April 2002 arXiv papers — page 3

Kh. M. Beshtoev

In the article considers some remarks to the standard approach to weak interactions. Higgs mechanism contains contradictions, therefore cannot be considered as a realistic mechanism for mass generations. The couple constant of the weak interactions cannot be changed in dependence on momenta transfer (it leads to violation of the law of energy-momenta convers

Gudrid Moortgat--Pick, Hans Fraas

The consequences of CP and CPT invariance for production and subsequent decay of Dirac and Majorana fermions in polarized fermion--antifermion annihilation are analytically studied. We derive general symmetry relations for the production spin density matrix and for the three--particle decay matrices and obtain constraints for the polarization and the spin--s

E. Bartos, S. R. Gevorkyan, E. A. Kuraev

Using the Sudakov technique we sum the perturbation series for the process $3\to 3$ and obtain the compact analytical expression for the amplitude of this process, which takes into account all possible Coulomb interactions between colliding particles. Compare it with the amplitude of the lepton pair production in heavy ion collision i.e. in the process $ 2\t

A. V. Anisovich, V. V. Anisovich, M. A. Matveev, V. A. Nikonov

We calculate partial widths of the gamma-gamma decay of the tensor q\bar q states a_2(1320), f_2(1270), f_2(1525), their radial excitations a_2(1660), f_2(1640), f_2(1800) as well as ^3F_2 q\bar q states. Calculations are performed in the framework of the same approach which was used before for the study of radiative decays f_0(980) -> gamma-gamma, a_0(980)

F. Becattini, G. Pettini

We develop a model to calculate strangeness production in both elementary and heavy ion collisions, within the framework of a statistical approach to hadronisation. Calculations are based on the canonical partition function of the thermal Nambu-Jona-Lasinio model with exact conservation of flavor and color. It turns out that the growth of strange quarks prod

E. Bartos, S. R. Gevorkyan, E. A. Kuraev, N. N. Nikolaev

We apply the Sudakov technique to description of the multiple production of lepton pairs in peripheral collisions of ultrarelativistic heavy ions. For heavy ions with $Z_1α\sim Z_2α\ll 1$ one needs a careful treatment of the multiple Coulomb exchange between colliding ions and screening effects, whereas interaction of real or virtual lepton pairs with collid

S. Alekhin, C. Balazs, R. Ball, T. Binoth

This Report documents the results obtained by the Working Group on Quantum ChromoDynamics and the Standard Model for the Workshop ``Physics at TeV Colliders'', Les Houches, France, 21 May - 1 June 2001. The account of uncertainties in Parton Distribution Functions is reviewed. Progresses in the description of multiparton final states at Next-to-Leadi

Manfried Faber, Joachim Wabnig, Andrei N. Ivanov

We show that mass generation in 1+1 and 3+1 dimensions may occur together with spontaneous symmetry breaking.

F. Gliozzi, M. Panero, P. Provero

We study the role of large clusters of center vortices in producing confinement in 3D Z(2) gauge theory. First, we modify each configuration of a Monte Carlo-generated ensemble in the confined phase by removing the largest cluster of center vortices, and show that the ensemble thus obtained does not confine. Conversely, we show that removing all of the small

Z. Fodor, S. D. Katz

We propose a method to study lattice QCD at finite temperature (T) and chemical potential (μ). We test the method and compare it with the Glasgow method using n_f=4 staggered QCD with imaginary μ. The critical endpoint (E) of QCD on the Re(μ)-T plane is located. We use n_f=2+1 dynamical staggered quarks with semi-realistic masses on L_t=4 lattices. Our resul

ALEPH Collaboration

Search for Scalar Quarks in e+e- Collisions at sqrt(s) up to 209 GeV Searches for scalar top, scalar bottom and mass-degenerate scalar quarks are performed in the data collected by the ALEPH detector at LEP, at centre-of-mass energies up to 209 GeV, corresponding to an integrated luminosity of 675 pb-1. No evidence for the production of such particles is fou

Tristan J. Beau

This is a talk presented at the XXXVIIth Rencontres de Moriond, Electroweak and Unified Theories session, March 2002. A short review of the solar neutrino Borexino experiment is given.

Y. Islamzade, H. Karadeniz, S. Sultansoy

Main parameters of a Linac*VLHC based ep collider are estimated and compared with resently suggested ep collider in the VLHC tunnel.

Janusz Karkowski, Edward Malec, Zdobyslaw Swierczynski

Disturbing of a spacetime geometry may result in the appearance of an oscillating and damped radiation - the so-called quasinormal modes. Their periods of oscillations and damping coefficients carry unique information about the mass and the angular momentum, that would allow one to identify the source of the gravitational field. In this talk we present recen

J. B. Griffiths, P. Docherty

We present a simple sandwich gravitational wave of the Robinson-Trautman family. This is interpreted as representing a shock wave with a spherical wavefront which propagates into a Minkowski background minus a wedge. (i.e. the background contains a cosmic string.) The deficit angle (the tension) of the string decreases through the gravitational wave, which t

Magnus Boman, Markus Bylund, Fredrik Espinoza, Mats Danielson

Some roaming users need services to manipulate autonomous processes. Trading agents running on agent trade servers are used as a case in point. We present a solution that provides the agent owners with means to upkeeping their desktop environment, and maintaining their agent trade server processes, via a briefcase service.

Qingguo Zheng, Ke Xu, Weifeng Lv, Shilong Ma

In order to control the process of data mining and focus on the things of interest to us, many kinds of constraints have been added into the algorithms of data mining. However, discovering the correlated alarms in the alarm database needs deep domain constraints. Because the correlated alarms greatly depend on the logical and physical architecture of network

M. I. Dykman, B. Golding, J. R. Kruse, L. I. McCann

We show that the rate of activated escape $W$ from a periodically modulated potential displays scaling behavior versus modulation amplitude $A$. For adiabatic modulation of an optically trapped Brownian particle, measurements yield $\ln W\propto (A_{\rm c} - A)^μ$ with $μ= 1.5$. The theory gives $μ=3/2$ in the adiabatic limit and predicts a crossover to $μ=2

Edval J. P. Santos, Anatoly A. Barybin

Recent theoretical results obtained by Barybin and Santos have suggested that the dynamic admittance of the $p-n$-junction is proportional to the modified Bessel function of the first kind which depend on an amplitude of ac signal. This result extends the conventional theory usually encountered in known papers and textbooks. In this letter, some experimental

E. Novais, E. Miranda, A. H. Castro Neto, G. G. Cabrera

We establish a mapping of a general spin-fermion system in one dimension into a classical generalized Coulomb gas. This mapping allows a renormalization group treatment of the anisotropic Kondo chain both at and away from half-filling. We find that the phase diagram contains regions of paramagnetism, partial and full ferromagnetic order. We also use the meth

Sanjib Sabhapandit, Deepak Dhar, Prabodh Shukla

We study hysteresis in the random-field Ising model with an asymmetric distribution of quenched fields, in the limit of low disorder in two and three dimensions. We relate the spin flip process to bootstrap percolation, and show that the characteristic length for self-averaging $L^*$ increases as $exp(exp (J/Δ))$ in 2d, and as $exp(exp(exp(J/Δ)))$ in 3d, for

J. R. Thompson, J. G. Ossandon, L. Krusin-Elbaum, H. J. Kim

Bulk polycrystalline HgBa(2)Ca(2)Cu(3)O(x) materials were irradiated with 0.8 GeV protons to form randomly oriented columnar defects, by induced fission of Hg-nuclei. Proton fluences from 0 to 35 times 10^{16} cm^{-2} were used to install defects with area densities up to a "matching field" of 3.4 Tesla. Studies were conducted on the dependence of th

I. R. Pimentel, T. Temesvari, C. De Dominicis

We study the transition of short range Ising spin glasses in a magnetic field, within a general replica symmetric field theory, which contains three masses and eight cubic couplings, that is defined in terms of the fields representing the replicon, anomalous and longitudinal modes. We discuss the symmetry of the theory in the limit of replica number n to 0,

M. Drndic, M. Vitasovic, N. Y. Morgan, M. A. Kastner

Transport properties of artificial solids composed of colloidal CdSe nanocrystals (NCs) are studied from 6 K to 250 K, before and after annealing. Annealing results in greatly enhanced dark and photocurrent in NC solids, while transmission electron microscopy (TEM) micrographs show that the inter-dot separation decreases. The increased current can be attribu

Michal Kolar, Frantisek Slanina

We compared the properties of the error threshold transition in quasispecies evolution for three different topologies of the genome space. They are a) hypercube b) rugged landscape modelled by an ultrametric space, and c) holey landscape modelled by Bethe lattice. In all studied topologies the phase transition exists. We calculated the critical exponents in

Ronald Dickman

I develop n-site cluster approximations for a stochastic sandpile in one dimension. A height restriction is imposed to limit the number of states: each site can harbor at most two particles (height z_i \leq 2). (This yields a considerable simplification over the unrestricted case, in which the number of states per site is unbounded.) On the basis of results

M. Cardona

Proceedings contribution to Symposium in Memory of Prof. E. Anastassakis, Publ. Center of Technical University of Athens (2002). (contains no abstract).

N. N. Degtyarenko, V. F. Elesin, L. A. Openov, A. I. Podlivaev

By means of ab initio and tight-binding calculations it is shown that metastable nitrogen clusters N_8 (boats) can form quasi-one-dimensional ensembles in which the nearest clusters N_8 are bound to each other by covalent bonds. Those ensembles are characterized by rather high energy barriers (~ 0.3 eV) that prevent the fission of the ensembles into isolated

B. Segev, Y. B. Band

We find a modified Bloch equation for the electronic magnetic moment when the magnetic moment explicitly contains a diamagnetic contribution (a magnetic field induced magnetic moment arising from the electronic orbital angular momentum) in addition to the intrinsic magnetic moment of the electron. The modified Bloch is coupled to equations of motion for the

J. Wakou

We propose a systematic expansion method which is applied to freely evolving granular fluids contained in sufficiently small systems. Restricting ourselves to small systems, we show that there exists a small parameter which characterizes a typical size of density and temperature inhomogeneities. A solution of the hydrodynamic equations for a fluid of inelast

O. Legeza, J. Roder, B. A. Hess

We have applied the momentum space version of the Density Matrix Renormalization Group method ($k$-DMRG) in quantum chemistry in order to study the accuracy of the algorithm in the new context. We have shown numerically that it is possible to determine the desired accuracy of the method in advance of the calculations by dynamically controlling the truncation

Andrew Das Arulsamy

Fermi-Dirac statistics has been utilized by introducing the average ionization energy ($E_I$) as an additional anomalous energy gap in order to derive the two-dimensional concentration of charge carriers and the phenomenological resistivity model for the superconducting polycrystalline materials. The best fitted values of $E_I$ and the charge carriers' c

I. R. Peterson

Modern statistical thermodynamics retains the concepts employed by Landau of the order parameter and a functional depending on it, now called the Hamiltonian. The present paper investigates the limits of validity for the use of the functional to describe the statistical correlations of a thermodynamic phase, particularly in connection with the experimentally

W. Goldacker, S. I. Schlachter, H. Reiner, S. Zimmer

In this contribution, different concepts for mechanically reinforced MgB2 wires with high transport currents are presented and characterised. It is shown that the achieved critical transport currents depend strongly on the conductor concept, the choice of the precursor route and the applied treatment method.

Gun Sang Jeon, Hyun Jin Kim, M. Y. Choi, Beom Jun Kim

We investigate dynamic transitions and stochastic resonance phenomena in two-dimensional fully frustrated Josephson-junction arrays driven by staggered oscillating magnetic fields. As the temperature is lowered, the dynamic order parameter, defined to be the average staggered magnetization, is observed to acquire nonzero values. The resulting transition is f

Yuri O. Popov

A hydrodynamic mechanism of interactions of colloidal particles is considered. The mechanism is based on the assumption of tiny background flows in the experimental cells during measurements by Grier at al. [1-6]. Both trivial (shear flow) and non-trivial (force propagation through viscous fluid) effects are taken into account for two colloidal particles nea

Michael Nowak, Sebastian Heinz, Mitchell Begelman

During a previous outburst phase, the neutron star 4U 2129+47 exhibited evidence for a spatially extended corona via broad, partial X-ray eclipses occurring periodically on the 5.24 hr orbit. Since 1983, however, 4U 2129+47 has entered a quiescent state several orders of magnitude fainter. We have performed a 37 ksec Chandra observation of 4U 2129+47 to dete

Valentin D. Ivanov, Jordanka Borissova

The near-infrared behavior of the red giant branch (RGB hereafter) as a function of abundance is examined with an unprecedented large sample of 27 Galactic globular clusters with Two Micron All Sky Survey photometry. We propose a new simplified analyses, involving the zero point of the RGB slope fit, and derive calibrations for the RGB slope, zero point, and

M. Paolillo

We present the study of three bright Early-Type galaxies hosted in groups or poor clusters: NGC 1399, NGC 1404 and NGC 507. We used ROSAT HRI, PSPC and, when available, higher resolution Chandra data to study the structure of the X-ray halo. The halo center of NGC 1399 and NGC 507 is dominated by a bright emission peak coincident with the position of the opt

Stephen D. Landy, Alexander S. Szalay

A precision method for determining the value of Beta= Omega_m^{0.6}/b, where b is the galaxy bias parameter, is presented. In contrast to other existing techniques that focus on estimating this quantity by measuring distortions in the redshift space galaxy-galaxy correlation function or power spectrum, this method removes the distortions by reconstructing th

J. Sollerman, S. T. Holland, P. Challis, C. Fransson

The probable association with GRB 980425 immediately put SN 1998bw at the forefront of supernova research. Here, we present revised late-time BVRI light curves of the supernova, based on template images taken at the VLT. To follow the supernova to the very last observable phases we have used HST/STIS. Deep images taken in June and November 2000 are compared

Jesper Sollerman, Veronica Flyckt

We present new data of the Crab pulsar and its environment. Images taken in the infrared with ISAAC allow us to measure the pulsar spectrum and to reveal the red knot close to the pulsar. Complementary optical data from VLT and HST are presented. The full article, with full resolution nice color images, is presented in Messenger, 107, 32

Anthony L. Piro, Lars Bildsten

Chandra observations of elliptical galaxies have revealed large numbers of Low Mass X-ray Binaries (LMXBs) accreting at rates above 10^-9 solar masses per year. One scenario which generates this transfer rate from an old stellar population is nuclear driven mass transfer onto a neutron star or black hole from a Roche lobe filling red giant. However, in our G

S. Rosswog

We describe the results high resolution, hydrodynamic calculations of neutron star mergers. The model makes use of a new, nuclear equation of state, accounts for multi-flavour neutrino emission and solves the equations of hydrodynamics using the smoothed particle hydrodynamics method with more than $10^6$ particles. The merger leaves behind a strongly differ

Manuel Merchan, Ariel Zandivarez

We construct a galaxy groups catalogue from the public 100K data release of the 2dF galaxy redshift survey. The group identification is carried out using a slightly modified version of the group finding algorithm developed by Huchra & Geller. Several tests using mock catalogues allow us to find the optimal conditions to increase the reliability of the final

Bruno Leibundgut, Jesper Sollerman

Review article on the cosmological implications of Type Ia Supernovae for Europhysics News.

P. Manoj, G. Maheswar, H. C. Bhatt

We present optical spectra of four intermediate mass candidate young stellar objects that have often been classified as Herbig Ae/Be stars. Typical Herbig Ae/Be emission features are not present in the spectra of these stars. Three of them, HD 36917, HD 36982 and HD 37062 are members of the young Orion Nebula Cluster (ONC). This association constrains their

M. C. Galvez, D. Montes, M. J. Fernandez-Figueroa, J. Lopez-Santiago

We present high resolution echelle spectra taken during four observing runs from 1999 to 2001 of the recently X-ray/EUV selected chromospherically active binary BK Psc (2RE J0039+103). Our observations confirm the single-lined spectroscopic binary(SB1) nature of this system and allow us to obtain, for the first time,the orbital solution of the system as in t

R. Mukherjee, J. Halpern, N. Mirabal, E. V. Gotthelf

We discuss the nature of the unidentified EGRET source 3EG J1621+8203. In an effort to identify the gamma-ray source, we have examined X-ray images of the field from ROSAT PSPC, ROSAT HRI, and ASCA GIS. Of the several faint X-ray point sources in the error circle of 3EG J1621+8203, most are stars or faint radio sources, unlikely to be counterparts to the EGR

A. C. Fabian, A. Celotti, R. M. Johnstone

A Chandra observation of the radio-loud quasar 3C9 at redshift z=2.012 has revealed extended X-ray emission coincident with the radio jet. Of particular interest is the appearance of both jet and counterjet, which argues against the X-ray emission being highly beamed. We present the properties of the jets and discuss possible scenarios for the X-ray emission

Ryuichi Takahashi, Naoki Seto

We calculate how accurately parameters of the short-period binaries $(10^{-4} {Hz} \lsim f\lsim 10^{-2} {Hz})$ will be determined from the gravitational waves by LISA. In our analysis the chirp signal ${\dot f}$ is newly included as a fitting parameters and dependence on observational period or wave frequency is studied in detail. Implications for gravitatio

Rachel Bean, Joao Magueijo

There is growing observational evidence for a population of supermassive black holes (SMBHs) in galactic bulges. We examine in detail the conditions under which these black holes must have originated from primordial black holes (PBHs). We consider the merging and accretion history experienced by SMBHs to find that, whereas it is possible that they were forme

R. Thieberger, E. A. Spiegel

We analyze examples of projected two dimensional fractals for the case where the objects studied have a Schechter luminosity function. Our results indicate that two dimensional catalogues of sources could be of value in detecting the effects of luminosity functions as well as of large scale structure.

Brian Warner, Patrick A. Woudt

The Dwarf Nova Oscillations observed in Cataclysmic Variable (CV) stars are interpreted in the context of a Low Inertia Accretor model, in which accretion on to an equatorial belt of the white dwarf primary causes the belt to vary its angular velocity. The rapid deceleration phase is attributed to propellering. Evidence that temporary expulsion rather than a

Patrick A. Woudt, Brian Warner

Short time scale photometric properties of eight faint Cataclysmic Variable (CV) stars are presented. Nova Carinae 1895 (RS Car) has a photometric modulation at 1.977 h which could be either an orbital or a superhump period. Nova Carinae 1948 (V365 Car) shows flickering, but any orbital modulation has a period in excess of 6 h. The nova-like variable and X-r

B. Ricci, F. L. Villante

Several properties of the solar interior are determined with a very high accuracy, which in some cases is comparable to that achieved in the determination of the Newton constant $G_N$. We find that the present uncertainty $ΔG_N/G_N=\pm 1.5\cdot 10^{-3}$ has significant effects on the profile of density and pressure, however it has negligible influence on the

Yury Lyubarsky, David Eichler

The recent Chandra image of the Crab nebula shows a striking, axisymmetric polar jet. It is shown that jets are formed in axisymmetric, magnetized pulsar winds and that the jet luminosity scales relative to the total as (γ_0σ_{eq})^{-4/3}, where σ_{eq} is the ratio of Poynting flux to particle kinetic energy output at the equator at the base of the flow and

Wei Zhou, Tong-Jie Zhang, Li Chen, Xiang-Tao He

Using semi-analytic approach, we present an estimate of the properties of the largest virialized dark halos in the present universe for three different scenarios of structure formation: SCDM, LCDM and OCDM models. The resulting virial mass and temperature increase from the lowest values of $1.6 \times 10^{15}h^{-1}M_{\odot}$ and 9.8 keV in OCDM, the mid-rang

Paul J. Steinhardt, Neil Turok

The Cyclic Model is a radical, new cosmological scenario which proposes that the Universe undergoes an endless sequence of epochs which begin with a `big bang' and end in a `big crunch.' When the Universe bounces from contraction to re-expansion, the temperature and density remain finite. The model does not include a period of rapid inflation, yet it

Jesper Sollerman

At late phases the powering of supernova light curves is often provided by the decay of radioactive elements synthesized in the explosions. This is unambiguously revealed when the light curve decline follows the half life time of the decaying elements, and the bolometric luminosity then directly provides the mass of ejected radioactive material. I will focus

A. M. Bratkovsky, P. E. Kornilovitch

We study the effects of gating and contact geometry on current through self-assembled monolayers of conjugated molecules strongly coupled to gold electrodes by sulfur ``anchor groups''. The current changes by more than an order of magnitude depending on the angle between the axis of the benzene-dithiolate molecules and the normal to the electrode on

A. V. Goltsev, S. N. Dorogovtsev, J. F. F. Mendes

We develop a phenomenological theory of critical phenomena in networks with an arbitrary distribution of connections $P(k)$. The theory shows that the critical behavior depends in a crucial way on the form of $P(k)$ and differs strongly from the standard mean-field behavior. The critical behavior observed in various networks is analyzed and found to be in ag

Mark D. Roberts

Whether a string has rotation and shear can be investigated by an anology with the point particle. Rotation and shear involve first covariant spacetime derivatives of a vector field and, because the metric stress tensor for both the point particle and the string have no such derivatives, the best vector fields can be identified by requiring the conservation

Dirk Tasche, Luisa Tibiletti

Approximate Incremental Value-at-Risk formulae provide an easy-to-use preliminary guideline for risk allocation. Both the cases of risk adding and risk pooling are examined and beta-based formulae achieved. Results highlight how much the conditions for adding new risky positions are stronger than those required for risk pooling. Key words: Incremental Value-

Wolfgang Lucha, F. F. Schoberl

The electric polarizability of mesons, in particular, that of the charged pion, is studied in the framework of a semirelativistic description of hadrons as bound states of valence quarks in terms of a Hamiltonian composed of the relativistic kinetic energy as well as a phenomenological potential describing the strong interactions between the quarks. The quar

Bin Chen, Feng-Li Lin

In this paper we map the D-brane projector states in the vacuum string field theory to the noncommutative GMS solitons based on the recently proposed map of Witten's star to Moyal's star. We find that the singular geometry conditions of Moore and Taylor are associated with the commutative modes of these projector states in our framework. The properti

Shlomo Dado, Arnon Dar, A. De Rujula

We use the cannonball (CB) model of gamma ray bursts (GRBs) to predict the spectral and temporal behaviour of their radio afterglows (AGs). A single simple expression describes the AGs at all times and frequencies; its high-frequency limit reproduces the successful CB model predictions for optical and X-ray AGs. We analyze all of the observed radio AGs of GR

Zuo-tang Liang, Chun-xiu Liu

We show that, in $ν_μN\to μ^-ΛX$ at the NOMAD energies, it is impossible to separate the products of the fragmentation of the struck quark from those of the nucleon remnant. The latter has a large contribution even in the current fragmentation region and has to be taken into account in calculating $Λ$ polarization using different pictures. Based on this, we

Ho-Meoyng Choi, Chueng-Ryong Ji, L. S. Kisslinger

We discuss a consistent treatment of the light-front gauge-boson and meson wave functions in the analyses of the generalized parton distributions(GPDs) and the scattering amplitudes in deeply virtual Compton scattering(DVCS) for the pion. The continuity of the GPDs at the crossover, where the longitudinal momentum fraction of the probed quark is same with th

J. J. Wlodarz

In a recent paper [PRE 62, 4665 (2000)] (quant-ph/0203102) Manfredi and Feix proposed an alternative definition of quantum entropy based on Wigner phase-space distribution functions and discussed its properties. They proposed also some simple rules to construct positive-definite Wigner functions which are crucial in their discussion. We show, however, that t

Jing-Ling Chen, Libin Fu, Abraham A. Ungar, Xian-Geng Zhao

In this paper, we present a measure to quantify the degree of entanglement for two qubits in a pure state.

Jerzy Stryla

To describe stochastic quantum processes I propose an integral equation of Volterra type which is not generally transformable to any differential one. The process is a composition of ordinary quantum evolution which admits presence of a quantum bath and reductions to pure states. It is proved that generically solutions stabilize asymptotically for $t\to +\in

Ariel Kaplan, Mikkel Fredslund Andersen, Nir Davidson

We present a novel method for reducing the inhomogeneous frequency broadening in the hyperfine splitting of the ground state of optically trapped atoms. This reduction is achieved by the addition of a weak light field, spatially mode-matched with the trapping field and whose frequency is tuned in-between the two hyperfine levels. We experimentally demonstrat

Mikhail Kozlov

We calculate nuclear spin-dependent parity non-conserving $E1$-amplitudes for optical transition $6p_{1/2,F} -> 6p_{3/2,F'}$ and for hyperfine transition $6p_{1/2,F} -> 6p_{1/2,F'}$ in Tl. Experimental limit on the former amplitude placed by Vetter et al. [PRL, 74, 2658 (1995)] corresponds to the anapole moment constant $κ_a = -0.26 \pm 0.27$. Experi

A. S. Rinat, M. F. Taragin

We consider a generalized convolution, linking Structure Functions (SF) $F^N_2$ for nucleons, $F^A_2$ for a physical nucleus and $f^{PN,A}$ for a nucleus, composed of point-nucleons. In order to extract $F_2^n$ we employ data on $F_2^{p,A}$ and the computed $f^{PN,A}$. Only for $Q^2\approx 3.5 {\rm GeV}^2$ do data permit the extraction of $F_2^A(x,3.5)$ over

Mukut Mani Tripathi, Jeong-Sik Kim, Jaedong Choi

Certain basic inequalities between intrinsic and extrinsic invariants for a submanifold in a (k, m)-contact space form are obtained. As applications we get some results for invariant submanifolds in a (k,m)-contact space form.

M. Bertola, D. Gouthier

We study the solvability of the equation for the smooth function F, H=-k F g, on a geodesically complete pseudo-Riemannian manifold (M,g), H being the covariant Hessian of F. A similar equation was considered by Obata and Gallot in the Riemannian case for positive values of the constant k; the result was that the manifold must be the canonical sphere. In thi

Eugene Lerman

In a recent preprint Yael Karshon showed that there exist non-conjugate tori in a group of symplectomorphisms of a Hirzebruch surface. She counted them in terms of the cohomology class of the symplectic structure. We show that a similar phenomenon exists in the contactomorphism groups of pre-quantum circle bundles over Hirzebruch surfaces. Note that the cont

Ruth Stella Huerfano, Mikhail Khovanov

We categorify representations of quantum sl(n) whose highest weight is twice a fundamental weight.

Pieter Moree, Herman J. J. te Riele

We establish Schmutz Schaller's conjecture that the hexagonal lattice is `better' than the square lattice. Schmutz Schaller (Bulletin of the AMS 35 (1998), p. 201), motivated by considerations from hyperbolic geometry, conjectured that in dimensions 2 to 8 the best known lattice sphere packings have `maximal lengths' and goes on to write: "In

Alejandro Rivero

We walk out the landscape of K-theoretic Poincare Duality for finite algebras. It paves the way to get continuum Dirac operators from discrete noncommutative manifolds.

Massimo Giovannini

It is shown that negative tension branes in higher dimensions may lead to an effective lower dimensional theory where the gauge-invariant vector fields associated with the fluctuations of the metric are always massless and localized on the brane. Explicit five-dimensional examples of this phenomenon are provided. Furthermore, it is shown that higher dimensio

S. I. Bityukov, N. V. Krasnikov

We describe a method for estimation of the discovery potential on new physics in planned experiments. The effective significance of signal for given probability of observation is proposed for planned experiments instead of the usual significances S_1 = n_s/sqrt{n_b} and S_2 = n_s/sqrt{n_s+n_b}, where n_s and n_b are the average numbers of signal and backgrou

Kh. M. Beshtoev

The theoretical schemes on neutrino oscillations are considered. The experimental data on neutrino oscillations from Super-Kamiokande (Japan) and SNO (Kanada) are given. Comparison of these data with theoretical schemes is done. Conclusion is made that the experimental data have confirmed the scheme only with transitions (oscillations) between aromatic $ν_e,

Zuo-tang Liang, Qing-hua Xu

We apply the picture proposed in a recent Letter for transverse hyperon polarization in unpolarized hadron-hadron collisions to the exclusive process e^-p --> e^-HK such as e^-p-->e^-ΛK^+, e^-p --> e^-Σ^+ K^0, or e^-p--> e^-Σ^0 K^+, or the similar process e^-p\to e^-nπ^+ with longitudinally polarized electron beams. We present the predictions for the longitu

O. Borisenko, S. Voloshin, M. Faber

We develop an analytical approach for non-abelian gauge models within the plaquette representation where the plaquette matrices play the role of the fundamental degrees of freedom. We start from the original Batrouni formulation and show how it can be modified in such a way that each non-abelian Bianchi identity contains two connectors instead of four. Using

L. C. Garcia de Andrade

Ghost neutrinos in radiative Kerr spacetime endowed with totally skew-symmetric Cartan contortion is presented. The computations are made by using the Newman-Penrose (NP) calculus. The model discussed here maybe useful in several astrophysical applications specially in black hole astrophysics.

G. Parisi, M. Ratieville

We get back to the computation of the leading finite size corrections to some random link matching problems, first adressed by Mezard and Parisi [J. Physique 48 (1987) 1451-1459]. In the so-called bipartite case, their result is in contradiction with subsequent works. We show that they made some mistakes, and correcting them, we get the expected result. In t

Davide Controzzi, Fabian H. L. Essler

We consider the one dimensional (1D) extended Hubbard model at half filling in the presence of a magnetic field. Using field theory techniques we calculate the dynamical density-density correlation function $χ_{nn}(ω,q)$ in the low-energy limit. When excitons are formed, a singularity appears in $χ_{nn}(ω,q)$ at a particular energy and momentum transfer.

K. D. Sviratcheva, A. I. Georgieva, J. P. Draayer

A fermion realization of the compact symplectic sp(4) algebra provides a natural framework for studying isovector pairing correlations in nuclei. While these correlations manifest themselves most clearly in the binding energies of 0^+ ground states, they also have a large effect on the energies of excited states, including especially excited 0^+ states. In t

R. J. McLure, M. J. Jarvis

A new technique is presented for determining the black-hole masses of high-redshift quasars from optical spectroscopy. The new method utilizes the full-width half maximum (FWHM) of the low-ionization MgII emission line and the correlation between broad-line region (BLR) radius and continuum luminosity at 3000 Angstroms. Using archival UV spectra it is found

J. M. Cline, U. A. Yajnik, S. N. Nayak, M. Rabikumar

It is shown that the dynamics of domain walls in Left-Right symmetric models, separating respective regions of unbroken SU(2)_L and SU(2)_R in the early universe, can give rise to baryogenesis via leptogenesis. Neutrinos have a spatially varying complex mass matrix due to CP-violating scalar condensates in the domain wall. The motion of the wall through the

M. Lundin, J. -O. Adler, M. Boland, K. Fissum

Differential cross sections for Compton scattering from the deuteron were measured at MAX-lab for incident photon energies of 55 MeV and 66 MeV at nominal laboratory angles of $45^\circ$, $125^\circ$, and $135^\circ$. Tagged photons were scattered from liquid deuterium and detected in three NaI spectrometers. By comparing the data with theoretical calculatio

Jesper Lykke Jacobsen, Jesús Salas, Alan D. Sokal

We study the chromatic polynomial P_G(q) for m \times n triangular-lattice strips of widths m <= 12_P, 9_F (with periodic or free transverse boundary conditions, respectively) and arbitrary lengths n (with free longitudinal boundary conditions). The chromatic polynomial gives the zero-temperature limit of the partition function for the q-state Potts antiferr

Artur B. Adib

In an attempt to derive thermodynamics from classical mechanics, an approximate expression for the equilibrium temperature of a finite system has been derived [M. Bianucci, R. Mannella, B. J. West, and P. Grigolini, Phys. Rev. E 51, 3002 (1995)] which differs from the one that follows from the Boltzmann principle S = k log (Omega(E)) via the thermodynamic re

Xiao-Jun Bi, Yuan-Ben Dai

We propose a phenomenological form of the charged lepton mass matrix, which extends the idea of ``lopsided&#39;&#39; mass matrix in the literature. The features of the form are that both the 2-3 and 1-3 elements of the charged lepton mass matrix are of order 1 and that the small elements have a new structure . This form leads to an interesting result that bo

Javid Atai, Boris A. Malomed

We introduce a model combining Kerr nonlinearity with a periodically changing sign (&#34;nonlinearity management&#34;) and a Bragg grating (BG). The main result, obtained by means of systematic simulations, is presented in the form of a soliton&#39;s stability diagram on the parameter plane of the model; the diagram turns out to be a universal one, as it pra

A. E. Kovalsky, G. P. Pronko

Considering the XXX spin-1/2 chain in the framework of the Algebraic Bethe Ansatz (ABA) we make the following short comment: the product of the creation operators corresponding to the recently found solution of the Bethe equations &#34;on the wrong side of the equator&#34; (hep-th/9808153) is just zero (not only its action on the pseudovacuum).

Panayotis G. Kevrekidis, Boris A. Malomed, H. E. Nistazakis, Dimitri J. Frantzeskakis

A model is introduced to describe guided propagation of a linear or nonlinear pulse which encounters a localized nonlinear defect, that may be either static or breather-like one (the model with the static defect applies to an optical pulse in a long fiber link with an inserted additional section of a nonlinear fiber). In the case when the host waveguide is l

Christian Hainzl

We look at an electron in the field of an arbitrary external potential $V$, such that the Schrödinger operator $p^2 + V$ has at least one eigenvalue, and show that by coupling to a quantized radiation field the binding energy increases, at least for small enough values of the coupling constant $α$. Moreover, we provide concrete numbers for $α$, the ultraviol