dynamical friction and the gravitational wave radiation. We performed $N$-body simulations of merging of two galaxies with wid

Junichiro Makino

A number of globular clusters appear to have undergone core collapse, in the sense that their predicted collapse time is much shorter than their current age. Simulations using gas models and Fokker-Planck approximation have shown that the central density of a globular cluster after the collapse undergoes nonlinear oscillation with large amplitude (gravotherm

Y. Mellier

In addition to the determination of the mass distribution of lenses (see P. Schneider, this conference), strong and weak lensing can also be powerfull tools to analyse the redshift distribution of faint galaxies. In this review, I summarize the present status of redshifts of galaxies beyond $B=25$ as they are inferred by spectroscopy of magnified galaxies, l

Re&#39;em Sari, Tsvi Piran

Internal (IS) or external (ES) shocks in relativistic expanding shells are currently the best known mechanism for producing GRBs. We calculate the hydrodynamic conditions and the cooling processes in internal shocks, that occur when one layer overtakes another. We compare these conditions with the conditions in external shocks that occur when the shell encou

Sourendu Gupta, K. Sridhar

We study J/ψproduction at fixed-target energies, including the colour-octet production mechanisms predicted by NRQCD. In an earlier paper, we found that the octet components were crucial in understanding p_T-integrated forward (x_F > 0) cross-sections. Here we make a detailed comparison of the theoretical predictions with measured x_F distributions from fixe

A. Leviatan, N. D. Whelan

Partial dynamical symmetry describes a situation in which some eigenstates have a symmetry which the quantum Hamiltonian does not share. This property is shown to have a classical analogue in which some tori in phase space are associated with a symmetry which the classical Hamiltonian does not share. A local analysis in the vicinity of these special tori rev

Lam Hui, Nickolay Y. Gnedin, Yu Zhang

We develop a method to calculate the column density distribution of the Lyman-alpha forest for column densities in the range $10^{12.5} - 10^{14.5} cm^{-2}$. The Zel&#39;dovich approximation, with appropriate smoothing, is used to compute the density and peculiar velocity fields. The effect of the latter on absorption profiles is discussed and it is shown to

Silvano Simula

The production of slow nucleons in semi-inclusive deep inelastic electron scattering off the deuteron is investigated in the region $x \gsim 0.3$ for kinematical conditions accessible at $HERA$. Within the spectator mechanism the semi-inclusive cross section exhibits a scaling property, which can be used as a model-independent test of the dominance of the sp

Steven P. Lewis, Phillip B. Allen, Taizo Sasaki

Local Spin Density Approximation (LSDA) is used to calculate the energy bands of both the ferromagnetic and paramagnetic phases of metallic CrO_2. The Fermi level lies in a peak in the paramagnetic density of states, and the ferromagnetic phase is more stable. As first predicted by Schwarz, the magnetic moment is 2 μ_B per Cr atom, with the Fermi level for m

Zachary Guralnik

We discuss the relationship between the boundary conditions of the Schwinger-Dyson equations and the phase diagram of a bosonic field theory or matrix model. In the thermodynamic limit, many boundary conditions lead to the same solution, while other boundary conditions have no such limit. The list of boundary conditions for which a thermodynamic limit exists

S. M. Kuzenko

We review the unified description of massless spinning particles, living in spaces of constant curvature, in the framework of the pseudoclassical approach with a gauged $N$-extended worldline supersymmetry and a local $O(N)$ invariance.

Shinji Ejiri, Shun-ichi Kitahara, Tsuneo Suzuki, Koji Yasuta

The critical properties of the abelian Polyakov loop and the Polyakov loop in terms of Dirac string are studied in finite temperature abelian projected $SU(2)$ QCD. We evaluate the critical point and the critical exponents from each Polyakov loop in the maximally abelian gauge using the finite-size scaling analysis. Abelian dominance in this case is proved q

Pedro F. Gonzalez-Diaz

It is shown that in a classical spacetime with multiply connected space slices having the topology of a torus, closed timelike curves are also formed. We call these spacetime ringholes. Two regions on the torus surface can be distinguished which are separated by angular horizons. On one of such regions (that which surrounds the maximum circumference of the t

Sandro S. Costa

The purpose of this work is to show a possible reconciliation between Mach&#39;s principle and the Schwarzschild solution, using a description of this solution in terms of a new radial cooordinate related to the behaviour of Unruh detectors.

Karl-Heinz Wagenblast, Anne van Otterlo, Gerd Schön, Gergely T. Zimányi

We study dynamic properties of thin films near the superconductor - insulator transition. We formulate the problem in a phase representation. The key new feature of our model is the assumption of a {\it local} ohmic dissipative mechanism. Coarse graining leads to a Ginzburg-Landau description, with non-ohmic dynamics for the order parameter. For strong enoug

Kenji Kobayashi, Chikaomi Ohe, Kaoru Iguchi

The one-dimensional t-J model is investigated by the variational Monte Carlo method. A variational wave function based on the Bethe ansatz solution is newly proposed, where the spin-charge separation is realized, and a long-range correlation factor of Jastrow-type is included. In most regions of the phase diagram, this wave function provides an excellent des

Nickolay Y. Gnedin, Lam Hui

We develop an analytical method based on the lognormal approximation to compute the column density distribution of the Lyman-alpha forest in the low column density limit. We compute the column density distributions for six different cosmological models and found that the standard, COBE-normalized CDM model cannot fit the observations of the Lyman-alpha fores

Vladimir M. Lipunov, Ivan E. Panchenko

Binary neutron stars mergers that are expected to be the most powerful source of energy in the Universe definitely exist in nature, as is proven by the observed behavior of the Hulse-Taylor binary radio pulsar. Though most of energy in such events is radiated in gravitational waves, there probably exist several mechanisms giving also electromagnetic radiatio

Andrei Okounkov

We prove a binomial formula for Macdonald polynomials and consider applications of it.

Andrei Okounkov, Grigori Olshanski

In this note we prove an explicit binomial formula for Jack polynomials and discuss some applications of it.

Lisa C. Jeffrey, Frances C. Kirwan

We prove formulas (found by Witten in 1992 using physical methods) for intersection pairings in the cohomology of the moduli space M(n,d) of stable holomorphic vector bundles of rank n and degree d (assumed coprime) on a Riemann surface of genus g greater than or equal to 2. We also use these formulas for intersection numbers to obtain a proof of the Verlind

Saurya Das, Arundhati Dasgupta, P. Ramadevi

We give several pieces of evidence to show that extremal black holes cannot be obtained as limits of non-extremal black holes. We review arguments in the literature showing that the entropy of extremal black holes is zero, while that of near-extremal ones obey the Bekenstein-Hawking formula. However, from the counting of degeneracy of quantum (BPS) states of

M. Gronau, D. London

We review and update the effects of physics beyond the standard model on CP asymmetries in B decays. These asymmetries can be significantly altered if there are important new-physics contributions to \bqbqbar mixing. This same new physics will therefore also contribute to rare, flavor-changing B decays. Through a study of such decays, we show that it is poss

Ziqiang Wang, Božidar Jovanović, Dung-Hai Lee

Under periodic boundary condition in the transverse direction, we calculate the averaged zero-temperature two-terminal conductance ($<G>$) and its statistical fluctuations ($<(\dg)^{2n}>$ for $n\le 4$) at the critical point of integer quantum Hall plateau transitions. We find {\it universal} values for $<G>=(0.58\pm0.03){e^2\over h}$, and $<(\dg)^{2n}>=({e^2

Esteban A. Calzetta, Sonia Gonorazky

We study the spectrum of primordial fluctuations in theories where the inflaton field is coupled to massless fields and/or to itself. Conformally invariant theories generically predict a scale invariant spectrum. Scales entering the theory through infrared divergences cause logarithmic corrections to the spectrum, tiltilng it towards the blue. We discuss in

M. Pillai

The contents of this document have been withdrawn pending its mailing at a future date.

Mike Bisset, Dilip Kumar Ghosh, Sreerup Raychaudhuri

Under the assumption of gaugino mass unification at a high scale, chargino and neutralino masses depend on the value of the gluino mass, which itself becomes a function of squark masses through self-energy corrections. We demonstrate that this leads to combined bounds on squark and gluino masses from the limits on chargino, neutralino and Higgs boson masses

J. A. Peacock

This paper investigates whether nonlinear gravitational instability can account for the clustering of galaxies on large and small scales, and for the evolution of clustering with epoch. No CDM-like spectrum is consistent with the shape of the observed nonlinear spectrum. Unbiased low-density models greatly overpredict the small-scale correlations; high-densi

Elizabeth Gasparim

We show that holomorphic bundles on O(-k) for k > 0 are algebraic. We also show holomorphic bundles on O(-1) are trivial outside the zero section.

A. N. Sissakian, O. Yu. Shevchenko, S. B. Solganik

The Chern-Simons topological term dynamical generation in the effective action is obtained at arbitrary finite density. By using the proper time method and perturbation theory it is shown that $μ^2 = m^2$ is the crucial point for Chern-Simons. So when $μ^2 < m^2 μ$--influence disappears and we get the usual Chern-Simons term. On the other hand when $μ^2 > m^

Francesca Federici, Andrei A. Varlamov

We study the effect of fluctuations on the {\bf ac} conductivity of a layered superconductor both for $c$-axis and $ab$-plane electromagnetic wave polarizations. The fluctuation contributions of different physical nature and signs (paraconductivity, Maki-Thompson anomalous contribution, one-electron density of states renormalization) are found to be suppress

D. H. E. Gross, M. E. Madjet, O. Schapiro

Here we first develop the thermodynamics of microcanonical phase transitions of first and second order in systems which are thermodynamically stable in the sense of van Hove. We show how both kinds of phase transitions can unambiguously be identified in relatively small isolated systems of $\sim 100$ atoms by the shape of the microcanonical caloric equation

S. Chaturvedi

A direct proof of the resolution of the identity in the odd sector of the Fock space in terms of squeezed number states $D(ξ)|2m+1>; D(ξ) = \exp((ξa^{\dagger2}-ξ^*{a^2})/2)$ is given. The proof entails evaluation of an integral involving Jacobi polynomials. This is achieved by the use of Racah identities.

Yuri Bespalov, Bernhard Drabant

We consider Hopf bimodules and crossed modules over a Hopf algebra $H$ in a braided category. They are the key-stones for braided bicovariant differential calculi and their invariant vector fields respectively, as well as for the construction of braided Hopf algebra cross products. We show that the notions of Hopf bimodules and crossed modules are equivalent

Bin Zhang, Miklos Gyulassy, Yang Pang

We study pre-equilibrium strangeness production at RHIC energies in a new parton cascade. Starting with the turbulent glue HIJING initial conditions we investigate the interplay between mini-jet and soft beam jet gluons for strangeness production prior to hadronization, and show the importance of soft beam jet gluons in the strangeness production.

Duiliu-Emanuel Diaconescu

We study the correspondence between IIb solitonic 1-branes and monopoles in the context of the 3-brane realization of $D=4$ $N=4$ super Yang-Mills theory. We show that a bound state of 1-branes stretching between two separated 3-branes exhibits a family of super-symmetric ground states that can be identified with the ADHMN construction of the moduli space of

Rainer Haeussling, Elisabeth Kraus

We analyze gauge parameter dependence by using an algebraic method which relates the gauge parameter dependence of Green functions to an enlarged Slavnov-Taylor identity. In the course of the renormalization it turns out that gauge parameter dependence of physical parameters is already restricted at the level of Green functions. In a first step we consider t

Hidenori Sonoda, Wang-Chang Su

In asymptotic free field theories we show that part of the OPE of the trace of the stress-energy tensor and an arbitrary composite field is determined by the anomalous dimension of the composite field. We take examples from the two-dimensional O(N) non-linear sigma model.

Alan Kostelecky

A mechanism for spontaneous CPT breaking appears in string theory. Possible implications for present-energy particle models are discussed. A realistic string theory might exhibit CPT violation at levels detectable in current or future experiments. Bounds on CPT from neutral-meson oscillations are considered.

B. Bailey, Edmond. L. Berger, L. E. Gordon

The two particle inclusive cross section for the reaction $p\bar{p}\rightarrow γ+c+X$ is studied in perturbative quantum chromodynamics at order $O(α_s^2)$. Differential distributions are provided for various observables, and a comparison is made with preliminary data from the CDF collaboration.

Francois Gelis

Strong collinear divergences, although regularized by a thermal mass, result in a breakdown of the standard hard thermal loop expansion in the calculation of the production rate of photons by a plasma of quarks and gluons using thermal field theory techniques.

Matthias Burkardt

Numerical results for the (rest-frame) $Q\bar{Q}$ potential in light-front quantized $QCD_{2+1}$ on a $\perp$ lattice are presented. Both in the longitudinal as well as the $\perp$ spatial directions one obtains linear confinement. The confinement mechanism in light-front QCD depends on the orientation of the external charges: for longitudinally (with respec

Vittorio Del Duca

In this talk I consider the formation of a rapidity gap in hadron production between two jets.

Vittorio Del Duca

In this talk I consider forward-jet production at HERA and at the Tevatron as a probe of the multiple gluon radiation induced by the BFKL evolution.

M. B. Gay Ducati, Victor P. B. Gonçalves

We present an analysis of the current methods of approximate determination of the gluon density $G(x,Q^2)$ at low-$x$ from the scaling violations of the proton structure function $F_2(x,Q^2)$. The gluon density is obtained from DGLAP equation by expansion at distinct points of expansion. We show that the different results given by the proposed methods can be

Dinesh Kumar Srivastava, Munshi Golam Mustafa, Berndt Müller

The chemical equilibration of the parton distribution in collisions of two heavy nuclei at the CERN Large Hadron Collider is investigated. Initial conditions are obtained from a self-screened parton cascade calculation. The onset of transverse expansion of the system is found to impede the chemical equilibration. The system initially approaches chemical equi

T. Hambye, R. B. Mann, U. Sarkar

A violation of the equivalence principle (VEP) in the Kaon system can, in principle, induce oscillations between $K^\circ$ and $\overline{K^\circ}$ in a manner that need not violate CPT conservation. We show that such a CPT-conserved VEP mechanism could be clearly tested experimentally through the energy dependence of the $K_L-K_S$ mass difference and discus

Axel Brandenburg, Kari Enqvist, Poul Olesen

We study the effects of plasma viscosity on the dynamics of primordial magnetic fields by simulating magnetohydrodynamics in the early universe by appropriate non-linear cascade models. We find numerically that even in the presence of large kinetic viscosity, magnetic energy is transferred to large length scales. There are indications, however, that the inve

Alon E. Faraggi

Superstring phenomenology aims at achieving two goals. The first is to reproduce the observed physics of the Standard Model. The second is to identify experimental signatures of superstring unification which, if observed, will provide further evidence for the validity of superstring theory. I discuss such potential signatures of superstring unification. I pr

Krishna Rajagopal

This paper presents work done in collaboration with E. Farhi, J. Goldstone, and A. Lue which is described in full in Ref. [1]. We consider a variant of the standard electroweak theory in which the Higgs sector has been modified so that there is a classically stable weak scale soliton. We explore fermion number violating processes which involve soliton decay.

Pilar Hernandez, Raman Sundrum

The importance of lattice gauge field interpolation for our recent non-perturbative formulation of chiral gauge theory is emphasized. We illustrate how the requisite properties are satisfied by our recent four-dimensional non-abelian interpolation scheme, by going through the simpler case of U(1) gauge fields in two dimensions.

Pilar Hernandez, Raman Sundrum

We review our recent proposal for a new lattice action for non-abelian gauge theories which reduces short-range lattice artifacts in the computation of the topological susceptibility. The standard Wilson action is replaced by the Wilson action of a gauge covariant interpolation of the original fields to a finer lattice. We illustrate the improved behavior of

Claudio Parrinello

We report on some attempts to use lattice QCD to investigate topics in strong interactions phenomenology which are usually interpreted in terms of soft Pomeron exchange.

Natsuko Arasaki, Shinji Ejiri, Shun-ichi Kitahara, Yoshimi Matsubara

Effective monopole actions for various extended monopoles are derived from vacuum configurations after abelian projection in the maximally abelian gauge in $T=0$ and $T\ne 0$ $SU(3)$ lattice QCD. The actions obtained appear to be independent of the lattice volume adopted. At zero temperature, monopole condensation is seen to occur from energy-entropy balance

J. B. Kogut, J. -F. Lagae, D. K. Sinclair

We compute the flavor singlet meson correlators and screening masses in quenched and $N_f=2$ QCD at $N_t=8$. The consequences of our results for the realization of the $U_A(1)$ symmetry at finite T are discussed and an interpretation of our measurements in terms of the behaviour of the low lying fermionic modes is proposed.

T. Blum, J. E. Hetrick, D. Toussaint

We study lattice QCD in the limit that the quark mass and chemical potential are simultaneously made large, resulting in a controllable density of quarks which do not move; this is similar in spirit to the quenched approximation for zero density QCD. In this approximation we find that the deconfinement transition seen at zero density becomes a smooth crossov