September 2002 arXiv papers — page 6

Xiao-Yin Pan, Viraht Sahni

Local(multiplicative) effective potential energy theories of electronic structure comprise the transformation of the Schr{ö}dinger equation for interacting fermi systems to model noninteracting fermi or bose systems whereby the equivalent density and energy are obtained. By employing the integrated form of the Kato electron-nucleus cusp condition, we prove t

D. Adamova, CERES/NA45 Collaboration

We report on first measurements of low-mass electron pairs in Pb-Au collisions at the lower SPS beam energy of 40 AGeV. The pair yield integrated over the range of invariant masses 0.2<m<1 GeV/c^2 is enhanced by a factor of 5.1+-1.3(stat)+-1.0/1.5(syst data/decays) over the expectation from neutral meson decays, more than previously observed at the higher en

Antonio Masiero, Sudhir K. Vempati, Oscar Vives

That $μ\to e, γ$ and $τ\to μ,γ$ are sensitive probes of SUSY models with a see-saw mechanism is a well accepted fact. Here we propose a `top-down&#39; approach in a general SUSY SO(10) scheme. In this framework, we show that at least one of the neutrino Yukawa couplings is as large as the top Yukawa coupling. This leads to a strong enhancement of these lepto

Stefano Olivares, Matteo G. A. Paris, Rodolfo Bonifacio

Inconclusive photon subtraction (IPS) is a conditional measurement scheme to force nonlinear evolution of a given state. In IPS the input state is mixed with the vacuum in a beam splitter and then the reflected beam is revealed by ON/OFF photodetection. When the detector clicks we have the (inconclusive) photon subtracted state. We show that IPS on both chan

D. Yu. Ivanov, B. Pire, L. Szymanowski, O. V. Teryaev

We consider the electroproduction of two vector mesons with a large rapidity gap between them on a nucleon target in the process $ γ^* N \to ρ_1 ρ_2 N&#39;$. We calculate the Born term for this process within the collinear factorization framework. The resulting scattering amplitude may be represented as a convolution of an impact factor describing the $γ^* \

Antonella Antonelli

Radiative phi decays give us an excellent opportunity to study scalar and pseudoscalar meson below 1 GeV. In this paper, results from different experiments are reviewed and compared.

A. Mercurio, M. Girardi, W. Boschin, P. Merluzzi

We study the internal dynamics of the rich galaxy cluster ABGC 209 on the basis of new spectroscopic and photometric data. The distribution in redshift shows that ABCG 209 is a well isolated peak of 112 detected member galaxies at z=0.209, characterised by a high value of the line-of-sight velocity dispersion, sigma_v=1250-1400 Km/s, on the whole observed ar

Choon-Lin Ho, Pinaki Roy

We present a general procedure for determining possible (nonuniform) magnetic fields such that the Pauli equation becomes quasi-exactly solvable (QES) with an underlying $sl(2)$ symmetry. This procedure makes full use of the close connection between QES systems and supersymmetry. Of the ten classes of $sl(2)$-based one-dimensional QES systems, we have found

Gilbert P. Holder, Paul L. Schechter

We use publicly available N-body simulations and semi-analytic models of galaxy formation to estimate the levels of external shear due to structure near the lens in gravitational lens systems. We also describe two selection effects, specific to four-image systems, that enhance the probability of observing systems to have higher external shear. Ignoring addit

Teruyuki Kitabayashi, Masaki Yasuè

We construct an $SU(3)_L \times U(1)_N$ gauge model based on an $S_{2L}$ permutation symmetry for left-handed $μ$ and $τ$ families, which provides the almost maximal atmospheric neutrino mixing and the large solar neutrino mixing of the LMA type. Neutrinos acquire one-loop radiative masses induced by the radiative mechanism of the Zee type as well as tree le

Th. John, U. Behn, R. Stannarius

This paper describes the application of a laser diffraction technique to the study of electroconvection in nematic liquid crystal cells. It allows a real-time quantitative access to pattern wave lengths and amplitudes. The diffraction profile of the spatial periodic pattern is calculated and compared quantitatively to experimental intensity profiles. For sma

N. Kleeorin, I. Rogachevskii

An effect of rotation on a developed turbulent stratified convection is studied. Dependencies of the hydrodynamic helicity, the alpha-tensor and the effective drift velocity of the mean magnetic field on the rate of rotation and an anisotropy of turbulent convection are found. It is shown that in an anisotropic turbulent convection the alpha-effect can chang

Pasquale Calabrese, Andrea Pelissetto, Ettore Vicari

We study the multicritical behavior arising from the competition of two distinct types of ordering characterized by O(n) symmetries. For this purpose, we consider the renormalization-group flow for the most general $O(n_1)\oplus O(n_2)$-symmetric Landau-Ginzburg-Wilson Hamiltonian involving two fields $ϕ_1$ and $ϕ_2$ with $n_1$ and $n_2$ components respectiv

V. A. Smirnov

A brief review of recent results on analytical evaluation of double-box Feynman integrals is presented. First steps towards evaluation of massless on-shell triple-box Feynman integrals within dimensional regularization are described. The leading power asymptotic behaviour of the dimensionally regularized massless on-shell master planar triple-box diagram in

Pinaki Majumdar, Sanjeev Kumar

A zero temperature Anderson-Mott transition driven by spin disorder can be `tuned&#39; by an applied magnetic field to achieve colossal magnetoconductance. Usually this is not possible since spin disorder by itself cannot localise a high density electron system. However, the presence of strong structural disorder can realise this situation, self consistently

Richard J. Szabo

We present an overview of the ways in which D-brane charges are classified in terms of K-theory, emphasizing the natural physical interpretations of a homological classification within a topological setting.

L. Bergamin, W. Kummer

Fermionic extensions of generic 2d gravity theories obtained from the graded Poisson-Sigma model (gPSM) approach show a large degree of ambiguity. In addition, obstructions may reduce the allowed range of fields as given by the bosonic theory, or even prohibit any extension in certain cases. In our present work we relate the finite W-algebras inherent in the

Anne M Green

Weakly Interacting Massive Particle (WIMP) direct detection experiments are closing in on the region of parameter space where neutralinos may constitute the Galactic halo dark matter. Numerical simulations and observations of galaxy halos indicate that the standard Maxwellian halo model is likely to be a poor approximation to the dark matter distribution. We

Jan W. T. Heemskerk, Yves Noat, David J. Bakker, Jan M. van Ruitenbeek

We have measured conductance histograms of atomic point contacts made from the noble-transition metal alloys CuNi, AgPd, and AuPt for a concentration ratio of 1:1. For all alloys these histograms at low bias voltage (below 300 mV) resemble those of the noble metals whereas at high bias (above 300 mV) they resemble those of the transition metals. We interpret

P. M. Woods, F. L. Schoeier, L. -A. Nyman, H. Olofsson

We present a millimetre molecular line survey of seven high mass loss rate carbon stars in both the northern and southern skies. A total of 196 emission lines (47 transitions) from 24 molecular species were detected. The observed CO emission is used to determine mass-loss rates and the physical structure of the circumstellar envelope, such as the density and

Yi-Ping Qin, En-Wei Liang, Guang-Zhong Xie, Cheng-Yue Su

The statistical shapes of the highest pulse have been studied by aligned method. A wavelet package analysis technique and a developed pulse--finding algorithm have been applied to select the highest pulse from burst profiles observed by BATSE on board CGRO from 1991 April 21 to 1999 January 26. The results of this work show that the statistical shapes of the

Yataro Horikawa, Akihiro Haga

The nuclear-polarization (NP) energies with the collective model commonly employed in the NP calculations for hydrogenlike heavy ions are found to have serious gauge violations when the ladder and cross diagrams only are taken into account. Using the equivalence of charge-current density with a schematic microscopic model, the NP energy shifts with the colle

Y. M. Cho, M. L. Walker, D. G. Pak

We resolve the controversy on the stability of the monopole condensation in the one-loop effective action of SU(2) QCD by calculating the imaginary part of the effective action with two different methods at one-loop order. Our result confirms that the effective action for the magnetic background has no imaginary part but the one for the electric background h

Chongxing Yue, Yanming Zhang, Lanjun Liu

There are many models beyond the standard model predicting the existence of non-universal gauge bosons $Z^{\prime}$, which can give rise to very rich phenomena. We calculate the contributions of the non-universal gauge bosons $Z^{\prime}$, predicted by topcolor-assisted technicolor (TC2) models and flavor-universal TC2 models, to the lepton flavor-violation

Jong-Phil Lee, Kang Young Lee

We explore the CP violation in $B \to ϕK$ decay processes in the presence of the anomalous right-handed $\bar{t}sW$ and $\bar{t}bW$ couplings. The complex anomalous top coupling can be a source of the new CP violation and lead to a deviation of the observed weak phase in $B \to ϕK$ decays, which takes account for the present disagreement of the observed $\si

B. Scott Gaudi, Heon-Young Chang, Cheongho Han

Planetary companions to the source stars of a caustic-crossing binary microlensing events can be detected via the deviation from the parent light curves created when the caustic magnifies the star light reflecting off the atmosphere or surface of the planets. The magnitude of the deviation is delta_p e_p rho_p^{-1/2}, where e_p is the fraction of starlight r

Patrick A. Lee, Guobin Sha

We explain qualitatively why the staggered flux state plays a central role in the SU(2) formulation of the t-J model, which we use to model the pseudogap state in underdoped cuprates. This point of view is supported by studies of projected wavefunctions. In addition to staggered orbital current correlations, we present here for the first time results of corr

S. R. Kulkarni, D. L. Kaplan, H. L. Marshall, D. A. Frail

It is now commonly believed that Soft gamma-ray repeaters (SGRs) and Anomalous X-ray pulsars (AXPs) are magnetars -- neutron stars powered by their magnetic fields. However, what differentiates these two seemingly dissimilar objects is, at present, unknown. We present Chandra observations of RX J052600.3-660433, the quiescent X-ray counterpart of SGR 0526-66

Xingxiang Zhou, Zheng-Wei Zhou, Guang-Can Guo, Marc J. Feldman

Most quantum computer realizations require the ability to apply local fields and tune the couplings between qubits, in order to realize single bit and two bit gates which are necessary for universal quantum computation. We present a scheme to remove the necessity of switching the couplings between qubits for two bit gates, which are more costly in many cases

Zakaria Giunashvili

Differential geometric structures such as the principal bundle for the canonical vector bundle on a complex Grassmann manifold, the canonical connection form on this bundle, the canonical symplectic form on a complex Grassmann manifold and the corresponding dynamical systems are investigated. The Grassmann manifold is considered as an orbit of the co-adjoint

Brian E. Granger, Chris H. Greene

Using time-independent scattering matrices, we study how the effects of nonclassical paths on the recurrence spectra of diamagnetic atoms can be extracted from purely quantal calculations. This study reveals an intimate relationship between two types of nonclassical paths: exotic ghost orbits and diffractive orbits. This relationship proves to be a previousl

Kieran Hunter, Erika Andersson, Claire R. Gilson, Stephen M. Barnett

In this paper we address the problem of optimal reconstruction of a quantum state from the result of a single measurement when the original quantum state is known to be a member of some specified set. A suitable figure of merit for this process is the fidelity, which is the probability that the state we construct on the basis of the measurement result is fou

M. Mehring, J. Mende, W. Scherer

We report on the preparation and detection of entangled states between an electron spin 1/2 and a nuclear spin 1/2 in a molecular single crystal. These were created by applying pulses at ESR (9.5 GHz) and NMR (28 MHz) frequencies. Entanglement was detected by using a special entanglement detector sequence based on a unitary back transformation including phas

M. A. Andreata, A. V. Dodonov, V. V. Dodonov

We study time dependence of various measures of entanglement (covariance entanglement coefficient, purity entanglement coefficient, normalized distance coefficient, entropic coefficients) between resonantly coupled modes of the electromagnetic field in ideal cavities with oscillating boundaries. Two types of cavities are considered: a three-dimensional cavit

M. A. Efremov, M. V. Fedorov, V. P. Yakovlev, W. P. Schleich

We consider the radiative decay of atoms scattered by a resonant standing light wave. Scattering is shown to suppress the Rabi oscillations and to slow down the atomic radiative decay giving rise to a power law behavior of the time-dependent level populations rather than the exponential one.

Stephen D. Bartlett, Barry C. Sanders

We present conditions for the efficient simulation of a broad class of optical quantum circuits on a classical machine: this class includes unitary transformations, amplification, noise, and measurements. Various proposed schemes for universal quantum computation using optics are assessed against these conditions, and we consider the minimum resource require

K. L. Pregnell, D. T. Pegg

Most methods for experimentally reconstructing the quantum state of light involve determining a quasiprobability distribution such as the Wigner function. In this paper we present a scheme for measuring individual density matrix elements in the photon number state representation. Remarkably, the scheme is simple, involving two beam splitters and a reference

Wang Xiang-bin

So far all the proven unconditionally secure prepare and measure protocols for the quantum key distribution(QKD) must solve the very complex problem of decoding the classical CSS code. In the decoding stage, Bob has to compare his string with an exponentially large number of all the strings in certain code space to find out the closest one. Here we have spot

H. Suno, B. D. Esry, Chris H. Greene

Three-body recombination of identical, spin-polarized fermionic atoms in the ultracold limit is investigated. The mechanisms for recombination are described in terms of the ``scattering volume&#39;&#39; $V_p$ in the framework of the adiabatic hyperspherical representation. We have calculated numerically the recombination rate $K_3$ as a function of $V_p$ and

Stéphane Pleutin, Hermann Grabert, Gert-Ludwig Ingold, Abraham Nitzan

We study the electrostatic potential of a molecular wire bridging two metallic electrodes in the limit of weak contacts. With the use of a tight-binding model including a fully three-dimensional treatment of the electrostatics of the molecular junction, the potential is shown to be poorly screened, dropping mostly along the entire molecule. In addition, we o

Amos Harpaz, Noam Soker

The appearance of the time derivative of the acceleration in the equation of motion (EOM) of an electric charge is studied. It is shown that when an electric charge is accelerated, a stress force exists in the curved electric field of the accelerated charge, and this force is proportional to the acceleration. This stress force acts as a reaction force which

H. Arenhoevel, E. M. Darwish, A. Fix, M. Schwamb

The present status of the theoretical description of electromagnetic reactions on the deuteron above pion threshold is reviewed. Three major topics are considered: (i) retardation effects in $π$-meson exchange contributions to $NN$-interaction and meson exchange currents in deuteron photodisintegration above $π$-threshold in the $Δ$-resonance region, (ii) of

R. Shomin, M. B. Tsang, O. Bjarki, C. K. Gelbke

Generalized isoscaling relationships are proposed that may permit one to relate the isotopic distributions of systems that may not be at the same temperature. The proposed relationships are applied to multifragmentation excitation functions for central Kr+Nb and Ar+Sc collisions.

Stefan Bathe

Recent results of the WA98 experiment with p and Pb induced reactions at 158 AGeV are presented. Azimuthal gamma-gamma correlations at high pT were studied in search for a signal of jet-like structures. A clear indication for back-to-back correlations can be seen in p+A with a strong dependence on the pT of the photons and the size of the system. In Pb+Pb co

Klaus Reygers

The status of the search for direct photons in Au+Au collisions at sqrt{s_NN} = 130 GeV and sqrt{s_NN} = 200 GeV with the PHENIX experiment is presented. Within errors, no excess of direct photons was found in a first analysis pass done on a limited data set. Significantly reduced systematic and statistical uncertainties are expected in future analyses.

A. Gomez, J. D. Meiss

Planar polynomial automorphisms are polynomial maps of the plane whose inverse is also a polynomial map. A map is reversible if it is conjugate to its inverse. Here we obtain a normal form for automorphisms that are reversible by an involution that is also in the group of polynomial automorphisms. This form is a composition of a sequence of generalized Henon

B. Rink

The Fermi-Pasta-Ulam (FPU) lattice with periodic boundary conditions and $n$ particles admits a large group of discrete symmetries. The fixed point sets of these symmetries naturally form invariant symplectic manifolds that are investigated in this short note. For each $k$ dividing $n$ we find $k$ degree of freedom invariant manifolds. They represent short w

G. Gaeta, P. Morando

Standard (Arnold-Liouville) integrable systems are intimately related to complex rotations. One can define a generalization of these, sharing many of their properties, where complex rotations are replaced by quaternionic ones. Actually this extension is not limited to the integrable case: one can define a generalization of Hamilton dynamics based on hyperKah

I. A. Shereshevskii

I offer a simple and useful formula for the resolvent of a small rank perturbation of large matrices. I discuss applications of this formula, in particular, to analytical and numerical solving of difference boundary value problems. I present examples connected with such problems for the difference Laplacian and estimate numerical efficiency of the correspond

G. B. Malykin, V. I. Pozdnyakova, I. A. Shereshevskii

We propose a new approach to the mathematical description of light propagation in a single-mode fiber light-guide (SMFLG) with random inhomogeneities. We investigate statistics of complex amplitudes of the electric field of light wave by methods of the random group theory. We have analyzed the behavior of the coherence matrix of a monochromatic light wave an

Adrian Constantin, Boris Kolev

For an integrable shallow water equation we describe a geometrical approach showing that any two nearby fluid configurations are successive states of a unique flow minimizing the kinetic energy.

D. R. Heath-Brown

These are notes of a series of lectures on sieves, presented during the Special Activity in Analytic Number Theory, at the Max-Planck Institute for Mathematics in Bonn, during the period January--June 2002.

Joao Jose de Farias Neto

A formula for the Riemannian metric tensor of differentiable manifolds of linear dynamical systems of same McMillan degree is presented in terms of their transfer function matrices. The necessary calculations for its application to ARMA and state space overlapping parametrizations are drafted. The importance of this approach for systems identification and mu

Aris Anagnostopoulos, Ioannis Kontoyiannis, Eli Upfal

We compare the long-term, steady-state performance of a variant of the standard Dynamic Alternative Routing (DAR) technique commonly used in telephone and ATM networks, to the performance of a path-selection algorithm based on the &#34;balanced-allocation&#34; principle; we refer to this new algorithm as the Balanced Dynamic Alternative Routing (BDAR) algori

David Callan

We present matrix identities which yield respectively the Jordan canonical form of the Pascal matrix P_n = (i -1 choose j -1)_{1 <= i,j <= n} modulo a prime, the eigenvectors of (i choose j)_{1 <= i,j <= n}, and the Smith normal form of powers of P_n - I_n.

Federico Ardila

We show how the set of Dyck paths of length 2n naturally gives rise to a matroid, which we call the &#34;Catalan matroid&#34; C_n. We describe this matroid in detail; among several other results, we show that C_n is self-dual, it is representable over the rationals but not over finite fields F_q with q < n-1, and it has a nice Tutte polynomial. We then gener

Mordechai Katzman

Let $(R,m)$ be a local Noetherian ring, let $I\subset R$ be any ideal and let $M$ be a finitely generated $R$-module. In 1990 Craig Huneke conjectured that the local cohomology modules $H^i_I(M)$ have finitely many associated primes for all $i$. In this paper I settle this conjecture by constructing a local cohomology module of a local $k$-algebra with an in

Markus P. Brodmann, Mordechai Katzman, Rodney Y. Sharp

The $i$-th local cohomology module of a finitely generated graded module $M$ over a standard positively graded commutative Noetherian ring $R$, with respect to the irrelevant ideal $R_+$, is itself graded; all its graded components are finitely generated modules over $R_0$, the component of $R$ of degree 0. This paper is concerned with the asymptotic behavio

Mordechai Katzman, Rodney Y. Sharp

This first part of the paper describes the support of top graded local cohomology modules. As a corrolary one obtains a simple criteria for the vanishing of these modules and also the fact that they have finitely many minimal primes. The second part of this paper constructs examples of cohomological Hilbert functions which are not of polynomial type.

Mordechai Katzman

Let R be monomial sub-algebra of $k[x_1,...,x_N]$ generated by square free monomials of degree two. This paper addresses the following question: when is R a complete intersection? For such a k-algebra we can associate a graph G whose vertices are $x_1,...,x_N$ and whose edges are $\{(x_i, x_j) | x_i x_j \in R \}$. Conversely, for any graph G with vertices $\

A. Alekseev, E. Meinrenken

We describe a relationship of the classical dynamical Yang-Baxter equation with the following elementary problem for Clifford algebras: Given a vector space $V$ with quadratic form $Q_V$, how is the exponential of an element in $\wedge^2(V)$ under exterior algebra multiplication related to its exponential under Clifford multiplication?

A. Alekseev, E. Meinrenken

We give a Poisson-geometric proof of the Kashiwara-Vergne conjecture for quadratic Lie algebras, based on the equivariant Moser trick.

Irena Swanson

Mayr and Meyer found ideals with the doubly exponential ideal membership property. In the analysis of the associated primes of these ideals (in math.AC/0209344), a new family of ideals arose. This new family is presented and analyzed in this paper. It is proved that this new family also satisfies the doubly exponential ideal membership property. Furthermore,

Irena Swanson

This paper investigates the doubly exponential ideal membership property of the Mayr-Meyer ideals from the point of view of their associated primes. A doubly-exponential upper bound on the set of associated primes is proved. In the paper a new family of ideals emerges which also has the doubly exponential ideal membership property. More on the new family can

Ingo Waschkies

We give an explicit construction of the stack of microlocal perverse sheaves on the projective cotangent bundle of a complex manifold. Microlocal perverse sheaves will be represented as complexes of analytic ind-sheaves which have recently been studied by Kashiwara-Schapira. This description allows us to formulate the microlocal Riemann-Hilbert correspondanc

T. Mansour, S. Kitaev

In [Kit1] Kitaev discussed simultaneous avoidance of two 3-patterns with no internal dashes, that is, where the patterns correspond to contiguous subwords in a permutation. In three essentially different cases, the numbers of such $n$-permutations are $2^{n-1}$, the number of involutions in $\mathcal{S}_n$, and $2E_n$, where $E_n$ is the $n$-th Euler number.

C. Briot, E. Ragoucy

We show that some finite W-superalgebras based on gl(M|N) are truncation of the super-Yangian Y(gl(M|N)). In the same way, we prove that finite W-superalgebras based on osp(M|2n) are truncation of the twisted super-Yangians Y(gl(M|2n))^{+}. Using this homomorphism, we present these W-superalgebras in an R-matrix formalism, and we classify their finite-dimens

Marc Chardin

We provide bounds on the Castelnuovo-Mumford regularity in terms of ``defining equations&#39;&#39; by using elements that annihilates some cohomology modules, inspired by works of Miyazaki, Nagel, Schenzel and Vogel. The elements in these annihilators are provided either by liaison or by tight closure theories. Our results hold in any characteristic.

Gerhard Rein, Thomas Rodewis

We consider spherically symmetric, asymptotically flat space-times with a collisionless gas as matter model. Many properties of the resulting Vlasov-Einstein system are not yet accessible by purely analytical means. We present a discretized version of this system which is suitable for numerical implementation and is based on the particle-in-cell technique. C

Eui Chul Kim

We study the Einstein-Dirac equation as well as the weak Killing equation on Riemannian spin manifolds with codimension one foliation. We prove that, for any manifold $M^n$ admitting real Killing spinors (resp. parallel spinors), there exist warped product metrics $\barη$ on $M^n \times {\mathbb R}$ such that $(M^n \times {\mathbb R}, \barη)$ admit Einstein

Toby Ord

Due to common misconceptions about the Church-Turing thesis, it has been widely assumed that the Turing machine provides an upper bound on what is computable. This is not so. The new field of hypercomputation studies models of computation that can compute more than the Turing machine and addresses their implications. In this report, I survey much of the work

Dapeng Xu

In this thesis, we apply the stack sorting operator to $r$-permutations and construct the functional equation for the generating function of two-stack-sortable $k$-tuple $r$-permutations counted by descents by using a factorization similar to Zeilberger&#39;s. We solve the functional equation and give explicit formulas for the number of two-stack-sortable $r

Ch. Okonek, A. Teleman

In general, a Kobayashi-Hitchin correspondence establishes an isomorphism between a moduli space of stable algebraic geometric objects and a moduli space of solutions of a certain (generalized) Hermite-Einstein equation. We believe that, for a large class of moduli problems, this correspondence respects the virtual fundamental classes defined in the two cate

Russell Lyons

The first Szego limit theorem has been extended by Bump-Diaconis and Tracy-Widom to limits of other minors of Toeplitz matrices. We extend their results still further to allow more general measures and more general determinants. We also give a new extension to higher dimensions, which extends a theorem of Helson and Lowdenslager.

Bill Jackson

We survey results and conjectures concerning the zero distribution of chromatic and flow polynomials of graphs, and characteristic polynomials of matroids.

Laurent Moret-Bailly

We give criteria for R-equivalence of torsors under finite constant group schemes over a field. In paticular, using bitorsors, we obtain a Galois devissage result which formalises and generalises a theorem of Philippe Gille in the case of local fields; for instance, Gille&#39;s theorem is shown to extend to higher local fields.

Dr. Scott Chapman

A new background field formulation of QCD is presented in which the background gluon field is not a classical field, but an operator made up of quantized quark fields. This background field allows colorless quark states to form exact quantum solutions of the QCD equations of motion for any value of the coupling constant. When matrix elements of the Hamiltoni

Joseph Polchinski, Matthew J. Strassler

We study deep inelastic scattering in gauge theories which have dual string descriptions. As a function of $gN$ we find a transition. For small $gN$, the dominant operators in the OPE are the usual ones, of approximate twist two, corresponding to scattering from weakly interacting partons. For large $gN$, double-trace operators dominate, corresponding to sca

Matthias Klein

I discuss effective field theories of brane-world models where different sectors break different halves of the extended bulk supersymmetry. It is shown how to consistently couple N=2 supersymmetric matter to N=1 superfields that lack N=2 partners but transform in a non-linear representation of the N=2 algebra. In particular, I explain how to couple an N=2 ve

Andrea Gregori

We investigate the consequences of two assumptions for String (or M) Theory, namely that: 1) all coordinates are compact and bound by the horizon of observation, 2) the ``dynamics&#39;&#39; of compactification is determined by the ``second law of thermodynamics&#39;&#39;, i.e. the principle of entropy. We discuss how this leads to a phenomenologically consis

I. Zakout, H. R. Jaqaman, W. Greiner

We derive the spin-dependent Bethe-Salpeter equation for $q\bar{q}$ bound state at finite temperature in the ladder and cross box diagram approximations. The imaginary time formalism is adopted in the adiabatic approximation where the flux tube thermal excitation is separated from the thermal excitation of the constituent quarks. The thermal excitation of th

S. Heinemeyer, G. Weiglein

The leading electroweak MSSM two-loop corrections to the electroweak precision observables are calculated. They are obtained by evaluating the two-loop O(α_t^2), O(α_t α_b), O(α_b^2) contributions to the quantity Δρin the limit of heavy scalar quarks, i.e. we consider the contributions of a Two-Higgs-Doublet model with MSSM restrictions. The full analytic re

Agnieszka Furman, Leonard Lesniak

We present results following from the coupled channel model of two a0 resonances decaying into the pi-eta and K anti-K mesons. The a0(980) resonance can be described by two distinct poles. It is shown that the discrepancy in the a0(980) mass position between the Crystal Barrel Collaboration and the E852 Group can be explained and removed. In our model with p

W. Buchmüller, P. Di Bari, M. Plümacher

Properties of neutrinos, the lightest of all elementary particles, may be the origin of the entire matter-antimatter asymmetry of the universe. This requires that neutrinos are Majorana particles, which are equal to their antiparticles, and that their masses are sufficiently small. Leptogenesis, the theory explaining the cosmic matter-antimatter asymmetry, p

N. Cosme

CP is a symmetry of pure gauge theories, that is without scalar interactions. Actually its violation originates in the Standard Model from the completely arbitrary Yukawa couplings. Thus, as the unification principle would wash out the arbitrariness of these couplings possibly relating them to the gauge interactions, the resulting theory should be expected a

I. P. Ivanov, N. N. Nikolaev, W. Schäfer, B. G. Zakharov

We review the recent finding of the two-plateau momentum distribution of sea quarks in deep inelastic scattering off nuclei in the saturation regime. The diffractive plateau which dominates for small $\bp$ measures precisely the momentum distribution of quarks in the beam photon, the rôle of the nucleus is simply to provide an opacity. The plateau for truly

A. Andonov, D. Bardin, S. Bondarenko, P. Christova

The project, aimed at the theoretical support of experiments at modern and future accelerators -- TEVATRON, LHC, electron Linear Colliders (TESLA, NLC, CLIC) and muon factories, is presented. Within this project a four-level computer system is being created, which must automatically calculate, at the one-loop precision level the pseudo- and realistic observa

Hannes Pichl

Pionic beta decay π^+ to π^0 e^+ ν_e is analyzed in chiral perturbation theory with virtual photons and leptons. All electromagnetic corrections up to order e^2 p^2 are taken into account. Theoretical results are confronted with preliminary data from a PSI measurement and a value for the CKM matrix element |Vud| is given. Although the precision is presently

V. I. Kuvshinov, A. V. Kuzmin, R. G. Shulyakovsky

The influence of chaos on properties of dilute instanton gas in quantum mechanics is studied. We demonstrate on the example of one-dimensional periodic potential that small perturbation leading to chaos squeezes instanton gas and increases the rate of instanton tunnelling.

S. Moretti

We show how a statistically significant signal of heavy charged Higgs bosons of a Type II Two-Higgs Doublet (2HDM) Model produced in association with tau-neutrino pairs can be established at future $e^+e^-$ Linear Colliders (LCs) in the $H^+\to t\bar b\to 4$ jet decay channel for large $\tanβ$ in the $M_{H^\pm}\gsim \sqrt s/2$ mass region

Naoyuki Haba, Noboru Nakamura, Tomoharu Suzuki

Recently the evidence of the neutrinoless double $β$ ($0νββ$) decay has been announced. This means that neutrinos are Majorana particles and their mass hierarchy is forced to inverted mass hierarchy (Type B) or degenerate mass (Type C) patterns in the diagonal basis of charged lepton mass matrix. We estimate the magnitude of $0νββ$ decay in the degenerate ne

Luis M. A. Bettencourt

I present a summary of recent work \cite{BRS} where we describe the time-evolution of a region of disoriented chiral condensate via Langevin field equations for the linear $σ$ model. We analyze the model in equilibrium, paying attention to subtracting ultraviolet divergent classical terms and replacing them by their finite quantum counterparts. We use result

V. Bornyakov, Y. Nakamura, M. Chernodub, Y. Koma

We study N_f=2 lattice QCD with nonperturbatively improved Wilson fermions at finite temperature on 16^3 \cdot 8 lattices. We determine the transition temperature at m_π/m_ρ \sim 0.8 and lattice spacing as small as 0.12fm. The string breaking at T < T_c is also studied. We find that the static potential can be fitted by a simple expression involving string m

W. Kamleh, D. J. Kusterer, D. B. Leinweber, A. G. Williams

APE smearing the links in the irrelevant operators of clover fermions (Fat-Link Irrelevant Clover (FLIC) fermions) provides significant improvement in the condition number of the Hermitian-Dirac operator and gives rise to a factor of two savings in computing the overlap operator. This report investigates the effects of using a highly-improved definition of t

W. Kamleh, D. B. Leinweber, A. G. Williams, J. B. Zhang

The action of the overlap-Dirac operator on a vector is typically implemented indirectly through a multi-shift conjugate gradient solver. The compute-time required depends upon the condition number, $\kappa$, of the matrix that is used as the overlap kernel. While the Wilson action is typically used as the overlap kernel, the FLIC (Fat Link Irrelevant Clover

Waseem Kamleh

The majority of compute time doing lattice QCD is spent inverting the fermion matrix. The time that this takes increases with the condition number of the matrix. The FLIC(Fat Link Irrelevant Clover) action displays, among other properties, an improved condition number compared to standard actions and hence is of interest due to potential compute time savings

G. Dissertori

New results from measurements of the strong coupling constant $α_s(M_Z)$ at LEP are presented. In particular, a new LEP combination of results based on event-shape variables has become available, where a new method for the estimation of the theoretical uncertainty has been implemented. Furthermore, two other analyses are quoted, based on power corrections an

The OPAL collaboration, G. Abbiendi

We have analysed the data collected by OPAL at centre-of-mass energies between 189 and 209 GeV searching for Higgs boson candidates from the process e+e- -> h0Z0 followed by the decay of h0 -> A0A0 where A0 is the CP-odd Higgs boson. The search is done in the region where the A0 mass, mA, is below the production threshold for bbbar, and the CP-even Higgs bos

Davide Perego

A limit on the tau neutrino mass is obtained using all the $Z^{0} \to τ^{+} τ^{-}$ data collected at LEP by the DELPHI detector between 1992 and 1995. In this analysis events in which one of the taus decays into one charged particle, while the second $τ$ decays into f{}ive charged pions (1-5 topology) have been used. The neutrino mass is determined from a bi

ALEPH Collaboration

The anomalous weak dipole moments of the tau lepton are measured in a data sample collected by ALEPHfrom 1990 to 1995 corresponding to an integrated luminosity of 155pb-1. Tau leptons produced in the reaction e+e- -> tau+tau- at energies close to the Z mass are studied using their semileptonic decays to pi, rho, a_1 -> pi 2pi0 or a_1 -> 3 pi. The real and im