May 2001 arXiv papers

Domenico Fiorenza, Riccardo Murri

This paper is an introduction to the language of Feynman Diagrams. We use Reshetikhin-Turaev graphical calculus to define Feynman diagrams and prove that asymptotic expansions of Gaussian integrals can be written as a sum over a suitable family of graphs. We discuss how different kind of interactions give rise to different families of graphs. In particular,

K. Abazajian, G. M. Fuller, W. H. Tucker

We point out a serendipitous link between warm dark matter (WDM) models for structure formation on the one hand and the high sensitivity energy range (1-10 keV) for x-ray photon detection on the Chandra and XMM-Newton observatories on the other. This fortuitous match may provide either a direct detection of the dark matter or exclusion of many candidates. We

A. DeBenedictis, D. Aruliah, A. Das

Black hole interiors (the $T$-domain) are studied here in great detail. Both the {\em general} and particular $T$-domain solutions are presented including non-singular ones. Infinitely many local $T$-domain solutions may be modeled with this scheme. The duality between the $T$ and $R$ domains is presented. It is demonstrated how generally well behaved $R$-do

G. N. Abramov, M. N. Achasov, V. M. Aulchenko, K. I. Beloborodov

The program of upgrade of the Spherical Neutral Detector for future experiments at a new VEPP-2000 $e^+e^-$ collider is presented. Modernization includes upgrades of electromagnetic calorimeter, tracking system, detector electronics, data acquisition system, and offline software. It is also planned to equip the detector with two new subsystems: particle iden

T. R. Kirkpatrick, D. Belitz, Thomas Vojta, R. Narayanan

It is shown that the critical temperature for spin-triplet, p-wave superconductivity mediated by spin fluctuations is generically much higher in a Heisenberg ferromagnetic phase than in a paramagnetic one, due to the coupling of the magnons to the longitudinal magnetic susceptibility. Together with the tendency of the low-temperature ferromagnetic transition

J. T. Lunardi, B. M. Pimentel, R. G. Teixeira

Here we study the behaviour of spin 0 sector of the DKP field in spaces with torsion. First we show that in a Riemann-Cartan manifold the DKP field presents an interaction with torsion when minimal coupling is performed, contrary to the behaviour of the KG field, a result that breaks the usual equivalence between the DKP and the KG fields. Next we analyse th

Alexandre Arbey, Julien Lesgourgues, Pierre Salati

The nature of the dark matter that binds galaxies remains an open question. The favored candidate has been so far the neutralino. This massive species with evanescent interactions is now in difficulty. It would actually collapse in dense clumps and would therefore play havoc with the matter it is supposed to shepherd. We focus here on a massive and non-inter

Marc Sher

In many models of CP violation, the electric dipole moments (EDMs) of leptons scale as the cube of the lepton mass. In these models, the EDM of a 100 GeV heavy lepton would be a billion times greater than that of the muon, and could be as large as a 0.01 e-fermi. In other models, in which the heavy leptons have different properties from the lighter generatio

J. Kluson

In this short note we would like to discuss general solutions of the Berkovits superstring field theory, in particular the string field action for fluctuation around such a solution. We will find that fluctuations obey the same equation of motion as the original field with the new BRST operator. Then we will argue that the superstring field theory action for

Francesco Toppan

The definition of "classical anomaly" is introduced. It describes the situation in which a purely classical dynamical system which presents both a lagrangian and a hamiltonian formulation admits symmetries of the action for which the Noether conserved charges, endorsed with the Poisson bracket structure, close an algebra which is just the centrally e

Anton Burkov, John Schliemann, A. H. MacDonald, S. M. Girvin

We present an effective Hamiltonian for a bilayer quantum Hall system at filling factor $ν=1$ neglecting charge fluctuations. Our model is formulated in terms of spin and pseudospin operators and is an exact representation of the system within the above approximation. We analyze its low-lying excitations in terms of spin-wave theory. Moreover we add to previ

Varun Sahni, M. Sami, Tarun Souradeep

We discuss a scenario in which extra dimensional effects allow a scalar field with a steep potential to play the dual role of the inflaton as well as dark energy (quintessence). The post-inflationary evolution of the universe in this scenario is generically characterised by a `kinetic regime' during which the kinetic energy of the scalar field greatly ex

Vivek Aji, Nigel Goldenfeld

We calculate analytically the dynamic critical exponent $z_{MC}$ measured in Monte Carlo simulations for a vortex loop model of the superconducting transition, and account for the simulation results. In the weak screening limit, where magnetic fluctuations are neglected, the dynamic exponent is found to be $z_{MC} = 3/2$. In the perfect screening limit, $z_{

David M. Thompson

The type 0 theories have twice as many stable D-branes as the type II theories. In light of this added complication, we find the descent relations for D-branes in the type 0A and 0B theories. In addition, we work out how the two types of D-branes differ in their couplings to NS-NS fields.

P. Jacob, P. Mathieu

Some simple (namely, single-channel) correlation functions involving an arbitrary number of fields are computed by means of a direct application of the residue calculus, through partial fraction expansions. Examples are presented in minimal models and parafermionic conformal theories. A generic factorized expression is deduced for the corresponding single-ch

ZEUS Collaboration

The cross section and the proton structure function F2 for neutral current deep inelastic e+p scattering have been measured with the ZEUS detector at HERA using an integrated luminosity of 30 pb-1. The data were collected in 1996 and 1997 at a centre-of-mass energy of 300 GeV. They cover the kinematic range 2.7 < Q^2 < 30000 GeV2 and 6.10^-5 < x < 0.65. The

Sergiu I. Vacaru, Florian Catalin Popa

We apply a new general method of anholonomic frames with associated nonlinear connection structure to construct new classes of exact solutions of Einstein-Dirac equations in five dimensional (5D)gravity. Such solutions are parametrized by off-diagonal metrics in coordinate (holonomic) bases, or, equivalently, by diagonal metrics given with respect to some an

Gérard Ben-Arous, Houman Owhadi

We show that the effective diffusivity matrix $D(V^n)$ for the heat operator $\partial_t-(Δ/2-\nabla V^n \nabla)$ in a periodic potential $V^n=\sum_{k=0}^n U_k(x/R_k)$ obtained as a superposition of Holder-continuous periodic potentials $U_k$ (of period $\T^d:=\R^d/\Z^d$, $d\in \N^*$, $U_k(0)=0$) decays exponentially fast with the number of scales when the s

GDH-Collaboration, A2-Collaboration, :, J. Ahrens

A direct measurement of the helicity dependence of the total photoabsorption cross section on the proton was carried out at MAMI (Mainz) in the energy range 200 < E_gamma < 800 MeV. The experiment used a 4$π$ detection system, a circularly polarized tagged photon beam and a frozen spin target. The contributions to the Gerasimov-Drell-Hearn sum rule and to th

Masayasu Harada, Koichi Yamawaki

We reveal the full phase structure of the effective field theory for QCD, based on the hidden local symmetry (HLS) through the one-loop renormalization group equation including quadratic divergences. We then show that vector dominance (VD) is not a sacred discipline of the effective field theory but rather an accidental phenomenon peculiar to three-flavored

A. Plecenik, L. Satrapinsky, P. Kus, S. Gazi

Thin films of MgB2 superconductor were prepared by three different procedures on sapphire and silicon substrates. Boron thin films, ex-situ annealed in magnesium vapour, resulted in textured polycrystalline films with crystal dimensions below about 1000 nm, onset critical temperature Tcon near 39 K and width of phase transition about 1 K. Both, ex-situ and i

Sz. Borsanyi, A. Patkos, D. Sexty, Zs. Szep

An increase in the size of coherent domains in the one component $Φ^4$ field theory under the influence of a uniformly changing external magnetic field near the critical end-point $T_Φ=T_c, h_Φ=0$ was proposed recently as an estimate also for the variation of the chiral correlation length of QCD near its respective hypothetical end point in the $T_{QCD}-μ_{Q

Deepak Jain, Abha Dev, N. Panchapakesan, S. Mahajan

Recent redshift-distance measurements of Type Ia supernovae (SNe Ia) at cosmological distances suggest that two-third of the energy density of the universe is dominated by dark energy component with an effective negative pressure. This dark energy component is described by the equation of state $p_{x} = w ρ_{x}$ $(w \geq -1)$. We use gravitational lensing st

Einar H. Gudmundsson, Gunnlaugur Bjornsson

We consider ever-expanding Big Bang models with a cosmological constant, $Λ$, and investigate in detail the evolution of the observable part of the universe. We also discuss quintessence models from the same point of view. A new concept, the $Λ$-sphere (or $Q$-sphere, in the case of quintessence) is introduced. This is the surface in our visible universe whi

H. Caps, N. Vandewalle

We have numerically studied a model of granular landscape eroded by wind. We show the appearance of labyrinthic patterns when the wind orientation turns by $90^\circ$. The occurence of such structures are discussed. Morever, we introduce the density $n_k$ of ``defects&#39;&#39; as the dynamic parameter governing the landscape evolution. A power law behavior

Ryutaroh Matsumoto, Tomohiko Uyematsu

We generalize the random coding argument of stabilizer codes and derive a lower bound on the quantum capacity of an arbitrary discrete memoryless quantum channel. For the depolarizing channel, our lower bound coincides with that obtained by Bennett et al. We also slightly improve the quantum Gilbert-Varshamov bound for general stabilizer codes, and establish

A. V. Anisovich, V. V. Anisovich, V. N. Markov, M. A. Matveev

A complete set of formulae in terms of the moment-operator expansion is presented for the two-meson, two-photon and fermion-antifermion states that can be used in the analysis of scalar (S) and pseudoscalar (P) meson production in anti-p p and gamma-gamma collisions: anti-p p -> SS, PP, SP and gamma gamma -> SS, PP, SP.

J. Ponce de Leon

We consider a version of Kaluza-Klein theory where the cylinder condition is not imposed. The metric is allowed to have explicit dependence on the &#34;extra&#34; coordinate(s). This is the usual scenario in brane-world and space-time-matter theories. We extend the usual discussion by considering five-dimensional metrics with off-diagonal terms. We replace t

V. Giovannetti, S. Lloyd, L. Maccone, F. N. C. Wong

The dispersion cancellation feature of pulses which are entangled in frequency is employed to synchronize clocks of distant parties. The proposed protocol is insensitive to the pulse distortion caused by transit through a dispersive medium. Since there is cancellation to all orders, also the effects of slowly fluctuating dispersive media are compensated. The

S. G. Schirmer, A. D. Greentree, V. Ramakrishna, H. Rabitz

Structured decompositions of a desired unitary operator are employed to derive control schemes that achieve certain control objectives for finite-level quantum systems using only sequences of simple control pulses such as square waves with finite rise and decay times or Gaussian wavepackets. The technique is applied to find control schemes that achieve popul

P. V. Panat, S. V. Lawande

We investigate the cooperative effects on optical forces in a system of N two level atoms occupying a volume of dimensions to within $λ^3$, where lambda is radiation wavelength and is driven by a coherent radiation field with a spatial profile like Laguerre-Gaussian beam or ideal Bessel beam.We show a dramatic enhancement on optical forces as well as the ang

M. Baranger, M. A. M. de Aguiar, F. Keck, H. J. Korsch

We present a complete derivation of the semiclassical limit of the coherent state propagator in one dimension, starting from path integrals in phase space. We show that the arbitrariness in the path integral representation, which follows from the overcompleteness of the coherent states, results in many different semiclassical limits. We explicitly derive two

V. P. Karassiov, A. A. Gusev, S. I. Vinitsky

We develop some calculation schemes to determine dynamics of a wide class of integrable quantum-optical models using their symmetry adapted reformulation in terms of polynomial Lie algebras $su_{pd}(2)$. These schemes, based on &#34;diagonal&#34; representations of model evolution operators (via diagonalizing Hamiltonians with the help of the $su_{pd}(2)$ de

Bob Coecke

We generalize the results of [B. Coecke, Helv. Phys. Acta 68, 396 (1995)] for the representation of coherent states of a spin-1 entity to spin-S entities with S>1 and to non-coherent spin states: through the introduction of &#39;hidden correlations&#39; (see quant-ph/0105093) we introduce a representation for a spin-S entity as a compound system consisting o

Grzegorz Lach, Krzysztof Pachucki

Nonrelativistically forbidden, single-photon transition rates between low lying states of the helium atom are rigorously derived within quantum electrodynamics theory. Equivalence of velocity and length gauges, including relativistic corrections is explicitly demonstrated. Numerical calculations of matrix elements are performed with the use of high precision

J. S. Pethkar, A. M. Selvam

The apparantly irregular (unpredictable) space-time fluctuations in atmospheric flows ranging from climate (thousands of kilometers - years) to turbulence (millimeters - seconds) exhibit the universal symmetry of self-similarity. Self-similarity or scale invariance implies long-range spatiotemporal correlations and is manifested in atmospheric flows as the f

Vladimir Korobov, Alexander Yelkhovsky

Ground state ionization potential of the He^4 atom is evaluated to be 5 945 204 221 (42) MHz. Along with lower order contributions, this result includes all effects of the relative orders alpha^4, alpha^3*m_e/m_alpha and alpha^5*ln^2(alpha).

B. M. Ovchinnikov, V. V. Parusov, Yu. B. Ovchinnikov

A shape of the signals in proportional chamber with preamplification gap and electron component extraction from proportional discharge has been investigated. It was shown for Penning mixtures that in proportional discharge besides the primary avalanches there is also the tail of secondary avalanches caused by metastable and nonmetastable Penning effects. For

Z. Papp, D. Caballero, C-. Y. Hu

Scattering and reaction cross sections of $e^{\pm}-Ps$ system are calculated for total angular momentum L=0, 1 and 2 and energies between the Ps(n=2)-Ps(n=3) threshold. We solved a set of Faddeev-Merkuriev and Lippmann-Schwinger integral equations by applying the Coulomb-Sturmian separable expansion technique. We found that the excited positronium states pla

A. Kievsky, S. Rosati, M. Viviani

Coulomb effects in the neutron-deuteron and proton-deuteron polarization-transfer coefficients $K_y^{y&#39;}$, $K_z^{x&#39;}$, $K_y^{x&#39;x&#39;-y&#39;y&#39;}$ and $K_y^{z&#39;z&#39;}$ are studied at energies above the deuteron breakup threshold. Theoretical predictions for these observables are evaluated in the framework of the Kohn Variational Principle u

A. A. Raduta, A. Escuderos, E. Moya de Guerra

A many body Hamiltonian comprising pairing, quadrupole-quadrupole and spin-spin interaction is treated within a projected spherical basis with the aim of describing the detailed structure of the magnetic states of orbital and spin-flip nature in $^{144, 148-154}$Sm. The mean field for the single particle motion takes care of the volume conservation of a phen

D. Bonatsos, C. Daskaloyannis, S. B. Drenska, N. Karoussos

The Delta I = 1 staggering (odd--even staggering) in octupole bands of light actinides is found to exhibit a ``beat&#39;&#39; behaviour as a function of the angular momentum I, forcing us to revise the traditional belief that this staggering decreases gradually to zero and then remains at this zero value. Various algebraic models (spf-Interacting Boson Model

Hartmut Schmieden

The extraction of the Coulomb quadrupole to magnetic dipole ratio from a p(e_pol,e&#39;p_pol)pi^0 measurement is discussed. Preliminary results from further asymmetry measurements with polarized and unpolarized electron beam indicate that the imaginary background is well under control in the MAID2000 parameterization, but not the real (Born-) amplitudes.

Andrey A. Sukhorukov, Yuri S. Kivshar

We overview the properties of nonlinear guided waves and (bright and dark) spatial optical solitons in a periodic medium created by a sequence of linear and nonlinear layers. First, we consider a single layer with a cubic nonlinear response (a nonlinear waveguide) embedded into a periodic layered linear medium, and describe nonlinear localized modes (guided

Rama Govindarajan, Victor S. L&#39;vov, Itamar Procaccia

Motivated by the large effect of turbulent drag reduction by minute concentrations of polymers we study the effects of minor viscosity contrasts on the stability of hydrodynamic flows. The key player is a localized region where the energy of fluctuations is produced by interactions with the mean flow (the &#34;critical layer&#34;). We show that a layer of we

B. Konopelchenko, L. Martinez Alonso

The quasi-classical limit of the scalar nonlocal dbar-problem is derived and a quasi-classical version of the dbar-dressing method is presented. Dispersionless KP, mKP and 2DTL hierarchies are discussed as illustrative examples. It is shown that the universal Whitham hierarchy it is nothing but the ring of symmetries for the quasi-classical dbar-problem. The

Akinori Nishino, Hideaki Ujino

Through an algebraic method using the Dunkl--Cherednik operators, the multivariable Hermite and Laguerre polynomials associated with the $A_{N-1}$- and $B_N$-Calogero models with bosonic, fermionic and distinguishable particles are investigated. The Rodrigues formulas of column type that algebraically generate the monic non-symmetric multivariable Hermite an

David M. J. Calderbank, Henrik Pedersen

It is well known that any 4-dimensional hyperkahler metric with two commuting Killing fields may be obtained explicitly, via the Gibbons-Hawking Ansatz, from a harmonic function invariant under a Killing field on R^3. In this paper, we find all selfdual Einstein metrics of nonzero scalar curvature with two commuting Killing fields. They are given explicitly

Chris Lomont

All binary plane curves of degree less than 7 are examined for curves with a large number of Fq rational points on their smooth model, for q = 2^m ; m = 3, 4,...,11. Previous results are improved, and many new curves are found meeting or close to Serre&#39;s, Lauter&#39;s, and Ihara&#39;s upper bounds.

David Goss

In math.NT/9907019 we proposed an analog of the classical Riemann hypothesis for characteristic p valued L-series based on the work of Wan, Diaz-Vargas, Thakur, Poonen, and Sheats for the zeta function $ζ_{\Fr[θ]}(s)$. During the writing of math.NT/9907019, we made two assumptions that have subsequently proved to be incorrect. The first assumption is that we

Charles Favre, Mattias Jonsson

Given a holomorphic selfmap f of the complex projective plane of algebraic degree at least 2, we give sufficient conditions on a positive closed (1,1) current S of unit mass under which the normalized pullbacks of S under iterates of f converge to the Green current T. In particular, we completely characterize the plane algebraic curves whose normalized pullb

N. Z. Iorgov

The tensor product of vector and arbitrary representations of the nonstandard q-deformation U&#39;_q(so(n)) of the universal enveloping algebra U(so(n)) of Lie algebra so(n) is defined. The Clebsch-Gordan coefficients of tensor product of vector and arbitrary classical or nonclassical type representations of q-algebra U&#39;_q(so(n)) are found in an explicit

Lee Rudolph

A closer look at an example introduced by Livingston & Melvin and later studied by Miyazaki shows that a plumbing of two fibered ribbon knots (along their fiber surfaces) may be algebraically slice yet not ribbon.

Florian Lengyel

We construct recursion categories from categories of coalgebras. Let $F$ be a nontrivial endofunctor on the category of sets that weakly preserves pullbacks and such that the category $\textbf{Set}_F$ of $F$-coalgebras is complete. The category $\textbf{Set}_F$ may be embedded in the category $\mathbf{Pfn}_F$ of $F$-coalgebras and partial morphisms, which is

Louis H. Kauffman

This paper is an exploration of relationships between the Jones polynomial and quantum computing. We discuss the structure of the Jones polynomial in relation to representations of the Temperley Lieb algebra, and give an example of a unitary representation of the braid group. We discuss the evaluation of the polynomial as a generalized quantum amplitude and

Michel Brion

We prove a conjecture of A. S. Buch concerning the structure constants of the Grothendieck ring of a flag variety with respect to its basis of Schubert structure sheaves. For this, we show that the coefficients in this basis of the structure sheaf of any subvariety with rational singularities, have alternating signs. Equivalently, the class of the dualizing

Lawrence Ein, Mircea Mustata

We prove that if Y is a hypersurface of degree d in P^n with isolated singularities, then the log canonical threshold of (P^n,Y) is at least min{n/d,1}. Moreover, if d is at least n+1, then we have equality if and only if Y is the projective cone over a (smooth) hypersurface in P^{n-1}. In the case when Y is a hyperplane section of a smooth hypersurface in P

Rainer Dick

This is an introductory review of gravity on branes with an emphasis on codimension 1 models. However, for a new result it is also pointed out that the cosmological evolution of the 3-brane in the model of Dvali, Gabadadze and Porrati may follow the standard Friedmann equation. Contents: 1. Introduction 2. Conventions 3. The Lanczos-Israel matching condition

F. Aceves de la Cruz, V. I. Tkach

Trace anomaly for conformally invariant higher derivative 4D scalar-dilaton theory is obtained by means of calculating divergent part of one-loop effective action for such system. Its applications are briefly mentioned

T. Hahn, C. Schappacher

We describe the implementation of the MSSM in the diagram generator FeynArts and the calculational tool FormCalc. This extension allows to perform loop calculations of MSSM processes almost fully automatically. The actual implementation has two aspects: The MSSM Feynman rules are specified in a new model file for FeynArts. The computation of the parameters i

Z. Fodor, S. D. Katz

We analyze the spectrum of the ultrahigh energy (above \approx 10^{9} GeV) cosmic rays. With a maximum likelihood analysis we show that the observed spectrum is consistent with the decay of extragalactic GUT scale particles. The predicted mass for these superheavy particles is m_X=10^b GeV, where b=14.6_{-1.7}^{+1.6}.

Z. Fodor, S. D. Katz

The clustering of ultrahigh energy (>10^{20} eV) cosmic rays (UHECR) suggests that they might be emitted by compact sources. Statistical analysis (Dubovsky et al., 2000) estimated the source density. We extend their analysis to give also the confidence intervals (CI) for the source density using a.) no assumptions on the relationship between clustered and un

K. N. Zyablyuk

2-point correlators of vector and axial currents, obtained from tau-decay data, are studied within the framework of perturbative QCD and Operator Product Expansion. Various sum rules, obtained from Borel transformation of the correlators in complex plane, are used to separate the contributions of different operators from each other. The analysis confirms the

F. Pisano, N. O. Reis

We describe one of the remarkable problems of theoretical physics persevering up to the beginning of the millennium. All gaugetheories with spontaneous gauge symmetry breaking from the standard model of particle physics with the electroweak symmetry breaking at the Fermi scale, 246 GeV, up to strings, supergravity, and the M(embrane)-theory superunification

Matej Pavsic

Having in mind that physical systems have different levels of structure we develop the concept of external, internal and total improper Lorentz transformation (space inversion and time reversal). A particle obtained from the ordinary one by the application of internal space inversion or time reversal is generally a different particle. From this point of view

Nguyen Van Hieu

In this series of lectures we present the functional integral method for studying the superconducting pairing of quarks with the formation of the diquarks as well as the quark-antiquark pairing in dense QCD. The dynamical equations for the superconducting order parameters are the nonlinear integral equations for the composite quantum fields describing the qu

Edi Halyo

We obtain brane inflation in configurations with Dp and D(p-2) branes which are far apart and almost perpendicular to each other. Chaotic brane inflation occurs when the branes can only rotate with the inflaton given by the angle between the branes. When the branes can also move hybrid brane inflation occurs where the inflaton is the distance between the bra

Hitoshi Yamamoto

We review the physics of CP violation in B decays. After introducing the CKM matrix and how it causes CP violation, we cover three types of CP violation that can occur in B decays: CP violation in mixing, CP violation by mixing-decay interference, and CP violation in decay.

Aleksey I. Alekseev

In the framework of analytic approach to QCD the nonperturbative contributions in running coupling of strong interaction up to 4-loop order are obtained in an explicit form. For all $Q>Λ$ they are shown to be represented in the form of an expansion in inverse powers of Euclidean momentum squared. The expansion coefficients are calculated for different number

H. -W. Hammer

Dispersion relations provide a powerful tool to describe the electromagnetic form factors of the nucleon both in the spacelike and timelike regions with constraints from unitarity and perturbative QCD. We give a brief introduction into dispersion theory for nucleon form factors and present results from a recent form factor analysis. Particular emphasis is gi

Z. Fodor, S. D. Katz, A. Ringwald

We consider the possibility that a large fraction of the ultrahigh energy cosmic rays are decay products of Z bosons which were produced in the scattering of ultrahigh energy cosmic neutrinos on cosmological relic neutrinos. We compare the observed ultrahigh energy cosmic ray spectrum with the one predicted in the above Z-burst scenario and determine the mas

Ian Balitsky

The small-x behavior of structure functions in the saturation region is determined by the non-linear generalization of the BFKL equation. I suggest the effective field theory for the small-x evolution which solves formally this equation. The result is the 2+1 functional integral for the structure functions at small x.

K. Golec-Biernat, M. Wusthoff

We construct diffractive parton distributions in the model of DIS diffraction in which the diffractive state is formed by the $q\bar{q}$ and $q\bar{q}g$ components. The interaction of such systems with the proton is described by the dipole cross section given by the saturation model. We find Regge factorization property with the measured at HERA depenedence

M. Grazzini

The main production channels of the Higgs boson at hadron colliders are briefly reviewed and recent developments in the calculation of QCD effects are discussed.

Adam P. Szczepaniak, Maciej Swat

We discuss two production mechanisms of the $J^{PC}=1^{-+}$ exotic meson, hadroproduction, using pion beams and photoproduction. We show that the ratio of exotic to non-exotic, in particular the $a_2$, meson production cross sections is expected to be by a factor of 5 to 10 larger, in photoproduction then in hadroproduction. Furthermore we show that the low-

Anton Rebhan

The real- and imaginary-time-formalisms of thermal field theory and their extension to gauge theories is reviewed. Questions of gauge (in-)dependence are discussed in detail, in particular the possible gauge dependences of the singularities of dressed propagators from which the quasiparticle spectrum is obtained. The existing results on next-to-leading order

A. L. Kataev, G. Parente, A. V. Sidorov

The new theoretical input to the analysis of the experimental data of the CCFR collaboration for $F_3$ structure function of $νN$ deep inelastic scattering is considered. This input comes from the next-to-next-to-leading order corrections to the anomalous dimensions of the Mellin moments of the $F_3$ structure function. The QCD scale $Λ_{\overline{MS}}^{(4)}

Frederic D. R. Bonnet, Derek B. Leinweber, Anthony G. Williams, James M. Zanotti

A systematic investigation of Symanzic improvement in the gauge field action is performed for the static quark potential in quenched QCD. We consider Symanzik improved gauge field configurations on a 16^3 X 32 lattice with a relatively coarse lattice spacing of 0.165(2)fm. A matched set of standard Wilson gauge configurations is prepared at β= 5.74 with the

Philipp Rufenacht

We present a method for constructing classically perfect anisotropic actions for SU(3) gauge theory based on a present isotropic Fixed Point Action. The action is parametrised using smeared (``fat&#39;&#39;) links. The construction is done explicitly for anisotropy $ξ=a_s/a_t=2,4$ and the renormalised anisotropies are determined using the torelon dispersion

N. Parashar, O. Bardon, R. Goodwin, S. Hansen

This paper presents a real-time application of the 16-bit fixed point Digital Signal Processors (DSPs), in the Muon System of the D0 detector located at the Fermilab Tevatron, presently the world&#39;s highest-energy hadron collider. As part of the Upgrade for a run beginning in the year 2000, the system is required to process data at an input event rate of

E. Tournefier

An update of the electroweak measurements at LEP and SLC is presented. These measurements are used to perform precise tests of the Standard Model. A constraint on the Standard Model Higgs mass is obtained when the direct measurements of $m_{top}$ and $M_W$ are included in the fit. A combination with the direct Higgs search is also shown.

G. J. Davies

The Standard Model Higgs boson was searched for at LEP, by the four collaborations in the year 2000, at centre-of-mass energies from 200-209GeV. An excess of events, potentially compatible with the production of a Higgs boson of mass ~115GeV was observed, largely in the four-jet channel. The search in this channel is discussed in this letter.

Jaime F. Villas da Rocha

A large class of Type II fluid solutions to Einstein field equations in N-dimensional spherical spacetimes is found, wich includes most of the known solutions. A family of the generalized collapsing Vaidya solutions with homothetic self-similarity, parametrized by a constant $λ$, is studied, and found that when $λ$ $>$ $λ_c(N)$, the collapse always forms bla

G. Tur, D. Hakkani-Tur, A. Stolcke, E. Shriberg

We present a probabilistic model that uses both prosodic and lexical cues for the automatic segmentation of speech into topically coherent units. We propose two methods for combining lexical and prosodic information using hidden Markov models and decision trees. Lexical information is obtained from a speech recognizer, and prosodic features are extracted aut

P. Miranovic, V. G. Kogan

Vortex lattice (VL) elastic response is analyzed within nonlocal London model. The squash modulus turns zero at the field $H_{\Box}$ where VL undergoes square-to-rhombus structural transition. In the field region $H>H_{\Box}$ where the square VL is stable, the rotation modulus turns zero at a field $H_r$ indicating instability of the square VL with respect t

M. P. Sarachik

For five different electron and hole systems in two dimensions (Si MOSFET&#39;s, p-GaAs, p-SiGe, n-GaAs and n-AlAs), the critical density, $n_c$ that marks the onset of strong localization is shown to be a single power-law function of the scattering rate $1/τ$ deduced from the maximum mobility. The resulting curve defines the boundary separating a localized

V. M. Silkin, E. V. Chulkov, P. M. Echenique

We present a self-consistent pseudopotential calculation of surface and image-potential states on $MgB_2(0001)$ for both $B$-terminated ($B-t$) and $Mg$-terminated ($Mg-t$) surfaces. We find a variety of very clear surface and subsurface states as well as resonance image-potential states n=1,2 on both surfaces. The surface layer DOS at $E_F$ is increased by

Rashmi Ray, B. Sakita

In this article, we shall focus on the collective dynamics of the fermions in a $ν= 1$ quantum Hall droplet. Specifically, we propose to look at the quantum Hall ferromagnet. In this system, the electron spins are ordered in the ground state due to the exchange part of the Coulomb interaction and the Pauli exclusion principle. The low energy excitations are

Peter Johansson

We develop a theory for light scattering from a disordered layer of metal nanoparticles resting on a sample. Averaging over different disorder realizations is done by a coherent potential approximation. The calculational scheme takes into account effects of retardation, multipole excitations, and interactions with the sample. We apply the theory to a system

Julia S. Meyer, Alexander Altland, B. L. Altshuler

We analyze the magnetoconductance of two-dimensional electron and hole gases (2DEGs) subject to a parallel magnetic field. It is shown that, for confining potential wells which are symmetric with respect to spatial inversion, a temperature-dependent weak localization signal exists even in the presence of a magnetic field. Deviations from this symmetry lead t

B. P. Dolan, C. P. Burgess

We derive the implications of particle-vortex duality for the electromagnetic response of Quantum Hall systems beyond the linear-response regime. This provides a first theoretical explanation of the remarkable duality which has been observed in the nonlinear regime for the electromagnetic response of Quantum Hall systems.

Yogesh N. Joglekar, Allan H. MacDonald

We present a microscopic theory of zero-temperature order parameter and pseudospin stiffness reduction due to quantum fluctuations in the ground state of double-layer quantum Hall ferromagnets. Collective excitations in this systems are properly described only when interactions in both direct and exchange particle-hole channels are included. We employ a func

M. Ausloos, K. Ivanova

The British Pound (GBP) is not part of the Euro (EUR) monetary system. In order to find out arguments on whether GBP should join the EUR or not correlations are calculated between GBP and EUR, including a reconstructed EUR for the time interval from 1993 till June 30, 2000. The distribution of fluctuations of the exchange rates is Gaussian for the central pa

P. Markos, C. M. Soukoulis

Left-handed materials are studied numerically using an improved version of the transfer-matrix method. The transmission, reflection, the phase of the reflection and the absorption are calculated and compared with experiments for both single split-ring resonators (SRR) with negative permeability and left-handed materials (LHMs) which have both the permittivit

Jerome Houdayer, Olivier C. Martin

We describe a numerical algorithm for computing spin glass ground states with a high level of reliability. The method uses a population based search and applies optimization on multiple scales. Benchmarks are given leading to estimates of the performance on large lattices.

Indranil Rudra, S. Ramasesha

We have studied the time evolution of magnetization of a high spin magnetic cluster in the ground state, in the presence of a sinusoidal axial magnetic field and a static transverse field by explicitly solving time dependent schrödinger equation. We observe oscillations of magnetization in the plateau region which has all the characteristics reminiscent of t

W. Hwang, S. Redner

We study the dissolution of a solid by continuous injection of reactive ``acid&#39;&#39; particles at a single point, with the reactive particles undergoing biased diffusion in the dissolved region. When acid encounters the substrate material, both an acid particle and a unit of the material disappear. We find that the lengths of the dissolved cavity paralle

A. Crépieux, J. Wunderlich, V. K. Dugaev, P. Bruno

In this paper, we report results on the anomalous Hall effect. First, we summarize analytical calculations based on the Kubo formalism : explicit expressions for both skew-scattering and side-jump are derived and weak-localization corrections are discussed. Next, we present numerical calculations of the anomalous Hall resistivity based on the Dirac equation.

M. A. Hein, P. J. Hirst, R. G. Humphreys, D. E. Oates

We have investigated the anomalous nonlinear microwave response of epitaxial electron-beam coevaporated YBa2Cu3O7-x films on MgO. The power and temperature dependent surface impedance and two-tone intermodulation distortion were measured in stripline resonators at several frequencies between 2.3 and 11.2 GHz and at temperatures between 1.7 K and Tc. All of t

Cheng-Ming Bai, Mo-lin Ge, Kang Xue

We find operators distinguishing the degenerate states for the Hamiltonian $H= x(K+{1/2})S_z +{\bf K}\cdot {\bf S}$ at $x=\pm 1$ that was given by Happer et al$^{[1,2]}$ to interpret the curious degeneracies of the Zeeman effect for condensed vapor of $^{87}$Rb. The operators obey Yangian commutation relations. We show that the curious degeneracies seem to v