July 2000 arXiv papers — page 2

Ryszard Manka, Grzegorz Przybyla

The quark star in the quark mean field (QMF) extended to include the strange mesons interaction is examined. The quark star properties in this model are studied.

Claus Hertling

A formula for the variance of the spectrum of a quasihomogeneous singularity is proved, using the G-function of a semisimple Frobenius manifold.

P. Bressler, J. Donin

Let $A$ be a star product on a symplectic manifold $(M,ω_0)$, $\frac{1}{t}[ω]$ its Fedosov class, where $ω$ is a deformation of $ω_0$. We prove that for a complex polarization of $ω$ there exists a commutative subalgebra, $O$, in $A$ that is isomorphic to the algebra of functions constant along the polarization. Let $F(A)$ consists of elements of $A$ whose c

J. A. Oller

It is the purpose of the present manuscript to emphasize those aspects that make the scalar sector with vacuum quantum numbers rather unique. Chiral symmetry is the basic tool for our study together with a resummation of Chiral Perturbation Theory (CHPT) that stresses the role of unitarity but also allows one to include explicit resonance fields and to match

Martin Erdmann

Structure function measurements of the proton, the photon, and of colour singlet exchange are analysed using fits based on logarithmic Q**2-dependence. The fits reveal the x-dependencies of the hadronic structures and the interaction dynamics as directed by the data.

Leonid G. Grechko, Vitaly N. Pustovit, Keith W. Whites

The optical properties of clusters with metallic spherical particles embedded in an insulating matrix are studied. A theoretical approach is proposed for the calculation of the macroscopic dielectric response for a collection of spheres at random positions embedded in a homogeneous medium. While accounting for the dipole interaction between particles, we hav

I. M. Sokolov

The Levy-flight dynamics can stem from simple random walks in a system whose operational time (number of steps n) typically grows superlinearly with physical time t. Thus, this processes is a kind of continuous-time random walks (CTRW), dual to usual Scher-Montroll model, in which $n$ grows sublinearly with t. The models in which Levy-flights emerge due to a

D. Yesilleten, T. A. Arias

We present a systematic trend study of the symmetric tilt grain boundaries about the <110> axis in molybdenum. Our results show that multiple structural phases, some incorporating vacancies, compete for the boundary ground state. We find that at low external stress vacancies prefer to bind to the boundaries in high concentrations, and moreover, that external

Brian Punsly, Gustavo E. Romero, Diego F. Torres, J. A. Combi

The unidentified, low-latitude, $γ$-ray source 3EG J1828+0142 presents high levels of variability and a steep spectral index $Γ\sim2.7$. Here we propose a model for this source where the high-energy emission is produced by a galactic Kerr-Newman black hole. The model takes into account electron-positron annihilation losses in the calculation of the expected

L. C. Garcia de Andrade

The evolution equation of cosmic density perturbation of a spin dominated universe in Einstein-Cartan gravity is obtained.Examples of inflationary cosmologies with spin are also given where we compute the density perturbations in terms of redshift and show that spin-torsion effects produce a growth on the inhomogeneity of the universe as the redshift is high

E. Schinnerer, A. Eckart, Th. Boller

NIR K band imaging spectroscopy of the central 8&#39;&#39; (1.3 kpc) in the Wolf-Rayet LINER galaxy NGC6764 shows that the most recent star formation is most likely still unresolved at sub-arcsecond resolution (< 100pc). The continuum source has a size of about 1.5&#39;&#39;. The H_2 emission is resolved showing a rotating ring/disk of ~1.2&#39;&#39; diamete

A. C. Fabian, J. S. Sanders, S. Ettori, G. B. Taylor

We report subarcsec-resolution X-ray imaging of the core of the Perseus cluster around the galaxy NGC 1275 with the Chandra X-ray Observatory. The ROSAT-discovered holes associated with the radio lobes have X-ray bright rims which are cooler than the surrounding gas and not due to shocks. The holes themselves may contain some hotter gas. We map strong photoe

Daniel C. Hong

We present exact results for the density profile of the one dimensional array of N hard spheres of diameter D and mass m under gravity g. For a strictly one dimensional system, the liquid-solid transition occurs at zero temperature, because the close-pakced density, $ϕ_c$, is one. However, if we relax this condition slightly such that $phi_c=1-δ$, we find a

E895 Collaboration, M. A. Lisa, N. N. Ajitanand, J. M. Alexander

Two-pion correlation functions, measured as a function of azimuthal emission angle with respect to the reaction plane, provide novel information on the anisotropic shape and orientation of the pion-emitting zone formed in heavy ion collisions. We present the first experimental determination of this information, for semi-central Au+Au collisions at 2-6 AGeV.

Arvind Rajaraman

We present a general method for constructing supergravity solutions for intersecting branes. The solutions are written in terms of a single function, which is the solution to a nonlinear differential equation. We illustrate this procedure in detail for the case of M2-branes ending on M5-branes. We also present supergravity solutions for strings ending on Dp-

A. N. W. Hone, V. B. Kuznetsov, O. Ragnisco

Elementary, one- and two-point, Backlund transformations are constructed for the generic case of the sl(2) Gaudin magnet. The spectrality property is used to construct these explicitly given, Poisson integrable maps which are time-discretizations of the continuous flows with any Hamiltonian from the spectral curve of the 2x2 Lax matrix.

J. Lehar, A. Buchalter, R. G. McMahon, C. S. Kochanek

We performed an automated comparison of the FIRST radio survey with the APM optical catalog to find radio lobes with optical counterparts. Based on an initial survey covering ~3000 square degrees, we selected a sample of 33 lens candidates for VLA confirmation. VLA and optical observations of these candidates yielded two lens systems, one a new discovery (J0

S. Sen, T. R. Seshadri

Recent cosmological observations reveal that we are living in a flat accelerated expanding universe. In this work we have investigated the nature of the potential compatible with the power law expansion of the universe in a self interacting Brans Dicke cosmology with a perfect fluid background and have analyzed whether this potential supports the accelerated

S. R. Choudhury, A. S. Cornell, G. C. Joshi

We examine the implications of the Randall-Sundrum gravity models on $γγ$ scattering in the TeV range.

Charles P. Boyer, Krzysztof Galicki, Paolo Piccinni

Using 3-Sasakian reduction techniques we obtain infinite families of new 3-Sasakian manifolds $\scriptstyle{{\cal M}(p_1,p_2,p_3)}$ and $\scriptstyle{{\cal M}(p_1,p_2,p_3,p_4)}$ in dimension 11 and 15 respectively. The metric cone on $\scriptstyle{{\cal M}(p_1,p_2,p_3)}$ is a generalization of the Kronheimer hyperkähler metric on the regular maximal nilpoten

Tiberiu Constantinescu, Aurelian Gheondea

In this paper we study hermitian kernels invariant under the action of a semigroup with involution. We characterize those hermitian kernels which realize the given action by bounded operators on a Krein space. Applications to the GNS representation of *-algebras associated to hermitian functionals are given. We explain the key role played by the Kolmogorov d

Petr P. Kulish, Vladimir D. Lyakhovsky

The nontrivial subspaces with primitive coproducts are found in the deformed universal enveloping algebras. They can form carrier spaces for additional Jordanian twists. The latter can be used to construct sequences of twists for algebras whose root systems contain long series of roots. The corresponding twist for the so(5) algebra is given explicitly.

Richard Shurtleff

Rotation symmetry is less constraining than space-time symmetry. The free electron propagator is a projection operator that we show can be constructed from rotation symmetric projection operators. Rotation-based identifications of time, space, energy, momentum, polarization matrices, and the positron hypothesis are determined by the constraints that turn rot

Luca Girlanda

The two-flavor Gell-Mann-Oakes-Renner ratio is expressed in terms of low-energy pi-pi observables including the O(p^6) double chiral logarithms, computed in Generalized Chiral Perturbation Theory. It is found that their contribution is important and tends to compensate the one from the single chiral logarithms.

Bipin R. Desai, Utpal Sarkar, Alexander R. Vaucher

We study a variety of different texture patterns in the basis in which the charged lepton mass matrix or neutrino mass matrix or neither are diagonal. The experimental results on the neutrinos provide sufficient restrictions to allow only a small number of simple patterns. We discuss particularly the texture zeroes which provide important relations among the

Zong-Hong Zhu, Li Cao

The Wheeler-DeWitt equation for the induced gravity theory is constructed in the minisuperspace approximation, and then solved using the WKB method under three types of boundary condition proposed respectively by Hartle & Hawking (``no boundary&#39;&#39;), Linde and Vilenkin (``tunneling from nothing&#39;&#39;). It is found that no matter how the gravitation

Joseph O&#39;Rourke

The resolution of a decades-old open problem is described: polygonal chains cannot lock in the plane.

Enzo Marinari, Giorgio Parisi

We compute and analyze couples of ground states of 3D spin glasses before and after applying a volume perturbation which adds to the Hamiltonian a repulsion from the true ground state. The physical picture based on Replica Symmetry Breaking is in excellent agreement with the observed behavior.

Wonkee Kim, J. P. Carbotte

Recently observed $c$-axis optical sum rule violations indicate non-Fermi liquid in-plane behavior. For coherent $c$-axis coupling, the observed flat, nearly frequency independent $c$-axis conductivity $σ_{1}(ω)$ implies a large in-plane scattering rate $Γ$ around $(0,π)$ and therefore any pseudogap that might form at low frequency in the normal state will b

S. -C. Chang, R. Shrock

We present exact calculations of the zero-temperature partition function for the $q$-state Potts antiferromagnet (equivalently, the chromatic polynomial) for families of arbitrarily long strip graphs of the square and triangular lattices with width $L_y=4$ and boundary conditions that are doubly periodic or doubly periodic with reversed orientation (i.e. of

V. Petkov, S. J. L. Billinge, S. D. Shastri, B. Himmel

Structure factors for Cax/2AlxSi1-xO2 glasses (x=0,0.25,0.5,0.67) extended to a wave vector of magnitude Q= 40 1/A have been obtained by high-energy x-ray diffraction. For the first time, it is possible to resolve the contributions of Si-O, Al-O and Ca-O coordination polyhedra to the experimental atomic pair distribution functions (PDF). It has been found th

Frederick K. Lamb, M. Coleman Miller

Previous work on the sonic-point beat-frequency (SPBF) model of the kilohertz quasi-periodic oscillations (QPOs) observed in the X-ray flux from neutron stars in low-mass binary systems has shown that it naturally explains many properties of these QPOs. These include the existence of just two principal QPOs in a given source, the commensurability of the freq

C. Beisbart, T. Buchert, H. Wagner

Minkowski functionals constitute a family of order parameters which discriminate spatial patterns according to size, shape and connectivity. Here we point out, that these scalar descriptors can be complemented by vector-valued curvature measures also known as Quermass vectors. Using examples of galaxy clusters, we demonstrate that the Quermass vectors provid

Zong-Hong Zhu

For a wide variety of cosmological models characterized by the cosmic mass density $Ω_M$ and the normalized cosmological constant $Ω_Λ$, we derive an analytic expression for the estimate of magnification cross-sections by an ensemble of isothermal spheres as models of galactic mass distributions. This provides a simple approach to demonstrate how the lensing

Fumitaka Nakamura

We examined the gravitational contraction of isothermal molecular cloud cores with slow rotation by means of two-dimensional numerical simulations. Applying a sink-cell method, we followed the evolution of the cloud cores up to the stages at which most of the matter accretes onto the central region (i.e., a protostar and a rotationally-supported circumstella

Don N. Page

Bekenstein&#39;s conjectured entropy bound for a system of linear size R and energy E, S < 2 pi E R, has counterexamples for many of the ways in which the &#34;system,&#34; R, E, and S may be defined. Here new ways are proposed to define these quantities for arbitrary nongravitational quantum field theories in flat spacetime, such as defining R as the smalle

Ori J. Ganor, Andrei Yu. Mikhailov, Natalia Saulina

We generalize the spectral-curve construction of moduli spaces of instantons on $\MT{4}$ and $K_3$ to noncommutative geometry. We argue that the spectral-curves should be constructed inside a twisted $\MT{4}$ or $K_3$ that is an elliptic fibration without a section. We demonstrate this explicitly for $T^4$ and to first order in the noncommutativity, for $K_3

Jussi Kalkkinen, Dario Martelli

We find the Holographic Renormalization Group equations for the holographic duals of generic gravity theories coupled to form fields and spin-1/2 fermions. Using Hamilton-Jacobi theory we discuss the structure of Ward identities, anomalies, and the recursive equations for determining the divergent terms of the generating functional. In particular, the Ward i

Axel Krause

We include the backreaction on the warped geometry induced by non-finetuned parameters in a two domain-wall set-up to obtain an exponentially small Cosmological Constant $Λ_4$. The mechanism to suppress the Cosmological Constant involves one classical fine-tuning as compared to an infinity of finetunings at the quantum level in standard D=4 field theory.

Dejan Stojkovic

We study fermionic zero modes in the domain wall background. The fermions have Dirac and left- and right-handed Majorana mass terms. The source of the Dirac mass term is the coupling to a scalar field $Φ$. The source of the Majorana mass terms could also be the coupling to a scalar field $Φ$ or a vacuum expectation value of some other field acquired in a pha

Marcos Verissimo-Alves, R. B. Capaz, Belita Koiller, Emilio Artacho

We use ab initio total-energy calculations to predict the existence of polarons in semiconducting carbon nanotubes (CNTs). We find that the CNTs&#39; band edge energies vary linearly and the elastic energy increases quadratically with both radial and with axial distortions, leading to the spontaneous formation of polarons. Using a continuum model parametrize

Alberto Fernandez-Soto, Kenneth M. Lanzetta, Hsiao-Wen Chen, Sebastian M. Pascarelle

We present a comparison between the spectroscopic catalog of the HDF recently published by Cohen et al and the redshifts measured by our group for those objects using photometric techniques. We perform this comparison in order to characterize the errors associated to the photometric redshift technique. The spectroscopic sample includes over 140 objects in th

C. Kopper, J. Magnen

Recently Neumayr and Metzner have shown that the connected N-point density- correlation functions of the two-dimensional and the one-dimensional Fermi gas at one-loop order generically vanish/are regular in the small momentum/small energy-momentum limits. Their result is based on an explicit analysis in the sequel of results of Feldman et al.[2]. In this not

S. Gheorghiu-Svirschevski

We derive a well-behaved nonlinear extension of the non-relativistic Liouville-von Neumann dynamics driven by maximal entropy production with conservation of energy and probability. The pure state limit reduces to the usual Schroedinger evolution, while mixtures evolve towards maximum entropy equilibrium states with canonical-like probability distributions o

E. Bielejec, Wenhao Wu

Quench-condensed granular Al films, with normal-state sheet resistance close to 10 k$Ω/\Box$, display strong hysteresis and ultraslow, non-exponential relaxation in the resistance when temperature is varied below 300 mK. The hysteresis is nonlinear and can be suppressed by a dc bias voltage. The relaxation time does not obey the Arrhenius form, indicating th

David Douglas

The Jefferson Lab (JLab) IR Demo Free Electron Laser (FEL) has completed commissioning and is initiating user service. The FEL - a high repetition rate, low extraction efficiency wiggler-driven optical cavity resonator - produces over 1 kW of tuneable light on intervals in a 3-6 micron wavelength range. It is driven by a 35-48 MeV, 5 mA superconducting RF (S

Robert S. Plant, Michael C. Birse

The effects of meson fluctuations are studied in a nonlocal generalization of the Nambu-Jona-Lasinio model, by including terms of next-to-leading order (NLO) in 1/N_c. In the model with only scalar and pseudoscalar interactions NLO contributions to the quark condensate are found to be very small. This is a result of cancellation between virtual mesons and Fo

M. Niedermaier

4D cylindrical gravitational waves with aligned polarizations (Einstein-Rosen waves) are shown to be described by a weight 1/2 massive free field on the double cover of AdS_2. Thorn&#39;s C-energy is one of the sl(2,R) generators, the reconstruction from the (timelike) symmetry axis is the CFT_1 holography. Classically the phase space is also invariant under

Jiannis Pachos, Paolo Zanardi

Holonomic Quantum Computation (HQC) is an all-geometrical approach to quantum information processing. In the HQC strategy information is encoded in degenerate eigen-spaces of a parametric family of Hamiltonians. The computational network of unitary quantum gates is realized by driving adiabatically the Hamiltonian parameters along loops in a control manifold

A. S. Moskvin, E. N. Kondrashov, V. I. Cherepanov

It has been made an extention of the conventional theory based on the assumption of the well isolated Zhang-Rice singlet to be a first electron-removal state in dielectric copper oxide. One assumes the photohole has been localised on either small (pseudo)Jahn-Teller polaron or large non-adiabatic polaron enclosed one or four to five $CuO_4$ centers, respecti

A S Vytheeswaran

For many systems with second class constraints, the question posed in the title is answered in the negative. We prove this for a range of systems with two second class constraints. After looking at two examples, we consider a fairly general proof. It is shown that, to unravel gauge invariances in second class constrained systems, it is sufficient to work in

C. -S. Huang, Ailin Zhang, Shi-Lin Zhu

We construct the interpolating currents for the fourteen p-wave excited heavy baryons in the framework of heavy quark effective theory (HQET). At the leading order in the 1/m_Q expansion these interpolating currents do not mix different states with the same J^P with each other. We use QCD sum rule to calculate the masses of the p-wave excited J=1/2 spin doub

P. K. Sahu, A. Ohnishi

We discuss the {\it SU}(2) chiral sigma model in the context of nuclear matter using a mean field approach at high density. In this model we include a dynamically generated isoscalar vector field and higher-order terms in the scalar field. With the inclusion of these, we reproduce the empirical values of the nuclear matter saturation density, binding energy,

Holger F. Hofmann, Takao Fuji, Takayoshi Kobayashi

A pair of coherent femtosecond pulse excitations applied to a molecule with strong electron-phonon coupling creates a coherent superposition of a low momentum and a high momentum wavepacket in the vibrational states of both the excited state and the ground state of the coherent transition. As the excited state is accelerated further, interference between the

D. S. Gorbunov

We study sensitivity of low-energy experiments to the scale of supersymmetry breaking $\sqrt{F}$ in models with light sgoldstinos --- superpartners of goldstino. The limits on $\sqrt{F}$ may be obtained from direct and indirect measurements of sgoldstino coupling to photons, leptons, mesons and nucleons. There are three sources of constraints: ($i$) astrophy

P. R. Hemmer, A. V. Turukhin, M. S. Shahriar, J. A. Musser

Raman excited spin coherences were experimentally observed in N-V diamond color centers via nondegenerate four-wave mixing (NDFWM) and electromagnetically induced transparency (EIT). The maximal absorption suppression was found to be 17%, which corresponds to 70% of what is possible given the random geometric orientation of the N-V center in diamond. In the

M. I. Dykman, P. M. Platzman

The system of electrons trapped in vacuum above the liquid helium surface displays the highest mobilities known in condensed matter physics. We provide a brief summary of the experimental and theoretical results obtained for this system. We then show that a quasi-2D set of N > 10^8 electrons in vacuum trapped in 1D hydrogenic levels above a micron-thick heli

Constantino Tsallis, Seth Lloyd, Michel Baranger

A bipartite spin-1/2 system having the probabilities $\frac{1+3x}{4}$ of being in the Einstein-Podolsky-Rosen entangled state $|Ψ^-$$> \equiv \frac{1}{\sqrt 2}(|$$\uparrow>_A|$$\downarrow>_B$$-|$$\downarrow>_A|$$\uparrow>_B)$ and $\frac{3(1-x)}{4}$ of being orthogonal, is known to admit a local realistic description if and only if $x<1/3$ (Peres criterion).

Alexander S. Shumovsky

Description of detection and emission in terms of the photon localization is discussed. It is shown that the standard representation of plane waves of photons should be revised to take into consideration the boundary conditions caused by the presence of quantum emitters and detectors. In turn, the change of the boundary conditions causes spatially inhomogene

A. S. Gevorkyan, A. A. Udalov

The problem of quantum harmonic oscillator with &#34;regular+random&#34; square frequency, subjected to &#34;regular+random external force, is considered in framework of representation of the wave function by complex-valued random process. Average transition probabilities are calculated. Stochastic density matrix method is developed, which is used for invest

Hai-Woong Lee, Jaewan Kim

A single-particle entangled state can be generated by illuminating a beam splitter with a single photon. Quantum teleportation utilizing such a single-particle entangled state can be successfully achieved with a simple setup consisting only of linear optical devices such as beam splitters and phase shifters. Application of the locality assumption to a single

Holger F. Hofmann, Takao Fuji, Atsushi Sugita, Takayoshi Kobayashi

Quantum interference between two distinct vibrational trajectories induced by two pulse femtosecond excitation in molecules is shown to result in a photon echo, providing direct evidence of the cat state superposition of Gaussian vibrational wavepackets.

Peter Sheridan Dodds, Daniel H. Rothman, Joshua S. Weitz

We examine the scaling law $B \propto M^α$ which connects organismal metabolic rate $B$ with organismal mass $M$, where $α$ is commonly held to be 3/4. Since simple dimensional analysis suggests $α=2/3$, we consider this to be a null hypothesis testable by empirical studies. We re-analyze data sets for mammals and birds compiled by Heusner, Bennett and Harve

Y. Huang, H. Saleur, D. Sornette

Based on several empirical evidence, a series of papers has advocated the concept that seismicity prior to a large earthquake can be understood in terms of the statistical physics of a critical phase transition. In this model, the cumulative Benioff strain (BS) increases as a power-law time-to-failure before the final event. This power law reflects a kind of

B. G. Sidharth

Recent work by Castro, Granik and El Naschie has given a rationale for the three dimensionality of our physical space within the framework of cantorian fractal space time using similar ideas of quantized fractal space time and noncommutativity. We also deduce the same result. Interestingly this is also seen to provide a rationale for an unproven conjecture o

Lloyd N. Trefethen, S. J. Chapman, Dan S. Henningson, Alvaro Meseguer

Although flow in a circular pipe is stable to infinitesimal perturbations, it can be excited to turbulence by finite perturbations whose minimal amplitude shrinks as R goes to infinity (R = Reynolds number). Laboratory experiments have appeared to disagree with one another and with theoretical predictions about the dependence of this minimal amplitude on $R$

Xuenan Li, Jon Machta

The dynamic critical behavior of the two-replica cluster algorithm is studied. Several versions of the algorithm are applied to the two-dimensional, square lattice Ising model with a staggered field. The dynamic exponent for the full algorithm is found to be less than 0.4. It is found that odd translations of one replica with respect to the other together wi

C. P. Welsch, K. -U. Kuehnel, A. Schempp

A focus of work at IAP has been the development and optimization of spiral loaded cavities since the 1970s [A. Schempp et al, NIM 135, 409 (1976)]. These cavities feature a high efficiency, a compact design and a big variety of possible fields of application. They find use both as bunchers and post accelerators to vary the final energy of the beam. In compar

Andras Czirok, Mitsugu Matsushita, Tamas Vicsek

The periodic swarming of bacteria is one of the simplest examples for pattern formation produced by the self-organized collective behavior of a large number of organisms. In the spectacular colonies of Proteus mirabilis (the most common species exhibiting this type of growth) a series of concentric rings are developed as the bacteria multiply and swarm follo

Mala Das, B. K. Chatterjee, B. Roy, S. C. Roy

How high the temperature of a liquid be raised beyond its boiling point without vaporizing (known as the limit of superheat) is an interesting subject of investigation. A new method of finding the limit of superheat of liquids is presented here. The superheated liquids are taken in the form of drops suspended in visco elastic gel. The nucleation is detected

T. Rauscher

This is an overview over the prediction of astrophysical reaction rates in the statistical model, with special emphasis on the parametrization of optical alpha+nucleus potentials.

Jutta Escher, Byron K. Jennings

The spectroscopic factor arises from short-range effects in the nuclear wave function. On the other hand, cross sections for external capture reactions, such as $^7$Be$(p,γ)^8$B at low energies, depend primarily on the asymptotic normalization of the bound-state wave function -- a long-range property. We investigate the relationship between potential models

P. K. Sahu

We discuss the relativistic nuclear equation of state (EOS) using a relativistic transport model in heavy-ion collisions. From the baryon flow for $Au + Au$ systems at SIS to AGS energies and above we find that the strength of the vector potential has to be reduced moderately at high density or at high relative momenta to describe the flow data at 1-10 A GeV

K. A. Brown, I. Gordon

Let H be a Hopf algebra which is a finite module over a central sub-Hopf algebra R. We continue the study of such algebras begun in RT/9911234, concentrating in this case on the example of $O_ε[G]$, a quantised function algebra at root of unity. In particular we determine the representation type and block structure of the family of reduced quantised function

Zinovy Reichstein, Boris Youssin

We construct a birational invariant for certain algebraic group actions. We use this invariant to classify linear representations of finite abelian groups up to birational equivalence, thus answering, in a special case, a question of E. B. Vinberg and giving a family of counterexamples to a related conjecture of P. I. Katsylo. We also give a new proof of a t

Silviu Olariu

Two distinct systems of commutative complex numbers in n dimensions are described, of polar and planar types. Exponential forms of n-complex numbers are given in each case, which depend on geometric variables. Azimuthal angles, which are cyclic variables, appear in these forms at the exponent, and this leads to the concept of residue for path integrals of n-

K. A. Brown, I. Gordon, J. T. Stafford

We show that the quantised function algebra O_e(G) of a simply-connected semisimple algebraic group G at a root of unity is a free module over the subring isomorphic to O(G).

A. Cossidente, O. H. King

A cap in PG(r,q) is a set of points, no three of which are collinear. A cap is said to be transitive if its automorphism group in PGammaL(r+1,q) acts transtively on the cap, and co-transitive if the automorphism group acts transtively on the cap&#39;s complement in PG(r,q). Transitive, co-transitive caps are characterized as being one of: an elliptic quadric

Don N. Page

If Bekenstein&#39;s conjectured bound on the microcanonical entropy, S < 2 pi E R, is applied to a closed subsystem of maximal linear size R and excitation energy up through E, it can be violated by an arbitrarily large factor by a scalar field having a symmetric potential allowing domain walls, and by the electromagnetic field modes in a coaxial cable.

Justin R. David

The D0/D4 system with a Neveu-Schwarz B-field in the spatial directions of the D4-brane has a tachyon in the spectrum of the (0,4) strings. The tachyon signals the instability of the system to form a bound state of the D0-brane with the D4-brane. We use the Wess-Zumino-Witten like open superstring field theory formulated by Berkovits to study the tachyon pot

Sergei M. Kuzenko, Stefan Theisen

We review self-duality of nonlinear electrodynamics and its extension to several Abelian gauge fields coupled to scalars. We then describe self-duality in supersymmetric models, both N = 1 and N = 2. The self-duality equations, which have to be satisfied by the action of any self-dual system, are found and solutions are discussed. One important example is th

M. Engelhardt, M. Faber, H. Reinhardt

A model for the infrared sector of SU(2) Yang-Mills theory, based on magnetic vortices represented by (closed) random surfaces, is presented. The random surfaces, governed by an action penalizing curvature, are investigated using Monte Carlo methods on a hypercubic lattice. A low-temperature confining phase and a high-temperature deconfined phase are generat

Gerard Clement, Dmitri Gal&#39;tsov

Static spherically symmetric asymptotically flat solutions to the U(1) Born-Infeld theory coupled to gravity and to a dilaton are investigated. The dilaton enters in such a way that the theory is $SL(2,R)$- symmetric for a unit value of the dilaton coupling constant. We find globally regular solutions for any value of the effective coupling which is the rati

G. Gabadadze, M. Shifman

Large N gluodynamics was shown to have a set of metastable vacua with the gluonic domain walls interpolating between them. The walls may separate the genuine vacuum from an excited one, or two excited vacua which are unstable at finite N (here N is the number of colors). One may attempt to stabilize them by switching on the axion field. We study how the ligh

O. Yakovlev, R. Rückl, S. Weinzierl

We give a short review of QCD sum rule results for B and D mesons and Lambda_Q and Sigma_Q baryons. We focus mainly on recent developments concerning semileptonic B->pion and D->pion transitions, pion couplings to heavy hadrons, decay constants and estimates of the b quark mass from a baryonic sum rule, and the extraction of the pion distribution amplitude f

L. Clavelli, T. Gajdosik, W. Majerotto

Unless squarks and sleptons are in the multi-TeV region or above, CP violating induced electric dipole moments of elementary particles can pose significant puzzles for supersymmetric (SUSY) models. We study the dipole-moment-inducing one-loop amplitudes as a function of the fundamental SUSY parameters and show that these puzzles are removed if there is a suf

J. C. Peng, G. T. Garvey, J. M. Moss, S. Sawada

We discuss the physics interest and the experimental feasibility for detecting high-mass dimuon pairs using the planned 50-GeV Proton Synchrotron (PS) at the KEK/JHF and JAERI/NSP joint accelerator project. The Drell-Yan measurement of $p+d$ versus $p+p$ at 50 GeV will provide unique information on the flavor asymmetry of proton&#39;s up and down sea-quark d

Adam F. Falk

These lectures contain an elementary introduction to heavy quark symmetry and the heavy quark expansion. Applications such as the expansion of heavy meson decay constants and the treatment of inclusive and exclusive semileptonic B decays are included. The use of heavy quark methods for the extraction of |V_cb| and |V_ub| is presented is some detail.

S. Peris, B. Phily, E. de Rafael

We use the Aleph data on vector and axial-vector spectral functions to test simple duality properties of QCD in the large Nc limit, which emerge in the approximation of a minimal hadronic ansatz of a spectrum of narrow states. These duality properties relate the short- and long-distance behaviours of specific correlation functions, which are order parameters

F. Assaoui, T. Lhallabi

The quantum actions of the (4,4) supersymmetric non-linear sigma model and its dual in the Abelian case are constructed by using the background superfield method. The propagators of the quantum superfield and its dual and the gauge fixing actions of the original and dual (4,4) supersymmetric sigma models are determined. On the other hand, the BRST transforma

A. A. Barrientos Bendezu, B. A. Kniehl

We study the squark loop correction to W^{+-} H^{-+} associated hadroproduction via gluon-gluon fusion within the minimal supersymmetric extension of the standard model. We list full analytic results and quantitatively analyze the resulting shift in the cross section at the CERN Large Hadron Collider assuming a supergravity-inspired scenario.

Costas G. Papadopoulos

A phase-space generation algorithm, capable to efficiently integrate the squared amplitude of any scattering process, is presented. The algorithm has been implemented in a Monte Carlo program, PHEGAS, which, using HELAC, a helicity amplitude computational package,can be used for automatic cross-section computation and event generation. Results for several sc

Anjan S. Joshipura, Saurabh D. Rindani

We formulate general conditions on $3\times 3$ neutrino mass matrices under which a degenerate pair of neutrinos at a high scale would split at low scale by radiative corrections involving only the standard model fields. This generalizes the original observations of Wolfenstein on pseudo Dirac neutrinos to three generations. A specific model involving partia

F. J. Yndurain

We consider the properties of the ground state of bottomium. The $Υ$ mass is evaluated to two loops, and including leading higher order [$O(α_s^5\logα_s)$] and $m_c^2/m_b^2$ corrections. This allows us to present updated values for the pole mass and $\bar{MS}$ mass of the $b$ quark: $m_b=5022\pm58$ MeV, for the pole mass, and $\bar{m}_b(\bar{m}_b)=4286\pm36$

A. K. Chaudhuri

We have investigated the phase transition and disoriented chiral condensate domain formation in linear sigma model. Solving the equation of motion for the sigma model fields in contact with a heat bath, we have shown that the fields undergo phase transition above a certain critical temperature(T_c). It was also shown that when the fields thermalised at tempe

L. Micu

The relativistic equivalent of the Schrödinger equation for a two particle bound state having the total angular momentum $S$ is written in the form of a Lorentz covariant set of equations (p_1^mu+p_2^mu+Omega^mu)Psi(p_1,p_2;P) chi_S(\vec{p}_1,\vec{p}_2)=P^mu Psi(p_1,p_2;P) chi_S(\vec{p}_1,\vec{p}_2) where the operators Omega^mu are the components of a 4-vect

M. Hori, H. Kawamura, J. Kodaira

We investigate the Sudakov double logarithmic corrections to the form factor of fermion in the SU(2)XU(1) electroweak theory. We adopt the familiar Feynman gauge and present explicit calculations at the two loop level. We show that the leading logarithmic corrections coming from the infrared singularities are consistent with the &#34;postulated&#34; exponent

Takeo Moroi

CP violation in the B_d system is discussed in the supersymmetric grand unified theory (GUT) with the right-handed neutrinos. Above the GUT scale, the right-handed down-type squarks couple to the right-handed neutrinos. Due to the renormalization group effect, flavor violations in the lepton sector may be transfered to the right-handed down-type squark mass

Shinji Komine, Masahiro Yamaguchi

Phenomenological issues of no-scale structure of Kähler potential are re-examined, which arises in various approaches to supersymmetry breaking. When no-scale boundary conditions are given at the Grand Unified scale and universal gaugino masses are postulated, a bino mass is quite degenerate with right-handed slepton masses and the requirement that the light

Y. Sumino

We report our theoretical study on how to probe the anomalous CP-violating couplings of the top quark in the ttbar region at future e+e- linear colliders. We focus on the unique role of the ttbar threshold region.