December 1999 arXiv papers — page 4

Susumu Koretune

By using the soft pion theorem in the inclusive reactions, soft pions' contribution to the structure function $F_2$ in the nucleon is estimated. It is shown that this contribution produces such a large flavor asymmetry in the light sea quark distributions that it gives about $30\sim 50 %$ of the NMC deficit in the Gottfried sum.

A. V. Glamazdin, V. G. Gorbenko, L. G. Levchuk, R. I. Pomatsalyuk

As part of the spin physics program at Jefferson Laboratory (JLab), a Møller polarimeter was developed to measure the polarization of electron beam of energies 0.8 to 5.0 GeV. A unique signature for Møller scattering is obtained using a series of three quadrupole magnets which provide an angular selection, and a dipole magnet for energy analysis. The design,

Yutaka Okabe, Tsukasa Miyajima, Toshiro Ito, Toshihiro Kawakatsu

We report the application of the Monte Carlo simulation to phase separation dynamics. First, we deal with the phase separation under shear flow. The thermal effect on the phase separation is discussed, and the anisotropic growth exponents in the late stage are estimated. Next, we study the effect of surfactants on the three-component solvents. We obtain the

N. D. Ramesh Bhat, Yashwant Gupta, A. Pramesh Rao

Refractive Interstellar Scintillation (RISS) effects on pulsar signals are powerful techniques for discriminating between different models that have been proposed for the power spectrum of plasma density fluctuations in the Interstellar Medium. The nature of the spectrum is considered to be a major input for understanding the underlying mechanism of interste

N. D. Ramesh Bhat, Yashwant Gupta, A. Pramesh Rao, P. B. Preethi

Results from new observations of pulsars using the Ooty Radio Telescope (ORT) are used for investigating the structure of the Local Interstellar Medium (LISM). The observations show anomalous scintillation effects towards several nearby pulsars, and these are modeled in terms of large-scale spatial inhomogeneities in the distribution of plasma density fluctu

Yutaka Fujita, Fumio Takahara

Using X-ray data, we investigate interrelations between gas density rho_0, virial density rho_vir, core radius R, temperature T, entropy S_gas, and metal abundance Z in the core region of clusters of galaxies. First, we confirm that fundamental relations among rho_0, R, and T found by Fujita and Takahara are reproduced by another data catalogue. Second, we f

Shinpei Shibata

First I emphasize the magnetospheric loop current system induced by the wind activity. Next, I address the formation of the field-aligned electric field. An interesting aspect is the reaction of the inner magnetosphere to an induced current. In the traditional outer gap, the current running through the gap is all carried by the particles created in the gap.

Jonathan L. Rosner, Scott A. Slezak

It is easy to construct classical 2-state systems illustrating the behavior of the short-lived and long-lived neutral $K$ mesons in the limit of CP conservation. The emulation of CP violation is more tricky, but is provided by the two-dimensional motion of a Foucault pendulum. Analogies are drawn between the pendulum and observables in neutral kaon decays. A

Youngman Kim, R. Rapp, G. E. Brown, Mannque Rho

Based on schematic two-level models extended to $a_1$-meson degrees of freedom, we investigate possible mechanisms of chiral restoration in the vector/axialvector channels in cold nuclear matter. In the first part of this article we employ the massive Yang-Mills framework to construct an effective chiral Lagrangian based on low-energy mesonic modes at finite

Andrew C. Doherty, Salman Habib, Kurt Jacobs, Hideo Mabuchi

We introduce and discuss the problem of quantum feedback control in the context of established formulations of classical control theory, examining conceptual analogies and essential differences. We describe the application of state-observer based control laws, familiar in classical control theory, to quantum systems and apply our methods to the particular ca

S. Codoban, M. Jurcisin, D. Kazakov

In the framework of the MSSM the non-universal boundary conditions of soft SUSY breaking parameters are considered. Taking as input the top, bottom and Z-boson masses, the values of the gauge couplings at the EW scale and the infrared quasi-fixed points for Yukawa couplings and the soft parameters the mass of the lightest CP-even Higgs boson is found to be m

M. Ciorga, A. S. Sachrajda, P. Hawrylak, C. Gould

Transport measurements are presented on a class of electrostatically defined lateral dots within a high mobility two dimensional electron gas (2DEG). The new design allows Coulomb Blockade(CB) measurements to be performed on a single lateral dot containing 0, 1 to over 50 electrons. The CB measurements are enhanced by the spin polarized injection from and in

M. Pernici, M. Raciti, F. Riva

In the 't Hooft-Veltman dimensional regularization scheme it is necessary to introduce finite counterterms to satisfy chiral Ward identities. It is a non-trivial task to evaluate these counterterms even at two loops. We suggest the use of Wilsonian exact renormalization group techniques to reduce the computation of these counterterms to simple master int

J. H. Kuhn, A. A. Penin, V. A. Smirnov

We apply the strategy of regions within dimensional regularization to find functions involved in evolution equations which govern the asymptotic dynamics of the Abelian form factor and four-fermion amplitude in the SU(N) gauge theory in the Sudakov limit up to the next-to-leading logarithmic approximation. The results are used for the analysis of the dominan

M. Caffo, H. Czyz, E. Remiddi

The values at pseudothreshold of two loop sunrise master amplitudes with arbitrary masses are obtained by solving a system of differential equations. The expansion at pseudothreshold of the amplitudes is constructed and some lowest terms are explicitly presented.

R. G. Vishwakarma

By modifying the Chen and Wu ansatz, we have investigated some Friedmann models in which $Λ$ varies as $ρ$. In order to test the consistency of the models with observations, we study the angular size - redshift relation for 256 ultracompact radio sources selected by Jackson and Dodgson. The angular sizes of these sources were determined by using very long-ba

M. Wakamatsu, T. Watabe

A theoretical prediction is given for the spin and orbital angular momentum distribution functions of the nucleon within the framework of an effective quark model of QCD, i.e. the chiral quark soliton model. An outstanding feature of the model is that it predicts fairly small quark spin fraction of the nucleon $ΔΣ\simeq 0.35$, which in turn dictates that the

S. Tsujikawa, T. Torii

Recently, Cormier and Holman pointed out that fluctuations of an inflaton field $ϕ$ are significantly enhanced in the model of {\it spinodal inflation} with a potential $V(ϕ)$ for which the second derivative $V^{(2)}(ϕ)$ changes sign. As an application of this model, we investigate particle production in the natural inflation model with a potential $V(ϕ)=m^4

G. Auberson, S. R. Jain, A. Khare

We prove that there is off-diagonal long-range order in the symmetrised version of the one-dimensional many-body problem presented by Jain and Khare (Phys. Lett. A262 (1999)35). This model is related to the short-range Dyson model employed to study intermediate statistics in systems like the Anderson model in three dimensions at the metal-insulator transitio

H. K. Jassal, A. Mukherjee

This brief report presents analytical solutions to the equations of motion of a null string. The background spacetime is a magnetically charged Kaluza-Klein black hole. The string coordinates are expanded with the world-sheet velocity of light as an expansion parameter. It is shown that the zeroth order solutions can be expressed in terms of elementary funct

Vladislav A. Bogoyavlenskiy

The present work is devoted to a model of bubble collapse in a Newtonian viscous liquid caused by an initial bubble wall motion. The obtained bubble dynamics described by an analytic solution significantly depends on the liquid and bubble parameters. The theory gives two types of bubble behavior: collapse and viscous damping. This results in a general collap

Yoshikazu Fujiwara, Michio Kohno, Tadashi Fujita, Choki Nakamoto

We formulate a Lippmann-Schwinger-type resonating-group equation to calculate invariant amplitudes of the quark-model baryon-baryon interaction. When applied to our recent SU6 quark model for the nucleon-nucleon and hyperon-nucleon interactions, this technique yields very accurate phase-shift parameters for all partial waves up to the energies of several GeV

M. Kohno, Y. Fujiwara, T. Fujita, C. Nakamoto

Using the SU6 quark-model baryon-baryon interaction recently developed by the Kyoto-Niigata group, we calculate NN, Lambda N and Sigma N G-matrices in ordinary nuclear matter. This is the first attempt to discuss the Lambda and Sigma single-particle potentials in nuclear medium, based on the realistic quark-model potential. The Lambda potential has the depth

G. Kim, R. R. Khaydarov, Il-Tong Cheon, F. A. Gareev

Magnetic dipole and electric quadrupole moments of the mirror nuclei 8Li and 8B are analysed in the framework of the multiparticle shell model by using two approaches : i) the one-particle spectroscopic factors and ii) the one-particle fractional parentage coefficients. These two approaches are compared both each to other and with a microscopic multicluster

Victor M. Buchstaber, Taras E. Panov

We show that the cohomology algebra of the complement of a coordinate subspace arrangement in m-dimensional complex space is isomorphic to the cohomology algebra of Stanley-Reisner face ring of a certain simplicial complex on m vertices. (The face ring is regarded as a module over the polynomial ring on m generators.) Then we calculate the latter cohomology

A. P. Isaev, O. V. Ogievetsky, P. N. Pyatov

In the framework of the Drinfeld theory of twists in Hopf algebras we construct quantum matrix algebras which generalize the Reflection Equation and the RTT algebras. Finite-dimensional representations of these algebras related to the theory of nonultralocal spin chains are presented. The Cayley-Hamilton-Newton identities are demonstrated. These identities a

Eli Berger

The paper deals with a polling game on a graph. Initially, each vertex is colored white or black. At each round, each vertex is colored by the color shared by the majority of vertices in its neighborhood. We say that a set of vertices is a dynamic monopoly if starting the game with the vertices of the set colored white, the entire system is white after a fin

Ashoke Sen, Barton Zwiebach

It has been conjectured that at a stationary point of the tachyon potential for the D-brane of bosonic string theory, the negative energy density exactly cancels the D-brane tension. We evaluate this tachyon potential by off-shell calculations in open string field theory. Surprisingly, the condensation of the tachyon mode alone into the stationary point of i

Glenn Barnich

The relevance of the BRST cohomology of the extended antifield formalism is briefly discussed along with standard homological tools needed for its computation.

H. W. Hamber

A model for quantized gravitation based on the simplicial lattice discretization is studied in detail using a comprehensive finite size scaling analysis combined with renormalization group methods. The results are consistent with a value for the universal critical exponent for gravitation $ν=1/3$, and suggest a simple relationship between Newton's consta

Eva Silverstein, Yun S. Song

We study renormalization-group flow patterns in theories arising on D1-branes in various supersymmetry-breaking backgrounds. We argue that the theory of N D1-branes transverse to an orbifold space can be fine-tuned to flow to the corresponding orbifold conformal field theory in the infrared, for particular values of the couplings and theta angles which we de

J. Baacke, C. Patzold

We derive the renormalized equations of motion and the renormalized energy-momentum tensor for fermions coupled to a spatially homogeneous scalar field (inflaton) in a flat FRW geometry. The fermion back reaction to the metric and to the inflaton field is formulated in one-loop approximation. Having determined the infinite counter terms in an $\bar{MS}$ sche

Sanghyeon Chang, Junji Hisano, Hiroaki Nakano, Nobuchika Okada

We discuss issues in an attempt to put the Standard Model (SM) in five-dimensional anti-de Sitter spacetime compactified on $S^1/Z_2$. The recently-proposed approach to the gauge hierarchy problem by using this background geometry, with the SM confined on a boundary, is extended to a situation where (some of) the SM particles reside in the five dimensional b

Anna Hasenfratz

We study the spatial correlator of the topological charge density operator in pure SU(3) gauge theory and in two flavor QCD. We show that the data for distances up to about 1 fm is consistent with a vacuum consisting of individual instantons and closely bound pairs. The percentage of paired objects is twice as large on the dynamical configurations than on th

Derek B. Leinweber, Anthony W. Thomas

The outcome of the SAMPLE Experiment suggests that the strange-quark contribution to the nucleon magnetic moment, G_M^s(0), may be greater than zero. This result is very difficult to reconcile with expectations based on the successful baryon magnetic-moment phenomenology of the constituent quark model. We show that careful consideration of chiral symmetry re

T. G. Kovács, E. T. Tomboulis

We review recent developments in the vortex picture of confinement. We discuss numerical simulations demonstrating that the entire asymptotic string tension is due to vortex-induced fluctuations of the Wilson loop. Analytical and numerical results concerning the presence of vortices as the necessary and sufficient condition for confinement at arbitrarily wea

J. A. Formaggio, E. D. Zimmerman, T. Adams, A. Alton

The E815 (NuTeV) neutrino experiment has performed a search for a 33.9 MeV/c^2 weakly-interacting neutral particle produced in pion decay. Such a particle may be responsible for an anomaly in the timing distribution of neutrino interactions in the KARMEN experiment. E815 has searched for this particle's decays in an instrumented decay region; no evidence

L. C. Garcia de Andrade

Fluctuations on de Sitter solution of Einstein-Cartan field equations are obtained in terms of the matter density primordial density fluctuations and spin-torsion density and matter density fluctuations obtained from COBE data. Einstein-de Sitter solution is shown to be unstable even in the absence of torsion.The spin-torsion density fluctuation is simply co

Shinji Mukohyama

There have been many attempts to understand the statistical origin of black-hole entropy. Among them, entanglement entropy and the brick wall model are strong candidates. In this paper, first, we show that the entanglement approach reduces to the brick wall model when we seek the maximal entanglement entropy. After that, the stability of the brick wall model

Jan Pachl, Shmuel Zaks

One of the key concepts in testing is that of adequate test sets. A test selection criterion decides which test sets are adequate. In this paper, a language schema for specifying a large class of test selection criteria is developed; the schema is based on two operations for building complex criteria from simple ones. Basic algebraic properties of the two op

A. V. Germanenko, V. A. Larionova, G. M. Minkov, S. A. Negashev

Statistics of closed paths in two-dimensional systems, which just determines the interference quantum correction to conductivity and anomalous magnetoconductance, has been studied by computer simulation of a particle motion over the plane with randomly distributed scatters. Both ballistic and diffusion regimes have been considered. The results of simulation

G. M. Minkov, S. A. Negashev, O. E. Rut, A. V. Germanenko

It is shown that a new kind of information can be extracted from the Fourier transform of negative magnetoresistance (MR) in 2D semiconductor structures. The procedure proposed provides the information on the area distribution function of the closed paths and on the area dependence of the mean length of closed paths $\bar{L} (S)$ . Based on this line of atta

N. V. Ardeljan, G. S. Bisnovatyi-Kogan, S. G. Moiseenko

We perform 2D numerical simulations of a magnetorotational explosion of a rotating magnetized gas cloud. We found that amplification of a toroidal magnetic field due to the differential rotation leads to a transformation of the part of the rotational energy of the cloud to the radial kinetic energy. Simulations have been made for 3 initial values of $ξ$ (the

V. V. Gvaramadze

Most of middle-aged supernova remnants (SNRs) have a distorted and complicated appearance which cannot be explained in the framework of the Sedov-Taylor model. We consider three typical examples of such SNRs (Vela SNR, MSH 15-52, G 309.2-00.6) and show that their structure could be explained as a result of interaction of a supernova (SN) blast wave with the

T. Kawaguchi, S. Mineshige, M. Machida, R. Matsumoto

Rapid fluctuation with a frequency dependence of $1/f^α$ (with $α\simeq 1 - 2$) is characteristic of radiation from black-hole objects. Its origin remains poorly understood. We examine the three-dimensional magnetohydrodynamical (MHD) simulation data, finding that a magnetized accretion disk exhibits both $1/f^α$ fluctuation (with $α\simeq 2$) and a fractal

Hiroshi Koyama, Shu-Ichiro Inutsuka

We investigate the propagation of a shock wave into a warm neutral medium and cold neutral medium by one-dimensional hydrodynamic calculations with detailed treatment of thermal and chemical processes. Our main result shows that thermal instability inside the shock-compressed layer produces a geometrically thin, dense layer in which a large amount of hydroge

Jusak Tandean

We study the contributions of physics beyond the standard model to the short-distance s->d gamma transition in Omega^- -> Cascade^- gamma decay. We explore the possibility that the new interactions remove the chirality suppression which occurs in the standard-model contribution to s->d gamma and enhance the effect of this coupling by factors of a heavy-mass

Ph. de Forcrand, O. Philipsen

We compute the static potential of adjoint sources in SU(2) Yang-Mills theory in four dimensions by numerical Monte Carlo simulations. Following a recent calculation in 2+1 dimensions, we employ a variational approach involving string and gluelump operators and obtain clear evidence for string breaking and the saturation of the potential at large distances.

Joel E. Moore, Prashant Sharma, Claudio Chamon

In this paper we formulate the theory of tunneling into general Abelian fractional quantum Hall edge states. In contrast to the simple Laughlin states, a number of charge transfer processes must be accounted for. Nonetheless, it is possible to identify a unique value corresponding to dissipationless transport as the asymptotic large-$V$ conductance through a

Taichiro Kugo, Koichi Yoshioka

We investigate a possibility that our four-dimensional world is a brane-like object embedded in a higher dimensional spacetime. In such a situation, the transverse coordinates of the brane become the Nambu-Goldstone bosons which appear as a result of spontaneous breaking of the translation symmetry. We determine the form of the effective action of the system

Peter Herczeg

We show that the present experimental limits on electron-nucleon interactions that violate both parity and time reversal invariance provide new stringent bounds on the imaginary parts of some of the products of the R-parity violating coupling constants in the R-parity violating Minimal Supersymmetric Standard Model.

Howard Baer, Pedro Mercadante, Xerxes Tata

Supersymmetric models with an inverted mass hierarchy (IMH: multi-TeV first and second generation matter scalars, and sub-TeV third generation scalars) can ameliorate problems arising from flavor changing neutral currents, $CP$ violating phases and electric dipole moments, while at the same time satisfying conditions on naturalness. It has recently been show

Tony Wong, Leo Blitz

We analyze the gas kinematics and star formation properties of the nearby RSab galaxy NGC 4736 using interferometric and single-dish CO(1-0) data and previously published Halpha and HI data. The CO morphology is dominated by a central molecular bar and tightly wound spiral arms associated with a bright ring of star formation. Strong HI emission is also found

R. A. Konoplya

We develop a method for constructing of the basic functions with witch to expand small perturbations of space-time in General Relativity. The method allows to obtain the tensor harmonics for perturbations of the background space-time admitting an arbitrary group of isometry, and to split the linearized Einstein equations into the irreducible combinations. Th

M. J. Davis, C. W. Gardiner, R. J. Ballagh

We extend earlier models of the growth of a Bose-Einstein condensate to include the full dynamical effects of the thermal cloud by numerically solving a modified quantum Boltzmann equation. We determine the regime in which the assumptions of the simple model are a reasonable approximation, and compare our new results with those that were earlier compared wit

S. F. King

Single right-handed neutrino dominance (SRHND) in the 23 sector of the light effective neutrino mass matrix has been proposed as a natural explanation for the concurrent large 23 mixing angle and large 23 mass hierarchy. In this paper we show how large 12 mixing angles, suitable for the large mixing angle (LMA) MSW solution to the solar neutrino problem, may

Martin Ahr, Michael Biehl

We apply the wavelet transform modulus maxima (WTMM) method to the analysis of simulated MBE-grown surfaces. In contrast to the structure function approach commonly used in the literature, this new method permits an investigation of the complete singularity spectrum. We focus on a kinetic Monte-Carlo model with Arrhenius dynamics, which in particular takes i

Cosmas Zachos

The geometric picture of the star-product based on its Fourier representation kernel is utilized in the evaluation of chains of star-products and the intuitive appreciation of their associativity and symmetries. Such constructions appear even simpler for a variant asymmetric product, and carry through for the standard star-product supersymmetrization.

A. Fabrocini, F. Arias de Saavedra, G. Co

We study the ground state properties of doubly closed shell nuclei $^{16}$O and $^{40}$Ca in the framework of Correlated Basis Function theory using state dependent correlations, with central and tensor components. The realistic Argonne $v_{14}$ and $v'_{8}$ two-nucleon potentials and three-nucleon potentials of the Urbana class have been adopted. By mea

D. Falcone

Assuming hierarchical neutrino masses we calculate the heavy neutrino mass scale in the seesaw mechanism from experimental data on oscillations of solar and atmospheric neutrinos and quark-lepton symmetry. The resulting scale is around or above the unification scale, unless the two lightest neutrinos have masses of opposite sign, in which case the resulting

A. Bacchetta, M. Boglione, A. Henneman, P. J. Mulders

We give bounds on the distribution and fragmentation functions that appear at leading order in deep inelastic 1-particle inclusive leptoproduction or in Drell-Yan processes. These bounds simply follow from positivity of the defining matrix elements and are an important guidance in estimating the magnitude of the azimuthal and spin asymmetries in these proces

CLEO Collaboration

We have investigated exclusive, radiative B meson decays to charmless mesons (ρ, ω, ϕ, K^*(892), K^*_2(1430)) in 9.7\times 10^6 BBbar decays accumulated with the CLEO detector. The B -> K^*(892)γbranching fractions are determined to be Br(B^0 -> K^{*0}(892)γ) = (4.55 +0.72-0.68 +-0.34)\times 10^-5 and Br(B^+ -> K^{*+}(892)γ) = (3.76 +0.89-0.83 +-0.28)\times

I. Cherednikov, S. Fedorov, M. Khalili, K. Sveshnikov

The three-phase version of the hybrid chiral bag model, containing the phase of asymptotic freedom, the hadronization phase as well as the intermediate phase of constituent quarks, is proposed. For this model the self-consistent solution, which takes into account the fermion vacuum polarization effects, is found in (1+1) D. Within this solution the total ene

G. Meylan

Galactic globular clusters are ancient building blocks of our Galaxy. They represent a very interesting family of stellar systems in which some fundamental dynamical processes have been taking place for more than 10 Gyr, but on time scales shorter than the age of the universe. In contrast with galaxies, these star clusters represent unique laboratories for l

S. F. Hassan

We explicitly construct the SO(d,d) transformations of Ramond-Ramond field strengths and potentials, along with those of the space-time supersymmetry parameters, the gravitinos and the dilatinos in type-II theories. The results include the case when the SO(d,d) transformation involves the time direction. The derivation is based on the compatibility of SO(d,d

Everton M. C. Abreu, Jorge Ananias Neto, Wilson Oliveira

The SU(2) Skyrme model,expanding in the collective coordinates variables, gives rise to second-class constraints. Recently this system was embedded in a more general Abelian gauge theory using the BFFT Hamiltonian method. In this work we quantize this gauge theory computing the Noether current anomaly using for this two different methods: an operatorial Dira

Scott Bogner, T. T. S. Kuo, L. Coraggio, A. Covello

A low momentum nucleon-nucleon (NN) potential V-low-k is derived from meson exhange potentials by integrating out the model dependent high momentum modes of V_NN. The smooth and approximately unique V-low-k is used as input for shell model calculations instead of the usual Brueckner G matrix. Such an approach eliminates the nuclear mass dependence of the inp

X. Y. Wang, Z. G. Dai, T. Lu

GRB{980519} is characterized by its rapidly declining optical and X-ray afterglows. Explanations of this behavior include models invoking a dense medium environment which makes the shock wave evolve quickly into the sub-relativistic phase, a jet-like outflow, and a wind-shaped circumburst medium environment. Recently, Frail {et al}. (1999a) found that the la

J. A. Grifols, Eduard Masso, Subhendra Mohanty

We generalize the Schwinger mechanism and calculate the probability of the decay of intense electromagnetic fields to pseudoscalar particles. We also point out that our estimate for axion emission in a previous paper was incorrect.

Misao Sasaki, Tetsuya Shiromizu, Kei-ichi Maeda

We carefully investigate the gravitational perturbation of the Randall-Sundrum (RS) single brane-world solution [hep-th/9906064], based on a covariant curvature tensor formalism recently developed by us. Using this curvature formalism, it is known that the `electric' part of the 5-dimensional Weyl tensor, denoted by $E_{μν}$, gives the leading order corr

Borut Bajc, Gregory Gabadadze

We study two issues, the localization of various spin fields, and the problem of the cosmological constant on a brane in five-dimensional anti de Sitter space. We find that spin-zero fields are localized on a positive-tension brane. In addition to the localized zero-mode there is a continuous tower of states with no mass gap. Spin one-half and three-half sta

Peter B. Blakie, Robert J. Ballagh

A unified semiclassical treatment of Bragg scattering from Bose-Einstein condensates is presented. The formalism is based on the Gross-Pitaevskii equation driven by classical light fields far detuned from atomic resonance. An approximate analytic solution is obtained and provides quantitative understanding of the atomic momentum state oscillations, as well a

Mark Adler, Pierre van Moerbeke

Vertex operators, which are disguised Darboux maps, transform solutions of the KP equation into new ones. In this paper, we show that the bi-infinite sequence obtained by Darboux transforming an arbitrary KP solution recursively forward and backwards, yields a solution to the discrete KP-hierarchy. The latter is a KP hierarchy where the continuous space x-va

Ron Folman, Peter Krüger, Donatella Cassettari, Björn Hessmo

Atoms can be trapped and guided using nano-fabricated wires on surfaces, achieving the scales required by quantum information proposals. These Atom Chips form the basis for robust and widespread applications of cold atoms ranging from atom optics to fundamental questions in mesoscopic physics, and possibly quantum information systems.

D. S. Naik, C. G. Peterson, A. G. White, A. J. Berglund

Using polarization-entangled photons from spontaneous parametric downconversion, we have implemented Ekert's quantum cryptography protocol. The near-perfect correlations of the photons allow the sharing of a secret key between two parties. The presence of an eavesdropper is continually checked by measuring Bell's inequalities. We investigated several

Antonio S. de Castro

A simple and illustrative rheonomic system is explored in the Lagrangian formalism. The difference between Jacobi's integral and energy is highlighted. A sharp contrast with remarks found in the literature is pointed out. The non-conservative system possess a Lagrangian not explicitly dependent on time and consequently there is a Jacobi's integral. T

D. A. Baiko, D. G. Yakovlev, H. E. De Witt, W. L. Slattery

The dynamic structure factor ${\tilde S}({\bf k},ω)$ and the two-particle distribution function $g({\bf r},t)$ of ions in a Coulomb crystal are obtained in a closed analytic form using the harmonic lattice (HL) approximation which takes into account all processes of multi-phonon excitation and absorption. The static radial two-particle distribution function

A. I. Fix, I. V. Glavanakov, Yu. F. Krechetov, O. K. Saiguschkin

The differential cross section for the reaction $^{12}$C$(γ,π^{+}p)$ has been measured in the $Δ$ resonance region at high recoil momenta of the residual nuclear system. The data are analysed under the assumption that the formation of $π^+p$ pairs may be interpreted as $γΔ^{++}\toπ^+p$ process, proceeding on the $Δ^{++}$ constituent in a target nucleus. As a

B. Blank, M. Chartier, S. Czajkowski, J. Giovinazzo

The paper reports on the first observation of doubly-magic Nickel-48 in an experimental at the SISSI/LISE3 facility of GANIL. Four Nickel-48 isotopes were identified. In addition, roughly 100 Nickel-49, 50 Iron-45, and 290 Chromium-42 isotopes were observed. This opens the possibility to search for two-proton emission from these nuclei.

A. G. Ramm

Asymptotic formula is derived for the behavior of the fundamental solution of the second-order elliptic self-adjoint operator with a piecewise-smooth coefficient in front of the senior derivatives near the discontinuity surface of the coefficient. Applications to inverse problems are discussed.

Simon Davis

The equality between the number of odd spin structures on a Riemann surface of genus g, with $2^g - 1$ being a Mersenne prime, and the even perfect numbers, is an indication that the action of the modular group on the set of spin structures has special properties related to the sequence of perfect numbers. A method for determining whether Mersenne numbers ar

Lev A. Borisov

The goal of this paper is to make the vertex operator algebra approach to mirror symmetry accessible to algebraic geometers. Compared to better-known approaches using moduli spaces of stable maps and special Lagrangian fibrations, this approach follows more closely the original line of thinking that lead to the discovery of mirror symmetry by physicists. The

Nikita Sidorov

To a given Pisot unit $β$ we associate a finite abelian group whose size appears to be equal to the discriminant of $β$. We call it the Pisot group and find its representation in the two-sided $β$-compactum in the case of $β$ satisfying the relation $Fin(β)=\Bbb Z[β]\cap[0,1)$. As a motivation for the definition, we show that the Pisot group is the kernel of

A. V. Karasev

The paper is devoted to generalization of well-known Michael's Selection theorem on the case of extension dimension.

Erik Koelink, Jasper V. Stokman

In this paper we present an addition to Askey's scheme of q-hypergeometric orthogonal polynomials involving classes of q-special functions which do not consist of polynomials only. The special functions are q-analogues of the Jacobi and Bessel function, and are Askey-Wilson functions, big q-Jacobi functions and little q-Jacobi functions and the corrrespo

Alan Kostelecky, Malcolm Perry, Robertus Potting

The off-shell structure of the string sigma model is investigated. In the open bosonic string, nonperturbative effects are shown to depend crucially on the regularization scheme. A scheme retaining the notion of string width reproduces the structure of Witten's string field theory and the associated unconventional gauge transformations.

Micha Berkooz

For the purpose of better understanding the AdS/CFT correspondence it is useful to have a description of the theory for all values of the 't Hooft coupling, and for all $N$. We discuss such a description in the framework of Matrix theory for SYM on D4-branes, which is given in terms of quantum mechanics on the moduli space of solutions of the Nahm equati

Dirk Schlingemann

This paper is concerned with a structural analysis of euclidean field theories on the euclidean sphere. In the first section we give proposal for axioms for a euclidean field theory on a sphere in terms of C*-algebras. Then, in the second section, we investigate the short-distance behavior of euclidean field theory models on the sphere by making use of the c

P. J. Mulders

In these lectures I want to discuss how the structure functions in deep inelastic scattering relate to quark and gluon correlation functions. In particular we will consider the issue of intrinsic transverse momenta of quarks, which becomes important in processes like 1-particle inclusive leptoproduction. Some examples of cross sections and asymmetries, in pa

B. E. Cox, J. R. Forshaw, L. Lonnblad

We have performed a detailed phenomenological investigation of the hard colour singlet exchange process observed at the Tevatron in events that have a large rapidity gap between outgoing jets. We include the effects of multiple interactions to obtain a prediction for the gap survival factor. Comparing the data on the fraction of gap events with the predictio

Vito Antonelli, Mrinal Dasgupta, Gavin P. Salam

We calculate the resummed distributions for the thrust in DIS in the limit T->1. Two variants of the thrust are considered: that normalised to Q/2, and that normalised to the energy in the current hemisphere. The results expanded to second order are compared to predictions from the Monte Carlo programs DISENT and DISASTER++. A prescription is given for match

N G Evanson, J R Forshaw

We examine the prospects for studying the diffractive production of high pt photons in the process gamma+gamma -> gamma+X at a future linear collider operating in both ee and gamma-gamma modes. The high luminosity associated with a linear collider make it the ideal place to measure this process.

B E Cox, J R Forshaw

We study the diffractive production of high pt photons at HERA. We have implemented the process as a new hard sub-process in the HERWIG event generator in order to prepare the ground for a future measurement.

Alekhin Sergey

A sensitivity of twist-4 and $α_s$ values extracted in the NLO QCD analysis of nonsinglet SLAC-BCDMS-NMC deep inelastic scattering data to the choice of QCD renormalization scale (RS) is analysed. It is obtained that the high twist (HT) contribution to structure function $F_2$, is retuned with the change of RS. This retuning depends on the choice of starting

Dmitri S. Kourashev

The method suggested in this paper allows to express the n-th order renorm-group equation solutions over the powers of the two-loop solution, that can be obtained explicitly in terms of the Lambert function. On the one hand this expansion helps to get more reliable theoretical predictions, on the other hand the scheme dependence problem can be understood bet

Vladimir G. Baryshevsky

It is shown that the T- and P-odd weak interactions yield to the existence of both electric field and magnetic (directed along the electric field) field around an electric charge. Similarly the assotiated magnetic field is directed along the vector of strength of stationary gravitational field.

K. F. Liu, S. J. Dong, T. Draper, J. Sloan

We reply to Nathan Isgur's critique that is directed at some of the conclusions drawn from the lattice simulation of valence QCD, regarding the valence quark model and effective chiral theories.

Giancarlo Rossi

A number of old and new methods for computing $K\toππ$ amplitudes on the lattice are reevaluated. They all involve a non-perturbative determination of matching coefficients. I will show how problems related to operator mixing can be greatly reduced by introducing the O.P.E. of hadronic currents directly on the lattice. Applications to the evaluation of CP-sy

H. Stüben

The improvement of simulations of QCD with dynamical Wilson fermions by combining the Hybrid Monte Carlo algorithm with parallel tempering is studied. As an indicator for decorrelation the topological charge is used.

The D0 Collaboration, B. Abbott

Using the D0 detector, we have studied events produced in proton-antiproton collisions that contain large forward regions with very little energy deposition (``rapidity gaps'') and concurrent jet production at center-of-mass energies of root-s = 630 and 1800 Gev. The fractions of forward and central jet events associated with such rapidity gaps are m