March 2002 arXiv papers — page 2

YounJoon Jung, Jianshu Cao

Electron transfer processes in Debye solvents are studied using a spectral analysis method recently proposed. Spectral structure of a nonadiabatic two-state diffusion equation is investigated to reveal various kinetic regimes characterized by a broad range of physical parameters; electronic coupling, energy bias, reorganization energy, and solvent relaxation

P. M. Gehring, S. Wakimoto, Z. -G. Ye, G. Shirane

We review results obtained from recent neutron scattering studies of the lead-oxide class of perovskite relaxors PMN and PZN. A ferroelectric soft mode has been identified in PMN at 1100 K that becomes overdamped near 620 K. This is the same temperature at which polar nanoregions (PNR) begin to form, denoted by Td, and suggests that a direct connection exist

P. Cren, C. F. Roos, A. Aclan, J. Dalibard

We demonstrate experimentally the continuous and pulsed loading of a slow and cold atomic beam into a magnetic guide. The slow beam is produced using a vapor loaded laser trap, which ensures two-dimensional magneto-optical trapping, as well as cooling by a moving molasses along the third direction. It provides a continuous flux larger than $10^9$ atoms/s wit

V. Ta Phuoc, E. Olive, R. De Sousa, A. Ruyter

The transverse Meissner effect (TME) in the highly layered superconductor $Bi_2Sr_2CaCu_2O_{8+y}$ with columnar defects is investigated by transport measurements. We present detailed evidence for the persistence of the Bose glass phase for $H_{\perp}<H_{\perp c}$ : (i) the variable-range vortex hopping process for low currents crosses over to the half-loops

Pieder Beeli

Exact expressions for all the steady-state fields (E, H, D, B) in uniaxial linear media composed of an arbitrary number of layers having arbitrary thicknesses subjected to normal incidence are derived. Generic boundary condition relations in terms of the surface wave impedance are applied at each surface so that fields between any sequence of layers can be r

C. Grimaldi, P. Ryser, S. Straessler

A number of evidences suggests that thick-film resistors are close to a metal-insulator transition and that tunneling processes between metallic grains are the main source of resistance. We consider as a minimal model for description of transport properties in thick-film resistors a percolative resistor network, with conducting elements governed by tunneling

R. J. Magyar, T. K. Whittingham, K. Burke

Coordinate scaling of each spin density separately is considered in spin density functional theory. A virial theorem relates the spin-scaled correlation energy to the spin-scaled correlation potentials. An adiabatic connection formula expresses energies at different spin interaction strengths in terms of spin scaling. Several popular approximate functionals

M. A. Yurishchev

The critical temperature of a three-dimensional Ising model on a simple cubic lattice with different coupling strengths along all three spatial directions is calculated via the transfer matrix method and a finite size scaling for L x L oo clusters (L=2 and 3). The results obtained are compared with available calculations. An exact analytical solution is foun

T. Rejec, A. Ramsak, J. H. Jefferson

Thermoelectric transport coefficients are determined for semiconductor quantum wires with weak thickness fluctuations. Such systems exhibit anomalies in conductance near 1/4 and 3/4 of 2e^2/h on the rising edge to the first conductance plateau, explained by singlet and triplet resonances of conducting electrons with a single weakly bound electron in the wire

Acerbi Carlo, Simonetti Prospero

We study Spectral Measures of Risk from the perspective of portfolio optimization. We derive exact results which extend to general Spectral Measures M_phi the Pflug--Rockafellar--Uryasev methodology for the minimization of alpha--Expected Shortfall. The minimization problem of a spectral measure is shown to be equivalent to the minimization of a suitable fun

Asad Niazi, P. L. Paulose, E. V. Sampathkumaran

The single crystalline form of an insulator, Sr$_3$CuIrO$_{6+δ}$, is shown to exhibit unexpectedly more than one magnetic transition (at 5 and 19 K) with spin-glass-like magnetic susceptibility behaviour. On the basis of this finding, viz., inhomogeneous magnetism in a chemically homogeneous material, we propose that the idea of &#34;phase- separation&#34; d

E. V. Sampathkumaran, Asad Niazi

We report the results of dc and ac magnetization measurements as a function of temperature (1.8 - 300 K) for the spin chain compound, Ca$_3$CoRhO$_6$, which has been recently reported to exhibit a partially disordered antiferromagnetic (PDAF) structure in the range 30 - 90 K and spin-glass freezing below 30 K. We observe an unexpectedly large frequency depen

M. Robles, M. López de Haro

A thermodynamic approach to derive the liquid-glass transition line in the reduced temperature vs reduced density plane for a monatomic Lennard-Jones fluid is presented. The approach makes use of a recent reformulation of the classical perturbation theory of liquids [M. Robles and M. López de Haro, Phys. Chem. Chem. Phys. {\bf 3}, 5528 (2001)] which is at gr

Kyungsik Kim, Y. S. Kong, M. K. Yum, J. T. Kim

The dynamical behavior for a quantum Brownian particle is investigated under a random potential of the fractional iterative map on a one-dimensional lattice. For our case, the quantum expectation values can be obtained numerically from the wave function of the fractional Schr$\ddot{o}$dinger equation. Particularly, the square of mean displacement which is en

Philip J. Armitage, Mario Livio, S. H. Lubow, J. E. Pringle

We investigate the migration of massive extrasolar planets due to gravitational interaction with a viscous protoplanetary disc. We show that a model in which planets form at 5 AU at a constant rate, before migrating, leads to a predicted distribution of planets that is a steeply rising function of log (a), where a is the orbital radius. Between 1 AU and 3 AU

J. C. Lee, K. Iwasawa, J. C. Houck, A. C. Fabian

We confirm the detection of the relativistically broadened iron K-alpha emission at 6.4 keV with simultaneous Chandra HETGS and RXTE PCA observations. Heavily binned HETGS data show a disk line profile with parameters very similar to those previously seen by ASCA. We observe a resolved narrow component with a velocity width ~4700 km/s (FWHM ~ 11,000 km/s), t

O. V. Verkhodanov, Yu. N. Parijskij, N. S. Soboleva, A. I. Kopylov

BVRI data for the majority of the objects of the RC catalogue with steep spectra and $m_R<24^m$ are presented. These data have been used to estimate colour redshifts and the age of stellar systems of host galaxies. By way of example of distant radio galaxies it is shown that this approach gives an accuracy of redshift estimates close to that for field galaxi

G. Li Causi, G. De Marchi, F. Paresce

We have studied the accuracy and reliability of the exposure time calculator (ETC) of the Wide Field Planetary Camera 2 (WFPC2) on board the Hubble Space Telescope (HST) with the objective of determining how well it represents actual observations and, therefore, how much confidence can be invested in it and in similar software tools. We have found, for examp

P. F. L. Maxted, M. R. Burleigh, T. R. Marsh, N. P. Bannister

We present spectra of the DAB white dwarf PG1115+166. Radial velocity measurements of the Balmer lines and the HeI6678 line show that this is a binary white dwarf with a period of 30.09d in which the Balmer lines move in anti-phase to the HeI line, i.e., PG1115+166 is a DA+DB binary. The minimum masses of the stars are M_DA=0.43+-0.15 solar masses and M_DB=0

E. J. Gaidos, G. Gonzalez

High-resolution (R ~ 90,000) spectra of 34 nearby, young Sun-like stars were analyzed using stellar atmosphere models to estimate effective photosphere temperatures, surface gravities, and the abundance of certain heavy elements (C, Na, Mg, Si, S, Ca, Ti, Fe, and Ni). The effective temperatures derived from spectroscopy were compared with temperatures estima

T. Joseph W. Lazio, Jill Tarter, Peter R. Backus

This paper reports new, more sensitive observations of nine of the eleven extrastatistical signals in the Megachannel Extraterrestrial Assay (META). These extrastatistical signals had all of the expected characteristics of a transmission from an extraterrestrial transmitter, except that they did not repeat. Cordes, Lazio, & Sagan showed that this lack of rep

Nancy Remage Evans, Derck Massa

We have measured the centroid shift of low resolution HST FOC spectra as the dominant star changes from the Cepheid to the hot companion. With this approach we have resolved the AW Per system and marginally resolved the U Aql system.

Peter Erwin, Linda S. Sparke

We present results from an imaging survey of an unbiased sample of thirty-eight early-type (S0--Sa), low-inclination, optically barred galaxies in the field. Our goal was to find and characterize central stellar and gaseous structures: secondary bars, inner disks, and nuclear rings. Bars inside bars are surprisingly common: at least one quarter of the sample

S. Deser, Bayram Tekin

In three dimensions, there are two distinct mass-generating mechanisms for gauge fields: adding the usual Proca/Pauli-Fierz, or the more esoteric Chern-Simons (CS), terms. Here we analyze the three-term models where both types are present, and their various limits. Surprisingly, in the tensor case, these seemingly innocuous systems are physically unacceptabl

J A Sellwood, J J Binney

We show that spiral waves in galaxy discs churn the stars and gas in a manner that largely preserves the overall angular momentum distribution and leads to little increase in random motion. Changes in the angular momenta of individual stars are typically as large as ~50% over the lifetime of the disk. The changes are concentrated around the corotation radius

Brian C. Hall, Jeffrey J. Mitchell

This paper concerns the coherent states on spheres studied by the authors in [J. Math. Phys. 43 (2002), 1211-1236]. We show that in the odd-dimensional case the coherent states on the sphere approach the classical Gaussian coherent states on Euclidean space as the radius of the sphere tends to infinity.

P. Fachini

Preliminary results on the K*(892)0 -> pi + K production using the mixed-event technique are presented. The measurements are performed at mid-rapidity by the STAR detector in sqrt(s_NN) = 130 GeV Au-Au collisions at RHIC. The K*0 to negative hadron, kaon and phi ratios are obtained and compared to the measurements in e+e-, pp and pbarp at various energies.

Antony Lewis, Anthony Challinor

We discuss the propagation of dark matter perturbations with non-zero velocity dispersion in cosmological models. In particular a non-zero massive neutrino component may well have a significant effect on the matter power spectrum and cosmic microwave background anisotropy. We present a covariant analysis of the evolution of a dark matter distribution via a t

L. Villain, S. Bonazzola

We present a new hydro code based on spectral methods using spherical coordinates. The first version of this code aims at studying time evolution of inertial modes in slowly rotating neutron stars. In this article, we introduce the anelastic approximation, developed in atmospheric physics, using the mass conservation equation to discard acoustic waves. We de

Toshio Tsuchiya

Multi-scale interaction between the LMC, Galactic halo, and the disk is examined with N-body simulations, and precise amplitudes of the Galactic warp excitation are obtained. The Galactic models are constructed most realistically to satisfy available observational constraints on the local circular velocity, the mass, surface density and thickness of the disk

Stig Bieling

In this paper the interaction of extended waves in a noncommutative modified 2+1 dimensional U(2) sigma model are studied. Using the dressing method, we construct an explicit two-wave solution of the noncommutative field equation. The scattering of these waves and large time factorization are discussed.

Kai-Peer O. Diener, Christian Schwanenberger, Michael Spira

W bosons can be produced in the channels e+- p -> W+- + X at HERA thus allowing to probe for anomalous trilinear couplings among the gauge bosons. We discuss the NLO QCD corrections to the photoproduction of W bosons with finite transverse momentum at HERA. The higher-order QCD corrections reduce the factorization scale dependence significantly and modify th

Michele Modugno, Ludovic Pricoupenko, Yvan Castin

We consider a 3D dilute Bose-Einstein condensate at thermal equilibrium in a rotating harmonic trap. The condensate wavefunction is a local minimum of the Gross-Pitaevskii energy functional and we determine it numerically with the very efficient conjugate gradient method. For single vortex configurations in a cigar-shaped harmonic trap we find that the vorte

R. Enberg, G. Ingelman, A. Kissavos, N. Timneanu

Improved possibilities to find the Higgs boson in diffractive events, having less hadronic activity, depend on whether the cross section is large enough. Based on the soft color interaction models that successfully describe diffractive hard scattering at HERA and the Tevatron, we find that only a few diffractive Higgs events may be produced at the Tevatron,

Xiaoguang Wang

We study the entanglement of thermal and ground states in Heisernberg $XX$ qubit rings with a magnetic field. A general result is found that for even-number rings pairwise entanglement between nearest-neighbor qubits is independent on both the sign of exchange interaction constants and the sign of magnetic fields. As an example we study the entanglement in t

Dietmar Klemm, Luciano Vanzo

We show that the spectrum of conical defects in three-dimensional de Sitter space is in one-to-one correspondence with the spectrum of vertex operators in Liouville conformal field theory. The classical conformal dimensions of vertex operators are equal to the masses of the classical point particles in dS_3 that cause the conical defect. The quantum dimensio

F. Hoefling, C. Nowak, C. Wetterich

A second order phase transition for the three dimensional Gross-Neveu model is established for one fermion species N=1. This transition breaks a paritylike discrete symmetry. It constitutes its peculiar universality class with critical exponent ν= 0.63 and scalar and fermionic anomalous dimension η_σ= 0.31 and η_ψ= 0.11, respectively. We also compute critica

C. Wetterich

Many models of quintessence predict a time variation of the fundamental constants as well as a composition-dependent gravity like long-range force mediated by the cosmon. We present bounds for the cosmon coupling to matter and radiation within a grand unified framework. The unification scale, the unified gauge coupling and the Fermi scale are allowed to vary

G. Schaller, R. Schützhold, G. Plunien, G. Soff

The phenomenon of particle creation within an almost resonantly vibrating cavity with losses is investigated for the example of a massless scalar field at finite temperature. A leaky cavity is designed via the insertion of a dispersive mirror into a larger ideal cavity (the reservoir). In the case of parametric resonance the rotating wave approximation allow

Jerome Novak, Silvano Bonazzola

We present a new formulation of the multipolar expansion of an exact boundary condition for the wave equation, which is truncated at the quadrupolar order. Using an auxiliary function, that is the solution of a wave equation on the sphere defining the outer boundary of the numerical grid, the absorbing boundary condition is simply written as a perturbation o

T. Lastovicka

Self-similar properties of proton structure in the kinematic region of low Bjorken x are introduced and studied numerically. A description of the proton structure function F2(x,Q2) reflecting self-similarity is proposed with a few parameters which are fitted to recent HERA data. The specific parameterisation provides an excellent description of the data whic

Kristian D. Kennaway

Starting from the geometrical construction of special Lagrangian submanifolds of a toric variety, we identify a certain subclass of A-type D-branes in the linear sigma model for a Calabi-Yau manifold and its mirror with the A- and B-type Recknagel-Schomerus boundary states of the Gepner model, by reproducing topological properties such as their labeling, int

M. Ciszak, O. Calvo, C. Masoller, Claudio R. Mirasso

We study the regime of anticipated synchronization in unidirectionally coupled model neurons subject to a common external aperiodic forcing that makes their behavior unpredictable. We show numerically and by implementation in analog hardware electronic circuits that, under appropriate coupling conditions, the pulses fired by the slave neuron anticipate (i.e.

Sergei Gukov, Michael Haack

Looking for string vacua with fixed moduli, we study compactifications of type IIA string theory on Calabi-Yau fourfolds in the presence of generic Ramond-Ramond fields. We explicitly derive the (super)potential induced by Ramond-Ramond fluxes performing a Kaluza-Klein reduction of the ten-dimensional effective action. This can be conveniently achieved in a

Chikako Uchiyama, Masaki Aihara

We present a general formulation to suppress pure dephasing by multipulse control. The formula is free from a specific form of interaction and is expressed in terms of the correlation function of arbitrary system-reservoir interaction.

T. Padmanabhan

A large class of evolutionary processes can be modeled by a rule which involves self-replication of some physical quantity with a non local rescaling. I show that a class of such models are exactly solvable -- in the discrete as well as continuum limit -- and can represent several physical situations as varied from the formation of galaxies in some cosmologi

Baigeng Wang, Jian Wang

We report a theoretical analysis of parametric electron pump through a quantum dot in the Kondo regime. In the adiabatic regime, we have derived the expression for pumped current in the Kondo regime using non-equilibrium Green&#39;s function. The pumped current versus different system parameters such as gate voltage, pumping amplitude, as well as the phase d

Andrei Galiautdinov

In modern physics, one of the greatest divides is that between space-time and quantum fields, as the fiber bundle of the Standard Model indicates. However on the operational grounds the fields and spacetime are not very different. To describe a field in an experimental region we have to assign coordinates to the points of that region in order to speak of the

Kazuyuki Fujii

In this paper we generalize the Jaynes--Cummings Hamiltonian by making use of some operators based on Lie algebras su(1,1) and su(2), and study a mathematical structure of Rabi floppings of these models in the strong coupling regime. We show that Rabi frequencies are given by matrix elements of generalized coherent operators (quant--ph/0202081) under the rot

J. Stockton, M. Armen, H. Mabuchi

We discuss the unique capabilities of programmable logic devices (PLD&#39;s) for experimental quantum optics and describe basic procedures of design and implementation. Examples of advanced applications include optical metrology and feedback control of quantum dynamical systems. As a tutorial illustration of the PLD implementation process, a field programmab

A. Messina

A new conditional scheme for generating Bell states of two spatially separated high-Q cavities is reported. Our method is based on the passage of one atom only through the two cavities. A distinctive feature of our treatment is that it incorporates from the very beginning the unavoidable presence of fluctuations in the atom-cavity interaction times. The poss

S. G. Clark, A. S. Parkins

We propose a scheme employing quantum-reservoir engineering to controllably entangle the internal states of two atoms trapped in a high finesse optical cavity. Using laser and cavity fields to drive two separate Raman transitions between metastable atomic ground states, a system is realized corresponding to a pair of two-state atoms coupled collectively to a

A. Peng, A. S. Parkins

We propose a scheme for entangling the motional mode of a trapped atom with a propagating light field via a cavity-mediated parametric interaction. We then show that if this light field is subsequently coupled to a second distant atom via a cavity-mediated linear-mixing interaction, it is possible to transfer the entanglement from the light beam to the motio

Alexandr V. Avdeenkov, John L. Bohn

Ultracold collisions of polar OH molecules are considered in the presence of an electrostatic field. The field exerts a strong influence on both elastic and state-changing inelastic collision rate constants, leading to clear experimental signatures that should help disentangle the theory of cold molecule collisions. Based on the collision rates we discuss th

O. Scholten, A. Yu. Korchin

Two-photon production in pp scattering is proposed as a means of studying virtual-pion emission. Such a process is complementary to real-pion emission in pp scattering. The virtual-pion signal is embedded in a background of double-photon bremsstrahlung. We have developed a model to describe this background process and show that in certain parts of phase spac

O. Scholten, S. Kondratyuk

A microscopic coupled-channels model for Compton and pion scattering off the nucleon is introduced which is applicable at the lowest energies (polarizabilities) as well as at GeV energies. To introduce the model first the conventional K-matrix approach is discussed to extend this in a following chapter to the &#34;Dressed K-Matrix&#34; model. The latter appr

Giovanni Filatrella, Boris A. Malomed, Sergio Pagano

We consider phase-locked dynamics of a Josephson junction driven by finite-spectral-linewidth ac current. By means of a transformation, the effect of frequency fluctuations is reduced to an effective additive noise, the corresponding (large) dephasing time being determined, in the logarithmic approximation, by the Kramers&#39; expression for the lifetime. Fo

Qiaoning Chen, Shiyi Chen, Gregory L. Eyink, Darryl D. Holm

The statistics of the energy and helicity fluxes in isotropic turbulence are studied using high resolution direct numerical simulation. The scaling exponents of the energy flux agree with those of the transverse velocity structure functions through refined similarity hypothesis, consistent with Kraichnan&#39;s prediction \cite{Kr74}. The helicity flux is eve

Edward Goldobin, Boris A. Malomed, Alexey V. Ustinov

A novel dynamical effect is presented: systematic drift of a topological soliton in ac-driven weakly damped systems with periodic boundary conditions. The effect is demonstrated in detail for a long annular Josephson junction. Unlike earlier considered cases of the ac-driven motion of fluxons (kinks), in the present case the long junction is_spatially unifor

V. V. Varlamov

A group theoretical description of basic discrete symmetries (space inversion P, time reversal T and charge conjugation C) is given. Discrete subgroups of orthogonal groups of multidimensional spaces over the fields of real and complex numbers are considered in terms of fundamental automorphisms of Clifford algebras. In accordance with a division ring struct

Jody Trout

This paper provides an E-theoretic proof of an exact form, due to E. Troitsky, of the Mischenko-Fomenko Index Theorem for elliptic pseudodifferential operators over a unital C*-algebra. The main ingredients in the proof are the use of asymptotic morphisms of Connes and Higson, vector bundle modification, a Baum-Douglas-type group, and a KK-argument of Kaspar

Dipendra Prasad, C. S. Rajan

We consider an Archimedean analogue of Tate&#39;s conjecture, and verify the conjecture in the examples of isospectral Riemann surfaces constructed by Vigneras and Sunada. We also enunciate a simple lemma in group theory which lies at the heart of T. Sunada&#39;s theorem about isospectral manifolds.

Rob Kusner

We describe some problems, observations, and conjectures concerning thickness and packing density of knots and links in $\sp^3$ and $\R^3$. We prove the thickness of a nontrivial knot or link in $\sp^3$ is no more than $\fracπ{4}$, the thickness of a Hopf link. We also give arguments and evidence supporting the conjecture that the packing density of thick li

Paolo Aluffi

Considerations based on the known relation between different characteristic classes for singular hypersufaces suggest that a form of the `inclusion-exclusion&#39; principle may hold for Segre classes. We formulate and prove such a principle for a notion closely related to Segre classes. This is used to provide a simple computation of the classes introduced i

Janko Gravner, Craig A. Tracy, Harold Widom

We continue to study a model of disordered interface growth in two dimensions. The interface is given by a height function on the sites of the one--dimensional integer lattice and grows in discrete time: (1) the height above the site $x$ adopts the height above the site to its left if the latter height is larger, (2) otherwise, the height above $x$ increases

Efton Park, Jody Trout

Let X be a locally compact space, and let A and B be Co(X)-algebras. We define the notion of an asymptotic Co(X)-morphism from A to B and construct representable E-theory groups RE(X;A,B). These are the universal groups on the category of separable Co(X)-algebras that are Co(X)-stable, Co(X)-homotopy-invariant, and half-exact. If A is RKK(X)-nuclear, these g

R. Dick, D. M. E. McArthur

We discuss the impact of a bulk photon mass in a Dvali-Gabadadze-Porrati type brane model with Maxwell terms both on the brane and in the bulk, as proposed by Dvali, Gabadadze and Shifman. The motivation to include the bulk photon mass is to suppress radiation loss into the bulk. We point out that this modifies the photon propagator in such a way that it gen

Amy E. Ksir, Stephen G. Naculich

We study the Seiberg-Witten curves for N=2 SUSY gauge theories arising from type IIA string configurations with two orientifold sixplanes. Such theories lift to elliptic models in M-theory. We express the M-theory background for these models as a nontrivial elliptic fibration over C. We discuss singularities of this surface, and write the Seiberg-Witten curv

Ashoke Sen

It is shown that classical decay of unstable D-branes in bosonic and superstring theories produces pressureless gas with non-zero energy density. The energy density is stored in the open string fields, even though around the minimum of the tachyon potential there are no open string degrees of freedom. We also give a description of this phenomenon in an effec

Dimitra Karabali, V. P. Nair

Following recent work on the quantum Hall effect on $S^4$, we solve the Landau problem on the complex projective spaces ${\bf C}P^k$ and discuss quantum Hall states for such spaces. Unlike the case of $S^4$, a finite spatial density can be obtained with a finite number of internal states for each particle. We treat the case of ${\bf C}P^2$ in some detail con

James Lindesay, H. Pierre Noyes

We here use our non-perturbative, cluster decomposable relativistic scattering formalism to calculate photon-spinor scattering, including the related particle-antiparticle annihilation amplitude. We start from a three-body system in which the unitary pair interactions contain the kinematic possibility of single quantum exchange and the symmetry properties ne

M. Sampaio, A. P. Baeta Scarpelli, B. Hiller, A. Brizola

We compare a momentum space implicit regularisation (IR) framework with other renormalisation methods which may be applied to dimension specific theories, namely Differential Renormalisation (DfR) and the BPHZ formalism. In particular, we define what is meant by minimal subtraction in IR in connection with DfR and dimensional renormalisation (DR) .We illustr

P. V. Pobylitsa

Positivity bounds for twist-two parton distributions in multicolored QCD are stronger than their analogs at finite $N_c$. They include the enhanced large $N_{c}$ version of Soffer inequality. These bounds are compatible with the DGLAP evolution to higher normalization points.

H. Athar, Guey-Lin Lin

Some of the non hadronic interactions, such as the ηresonance formation in the γγinteractions and the muon pair production in the eγinteractions, are identified as possible source interactions for generating high energy neutrinos in the cosmos.

N. Kivel, M. V. Polyakov

We computed the leading non-analytic chiral corrections to the generalized parton distributions (GPDs) of the pion and to the two-pion distribution amplitudes. This allows us to obtain the corresponding corrections for the hard exclusive processes, such as gamma^* gamma -> pi pi, gamma^* N -> 2pi N&#39; and deeply virtual Compton scattering on the pion targe

L. C. Garcia de Andrade

Static spherically symmetric Kalb-Ramond (KR) traversable wormholes in torsioned spacetime are shown not to exist globally since torsion vanishes not only at the wormhole throat but in all spacetime points which means that all components of the KR field vanish identically. With this result Hochberg-Visser result on the non-violation of the weak energy (WEC)

Tadashi Kon, Jun-ichi Kamoshita, Tetsuro Kobayashi, Shoichi Kitamura

We investigate a single scalar neutrino production at the upgraded HERA with high luminosity in the framework of an R-parityviolating supersymmetric model. We find that the scalar neutrino with mass around 100GeV could be observed through investigating the multilepton production process e- p -> mu- sneutrino(tau) X -> mu- (e- mu+) X. The signal would be char

Wieslaw Sobkow

In this paper a scenario admitting the participation of the exotic right-handed scalar $S_{R}$ coupling in addition to the standard left-handed $(V, A)_{L}$ couplings in the low energy neutrino-electron scattering is considered. The main goal is to show how the presence of the right-handed neutrinos in the $(νe)$ scattering changes the laboratory differentia

Nigel Cundy, Michael Teper, Urs Wenger

We study the low-lying eigenmodes of the lattice overlap Dirac operator for SU(N) gauge theories with N=2,3,4 and 5 colours. We define a fermionic topological charge from the zero-modes of this operator and show that, as N grows, any disagreement with the topological charge obtained by cooling the fields, becomes rapidly less likely. By examining the fields

Pilar Hernandez, Karl Jansen, Laurent Lellouch

The physics of strong interactions is invariant under the exchange of left-handed and right-handed quarks, at least in the massless limit. This invariance is reflected in the chiral symmetry of quantum chromodynamics. Surprisingly, it has become clear only recently how to implement this important symmetry in lattice formulations of quantum field theories. We

The BABAR Collaboration, B. Aubert

In this report, we present the observation of the exclusive decays B0 -> EtaC K0 and B+ -> EtaC K+, and the measurement of the related branching fractions. Using a sample of 22.7x10^6 Upsilon(4S) -> BBbar decays collected with the BABAR detector at the SLAC PEP-II asymmetric B Factory during 1999-2000, we have observed statistically significant signals in th

Friedrich W. Hehl, Yuri N. Obukhov, Guillermo F. Rubilar

Within the framework of generally covariant (pre-metric) electrodynamics, we specify a local vacuum spacetime relation between the excitation $H=({\cal D},{\cal H})$ and the field strength $F=(E,B)$. We study the propagation of electromagnetic waves in such a spacetime by Hadamard&#39;s method and arrive, with the constitutive tensor density $κ\sim\partial H

Mayeul Arminjon

According to Schroedinger&#39;s ideas, classical dynamics of point particles should correspond to the &#34; geometrical optics &#34; limit of a linear wave equation, in the same way as ray optics is the limit of wave optics. It is shown that, using notions of modern wave theory, the &#34; geometrical optics &#34; analogy leads to the correspondence between a

A. Bhadra, K. K. Nandi

It is shown that the general scalar tensor cosmologies may explain all the current cosmological observations without the need of invoking any ad hoc missing energy density. The explanation is based entirely on the internal dynamics of the theories. Two important predictions of the present analysis are: the universe is tending towards a matter dominated state

László Á. Gergely

We prove that given a solution of the Einstein equations $g_{ab}$ for the matter field $T_{ab}$, an autoparallel null vector field $l^{a}$ and a solution $(l_{a}l_{c}, \mathcal{T}_{ac})$ of the linearized Einstein equation on the given background, the Kerr-Schild metric $g_{ac}+λl_{a}l_{c}$ ($λ$ arbitrary constant) is an exact solution of the Einstein equati

Matthew Frank

This paper gives a self-contained, elementary, and largely pictorial statement of Einstein&#39;s equation.

Matthew Andrews, Antonio Fernandez, Ashish Goel, Lisa Zhang

We study {\em routing} and {\em scheduling} in packet-switched networks. We assume an adversary that controls the injection time, source, and destination for each packet injected. A set of paths for these packets is {\em admissible} if no link in the network is overloaded. We present the first on-line routing algorithm that finds a set of admissible paths wh

G. Litak, J. F. Annett, B. L. Gyorffy, K. I. Wysokinski

Two models for the superconducting state of Sr2RuO4 have been analyzed. In an &#34;orbital model&#34; the in-plane and out of-plane interactions between electrons on neighboring Ru atoms are assumed to be attractive. In spite of the single particle hybrisation of the orbitals the model shows two superconducting transitions and fine-tuning of parameters is ne

R. K. Bhaduri, M. V. N. Murthy, Muoi N. Tran

It is well-known that the number fluctuation in the grand canonical ensemble, which is directly proportional to the compressibility, diverges for an ideal bose gas as T -> 0. We show that this divergence is removed when the atoms interact in one dimension through an inverse square two-body interaction. In two dimensions, similar results are obtained using a

Markus Deserno, Christian Holm

We present theoretical and numerical studies on stiff, linear polyelectrolytes within the framework of the cell model. We first review analytical results obtained on a mean-field Poisson-Boltzmann level, and then use molecular dynamics simulations to show, under which circumstances these fail quantitatively and qualitatively. For the hexagonally packed nemat

Nikolai V. Brilliantov, Frank Spahn, Jan-Martin Hertzsch, Thorsten Poeschel

We propose a model for collisions between particles of a granular material and calculate the restitution coefficients for the normal and tangential motion as functions of the impact velocity from considerations of dissipative viscoelastic collisions. Existing models of impact with dissipation as well as the classical Hertz impact theory are included in the p

M. Raberto, E. Scalas, F. Mainardi

In financial markets, not only prices and returns can be considered as random variables, but also the waiting time between two transactions varies randomly. In the following, we analyse the statistical properties of General Electric stock prices, traded at NYSE, in October 1999. These properties are critically revised in the framework of theoretical predicti

F. Baldovin, C. Tsallis, B. Schulze

We investigate the time evolution of the entropy for a paradigmatic conservative dynamical system, the standard map, for different values of its controlling parameter $a$. When the phase space is sufficiently ``chaotic&#39;&#39; (i.e., for large $|a|$), we reproduce previous results. For small values of $|a|$, when the phase space becomes an intricate struct

A. Minguzzi, B. Davoudi, M. P. Tosi

A study by W. R. Magro and D. M. Ceperley [Phys. Rev. Lett. {\bf 73}, 826 (1994)] has shown that the ground state of the two-dimensional fluid of charged bosons with logarithmic interactions is not Bose-condensed, but exhibits algebraic off-diagonal order in the single-particle density matrix $ρ(r)$. We use a hydrodynamic Hamiltonian expressed in terms of de

Jaan Kalda

A simple scenario of the formation of geological landscapes is suggested and the respective lattice model is derived. Numerical analysis shows that the arising non-Gaussian surfaces are characterized by the scale-dependent Hurst exponent, which varies from 0.7 to 1, in agreement with experimental data.

B. Sanyal, S. Mirbt

We have performed first principles electronic structure calculations to investigate the structural and magnetic properties of Fe/ZnSe(001) interfaces. Calculations involving full geometry optimizations have been carried out for a broad range of thickness of Fe layers(0.5 monolayer to 10 monolayers) on top of a ZnSe(001) substrate. Both Zn and Se terminated i

Kestutis Staliunas

Statistical dynamics of financial systems is investigated, based on a model of a randomly coupled equation system driven by a stochastic Langevin force. Anticorrelations of price returns, and subdiffusion of prices is found from the model, and and compared with those calculated from historical $/EURO exchange rates.

J. Demsar, L. Forro, H. Berger, D. Mihailovic

Time-resolved optical spectroscopy of collective and single-particle excitations of 1T-TaS2 and 2H-TaSe2 reveals the presence of a large gap in the excitation spectrum on the femtosecond timescale, associated with the formation of various degrees of CDW order. In common with superconducting cuprates, excitations with energies less than the full gap show much

Volkhard Buchholtz, Thorsten Poeschel, Hans-Juergen Tillemans

We investigate the flow of granular material in a rotating cylinder numerically using molecular dynamics in two dimensions. The particles are described by a new model which allows to simulate geometrically complicated shaped grains. The results of the simulation agree significantly better with experiments than the results which are based on circular particle

Thorsten Poeschel, Volkhard Buchholtz

We propose a new model for the description of complex granular particles and their interaction in molecular dynamics simulations of granular material in two dimensions. The grains are composed of triangles which are connected by deformable beams. Particles are allowed to be convex or concave. We present first results of simulations using this particle model.