August 2002 arXiv papers — page 8

Marc S. Seigar, Andy J. Adamson, Nicholas P. Rees, Timothy G. Hawarden

From 1991 until 1997, the 3.8m UK Infrared Telescope (UKIRT) underwent a programme of upgrades aimed at improving its intrinsic optical performance. This resulted in images with a FWHM of 0."17 at 2.2 um in September 1998. To understand and maintain the improvements to the delivered image quality since the completion of the upgrades programme, we have re

Mayumi Aoki, Kaoru Hagiwara, Naotoshi Okamura

We study the sensitivity of a long-base-line (LBL) experiment with neutrino beams from the High Intensity Proton Accelerator (HIPA), that delivers 10^{21} POT per year, and a proposed 1Mt water-Cherenkov detector, Hyper-Kamiokande (HK) 295km away from the HIPA, to the CP phase (delta_{M N S}) of the three-flavor lepton mixing matrix. We examine a combination

Jose P. Palao, Ronnie Kosloff

A quantum gate is realized by specific unitary transformations operating on states representing qubits. Considering a quantum system employed as an element in a quantum computing scheme, the task is therefore to enforce the pre-specified unitary transformation. This task is carried out by an external time dependent field. Optimal control theory has been sugg

R. M. Jones, V. Dolgashev, K. L. F. Bane, E. Lin

In the NLC project multiple bunches of electrons and positrons will be accelerated initially to a centre of mass of 500 GeV and later to 1 TeV or more. In the process of accelerating 192 bunches within a pulse train, wakefields are excited which kick the trailing bunches off axis and can cause luminosity dilution and BBU (Beam Break Up). Several structures t

S. J. Dilworth, Vladimir G. Troitsky

It is shown that every component of the spectrum of a weakly hypercyclic operator meets the unit circle. The proof is based on the lemma that a sequence of vectors in a Banach space whose norms grow at geometrical rate doesn't have zero in its weak closure.

N. Brodsky, A. Chigogidze, E. V. Shchepin

It was proved by H. Whitney in 1933 that it is possible to mark a point in all curves in a continuous way. The main result of this paper extends the Whitney theorem to dimensions 2 and 3. Namely, we prove that it is possible to choose a point continuously in all two-dimensional surfaces sufficiently close to a given surface, and in all 3-manifolds sufficient

L. Bonora, C. P. Constantinidis, L. A. Ferreira, E. E. Leite

We give the exact construction of Riemannian (or stringy) instantons, which are classical solutions of 2d Yang-Mills theories that interpolate between initial and final string configurations. They satisfy the Hitchin equations with special boundary conditions. For the case of U(2) gauge group those equations can be written as the sinh-Gordon equation with a

K. Hornbostel, G. P. Lepage, C. Morningstar

We present a general procedure for incorporating higher-order information into the scale-setting prescription of Brodsky, Lepage and Mackenzie. In particular, we show how to apply this prescription when the leading coefficient or coefficients in a series in the strong coupling alpha_s are anomalously small and the original prescription can give an unphysical

A. D. Dolgov

The lectures describe several cosmological effects produced by neutrinos. Upper and lower cosmological limits on neutrino mass are derived. The role that neutrinos may play in formation of large scale structure of the universe is described and neutrino mass limits are presented. Effects of neutrinos on cosmological background radiation and on big bang nucleo

D. Asner, B. Grzadkowski, J. F. Gunion, H. E. Logan

We present new results from studies in progress on physics at a two-photon collider. We report on the sensitivity to top squark parameters of MSSM Higgs boson production in two-photon collisions; Higgs boson decay to two photons; radion production in models of warped extra dimensions; chargino pair production; sensitivity to the trilinear Higgs boson couplin

Maria Krawczyk

We discuss the implications of the recent evaluations of the SM contribution to a_mu=(g-2)_mu/2 in the light of the latest E821 measurement, which indicate \~ 3 sigma deviation. We derive the 95 % CL interval, delta a_mu, to be used to constrain any additional contribution to a_mu, beyond the SM ones; it has to have a positive sign. We apply the delta a_mu t

R. S. Raghavan

A natural nuclear fission reactor with a power output of 3- 10 terawatt at the center of the earth has been proposed as the energy source of the earth's magnetic field. The proposal can be directly tested by a massive liquid scintillation detector that can detect the signature spectrum of antineutrinos from the geo-reactor as well as the direction of the

Andrew Allison, Derek Abbott

Several authors have implied that the original inspiration for Parrondo's games was a physical system called a ``flashing Brownian ratchet''. The relationship seems to be intuitively clear but, surprisingly, has not yet been established with rigor. In this paper, we apply standard finite-difference methods of numerical analysis to the Fokker-Plan

S. Peysson, P. Degiovanni, B. Douçot, R. Mélin

We derive non equilibrium statistical ensembles for a ballistic Aharonov-Bohm loop connected to several electrodes connected to reservoirs with different chemical potentials. A striking consequence of these non trivial ensembles is the emergence of quantum zero point fluctuations of the persistent current around the loop. Detailed predictions for the low fre

M. V. Indenbom, E. H. Brandt, C. J. van der Beek, M. Konczykowski

Magneto-optical observations of a second flux front, which occurs at the second peak in the magnetization of Bi_2 Sr_2 CaCu_2 O_x single crystals related to the known first order ``vortex-lattice melting'', are reconsidered. We show that, in thin samples, electrodynamics necessarily leads to an extended region in which the magnetic induction adopts a

K. Yamaura, Q. Huang, D. P. Young, Y. Noguchi

The bilayered rhodium oxide Sr3Rh2O7 was synthesized by high-pressure and high-temperature heating techniques. The single-phase polycrystalline sample of Sr3Rh2O7 was characterized by measurements of magnetic susceptibility, electrical resistivity, specific heat, and thermopower. The structural characteristics were investigated by powder neutron diffraction

M. A. T. Groenewegen

The current status of carbon stars in the Local Group and beyond, is discussed. Although many carbon stars and late M-stars have been identified in Local Group galaxies, a coherent understanding in terms of the chemical evolution- and star formation history of a galaxy is still largely lacking. Although a few major new surveys have been carried out over the

Jonathan Mackey, Volker Bromm, Lars Hernquist

We investigate the impact of an early population of massive stars on their surroundings. Dissociation of molecular hydrogen by strong UV emission from such stars is expected to produce a global transition in the cooling mechanism of minihalos at a redshift of approximately 30, strongly inhibiting star formation until more massive halos can collapse. Furtherm

Bae-Yeun Ha, D. Thirumalai

We study the bending rigidity of highly charged stiff polyelectrolytes, for both a single chain and many chains forming a bundle. A theory is developed to account for the interplay between competitive binding of counterions and charge correlations in softening the polyelectrolyte (PE) chains. The presence of even a small concentration of multivalent counteri

Jonathan Arons

I show that the relativistic winds of newly born magnetars with khz initial spin rates, occurring in all normal galaxies, can accelerate ultrarelativistic light ions with an E^{-1} injection spectrum, steepening to E^{-2} at higher energies, with an upper cutoff above 10^{21} eV. Interactions with the CMB yield a spectrum in good accord with the observed spe

M. B. Gay Ducati, W. K. Sauter

The meson (pion and kaon) form factor is calculated in the perturbative framework with alternative forms for the running coupling constant and the gluon propagator in the infrared kinematic region. These modified forms are employed to test the sensibility of the meson form factor to the nonperturbative contributions. Its is a powerful discriminating quantity

Kenichi Torikoshi, Paul J. Ellis

We study pion--nucleon scattering with a chiral lagrangian of pions, nucleons, and $Δ$-isobars to order $Q^3$, where $Q$ is a generic small momentum. We compare the results from heavy baryon chiral perturbation theory with those from the infrared regularization scheme. While the former provides a reasonable fit to the data out to a pion c.m. kinetic energy o

A. V. Kotikov, L. N. Lipatov

We derive the DGLAP and BFKL evolution equations in the N=4 supersymmetric gauge theory in the next-to-leading approximation. The eigenvalue of the BFKL kernel in this model turns out to be an analytic function of the conformal spin |n|. Its analytic continuation to negative |n| in the leading logarithmic approximation allows us to obtain residues of anomalo

L. M. Sehgal, J. van Leusen

The decay (B^0)bar -> pi^+ pi^- gamma has a bremsstrahlung component determined by the amplitude for (B^0)bar -> pi^+ pi^-, as well as a direct component determined by the penguin interaction V_tb V^*_td c_7 O_7. Interference of these amplitudes produces a photon energy spectrum d Gamma/d x = a/x + b + c_1 x + c_2 x^2 + ... (x = 2 E_gamma/m_B) where the term

A. Bytsko, J. Teschner

A certain class of unitary representations of U_q(sl(2,R)) has the property of being simultanenously a representation of U_{tilde{q}}(sl(2,R)) for a particular choice of tilde{q}(q). Faddeev has proposed to unify the quantum groups U_q(sl(2,R)) and U_{tilde{q}}(sl(2,R)) into some enlarged object for which he has coined the name ``modular double''. We

A. Sandoval-Villalbazo, L. S. Garcia-Colin

Analytical expressions for the non-relativistic and relativistic Sunyaev-Zel'dovich effect (SZE) are derived by means of suitable convolution integrals. The establishment of these expressions is based on the fact that the SZE disturbed spectrum, at high frequencies, possesses the form of a Laplace transform of the single line distortion profile (structur

Jonathan Granot, Paul L. Schechter, Joachim Wambsganss

When a gravitationally lensed source crosses a caustic, a pair of images is created or destroyed. We calculate the mean number of such pairs of micro-images $<n>$ for a given macro-image of a gravitationally lensed point source, due to microlensing by the stars of the lensing galaxy. This quantity was calculated by Wambsganss, Witt & Schneider (1992) for the

F. E. Close, H. J. Lipkin

We identify two Cabibbo suppressed $D^+$ decay modes with anomalously high branching ratios which are not simply explained by any model. All standard model diagrams that can contribute to these decays are related by symmetries to diagrams for other decays that do not show any such enhancement. If these high branching ratios are confirmed by more precise expe

Shwetabh Singh, Chung-Pei Ma

We develop a method based on the collisionless Boltzmann equation to calculate the gravitational clustering of relic neutrinos in realistic cosmological models dominated by cold dark matter (CDM) and the cosmological constant. This method can be used to estimate the phase-space distribution of any light particles in CDM halos. We find that neutrinos with mas

R. Mulet, A. Pagnani, M. Weigt, R. Zecchina

We study the graph coloring problem over random graphs of finite average connectivity $c$. Given a number $q$ of available colors, we find that graphs with low connectivity admit almost always a proper coloring whereas graphs with high connectivity are uncolorable. Depending on $q$, we find the precise value of the critical average connectivity $c_q$. Moreov

Jeremy L. England, Eugene I. Shakhnovich

Here we present an approximate analytical theory for the relationship between a protein structure&#39;s contact matrix and the shape of its energy spectrum in amino acid sequence space. We demonstrate a dependence of the number of sequences of low energy in a structure on the eigenvalues of the structure&#39;s contact matrix, and then use a Monte Carlo simul

ZEUS Collaboration

Cross sections for e^-p neutral current deep inelastic scattering have been measured at a centre-of-mass energy of 318 GeV using an integrated luminosity of 15.9 pb^-1 collected with the ZEUS detector at HERA. Results on the double-differential cross-section d^2s/dxdQ^2 in the range 185 < Q^2 < 50000 GeV^2 and 0.0037 < x < 0.75, as well as the single-differe

Eddy Yusuf, Kun Yang

Low temperature properties of antiferromagnetic two-leg spin-1/2 ladders with bond randomness and site dilution (or doping with nonmagnetic impurities) are studied using the real-space renormalization-group technique. We find that for non zero doping concentrations the systems are driven into a phase dominated by large effective spins, i.e. the Large Spin ph

A. J. Barr, B. C. Allanach, C. G. Lester, M. A. Parker

The discovery potential of the LHC is investigated for the minimal anomaly-mediated supersymmetry breaking (mAMSB) scenario, using the ATLAS fast detector simulator, including track reconstruction and particle identification. Generic supersymmetry search cuts are used to map the 5-sigma (and >=10 event) discovery contours in the m_0 - m_3/2 plane. With 100 i

B. Schlittgen, T. Wettig

We present the color-flavor transformation for gauge group SU(N_c) and discuss its application to lattice QCD.

M. van Leeuwen

The energy dependence of hadron production in central Pb+Pb collisions is presented and discussed. In particular, midrapidity $m_T$-spectra for $π^-$, $K^-$, $K^+$, $p$, $\bar{p}$, $d$, $ϕ$, $Λ$ and $\barΛ$ at 40, 80 and 158 $A$GeV are shown. In addition $Ξ$ and $Ω$ spectra are available at 158 $A$GeV. The spectra allow to determine the thermal freeze-out te

Ian Smail, F. N. Owen, G. E. Morrison, W. C. Keel

We present a multi-wavelength study of Extremely Red Objects (EROs) employing deep RIzJHK photometry of a 8.5&#39;x8.5&#39; region to identify 68 EROs with R-K>5.3 and K<20.5 (5-sigma). This is combined with an extremely deep 1.4-GHz radio map (sigma=3.5uJy), sensitive enough to detect an active galaxy with L_1.4>10^23 W/Hz at z>1 or a SFR of >25Mo/yr. We de

Axel Pelster, Hagen Kleinert, Michael Schanz

We develop a convergent variational perturbation theory for the frequency of time-periodic solutions of nonlinear dynamical systems. The power of the theory is illustrated by applying it to the Duffing oscillator.

Hiroshi Umetsu, Naoto Yokoi

We investigate the quantum aspects of three-dimensional gravity with a positive cosmological constant. The reduced phase space of the three-dimensional de Sitter gravity is obtained as the space which consists of the Kerr-de Sitter space-times and their Virasoro deformations. A quantization of the phase space is carried out by the geometric quantization of t

Andrew E. Chubykalo, Augusto Espinoza, B. P. Kosyakov

If the conventional Maxwell--Lorentz formulation of classical electrodynamics is adopted in a flat spacetime of arbitrary odd dimension, then the retarded vector potential $A^μ$ generated by a point charge turns out to be pure gauge, $A^μ=\partial^μχ$. By Gauss&#39; law, the charge shows up as zero. The classical electromagnetic coupling is thus missing from

Tobias H. Colding, W. P. Minicozzi, II

What are the possible shapes of various things and why? For instance, when a closed wire or a frame is dipped into a soap solution and is raised up from the solution, the surface spanning the wire is a soap film. What are the possible shapes of soap films and why? Or, for instance, why is DNA like a double spiral staircase? ``What..?&#39;&#39; and ``why..?&#

Tom Theuns, Matteo Viel, Scott Kay, Joop Schaye

We have performed hydrodynamical simulations to investigate the effects of galactic winds on the high-redshift (z=3) universe. Strong winds suppress the formation of low-mass galaxies significantly, and the metals carried by them produce C IV absorption lines with properties in reasonable agreement with observations. The winds have little effect on the stati

J. Maalampi, V. Sipilainen, I. Vilja

We investigate a particle physics model in a six-dimensional spacetime, where two extra dimensions form a torus. Particles with Standard Model charges are confined by interactions with a scalar field to four four-dimensional branes, two vortices accommodating ordinary type fermions and two antivortices accommodating mirror fermions. We investigate the phenom

Najmuddin Fakhruddin

We show that two smooth projective curves C_1 and C_2 of genus g which have isomorphic symmetric products are isomorphic unless g=2. This extends a theorem of Martens.

Marcela Carena, Howard E. Haber

Precision electroweak data presently favors a weakly-coupled Higgs sector as the mechanism responsible for electroweak symmetry breaking. Low-energy supersymmetry provides a natural framework for weakly-coupled elementary scalars. In this review, we summarize the theoretical properties of the Standard Model (SM) Higgs boson and the Higgs sector of the minima

Caspar P. Heidbrink, Götz S. Uhrig

A renormalization scheme for interacting fermionic systems is presented where the renormalization is carried out in terms of the fermionic degrees of freedom. The scheme is based on continuous unitary transformations of the hamiltonian which stays hermitian throughout the renormalization flow, whereby any frequency dependence is avoided. The approach is illu

R. G. Unanyan, M. Fleischhauer

We discuss the creation of many-particle entanglement in an ion trap where all ions are simultaneously coupled to bichromatic laser fields. It is shown that in a time-averaged, coarse-grained picture the system can be mapped onto a spin ensemble with controllable collective interactions. An adiabatic change of laser parameters allows a transfer from separabl

Arthur Lue

We detail the global structure of the five-dimensional bulk for the cosmological evolution of Dvali-Gabadadze-Porrati braneworlds. The picture articulated here provides a framework and intuition for understanding how metric perturbations leave (and possibly reenter) the brane universe. A bulk observer sees the braneworld as a relativistically expanding bubbl

K. A. Oganessyan, L. S. Asilyan, M. Anselmino, E. De Sanctis

We consider the cos(phi) dependence of the longitudinal double-spin asymmetry for charged pion electroproduction in semi-inclusive deep inelastic scattering, emphasizing intrinsic transverse momentum effects. This azimuthal asymmetry allows to measure the cos(phi) moments of the unpolarized and double-spin cross-section, simultaneously. The size of the asymm

Haiqing Wei, Xin Xue

Optical modes with different orbital angular momentums (OAMs) per photon may be sorted by Mach-Zehnder interferometers incorporated with beam rotators, without resorting to OAM mode converters.

Vladimir L. Ermakov, B. M. Fung

A continuous, analog version of the Grover algorithm is realized using NMR. The system studied is 23Na in a liquid crystal medium. The presence of quadrupolar coupling makes the spin I=3/2 nucleus a 2-qubit system. Applying a specially designed pulse sequence, the time evolution of the spin density operator is described in an interaction representation which

J. J. Garcia-Ripoll, J. I. Cirac

We show how it is possible to realize quantum computations on a system in which most of the parameters are practically unknown. We illustrate our results with a novel implementation of a quantum computer by means of bosonic atoms in an optical lattice. In particular we show how a universal set of gates can be carried out even if the number of atoms per site

Alec Maassen van den Brink, A. M. Zagoskin

The density-matrix and Heisenberg formulations of quantum mechanics follow--for unitary evolution--directy from the Schr&#34;odinger equation. Nevertheless, the symmetries of the corresponding evolution operator, the Liouvillian L=i[.,H], need not be limited to those of the Hamiltonian H. This is due to L only involving eigenenergy_differences_, which can be

Ching-Chuan Su

Based on the local-ether wave equation for free particle, the dispersion of matter wave is examined. From the dispersion relation, the angular frequency and wavelength of matter wave are derived. These formulas look like the postulates of de Broglie in conjunction with the Lorentz mass-variation law. However, the fundamental difference is that for terrestria

Ching-Chuan Su

By taking both the Doppler frequency shift for electromagnetic wave and the quantum energy variation of matter wave into consideration, a resonant-absorption condition based on the local-ether wave equation is presented to account for a variety of phenomena consistently, including the Ives-Stilwell experiment, the output frequency from ammonia masers, and th

Ching-Chuan Su

Recently, we have presented a local-ether wave equation incorporating a nature frequency and the electric scalar potential, from which the speed-dependences in the angular frequency and wavelength of matter wave, in the mass of particle, and in the energy of quantum states are derived. These relations look like the postulates of de Broglie and the Lorentz ma

Ching-Chuan Su

Recently, we have presented the local-ether model, whereby the propagation of earthbound waves is supposed to be referred uniquely to a geostationary inertial frame. Further, in order to comply with this propagation model, the modified Lorentz force law is developed. Thereby, the corresponding wave equations of potentials and fields are derived in this inves

S. Bellucci, V. M. Biryukov, Yu. A. Chesnokov, V. Guidi

We present simulations of particle beam channeling in carbon nanotubes and evaluate the possibilities for experimental observation of channeling effect in straight and bent nanotubes at IHEP and LNF. Different particle species are considered: protons of 1.3 and 70 GeV, and positrons of 0.5 GeV. Predictions are made for the experiments, with analysis of requi

A. V. Avdeenkov, J. L. Bohn

We predict that pairs of polar molecules can be weakly bound together in an ultracold environment, provided that a dc electric field is present. The field that links the molecules together also strongly influences the basic properties of the resulting dimer, such as its binding energy and predissociation lifetime. Because of their long-range character these

Stepan G. Mashnik, Arnold J. Sierk, Konstantin K. Gudima

A brief description of our improvements and refinements that led from the CEM95 version of the Cascade-Exciton Model (CEM) code to CEM97 and to CEM2k is given. The increased accuracy and predictive power of the code CEM2k are shown by several examples. To describe fission and light-fragment (heavier than 4He) production, the CEM2k code has been merged with t

Jens Bolte, Rainer Glaser, Stefan Keppeler

We point out that a certain kind of combined classical translational and spin dynamics -- claimed in [M. Pletyukhov, et al. Phys. Rev. Lett. 89 (2002) 116601] to arise from the Pauli equation in the semiclassical limit $\hbar\to0$ for fixed spin -- only shows up if one simultaneously considers the high spin limit $S\to\infty$.

Ph. Jacquod, I. Adagideli, C. W. J. Beenakker

Quantum states extended over a large volume in phase space have oscillations from quantum interferences in their Wigner distribution on scales smaller than $\hbar$ [W.H. Zurek, Nature {\bf 412}, 712 (2001)]. We investigate the influence of those sub-Planck scale structures on the sensitivity to an external perturbation of the state&#39;s time evolution. Whil

Bin Zhou, Han-Ying Guo, Ke Wu

In this letter, we present the general form of equations that generate a volume-preserving flow on a symplectic manifold (M, ω). It is shown that every volume-preserving flow has some 2-forms acting the role of the Hamiltonian functions in the Hamiltonian mechanics and the ordinary Hamilton equations are included as a special case with a 2-form \frac{1}{n-1}

Tim Hoffmann, Nadja Kutz

In this paper we investigate flows on discrete curves in $\C^2$, $\CP^1$, and $\C$. A novel interpretation of the one dimensional Toda lattice hierarchy and reductions thereof as flows on discrete curves will be given.

Ilya Kapovich

We observe that the results of Feighn-Handel and Geoghegan-Mihalik-Sapir-Wise about coherence and Hopficity of mapping tori of injective endomorphisms of free groups extend to non-injective endomorphisms.

Davide L. Ferrario

We show the existence of some infinite families of periodic solutions of the planar Newtonian n-body problem --with positive masses-- which are symmetric with respect to suitable actions of finite groups (under a strong--force assumption, or just numerically). The method is by minimizing a discretization of the action functional under symmetry constraints.

Hans-Joachim Baues, Davide L. Ferrario

We study fibred spaces with fibres in a structure category $\V$ and we show that cellular approximation, Blakers--Massey theorem, Whitehead theorems, obstruction theory, Hurewicz homomorphism, Wall finiteness obstruction, and Whitehead torsion theorem hold for fibred spaces. For this we introduce the cohomology of fibred spaces.

Hans-Joachim Baues, Davide L. Ferrario

We show that the Atiyah-Hirzebruch K-theory of spaces admits a canonical generalization for stratified spaces. For this we study algebraic constructions on stratified vector bundles. In particular the tangent bundle of a stratified manifold is such a stratified vector bundle.

Aarno Hohti

This paper presents mathematics as a general science of computation in a way different from the tradition. It is based on the radical philosophical standpoint according to which the content, meaning and justification of experience lies in its precise formulation. The requirement on precise, formal content discloses the relational structure of (mathematical)

Jan Snellman

We study a certain truncation of the ring of arithmetical functions with unitary convolution, consisting of functions vanishing on arguments >n. The truncations are artinian monomial quotients of a polynomial ring in finitely many indeterminates, and are isomorphic to the ``artinified&#39;&#39; Stanley-Reisner rings of certain simplicial complexes.

Aarno Hohti, Miroslav Husek, Jan Pelant

We prove that the countable product of supercomplete spaces having a countable closed cover consisting of partition-complete subspaces is supercomplete with respect to its metric-fine coreflection. Thus, countable products of sigma-partition-complete paracompact spaces are again paracompact. On the other hand, we show that in arbitrary products of partition-

Najmuddin Fakhruddin

We show that given a smooth projective variety X over C with dim(X) > 2, an ample line bundle O(1) on X and an integer n > 1, any n distinct points on a generic hypersurface of degree d in X are linearly independent in CH_0(X) if d >> 0. This generalizes a result of C. Voisin.

Najmuddin Fakhruddin

Let X be a smooth projective toric surface and L and M two line bundles on X. If L is ample and M is generated by global sections, then we show that the natural map from H^0(X,L) tensor H^0(X,M) to H^0(X, L tensor M) is surjective. We also consider a generalization to the case when M is an arbitrary line bundle with h^0(X,M) > 0.

Xiaoping Xu

Novikov algebras are algebras whose associators are left-symmetric and right multiplication operators are mutually commutative. A Gel&#39;fand-Dorfman bialgebra is a vector space with a Lie algebra structure and a Novikov algebra structure, satisfying a certain compatibility condition. Such a bialgebraic structure corresponds to a certain Hamiltonian pairs i

Miriam Abdon, Fernando Torres

We show that a F_{q^2}-maximal curve of genus q(q-3)/6 in characteristic three is either a non-reflexive space curve of degree q+1, or it is uniquely determined up to F_{q^2}-isomorphism by a plane model of Artin-Schreier type

Stefan Schraml

Gauge theories on q-deformed spaces are constructed using covariant derivatives. For this purpose a ``vielbein&#39;&#39; is introduced, which transforms under gauge transformations. The non-Abelian case is treated by establishing a connection to gauge theories on commutative spaces, i.e. by a Seiberg-Witten map. As an example we consider the Manin plane. Rem

J. C. Brunelli, A. Constandache, Ashok Das

We propose a Lax equation for the non-linear sigma model which leads directly to the conserved local charges of the system. We show that the system has two infinite sets of such conserved charges following from the Lax equation, much like dispersionless systems. We show that the system has two Hamiltonian structures which are compatible so that it is truly a

G. G. Ross, L. Velasco-Sevilla

We discuss whether quark, charged lepton and neutrino masses and mixing angles may be related by an extended flavour and family symmetry group. We show that current measurements of all fermion masses and mixing angles are consistent with a combination of an underlying SU(3) family symmetry together with a GUT symmetry such as SO(10). In this the near bi-maxi

J. -M. Laget

A consistent description of exclusive photoproduction of mesons at high momentum transfer t relies on a few effective degrees of freedom which can be checked against Lattice calculation or more effective models of QCD.

Stefan Berge, Michael Klasen

We study the potential of high-energy linear $e^+e^-$ colliders for the production of gluino pairs within the Minimal Supersymmetric Standard Model (MSSM). In this model, the process $e^+e^-\to\tilde{g}\tilde{g}$ is mediated by quark/squark loops, dominantly of the third generation, where the mixing of left- and right-handed states can become large. Taking i

Wojciech Krolikowski

In the simple model of neutrino texture presented in this paper, the Majorana left-handed mass matrix is zero, the Majorana righthanded mass matrix - diagonal and degenerate, and the Dirac mass matrix has a hierarchical structure, deformed unitarily by nearly bimaximal mixing. In the case, when the Majorana righthanded term dominates over the Dirac term, the

K. A. Oganessyan, P. J. Mulders, E. De Sanctis, L. S. Asilyan

We discuss the contributions of the transverse spin component of the target to the double-spin asymmetries in semi-inclusive deep inelastic scattering of longitudinally polarized electrons off longitudinally polarized protons.

David B. Kaplan

A method is proposed for latticizing a class of supersymmetric gauge theories, including N=4 super Yang-Mills. The technique is inspired by recent work on ``deconstruction&#39;&#39;. Part of the target theory&#39;s supersymmetry is realized exactly on the lattice, reducing or eliminating the need for fine tuning. (Talk based on the paper &#34;Supersymmetry o

Terrence Draper, Shao-Jing Dong, Ivan Horvath, Frank Lee

We study the quenched chiral behavior of the pion with mass as low as $\approx 180$ MeV. The calculation is done on a quenched lattice of size $16^3\times 28$ and $a = 0.2$ fm with 80 configurations using overlap fermions and an improved gauge action. Using an improved constrained curve fitting technique, we find that the ground state pseudoscalar mass versu

Noriyoshi Ishii, Hideo Suganuma, Hideo Matsufuru

We use SU(3) anisotropic lattice QCD at quenched level to study the 0++ glueball correlator at various temperature taking into account the possible existence of the thermal width in the ground-state peak. For this purpose, we adopt the Breit-Wigner ansatz for the appropriate fit-function for the lattice data obtained with 5,500-9,900 gauge configurations at

Ignacio Bediaga

We present recent results on scalar light mesons based on Dalitz plot analyses of charm decays from Fermilab experiment E791. Scalar mesons are found to have large contributions to the decays studied, $D^+\to K^-π^+π^+$ and $D^+, D_s^+\toπ^-π^+π^+$. From the first decay, we find good evidence for the existence of the light and broad $κ$ meson and we measure

S. V. Sushkov, S. -W. Kim

We study the problem of existence of static spherically symmetric wormholes supported by the kink-like configuration of a scalar field. With this aim we consider a self-consistent, real, nonlinear, nonminimally coupled scalar field $ϕ$ in general relativity with the symmetry-breaking potential $V(ϕ)$ possessing two minima. We classify all possible field conf

S. C. Tiwari

Recently there has been a lot of intersest in the superluminal phenomena, and time varying velocity of light cosmological models. More than two decades ago at Einstein centenary symposium, Nagpur I had put forward space-time interaction hypothesis. One of its predictions was that velocity of light decreased with the age of Universe. In view of the profoundne

Han-Ying Guo, Chao-Guang Huang, Xiaoning Wu

It is shown in the covariant phase space formalism that the Noether charges with respect to the diffeomorphism generated by vector fields and their horizontal variations in general relativity form a diffeomorphism algebra. It is also shown with the help of the null tetrad which is well defined everywhere that the central term of the reduced diffeomorphism al

Elizabeth Anderson, Robert Atkinson, Elizabeth Buckley-Geer, Cynthia Crego

Through a collaborative effort, the Fermilab Information Resources Department and Computing Division have created a &#34;virtual library&#34; of technical publications that provides public access to electronic full-text documents. This paper will discuss the vision, planning and milestones of the project, as well as the hardware, software and interdepartment

E. S. Choi, E. Jobiling, A. Wade, E. Goetz

The quantum oscillatory effect and superconductivity in a non-tetrachalcogenafulvalene (TCF) structure based organic superconductor beta-(BDA-TTP)_2SbF_6 are studied. Here the Shubnikov-de Haas effect (SdH) and angular dependent magnetoresistance oscillations (AMRO) are observed. The oscillation frequency associated with a cylindrical Fermi surface is found

M. Dzero, L. P. Gor&#39;kov, A. K. Zvezdin, K. A. Zvezdin

Difference in density of states for the spin&#39;s majority and minority bands in a ferromagnet changes the electrostatic potential along the domains, introducing the discontinuities of the potential at domain boundaries. The value of discontinuity oscillates with number of domains. Discontinuity depends on the positions of domain walls, their motion or coll

Leonardo E. Silbert, Gary S. Grest, James W. Landry

Simulated granular packings with different particle friction coefficient mu are examined. The distribution of the particle-particle and particle-wall normal and tangential contact forces P(f) are computed and compared with existing experimental data. Here f equivalent to F/F-bar is the contact force F normalized by the average value F-bar. P(f) exhibits expo

M. Yamada, H. E. Stanley, F. Sciortino

To study the coexistence of two liquid states of water within one simulation box, we implement an equilibrium sedimentation method--which involves applying a gravitational field to the system and measuring/calculating the resulting density profile in equilibrium. We simulate a system of particles interacting via the ST2 potential, a model for water. We detec

E. Giannini, I. Savysyuk, V. Garnier, R. Passerini

The decomposition and the reformation of the (Bi,Pb)2Sr2Ca2Cu3O10+d (?Bi,Pb(2223)?) phase have been investigated in-situ by means of High-Temperature Neutron Diffraction, both in sintered bulk samples and in Ag-sheathed monofilamentary tapes. Several decomposition experiments were performed at various temperatures and under various annealing atmospheres, und

H. Schomerus, M. Titov

We analyze the conductance distribution function in the one-dimensional Anderson model of localization, for arbitrary energy. For energy at the band center the distribution function deviates from the universal form assumed in single-parameter scaling theory. A direct link to the break-down of the random-phase approximation is established. Our findings are co

Thierry Dauxois, Vito Latora, Andrea Rapisarda, Stefano Ruffo

The thermodynamics and the dynamics of particle systems with infinite-range coupling display several unusual and new features with respect to systems with short-range interactions. The Hamiltonian Mean Field (HMF) model represents a paradigmatic example of this class of systems. The present study addresses both attractive and repulsive interactions, with a p

Thierry Dauxois, Stefano Ruffo, Ennio Arimondo, Martin Wilkens

We review theoretical results obtained recently in the framework of statistical mechanics to study systems with long range forces. This fundamental and methodological study leads us to consider the different domains of applications in a trans-disciplinary perspective (astrophysics, nuclear physics, plasmas physics, metallic clusters, hydrodynamics,...) with

J. E. Han, O. Gunnarsson, V. H. Crespi

We analyze fulleride superconductivity at experimental doping levels, treating the electron-electron and electron-phonon interactions on an equal footing, and establish the existence of novel physics which helps explain the unusually high superconducting transition temperatures in these systems. The Jahn-Teller phonons create a local (intramolecular) pairing

Wolfgang Kinzel, Ido Kanter

Two neural networks which are trained on their mutual output bits show a novel phenomenon: The networks synchronize to a state with identical time dependent weights. It is shown how synchronization by mutual learning can be applied to cryptography: secret key exchange over a public channel.