August 1999 arXiv papers — page 11

Soon-Tae Hong, Won Tae Kim, Young-Jai Park

We newly apply the improved Batalin-Fradkin-Tyutin(BFT) Hamiltonian method to the O(3) nonlinear sigma model, and directly obtain the compact form of nontrivial first class Hamiltonian by introducing the BFT physical fields. Furthermore, following the BFV formalism, we derive the BRST invariant gauge fixed Lagrangian through the standard path-integral proced

E. Bergshoeff, E. Eyras, R. Halbersma, C. M. Hull

We discuss branes whose worldvolume dimension equals the target spacetime dimension, i.e. ``spacetime-filling branes''. In addition to the D9-branes, there are 9-branes in the NS-NS sectors of both the IIA and IIB strings. The worldvolume actions of these branes are constructed, via duality, from the known actions of branes with codimension larger th

Paolo Gondolo, Katherine Freese

We show that in some regions of supersymmetric parameter space, CP violating effects that mix the CP-even and CP-odd Higgs bosons can enhance the neutralino annihilation rate, and hence the indirect detection rate of neutralino dark matter, by factors of 10^6. The same CP violating effects can reduce the neutralino scattering rate off nucleons, and hence the

P. C. Beggio, M. J. Menon, P. Valin

Starting from a short range expansion of the inelastic overlap function, capable of describing quite well the elastic pp and $\bar{p}p$ scattering data, we obtain extensions to the inelastic channel, through unitarity and an impact parameter approach. Based on geometrical arguments we infer some characteristics of the elementary hadronic process and this all

Stefano Frixione, Werner Vogelsang

We perform a detailed study of the production of isolated prompt photons in polarized hadronic collisions, in the centre-of-mass energy range relevant to RHIC. We compare the results obtained for a traditional cone-isolation prescription, with those obtained by imposing an isolation condition that eliminates any contribution to the cross section from the fra

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

We study the pair production of charged Higgs bosons at the CERN Large Hadron Collider in the context of the minimal supersymmetric extension of the standard model. We compare the contributions due to qq-bar annihilation at the tree level and gg fusion, which proceeds at one loop. At small or large values of tan(beta), H^+H^- production proceeds dominantly v

J. P. B. C de Melo, T. Frederico, H. W. L. Naus, P. U. Sauer

We compute the "+" component of the electromagnetic current of a composite spin-one two-fermion system for vanishing momentum transfer component $q^+=q^0+q^3$. In particular, we extract the nonvanishing pair production amplitude on the light-front. It is a consequence of the longitudinal zero momentum mode, contributing to the light-front current in

Arnd Brandenburg

The production of top quark pairs together with a hard gluon in e+e- annihilation is studied including next-to-leading order corrections in the strong coupling.

Zhi-zhong Xing

I introduce a simple phenomenological model of lepton flavor mixing and CP violation based on the flavor democracy of charged leptons and the mass degeneracy of neutrinos. The nearly bi-maximal mixing pattern, which can interpret current data on atmospheric and solar neutrino oscillations, emerges naturally from this model. The rephasing-invariant strength o

Gabriel German, Graham Ross, Subir Sarkar

We study inflation driven by a slow-rolling inflaton field, characterised by a quadratic potential, and incorporating radiative corrections within the context of supergravity. In this model the energy scale of inflation is not overly constrained by the requirement of generating the observed level of density fluctuations and can have a physically interesting

E. Levin

This is a talk given at Ringberg Workshop:"New Trends in HERA Physics", 30 May - 4 June, 1999.In this talk we discuss how deeply the region of high parton densities has been studied experimentally at HERA. We show that the measurements of deep inelastic structure functions at HERA confirm our theoretical expectation that at HERA we face a challenging

D. Rainwater

Weak boson fusion is a copious source of intermediate mass Higgs bosons at the LHC. The additional very energetic forward jets in these events are powerful background suppression tools. I analyze the decays H -> gamma gamma and H -> W^(*)W^(*) -> e mu pTmiss, with the latter a potential discovery channel, and the decay H -> tau tau -> lep had pTmiss as a met

A. K. Chaudhuri

We investigate the effect of friction on domain formation in disoriented chiral condensate. We solve the equation of motion of the linear sigma model, in the Hartree approximation, including a friction and a white noise term. For quenched initial condition, we find that even in presence of noise and dissipation domain like structure emerges after a few fermi

Mohammad R. Ahmady, Victor Elias

The nonperturbative content of the QCD vacuum permits the occurrence of QCD-vaccum condensate contributions to penguin amplitudes. We calculate the dimension-4 $<m_q\bar qq>$ and $<α_s G^2>$ contributions to the effective Wilson coefficients for penguin four-Fermi operators, and discuss how such contributions may contribute to nonleptonic B decays.

J. Ambjorn, J. Giedt, J. Greensite

We report on a breakdown of both monopole dominance and positivity in abelian-projected lattice Yang-Mills theory. The breakdown is associated with observables involving two units of the abelian charge. We find that the projected lattice has at most a global $Z_2$ symmetry in the confined phase, rather than the global U(1) symmetry that might be expected in

A. M. Green, J. Koponen, P. Pennanen

By comparing lattice data for the two heavy-light meson system (Q^2 qbar^2) with a standard many-body approach employing only interquark potentials, it is shown that the use of unmodified two-quark potentials leads to a gross overestimate of the binding energy.

Philippe de Forcrand, Victor Laliena

If the fermion mass is large enough, the phase of the fermion determinant of QCD at finite density is strongly correlated with the imaginary part of the Polyakov loop. This fact can be exploited to reduce the fluctuations of the phase significantly, making numerical simulations feasible in regions of parameters where the naive brute force method does not wor

V. Dzhunushaliev, H. -J. Schmidt

The Bach equation, i.e., the vacuum field equation following from the Lagrangian L=C_{ijkl}C^{ijkl}, will be completely solved for the case that the metric is conformally related to the cartesian product of two 2-spaces; this covers the spherically and the plane symmetric space-times as special subcases. Contrary to other approaches, we make a covariant 2+2-

M. G. Ivanov, I. V. Volovich

A simple derivation of the bound on entropy is given and the holographic principle is discussed. We estimate the number of quantum states inside space region on the base of uncertainty relation. The result is compared with the Bekenstein formula for entropy bound, which was initially derived from the generalized second law of thermodynamics for black holes.

David H. Wolpert, Kagan Tumer

This paper surveys the emerging science of how to design a ``COllective INtelligence&#39;&#39; (COIN). A COIN is a large multi-agent system where: (i) There is little to no centralized communication or control; and (ii) There is a provided world utility function that rates the possible histories of the full system. In particular, we are interested in COINs i

David H. Wolpert, Kevin R. Wheeler, Kagan Tumer

We consider the El Farol bar problem, also known as the minority game (W. B. Arthur, ``The American Economic Review&#39;&#39;, 84(2): 406--411 (1994), D. Challet and Y.C. Zhang, ``Physica A&#39;&#39;, 256:514 (1998)). We view it as an instance of the general problem of how to configure the nodal elements of a distributed dynamical system so that they do not

H. M. Gladney

E-business, information serving, and ubiquitous computing will create heavy request traffic from strangers or even incognitos. Such requests must be managed automatically. Two ways of doing this are well known: giving every incognito consumer the same treatment, and rendering service in return for money. However, different behavior will be often wanted, e.g.

H. Buhrman, R. Cleve, R. de Wolf, Ch. Zalka

We present a number of results related to quantum algorithms with small error probability and quantum algorithms that are zero-error. First, we give a tight analysis of the trade-offs between the number of queries of quantum search algorithms, their error probability, the size of the search space, and the number of solutions in this space. Using this, we ded

Dmitry N. Chigrin, Andrei V. Lavrinenko, Dmitry A. Yarotsky, Sergey V. Gaponenko

A remarkable property of one-dimensional all-dielectric periodic structures has recently been reported, namely a one-dimensional lattice can totally reflect electromagnetic wave of any polarization at all angles within a prescribed frequency region. Unlike their metallic counterpart, such all-dielectric omnidirectional mirrors are nearly free of loss at opti

Ady Stern, S. Das Sarma, Matthew P. A. Fisher, S. M. Girvin

In a bilayer electronic system the layer index may be viewed as the z-component of an isospin-1/2. An XY isospin-ordered ferromagnetic phase was observed in quantum Hall systems and is predicted to exist at zero magnetic field at low density. This phase is a superfluid for opposite currents in the two layers. At B=0 the system is gapless but superfluidity is

Elbio Dagotto

In recent years, the study of ladder materials has developed into a well-established area of research within the general context of Strongly Correlated Electrons. This effort has been triggered by an unusual cross-fertilization between theory and experiments. In this paper, the main experimental results obtained in the context of ladders are reviewed from th

Nicolas Mujica, Francisco Melo

From pressure and surface dilation measurements, we show that a solid-liquid-type transition occurs at low excitation frequencies in vertically vibrated granular layers. This transition precedes subharmonic bifurcations from flat surface to standing wave patterns, indicating that these waves are in fact associated with the fluid like behavior of the layer. I

Th. M. Nieuwenhuizen

Star clusters in isothermal spheres are studied from a thermodynamic point of view. New density profiles are presented, that describe the collapsed phase at low temperatures. At the transition a set of binaries is formed that carries 13 % of the gravitational energy, while also a huge latent heat is generated. The total energy of the binaries is fixed by the

Gernot Münster, Sabine Rotsch

First order phase transitions in general proceed via nucleation of bubbles. A theoretical basis for the calculation of the nucleation rate is given by the homogeneous nucleation theory of Langer and its field theoretical version of Callan and Coleman. We have calculated the nucleation rate beyond the thin wall approximation by expanding the bubble solution a

A. Rosch

We discuss three different scenarios recently proposed to account for the non-Fermi liquid behavior near antiferromagnetic (AFM) quantum critical points in heavy-Fermion systems: (i) scattering of Fermi liquid quasiparticles by strong spin fluctuations near the spin-density-wave instability, (ii) the breakdown of the Kondo effect due to the competition with

Raz Carmi, Emil Polturak

We describe an experimental search for spontaneous formation of flux lines during a rapid quench of thin YBaCuO films through Tc. This effect is expected according to the Kibble-Zurek mechanism of a creation of topological defects of the order parameter during a symmetry breaking phase transition. Spontaneously formed vortices were previously observed in sup

Ingo Morgenstern, Werner Fettes, Thomas Husslein

The high-T_c glass model can be combined with the repulsive tt&#39;--Hubbard model as microscopic description of the striped domains found in the high-T_c materials. In this picture the finite Hubbard clusters are the origin of the d-wave pairing. In this paper we show, that the glass model can also explain the critical currents usually observed in the high-

V. Janis, G. Czycholl

We consider a model for a metal-insulator transition of correlated electrons in an external magnetic field. We find a broad region in interaction and magnetic field where metallic and insulating (fully magnetized) solutions coexist and the system undergoes a first-order metal-insulator transition. A global instability of the magnetically saturated solution p

V. V. Savkin, A. A. Fedyanin, A. N. Rubtsov, F. A. Pudonin

DC-electric field, being screened in 3D semiconductors, normally decays monotonically in space. Experimental studies of the DC electric field screening in Si-SiO$_2$ multiple quantum wells by electric field induced optical second-harmonic generation show a non-monotonic, oscillatory-like decay. The model of electrons localized inside quantum wells, with the

Yasufumi Yamashita, Naokazu Shibata, Kazuo Ueda

We numerically study the SU(2)$\otimes$SU(2) symmetric spin-orbit coupled model as a lower symmetric generalization of the SU(4) exchange model. On the symmetric line with respect to the spin and orbit, our result shows the essentially singular gap formation in consistent with the analytic approach, which is different from the previous numerical calculation.

B. P. van Zyl, E. Zaremba, D. A. W. Hutchinson

We have investigated the magnetoplasmon excitations in arrays of circular and noncircular quantum dots within the Thomas-Fermi-Dirac-von Weizsäcker approximation. Deviations from the ideal collective excitations of isolated parabolically confined electrons arise from local perturbations of the confining potential as well as interdot Coulomb interactions. The

M. Schmidt

We have searched for gamma-ray bursts (GRB) in the BATSE DISCLA data covering the period TJD 8365-10528. We employ an algorithm that uses the background both before and after the onset of the burst, and that requires an excess of at least 5 sigma over background in the energy range 50-300 keV. For the initial set of 7536 triggers, we find strong concentratio

Richard B. Larson

The current status of both the observational evidence and the theory of the stellar initial mass function (IMF) is reviewed, with particular attention to the two basic, apparently universal features shown by all observations of nearby stellar systems: (1) a characteristic stellar mass of the order of one solar mass, and (2) a power-law decline of the IMF at

I. F. Mirabel, O. Laurent

We present some highlights from the mid-infrared (5-16 micron) images of mergers of massive galaxies obtained with the Infrared Space Observatory (ISO). We have observed: 1) ultraluminous infrared nuclei, 2) luminous dust-enshrouded extranuclear starbursts, and 3) active galaxy nuclei (AGNs). In this contribution we discuss the observations of Arp 299, a pro

Dennis Zaritsky, Anthony H. Gonzalez

We examine a possible connection between the anisotropic distribution of satellite galaxies around giant spiral galaxies and the evolution of satellite systems. The observed polar anisotropy (Zaritsky et al.1997) is either imprinted by initial conditions or develops from an initially symmetric distribution. We attempt to discriminate between these two possib

James M. Stone, James E. Pringle, Mitchell C. Begelman

Two-dimensional (axially symmetric) numerical hydrodynamical calculations of accretion flows which cannot cool through emission of radiation are presented. The calculations begin from an equilibrium configuration consisting of a thick torus with constant specific angular momentum. Accretion is induced by the addition of a small anomalous azimuthal shear stre

F. Lignieres, F. Califano, A. Mangeney

The linear stability of a shear layer in a highly diffusive stably stratified atmosphere has been investigated. This study completes and extends previous works by Dudis (1974) and Jones (1977). We show that: (i) an asymptotic regime is reached in the limit of large thermal diffusivity, (ii) there exists two different types of unstable modes. The slowest grow

William C. Keel, Seth H. Cohen, Rogier A. Windhorst, Ian Waddington

We present deep wide-field medium-band imaging in redshifted Lyman alpha of fields surrounding HST detections of faint emitters, to characterize their larger-scale environment. The radio galaxy 53W002 was previously found to be part of a rich grouping at z=2.39, including 5 confirmed, compact, star-forming objects. This is now shown to be part of a larger st

F. Lignieres

We present an asymptotic form of the Boussinesq equations in the limit of small Peclet numbers i.e. when the time scale of motions is much larger than the time scale of thermal diffusion. We find that, in this limit, the effects of thermal diffusion and stable stratification combine in a single physical process. This process is an anisotropic dissipation (no

Ralf Napiwotzki

The results of a NLTE model atmosphere analysis of 27 hydrogen-rich central stars of old planetary nebulae (PN) are reported. These stars were selected from a previous paper in this series, where we gave classifications for a total of 38 central stars. Most of the analyzed central stars fill a previously reported gap in the hydrogen-rich evolutionary sequenc

B. M. Poggianti, H. Wu

We analyse the optical spectral properties of the complete sample of Very Luminous Infrared Galaxies presented by Wu et al. (1998a,b) and we find a high fraction (~50 %) of spectra showing both a strong H_delta line in absorption and relatively modest [OII] emission (e(a) spectra). The e(a) signature has been proposed as an efficient method to identify dusty

R. Srianand

We present the results of a careful analysis of associated absorption systems toward NGC 5548. Most of the well resolved narrow components in the associated system, defined by the Lyman alpha, C IV and N V profiles, show velocity separation similar (to within 10~\kms) to the C IV doublet splitting. We estimate the chance probability of occurrence of such pai

Naomi Ota, Kazuhisa Mitsuda, Makoto Hattori, Tatehiro Mihara

We have detected an emission line feature at 4 keV in the X-ray emission from a sky region including the distant radio galaxy 3C220.1(z=0.62) obtained with ASCA. The line energy is 6.1 - 7.0 keV (90% confidence) in the rest frame of 3C220.1. Within the present statistics, the observed spectra are consistent with two different models: a non-thermal model cons

Dara J. Norman, Liliya L. R. Williams

We find angular correlations between high redshift radio selected QSOs from the 1 Jy Catalog and APM galaxies on ~1 degree scales. We demonstrate that observed correlations are qualitatively consistant with a gravitational lensing explanation and are inconsistant with a Galactic dust obscuration model. Comparing our results with those of Benitez and Martinez

R. X. Xu, G. J. Qiao

Using the Thomas-Fermi model, we investigated the electric characteristics of a static non-magnetized strange star without crust in this paper. The exact solutions of electron number density and electric field above the quark surface are obtained. These results are useful if we are concerned about physical processes near the quark matter surfaces of strange

Andrei V. Frolov

This paper studies near-critical evolution of the spherically symmetric scalar field configurations close to the continuously self-similar solution. Using analytic perturbative methods, it is shown that a generic growing perturbation departs from the critical Roberts solution in a universal way. We argue that in the course of its evolution, initial continuou

M. W. Cole, V. H. Crespi, G. Stan, J. M. Hartman

Helium atoms are strongly attracted to the interstitial channels within a bundle of carbon nanotubes. The strong corrugation of the axial potential within a channel can produce a lattice gas system where the weak mutual attraction between atoms in neighboring channels of a bundle induces condensation into a remarkably anisotropic phase with very low binding

R. R. Caldwell

It is extraordinary that a number of observations indicate that we live in a spatially flat, low matter density Universe, which is currently undergoing a period of accelerating expansion. The effort to explain this current state has focused attention on cosmological models in which the dominant component of the cosmic energy density has negative pressure, wi

R. V. Kulkarni, E. Almaas, D. Stroud

We study the distribution function for minimal paths in small-world networks. Using properties of this distribution function, we derive analytic results which greatly simplify the numerical calculation of the average minimal distance, $\bar{\ell}$, and its variance, $σ^2$. We also discuss the scaling properties of the distribution function. Finally, we study

M. S. Hussein, V. Kharchenko, L. F. Canto, R. Donangelo

We develop a semiclassical theory for the long range excitation of plasmon resonances in atomic clusters, based on the doorway hypothesis. The effect of the width of the plasmon resonance is fully taken into account. As an application we study plasmon excitation in small Sodium clusters, in collisions with electrons and protons.

R. Baier, K. Redlich

We compute the pressure of a finite density quark-gluon plasma at zero temperature to leading order in hard-thermal-loop perturbation theory, which includes the fermionic excitations and Landau damping. The result is compared with the weak-coupling expansion for finite positive chemical potential $μ$ through order $α_s^2$ and with a quasiparticle model with

A. A. Tseytlin

We review and elaborate on some aspects of Born-Infeld action and its supersymmetric generalizations in connection with string theory. Contents: BI action from string theory; some properties of bosonic D=4 BI action; N=1 and N=2 supersymmetric BI actions with manifest linear D=4 supersymmetry; four-derivative terms in N=4 supersymmetric BI action; BI actions

D. Castro, K. Haegele, J. E. Morais, L. M. Pardo

In this extended abstract we deal with the relations between the numerical/diophantine approximation and the symbolic/algebraic geometry approachs to solving of multivariate diophentine polynomial systems, obtaining several consecuences ranging from diophantine approximation to effective number theory.

Brahim Elattari, S. A. Gurvitz

We investigated the electron tunneling out of a quantum dot in the presence of a continuous monitoring by a detector. It is shown that the Schrödinger equation for the whole system can be reduced to new Bloch-type rate equations describing the time-development of the detector and the measured system at once. Using these equations we find that the continuous

Ferenc Kun, Stefano Zapperi, Hans J. Herrmann

We introduce a continuous damage fiber bundle model that gives rise to macroscopic plasticity and compare its behavior with that of dry fiber bundles. Several interesting constitutive behaviors are found in this model depending on the value of the damage parameter and on the form of the disorder distribution. In addition, we compare the behavior of global lo

U. Zuelicke

We consider the low-energy, long-wave-length excitations of a reconstructed quantum-Hall edge where three branches of chiral one-dimensional edge excitations exist. We find that, in addition to forward scattering between the three edge-excitation branches, Coulomb interaction gives rise to a novel Umklapp-type scattering process that cannot be accounted for

Dumitru Ghilencea, Graham Ross

We consider the calculation of threshold effects due to Kaluza Klein and winding modes in string theory. We show that for a large radius of compactification these effects may be approximated by an effective field theory applicable below the string cut-off scale. Using this formalism we show that the radiative contribution to gauge couplings involving only ma

S. W. Hawking, H. S. Reall

Black hole solutions that are asymptotic to $ AdS_5 \times S^5$ or $ AdS_4 \times S^7$ can rotate in two different ways. If the internal sphere rotates then one can obtain a Reissner-Nordstrom-AdS black hole. If the asymptotically AdS space rotates then one can obtain a Kerr-AdS hole. One might expect superradiant scattering to be possible in either of these

E. G. Floratos, G. K. Leontaris

This is a short note on the relation of the Matrix model with the non-commutative geometry of the 11-dimensional supermembrane. We put forward the idea that M-theory is described by the &#39;t Hooft topological expansion of the Matrix model in the large N-limit where all topologies of membranes appear. This expansion can faithfully be represented by the Moya

Mark Wardle

Cosmic-ray and X-ray ionisations in molecular gas produce a weak far-ultraviolet flux through the radiative decay of H2 molecules that have been excited by collisions with energetic electrons (the Prasad-Tarafdar mechanism). I consider the effect of this dissociating flux on the oxygen chemistry in C-type shocks. Typically a few percent of the water molecule

Jaehyun Kim, Jae-Seung Lee, Soonchil Lee

We present a general method which expresses a unitary operator by the product of operators allowed by the Hamiltonian of spin-1/2 systems. In this method, the generator of an operator is found first, and then the generator is expanded by the base operators of the product operator formalism. Finally, the base operators disallowed by the Hamiltonian, including

James S. Bullock, Tsafrir S. Kolatt, Yair Sigad, Rachel S. Somerville

We study dark-matter halo density profiles in a high-resolution N-body simulation of an LCDM cosmology. Our statistical sample contains ~5000 haloes in the range 10^{11}-10^{14} M_sun. The profiles are parameterized by an NFW form with two parameters, an inner radius r_s and a virial radius r_v, and we define the halo concentration c_v = r_v/r_s. First, we f

Sunish Menon, G. S. Agarwal

We consider non-degenerate pump-probe spectroscopy of V-systems under conditions such that interference among decay channels is important. We demonstrate how this interference can result in new gain features instead of the usual absorption features. We relate this gain to the existence of a new vacuum induced quasi-trapped-state. We further show how this als

Czeslaw Lewa, Pawel Horodecki, Ryszard Horodecki, Michal Horodecki

The spectrum of the spin particle in oscillatory potential subjected to external parabolic magnetic field ${\bf B}=(B_0+Gx+\tilde G x^2){\bf \hat z}$ is obtained. The structure of energy levels of the considered system allows to identify the frequency of the oscillator via the spectrum of spin sublevels coming only from {\it one} oscillatory level. The effec

Dirk Mueller, Dana Z. Anderson, Randal J. Grow, Peter D. D. Schwindt

Laser-cooled neutral atoms from a low-velocity atomic source are guided via a magnetic field generated between two parallel wires on a glass substrate. The atoms bend around three curves, each with a 15-cm radius of curvature, while traveling along a 10-cm-long track. A maximum flux of 2*10^6 atoms/sec is achieved with a current density of 3*10^4 A/cm^2 in t

Alisher S. Kadyrov, Igor Bray

The positron-hydrogen atom scattering system is considered within the S-wave model. Convergence in the elastic scattering, excitation, ionization, and positronium formation channels is studied as a function of the number and type of states used to expand the total wave function. It is found that all unphysical resonances disappear only if near-complete pseud

N. H. Dekker, C. S. Lee, V. Lorent, J. H. Thywissen

We demonstrate the guiding of neutral atoms by the magnetic fields due to microfabricated current-carrying wires on a chip. Atoms are guided along a magnetic field minimum parallel to and above the current-carrying wires. Two waveguide configurations are demonstrated: one using two wires with an external magnetic field, and a second using four wires without

Markus Baer, Aric Hagberg, Ehud Meron, Uwe Thiele

Numerical simulations of two dimensional pattern formation in an anisotropic bistable reaction-diffusion medium reveal a new dynamical state, stratified spatiotemporal chaos, characterized by strong correlations along one of the principal axes. Equations that describe the dependence of front motion on the angle illustrate the mechanism leading to stratified

Cornelis Storm, Willem Spruijt, Ute Ebert, Wim van Saarloos

We investigate the asymptotic relaxation of so-called pulled fronts propagating into an unstable state. The ``leading edge representation&#39;&#39; of the equation of motion reveals the universal nature of their propagation mechanism and allows us to generalize the universal algebraic velocity relaxation of uniformly translating fronts to fronts, that genera

M. S. Hussein, A. F. R. de Toledo Piza, O. K. Vorov

We propose a soluble model to incorporate the nonlinear effects in the transition probabilities of the multiphonon Giant Dipole Resonances based on the SU(1,1) algebra. Analytical expressions for the multi-phonon transition probabilities are derived. For reasonably small magnitude of nonlinearity $x\simeq 0.1-0.2$ enhancement factor for the Double Giant Reso

Zoltan Batiz, Franz Gross

The momentum conservation sum rule for deep inelastic scattering (DIS) from composite particles is investigated using the general theory of relativity. For two 1+1 dimensional examples, it shown that covariant theories automatically satisy the DIS momentum conservation sum rule provided the bound state is covariantilly normalized. Therefore, in these cases t

Thomas D. Cohen, James M. Hansen

The convergence of the Q expansion in the ^3S_1-^3D_1 mixing angle is investigated through the renormalization condition used to fit the free paramteter encountered at NNLO. Although the NNLO calculation describes the data well at momenta much less than 50 MeV, a variation in the renormalization condition results in 100% expected uncertainties at momenta as

T. Yoshimoto, T. Sato, M. Arima, T. -S. H. Lee

A dynamical approach is developed to predict the $πN$ scattering amplitudes starting with the constituent quark models. The first step is to apply a variational method to solve the three-quark bound state problem. The resulting wave functions are used to calculate the $N^* \to πN, ηN, πΔ$ vertex functions by assuming that the $π$ and $η$ mesons couple direct

Alex Chigogidze, Vesko Valov

For any countable $CW$-complex $K$ and a cardinal number $τ\geqω$ we construct a completely metrizable space $X(K,τ)$ of weight $τ$ with the following properties: $\e X(K,τ)\leq K$, $X(K,τ)$ is an absolute extensor for all normal spaces $Y$ with $\e Y\leq K$, and for any completely metrizable space $Z$ of weight $\leqτ$ and $\e Z\leq K$ the set of closed emb

Pierre Collet, Jean-Pierre Eckmann

We study damped hyperbolic equations on the infinite line. We show that on the global attracting set $G$ the $ε$-entropy (per unit length) exists in the topology of $W^{1,\infty}$. We also show that the topological entropy per unit length of $G$ exists. These results are shown using two main techniques: Bounds in bounded domains in position space and for lar

Joseph D. Masters

Let $M = H^3/Γ$ be a hyperbolic 3-manifold, where $Γ$ is a non-elementary Kleinian group. It is shown that the length spectrum of $M$ is of unbounded multiplicity.

Changhyun Ahn, Soo-Jong Rey

Utilizing AdS/CFT correspondence in M-theory, an example of interacting d=3 conformal field theories and renormalization group flow between them is presented. Near-horizon geometry of N coincident M2-branes located on a conical singularity on eight-dimensional hyperkähler manifold or manifold with Spin(7) holonomy is, in large-N limit, AdS4*X7, where X7 is s

S. T. Tsou, I. P. Zois

It is found that the 2-index potential in nonabelian theories does not behave geometrically as a connection but that, considered as an element of the second de Rham cohomology group twisted by a flat connection, it fits well with all the properties assigned to it in various physical contexts. We also prove some results on the Euler characteristic of the twis

Mans Henningson, Bengt E. W. Nilsson, Per Salomonson

We consider a free (2 k)-form gauge-field on a Euclidean (4 k + 2)-manifold. The parameters needed to specify the action and the gauge-invariant observables take their values in spaces with natural complex structures. We show that the correlation functions can be written as a finite sum of terms, each of which is a product of a holomorphic and an anti-holomo

O. J. P. Eboli, E. M. Gregores, F. Halzen

We show that soft color rearrangement of final states can account for the appearance of rapidity gaps between jets. In the color evaporation model the probability to form a gap is simply determined by the color multiplicity of the final state. This model has no free parameters and reproduces all data obtained by the ZEUS, H1, D0, and CDF collaborations.

A. J. Buras, G. Colangelo, G. Isidori, A. Romanino

We analyze the rare kaon decays $K_L \to π^0 ν\bar ν$, $K^+ \to π^+ ν\bar ν$, $K_L \to π^0 e^+ e^-$ and $K_L \to μ^+ μ^-$ in conjunction with the CP violating ratio $ε&#39;/ε$ in a general class of supersymmetric models in which $Z$- and magnetic-penguin contributions can be substantially larger than in the Standard Model. We point out that radiative effects

M. Engelhardt, K. Langfeld, H. Reinhardt, O. Tennert

In the framework of the center vortex picture of confinement, the nature of the deconfining phase transition is studied. Using recently developed techniques which allow to associate a center vortex configuration with any given lattice gauge configuration, it is demonstrated that the confining phase is a phase in which vortices percolate, whereas the deconfin

Leif Lonnblad

I present a modification of the Colour Dipole Model for DIS as implemented in Ariadne to better describe events at high Q^2.

Nick Brook, Leif Lonnblad

We summarize the activities in working group 10 concerned with QCD cascades, and find that although much work still needs to be done, much progress was made during this workshop in understanding the merits and deficiencies of different programs.

A. G. Grozin

Heavy Quark Effective Theory (HQET) is a new approach to QCD problems involving a heavy quark. In the leading approximation, the heavy quark is considered as a static source of the gluon field; 1/m corrections can be systematically included in the perturbation theory. New symmetry properties not apparent in QCD appear in HQET. They are used, in particular, t

V. N. Baier, A. G. Grozin

Semileptonic B decays are described by the Isgur-Wise form factor to the leading order in 1/m; four new functions appear in the first order [Luke]. Values of these functions are crucial for the applicability of the whole approach to processes involving c quark. We obtain the sum rules for three subleading form factors from the QCD sum rules with finite masse

A. G. Grozin, O. I. Yakovlev

HQET currents with the quantum numbers of the ground-state baryons are discussed. One-loop anomalous dimensions are calculated, and exact one-loop matching to QCD currents is found. Two-point correlators of these currents are calculated taking into account $d\le9$ terms of the OPE. Sum rules for heavy baryons Lambda_Q and Sigma^(*)_Q are analyzed. Three-poin

D. J. Broadhurst, A. G. Grozin

We calculate the coefficients of operators with dimensions d <= 7 in the operator product expansion of correlators of q Gamma Q currents, for the effective field theory of an infinite-mass quark, Q. Exact two-loop results are obtained, with an arbitrary gauge group and spacetime dimension, for the perturbative (d=0) and quark-condensate (d=3) contributions,

D. J. Broadhurst, A. G. Grozin

We give a recurrence relation for two-loop integrals encountered in the effective field theory of an infinitely heavy quark, Q, interacting with gluons and Nl massless quarks, q, from which we obtain exact two-loop results, in any dimension and covariant gauge, for the propagator of Q and the vertex function of the heavy-light current J = Q Gamma q, at zero

A. B. Arbuzov

Iterative solution of QED evolution equations for non-singlet electron structure functions is considered. Analytical expressions in the fourth and fifth orders are presented in terms of splitting functions. Relation to the existing exponentiated solution is discussed.

T. Reisz, H. J. Rothe

We give a perturbative proof that U(1) lattice gauge theories generate the axial anomaly in the continuum limit under very general conditions on the lattice Dirac operator. These conditions are locality, gauge covariance and the absense of species doubling. They hold for Wilson fermions as well as for realizations of the Dirac operator that satisfy the Ginsp

T. Reisz, H. J. Rothe

Using functional techniques, we prove, to all orders of perturbation theory, that lattice vector gauge theories with Ginsparg Wilson fermions are renormalizable. For two or more massless fermions, they satisfy a flavour mixing axial vector Ward identity. It involves a lattice specific part that is quadratic in the vertex functional and classically irrelevant

Bazhutov Yu. N

A telescope of two coaxial scintillation detectors (an upper thin CsJ crystal of d63x0,35mm2 and a lower thick NaJ crystal of d150x100 mm2) located vertically on the surface of the Earth was used to have during T=106 hours 20 events registered with increased specific ionization in each detector that turned out to exceed 10 times the specific ionization cause

Dumitru Baleanu

In this paper the isometries of the dual space were investigated. The dual structural equations of a Killing tensor of order two were found . The flat space case was analyzed in details.

J. A. Katine, F. J. Albert, R. A. Buhrman, E. B. Myers

Using thin film pillars ~100 nm in diameter, containing two ferromagnetic Co layers of different thicknesses separated by a paramagnetic Cu spacer, we examine effects of torques due to spin-polarized currents flowing perpendicular to the layers. In accordance with spin-transfer theory, spin-polarized electrons flowing from the thin to the thick Co layer can