April 2002 arXiv papers — page 17

Yoonbai Kim, Kimyeong Lee

The low energy dynamics of vortices in selfdual Abelian Higgs theory is of second order in vortex velocity and characterized by the moduli space metric. When Chern-Simons term with small coefficient is added to the theory, we show that a term linear in vortex velocity appears and can be consistently added to the second order expression. We provides an additi

Chanju Kim, Kimyeong Lee, Sang-Heon Yi

We investigate a class of matrix model which describes the dynamics of identical particles in even dimentional space. We show that the degrees of freedom after some constraints are implimented is proportional to particle number and consist of those for positions and internal degrees. The particle dynamics is given by the metric on the smooth moduli space. Th

Robin Booth

We highlight the fact that the lack of scale invariance in the gravitational field equations of General Relativity results from the underlying assumption that the appropriate scale for the gravitational force should be linked to the atomic scale. We show that many of the problems associated with cosmology and quantum gravity follow directly from this assumpt

P. Mohanty, R. A. Webb

We report measurements of conductance distribution in a set of quasi-one-dimensional gold wires. The distribution includes the second cumulant or the variance which describes the universal conductance fluctuations, and the third cumulant which denotes the leading deviation. We have observed an asymmetric contribution--or, a nonvanishing third cumulant--contr

Tim K. Hossain, James V. Lindesay, Michael G. Spencer

A major issue in the development of the technology of nitride based materials is the choice of substrate. The structural and optical properties of the layers are intimately connected to the substrate material used in the epitaxial growth. Key issues include lattice matching of substrate and epitaxial layer and the difference in the thermal expansion between

Fa-Min Liu, Tian-Min Wang, Li-De Zhang, Guo-Hua Li

The GaSb and Ga0.62In0.38Sb nanocrystals were embedded in the SiO2 films by radio-frequency magnetron co-sputtering and were grown on GaSb and Si substrates at different temperatures. We present results on the 10K excitonic photoluminescence (PL) properties of nanocrystalline GaSb and Ga0.62In0.38Sb as a function of their size. The measurements show that the

Hans-Christian v. Bothmer, Christian Meister

Several authors have noticed the signature of log-periodic oscillations prior to large stock market crashes [cond-mat/9509033, cond-mat/9510036, Vandewalle et al 1998]. Unfortunately good fits of the corresponding equation to stock market prices are also observed in quiet times. To refine the method several approaches have been suggested: 1) Logarithmic Dive

M H Szymanska

In the first part of this thesis I study the intermediate regime between ordinary lasing and a BEC of exciton polaritons. I take into account the fermionic structure of polaritons, treating the excitons as two-level systems coupled to a single mode in a microcavity. I introduce decoherence and dissipation processes to this system. Employing many-body Green f

C. A. Stafford

Metal nanowires exhibit a number of interesting properties: their electrical conductance is quantized, their shot-noise is suppressed by the Pauli principle, and they are remarkably strong and stable. We show that many of these properties can be understood quantitatively using a nanoscale generalization of the free-electron model. Possible technological appl

V. Brouet, H. Alloul, S. Garaj, L. Forro

We present 13C NMR spin-lattice relaxation measurements (1/T1) in Na2CsC60 and Rb3C60 from 10 to 700K. The large temperature range of this measurement allow to define unambiguously an increase of 1/T1T with increasing temperature, which is anomalous in a simple metallic picture, where the Korringa law predicts 1/T1T = cst. We attribute this increase to the e

Jonathan Kemp, Joseph Patterson, John Thorstensen, Robert Fried

We present photometry and spectroscopy of HT Camelopardalis, a recently discovered X-ray-bright cataclysmic variable. The spectrum shows bright lines of H, He I, and He II, all moving with a period of 0.059712(1) d, which we interpret as the orbital period. The star's brightness varies with a strict period of 515.0592(2) s, and a mean full amplitude of 0

D. G. Yakovlev, O. Y. Gnedin, A. D. Kaminker, A. Y. Potekhin

Cooling of neutron stars (NSs) with the cores composed of neutrons, protons, and electrons is analyzed. The main cooling regulators are discussed: opening of direct Urca process in a NS central kernel; superfluidity of nucleons in NS interiors; surface layers of light (accreted) elements; strong surface magnetic fields. An emphasis is paid on the cooling sce

S. Seager, Lam Hui

(Abridged) The solar system gas giant planets are oblate due to their rapid rotation. A measurement of the planet's projected oblateness would constrain the planet's rotational period. Planets that are synchronously rotating with their orbital revolution will be rotating too slowly to be significantly oblate; these include planets with orbital semi-m

S. Iwamoto, F. Takahara

We investigate a novel mechanism of bulk acceleration for relativistic jets of pure electron-positron pair plasma.We assumed that relativistically hot plasma is optically thick for Compton scattering and then pair plasma coupled dynamically to photons may establish quasi-Wien equilibria. We name such an electron-positron pair plasma the "Wien-fireball&#3

Akio K. Inoue

We examine what types of galaxies the conversion formula from dust infrared (IR) luminosity into the star formation rate (SFR) derived by Kennicutt (1998) is applicable to. The ratio of the observed IR luminosity, $L_{\rm IR}$, to the intrinsic bolometric luminosity of the newly ($\la$ 10 Myr) formed stars, $L_{\rm SF}$, of a galaxy can be determined by a me

Tzihong Chiueh, Jounghun Lee, Lihwai Lin

We derive the distribution of the dimensionless specific angular momentum of dark matter halos, $P(j)$, in the framework of the standard tidal torque theory, and explain the characteristic shape of $P(j)$ commonly observed in N-body simulations. A scalar quantity (shear scalar), $r$, is introduced for measuring the effective strength of the tidal torque forc

M. A. Malkan, E. K. Hicks, H. I. Teplitz, I. M. McLean

We present a catalog of J-band (1.08 um to 1.35 um) stellar spectra at low resolution (R ~ 400). The targets consist of 105 stars ranging in spectral type from O9.5 to M7 and luminosity classes I through V. The relatively featureless spectra of hot stars, earlier than A4, can be used to remove the atmospheric features which dominate ground-based J-band spect

F. Camilo, I. H. Stairs, D. R. Lorimer, D. C. Backer

We report the discovery with the 100 m Green Bank Telescope of 65 ms radio pulsations from the X-ray pulsar J0205+6449 at the center of supernova remnant 3C58, making this possibly the youngest radio pulsar known. From our observations at frequencies of 820 and 1375 MHz, the free electron column density to PSR J0205+6449 is found to be 140.7 +- 0.3 pc/cc. Th

Martin Kruczenski, Robert C. Myers, Amanda W. Peet, David J. Winters

We find supersymmetric solutions of the D4 brane Born-Infeld action describing D2 supertubes ending on an arbitrary curve inside a D4 brane. From the D4 brane point of view, these are dyonic strings. We also consider various higher dimensional extensions of the usual supertubes, involving expanded D4 and D3 brane configurations. Finally, considering the worl

E791 Collaboration

We study the Dalitz plot of the decay D^+ --> K^- pi^+ pi^+ with a sample of 15090 events from Fermilab experiment E791. Modeling the decay amplitude as the coherent sum of known K pi resonances and a uniform nonresonant term, we do not obtain an acceptable fit. If we allow the mass and width of the K^*_0(1430) to float, we obtain values consistent with thos

J. D. Jackson

The main purposes of this paper are (i) to illustrate explicitly by a number of examples the gauge functions chi(x, t) whose spatial and temporal derivatives transform one set of electromagnetic potentials into another equivalent set; and (ii) to show that, whatever propagation or non-propagation characteristics are exhibited by the potentials in a particula

M. C. Bento, O. Bertolami, A. A. Sen

We study N=1 Supergravity inflation in the context of the braneworld scenario. Particular attention is paid to the problem of the onset of inflation at sub-Planckian field values and the ensued inflationary observables. We find that the so-called $η$-problem encountered in supergravity inspired inflationary models can be solved in the context of the branewor

Z. Chacko, C. Grojean, M. Perelstein

Recent experimental data indicates that the fine structure constant alpha may be varying on cosmological time scales. We consider the possibility that such a variation could be induced by a second order phase transition which occurs at late times (z ~ 1 - 3) and involves a change in the vacuum expectation value (vev) of a scalar with milli-eV mass. Such ligh

W. Bietenholz

We construct new Ginsparg-Wilson fermions for QCD by inserting an approximately chiral Dirac operator - which involves ingredients of a perfect action - into the overlap formula. This accelerates the convergence of the overlap Dirac operator by a factor of 5 compared to the standard construction, which inserts the Wilson fermion as a point of departure. Taki

Levon Pogosian, Daniele A. Steer, Tanmay Vachaspati

We investigate all spherically symmetric fundamental monopole solutions with fixed topological charge in the SU(5) --> SU(3)xSU(2)xU(1)/Z_3xZ_2 symmetry breaking. We find that there is three-fold replication of the monopoles. The three copies correspond to bound states with ``monopole clouds'' arising from the non-Abelian nature of the SU(3) factor.

Martin Snethlage, Vicent J. Martinez, Dietrich Stoyan, Enn Saar

There is empirical evidence that the two-point correlation function of the galaxy distribution follows, for small scales, reasonably well a power-law expression $ξ(r)\propto r^{-γ}$ with $γ$ between 1.5 and 1.9. Nevertheless, most of the point field models suggested in the literature do not have this property. This paper presents a new class of models, which

Tatsuo Shibata, Kunihiko Kaneko

A model of interacting motile chaotic elements is proposed. The chaotic elements are distributed in space and interact with each other through interactions depending on their positions and their internal states. As the value of a governing parameter is changed, the model exhibits successive phase changes with novel pattern dynamics, including spatial cluster

K. W. Edwards

We have searched a sample of 9.6 million BB-bar events for the lepton-flavor-violating decays B --> h e^{+-} mu^{-+}, B^+ --> h^- e^+ e^+, B^+ --> h^- e^+ mu^+, and B^+ --> h^- mu^+ mu^+, where h is pi, K, rho, and K*(892), a total of sixteen modes. We find no evidence for these decays, and place 90% confidence level upper limits on their branching fractions

I. M. Khalatnikov, A. Yu. Kamenshchik, A. A. Starobinsky

We generalize for the case of arbitrary hydrodynamical matter the quasi-isotropic solution of Einstein equations near cosmological singularity, found by Lifshitz and Khalatnikov in 1960 for the case of radiation-dominated universe. It is shown that this solution always exists, but dependence of terms in the quasi-isotropic expansion acquires a more complicat

David J. Ward, David J. C. MacKay

We describe a method for text entry based on inverse arithmetic coding that relies on gaze direction and which is faster and more accurate than using an on-screen keyboard. These benefits are derived from two innovations: the writing task is matched to the capabilities of the eye, and a language model is used to make predictable words and phrases easier to w

Thomas Appelquist, Robert Shrock

We address the problem of accounting for light neutrino masses in theories with dynamical electroweak symmetry breaking. We discuss this in the context of a class of (extended) technicolor (ETC) models and analyze the full set of Dirac and Majorana masses that arise in such theories. As a possible solution, we propose a combination of suppressed Dirac masses

Dan Radu Grigore, Gunter Scharf

We consider a supersymmetric extension of quantum gauge theory based on a vector multiplet containing supersymmetric partners of spin 3/2 for the vector fields. The constructions of the model follows closely the usual construction of gauge models in the Epstein-Glaser framework for perturbative field theory. Accordingly, all the arguments are completely of q

Jaromir Fiurasek

We prove that it is impossible to distill more entanglement from a single copy of a two-mode bipartite entangled Gaussian state via LOCC Gaussian operations. More generally, we show that any hypothetical distillation protocol for Gaussian states involving only Gaussian operations would be a deterministic protocol. Finally, we argue that the protocol consider

Sergiu Moroianu

We extend the calculus of adiabatic pseudo-differential operators to study the adiabatic limit behavior of the eta and zeta functions of a differential operator $δ$, constructed from an elliptic family of operators indexed by $S^1$. We show that the regularized values $η(δ_t,0)$ and $tζ(δ_t,0)$ are smooth functions of $t$ at $t=0$, and we identify their valu

A. I. Posazhennikova, T. Dahm, K. Maki

The recently discovered superconductivity in MgB2 has captured world attention due to its simple crystal structure and relatively high superconducting transition temperature Tc=39K. It appears to be generally accepted that it is phonon-mediated s-wave BCS-like superconductivity. Surprisingly, the strongly temperature dependent anisotropy of the upper critica

Vasilis Archontis, Bertil Dorch, Aake Nordlund

Numerical simulations of kinematic dynamo action in steady and 3-d ABC flows are presented with special focus on growth rates and multiple periods of the prescribed velocity field. It is found that the difference in growth rate is due to differences in the recycling of the weakest part of the magnetic field. Differences in the topology in cases with and with

G. C. Branco, M. E. Gomez, S. Khalil, A. M. Teixeira

We analyse the CP problem in the context of a supersymmetric extension of the standard model with universal strength of Yukawa couplings. A salient feature of these models is that the CP phases are constrained to be very small by the hierarchy of the quark masses, and the pattern of CKM mixing angles. This leads to a small amount of CP violation from the usu

V. Bertin, E. Nezri, J. Orloff

We study potential signals of neutralino dark matter indirect detection by neutrino telescopes in a wide range of CMSSM parameters. We also compare with direct detection potential signals taking into account in both cases present and future experiment sensitivities. Only models with neutralino annihilation into gauge bosons can satisfy cosmological constrain

Vicente Garzo

Tracer diffusion in a granular gas in simple shear flow is analyzed. The analysis is made from a perturbation solution of the Boltzmann kinetic equation through first order in the gradient of the mole fraction of tracer particles. The reference state (zeroth-order approximation) corresponds to a Sonine solution of the Boltzmann equation, which holds for arbi

Hideo Kodama

In this paper, we give a complete classification of vacuum branes, i.e., everywhere umbilical time-like hypersurfaces whose extrinsic curvature is a constant multiple of the induced metric, K_mn=k g_mn, in D-dimensional static spacetimes with spatial symmetry G(D-2,K), where G(n,K) is the isometry group of an n-dimensional space with constant sectional curva

V. P. Mineev

The symmetry of the superconducting states arising directly from ferromagnetic states in the crystals with cubic and orthorombic symmetries is described. The symmetry nodes in the quasiparticle spectra of such the states are pointed out if they exist. The superconducting phase transition in the ferromagnet is accompanied by the formation of superconducting d

Metin Gurses, Emre O. Kahya, Atalay Karasu

We give a higher even dimensional extension of vacuum colliding gravitational plane waves with the combinations of collinear and non-collinear polarized four-dimensional metric. The singularity structure of space-time depends on the parameters of the solution.

Hou Bo-yu, Shi Kangjie, Yang Zhan-ying

Following the construction of the projection operators on $T^2$ presented by Gopakumar, Headrick and Spradlin, we construct a set of projection operators on the integral noncommutative orbifold $T^2/G (G=Z_N, N=2, 3, 4, 6)$ which correspond to a set of solitons on $T^2/Z_N$ in noncommutative field theory. In this way, we derive an explicit form of projector

Hitoshi Nishino, Subhash Rajpoot

By studying singularities in stationary axisymmetric Kerr and Tomimatsu-Sato solutions with distortion parameter \d = 2, 3, ... in general relativity, we conclude that these singularities can be regarded as nothing other than closed string-like circular mass distributions. We use two different regularizations to identify \d-function type singularities in the

Chin-Lung Wang

We give a survey of the background and recent development on the $K$-equivalence relation among birational manifolds. After a brief historical sketch of birational geometry, we define the $K$-partial ordering and $K$-equivalence in a birational class and discuss geometric situations that lead to these notions. One application to the filling-in problem for th

Richard Easther, Brian R. Greene, Mark G. Jackson

It has long been known that strings wound around incontractible cycles can play a vital role in cosmology. In particular, in a spacetime with toroidal spatial hypersurfaces, the dynamics of the winding modes may help yield three large spatial dimensions. However, toroidal compactifications are phenomenologically unrealistic. In this paper we therefore take a

Raoul Nakhmanson

The notions of wavepacket and collapse are discussed and a local-realistic interpretation of Berkeley experiment is done.

H. Kleinert, A. Chervyakov

In perturbative calculations of quantum-statistical zero-temperature path integrals in curvilinear coordinates one encounters Feynman diagrams involving multiple temporal integrals over products of distributions, which are mathematically undefined. In addition, there are terms proportional to powers of Dirac delta-functions at the origin coming from the meas

Navin Khaneja, Steffen Glaser

Experiments in coherent spectroscopy correspond to control of quantum mechanical ensembles guiding them from initial to final target states by unitary transformations. The control inputs (pulse sequences) that accomplish these unitary transformations should take as little time as possible so as to minimize the effects of relaxation and to optimize the sensit

Jacques Gabarro-Arpa

On the basis of empirical evidence from molecular dynamics simulations, molecular conformational space can be described by means of a partition of central conical regions characterized by the dominance relations between cartesian coordinates. This work presents a geometric and combinatorial description of this structure.

Edoardo Milotti

This is a pedagogical review of the ubiquitous 1/f^αnoises. The sections include the representation of 1/f^αnoise as a superposition of many relaxation processes; a discussion of the infinitely large fluctuations in the low frequency limit; 1/f^αnoise from diffusion processes; the measured statistical properties of 1/f^αnoises; 1/f^αnoises in self organized

Florida Estrella, Richard McClatchey, Zsolt Kovacs, Jean-Marie Le Goff

In the web age systems must be flexible, reconfigurable and adaptable in addition to being quick to develop. As a consequence, designing systems to cater for change is becoming not only desirable but required by industry. Allowing systems to be self-describing or description-driven is one way to enable these characteristics. To address the issue of evolvabil

Mikhail L. Gershteyn, Lev I. Gershteyn, Arkady Gershteyn, Oleg V. Karagioz

In 1687, Isaac Newton published the universal law of gravitation stating that two bodies attract each other with a force proportional to the product of their masses and the inverse square of the distance. The constant of proportionality, G, is one of the fundamental constants of nature. As the precision of measurements increased the disparity between the val

P. Bozek

Symmetric nuclear matter is studied within the conserving, self-consistent T-matrix approximation. This approach involves off-shell propagation of nucleons in the ladder diagrams. The binding energy receives contributions from the background part of the spectral function, away form the quasiparticle peak. The Fermi energy at the saturation point fulfills the

Kazuhiro Oyamatsu, Kei Iida

We examine relations among the parameters characterizing the phenomenological equation of state (EOS) of nearly symmetric, uniform nuclear matter near the saturation density by comparing macroscopic calculations of radii and masses of stable nuclei with the experimental data. The EOS parameters of interest here are the symmetry energy S_0, the symmetry energ

K. Amos, P. K. Deb

A simple functional form has been found that gives a good representation of the total reaction cross sections for the scattering of protons from (15) nuclei spanning the mass range ${}^{9}$Be to ${}^{238}$U and for proton energies ranging from 20 to 300 MeV.

Raquel G. Catalan, Jose Garay, Ricardo Lopez-Ruiz

We discuss some aspects of the extension to continuous systems of a statistical measure of complexity introduced by Lopez-Ruiz, Mancini and Calbet (LMC) [Phys. Lett. A 209 (1995) 321]. In general, the extension of a magnitude from the discrete to the continuous case is not a trivial process and requires some choice. In the present study, several possibilitie

Tov Elperin, Nathan Kleeorin, Victor S. L'vov, Igor Rogachevskii

A theory of clustering of inertial particles advected by a turbulent velocity field caused by an instability of their spatial distribution is suggested. The reason for the clustering instability is a combined effect of the particles inertia and a finite correlation time of the velocity field. The crucial parameter for the clustering instability is a size of

S. Lafortune, S. Tremblay, P. Winternitz

A symmetry classification of possible interactions in a diatomic molecular chain is provided. For nonlinear interactions the group of Lie point transformations, leaving the lattice invariant and taking solutions into solutions, is at most five-dimensional. An example is considered in which subgroups of the symmetry group are used to reduce the dynamical diff

M. El Baz, Y. Hassouni, F. Madouri

A dynamical algebra ${\cal A}_q$, englobing many of the deformed harmonic oscillator algebras is introduced. One of its special cases is extensively developed. A general method for constructing coherent states related to any algebra of the type ${\cal A}_q$ is discussed. The construction following this method is carried out for the special case.

Otmar Venjakob

In this paper and a forthcoming joint one with Y. Hachimori we study Iwasawa modules over an infinite Galois extension K of a number field k whose Galois group G=G(K/k) is isomorphic to the semidirect product of two copies of the p-adic numbers. After first analyzing some general algebraic properties of the corresponding Iwasawa algebra, we apply these resul

Rosa Cid Manuel Pedreira

The aim of this paper is to obtain a classification of the scrolls in Pn which are defined by a one-dimensional family of lines meeting a certain set of linear spaces in Pn, a first classification for genus 0 and 1 is given in paper [1]. These ruled surfaces are called incidence scrolls, and such an indicated set is a base of the incidence scroll. In particu

Petr Simon

This collection of thirty two reviewed articles covers several fields of General Topology. Several contributions represent invited presentations at the Ninth Prague Topological Symposium.

F. J. Castro-Jimenez, J. M. Ucha

Let $D$ be a divisor in ${\bf C}^n$. We present methods to compare the ${\mathcal D}$-module of the meromorphic functions ${\mathcal O}[* D]$ to some natural approximations. We show how the analytic case can be treated with computations in the Weyl algebra.

Ruslan Sharipov

It is known that some equations of differential geometry are derived from variational principle in form of Euler-Lagrange equations. The equations of geodesic flow in Riemannian geometry is an example. Conversely, having Lagrangian dynamical system in a manifold, one can consider it as geometric equipment of this manifold. Then properties of other dynamical

Martin Henk

The main purpose of this note is to prove an upper bound on the number of lattice points of a centrally symmetric convex body in terms of the successive minima of the body. This bound improves on former bounds and narrows the gap towards a lattice point analogue of Minkowski's second theorem on successive minima. Minkowski's proof of his second theor

Stephen D. Miller

These notes are from the Database of Automorphic L-functions at http://www.math.rutgers.edu/~sdmiller/l-functions . They were written up by Stephen Miller, and are based on discussions with Freydoon Shahidi, Purdue University. They are meant to serve as an introduction to the Langlands-Shahidi method of studying L-functions through the Fourier coefficients o

Julian D. Gilbey

We consider the permutation group algebra defined by Cameron and show that if the permutation group has no finite orbits, then no homogeneous element of degree one is a zero-divisor of the algebra. We proceed to make a conjecture which would show that the algebra is an integral domain if, in addition, the group is oligomorphic. We go on to show that this con

E. Deotto, G. Furlan, E. Gozzi

In this paper a new supersymmetric extension of conformal mechanics is put forward. The beauty of this extension is that all variables have a clear geometrical meaning and the super-Hamiltonian turns out to be the Lie-derivative of the Hamiltonian flow of standard conformal mechanics. In this paper we also provide a supersymmetric extension of the other conf

Michael R. Douglas, Suresh Govindarajan, T. Jayaraman, Alessandro Tomasiello

We show how to compute terms in an expansion of the world-volume superpotential for fairly general D-branes on the quintic Calabi-Yau using linear sigma model techniques, and show in examples that this superpotential captures the geometry and obstruction theory of bundles and sheaves on this Calabi-Yau.

Cesar Gomez, Juan Jose Manjarin

We study the dyonic charge of type IIA D6-branes interpreted as M-theory Kaluza-Klein monopoles. The connection between the dyonic properties of type IIA D6-branes and the existence of eleven dimensions is discussed. We also study dyonic properties of non-commutative monopoles. Variations of the external antisymmetric B-field generate the electric charge of

Mauro Napsuciale, Simon Rodriguez

It is shown that most of the unusual properties of the lowest lying scalar (and pseudoscalar) mesons can be understood, at the qualitative and quantitative level, on the basis of the breakdown of the $U_A(1)$ symmetry coupled to the vacuum expectation values of scalars by the spontaneous breaking of chiral symmetry.

Chen Gang, Liu Lianshou

The Levy stability analysis is carried out for e+e- collisions at Z^0 mass using Monte Carlo method. The Levy index μis found to be μ=1.701 +- 0.043. The self-similar generalized dimensions D(q) and multi-fractal spectrum f(α) are presented. The Renyi dimension D(q) decreases with increasing q. The self-similar multi-fractal spectrum is a convex curve with a

P. Aurenche, F. Gelis, H. Zaraket

In this paper, we derive a simple sum rule satisfied by the gluon spectral function at finite temperature. This sum rule is useful in order to calculate exactly some integrals that appear frequently in the photon or dilepton production rate by a quark gluon plasma. Using this sum rule, we rederive simply some known results and obtain some new results that wo

P. Aurenche, F. Gelis, H. Zaraket

In the framework of the Hard Thermal Loop effective theory, we calculate the two-loop contributions to hard lepton pair production in a quark-gluon plasma. We show that the result is free of any infrared and collinear singularity. We also recover the known fact that perturbation theory leads to integrable singularities at the location of the threshold for $q

P. Domin, F. Simkovic, S. V. Semenov, Yu. V. Gaponov

The detection of solar-neutrinos of different origin via induced beta beta process of Mo100 is investigated. The particular counting rates and energy distributions of emitted electrons are presented. A discussion in respect to solar-neutrino detector consisting of 10 tones of Mo100 is included. Both the cases of the standard solar model and neutrino oscillat

Ugo Aglietti, Marco Ciuchini, Paolo Gambino

The ratio between the photon spectrum in B -> X_s gamma and the differential semileptonic rate wrt the hadronic variable M_X/E_X is a short-distance quantity calculable in perturbation theory and independent of the Fermi motion of the b quark in the B meson. We present a NLO analysis of this ratio and show how it can be used to determine |V_ub/V_cb| independ

Eef van Beveren, Frieder Kleefeld, George Rupp, Michael D. Scadron

The quark-level linear sigma model is revisited, in particular concerning the identification of the f_0(400-1200) (or σ(600)) scalar meson as the chiral partner of the pion. We demonstrate the predictive power of the linear sigma model through the pi-pi and pi-N s-wave scattering lengths, as well as several electromagnetic, weak, and strong decays of pseudos

E. A. Paschos

We discuss the calculations for several neutrino induced reactions from low energies to the GeV region. Special attention is paid to nuclear corrections when the targets are medium or heavy nuclei. Finally, we present several ratios of neutral to charged current reactions whose values on isoscalar targets can be estimated accurately. The ratios are useful fo

E. A. Paschos

I review the origin of the lepton asymmetry which is converted to a baryon excess at the electroweak scale. This scenario becomes more attractive if we can relate it to other physical phenomena. For this reason I elaborate on the conditions of the early universe which lead to a sizable lepton asymmetry. Then I describe methods and models which relate the low

V. A. Dzuba, V. V. Flambaum, J. S. M. Ginges

We have calculated the 6s-7s parity nonconserving (PNC) E1 transition amplitude, E_{PNC}, in cesium. We have used an improved all-order technique in the calculation of the correlations and have included all significant contributions to E_{PNC}. Our final value E_{PNC} = 0.904 (1 +/- 0.5 %) \times 10^{-11}iea_{B}(-Q_{W}/N) has half the uncertainty claimed in

M. E. Gomez, D. F. Carvalho

We study whether the individual violation of the lepton numbers L_{e,mu,tau} in the charged sector can lead to measurable rates for BR(mu->e gamma) and BR(tau->mu gamma). We consider three different scenarios, the fist one corresponds to the Minimal Supersymmetric Standard Model with non-universal soft terms. In the other two cases the violation of flavor in

F. V. Gubarev

We consider lattice implementation of the recently proposed gauge invariant definition of the monopole charge. Because of the lattice discretization the algorithm gives rise to specific lattice artifacts and an effective Ising model. The Ising-model problem might in principle be solved and we discuss the role of the Maximal Abelian gauge in this respect. The

F. V. Gubarev, V. I. Zakharov

We introduce a gauge invariant topological definition of monopole charge in pure SU(2) gluodynamics. The non-trivial topology is provided by hedgehog configurations of the non-Abelian field strength tensor on the two-sphere surrounding the monopole. It is shown that this definition can be formulated entirely in terms of Wilson loops which makes the gauge inv

I. L. Bogolubsky, V. K. Mitrjushkin

We study numerically magnetic $G_M(p)$ and electric $G_E(p)$ gluon propagators and their dependence on the choice of the lattice gauge field $\caa_{xμ}$ in SU(2) gauge theory, especially, in the low--momentum limit. We find that two different $\caa_{xμ}$ definitions are equivalent up to a trivial renormalization of the propagator, at least, in the main appro

Hans Ringstrom

By Fuchsian techniques, a large family of Gowdy vacuum spacetimes have been constructed for which one has detailed control over the asymptotic behaviour. In this paper we formulate a condition on initial data yielding the same form of asymptotics.

Sascha Husa

This talk reports on the status of an approach to the numerical study of isolated systems with the conformal field equations. We first describe the algorithms used in a code which has been developed at AEI in the last years, and discuss a milestone result obtained by Huebner. Then we present more recent results as examples to sketch the problems we face in t

Adrian Butscher

One method of studying the asymptotic structure of spacetime is to apply Penrose's conformal rescaling technique. In this setting, the Einstein equations for the metric and the conformal factor in the unphysical spacetime degenerate where the conformal factor vanishes, namely at the boundary representing null infinity. This problem can be avoided by mean

Yi-Dong Shen, Jia-Huai You, Li-Yan Yuan, Samuel S. P. Shen

We present a new characterization of termination of general logic programs. Most existing termination analysis approaches rely on some static information about the structure of the source code of a logic program, such as modes/types, norms/level mappings, models/interargument relations, and the like. We propose a dynamic approach which employs some key dynam

Eneko Agirre, Elena Garcia, Mikel Lersundi, David Martinez

In this paper we describe the Senseval 2 Basque lexical-sample task. The task comprised 40 words (15 nouns, 15 verbs and 10 adjectives) selected from Euskal Hiztegia, the main Basque dictionary. Most examples were taken from the Egunkaria newspaper. The method used to hand-tag the examples produced low inter-tagger agreement (75%) before arbitration. The fou

Eneko Agirre, David Martinez

In this paper we describe the systems we developed for the English (lexical and all-words) and Basque tasks. They were all supervised systems based on Yarowsky's Decision Lists. We used Semcor for training in the English all-words task. We defined different feature sets for each language. For Basque, in order to extract all the information from the text,

V. Brouet, H. Alloul, L. Forro

We present a detailed NMR study of simple cubic CsC60, the only metallic cubic fullerides known so far besides A3C60. 133Cs NMR signals the presence of about 12 to 15% of ``anomalous'' C60 balls, characterized by a 15 meV gap. We present different experimental observations supporting the idea that a spin-singlet (i.e. a C60^{2-}) is localized on thes

V. Brouet, H. Alloul, S. Garaj, L. Forro

We present an NMR study of Na2C60 and K4C60, two compounds that are related by electron-hole symmetry in the C60 triply degenerate conduction band. In both systems, it is known that NMR spin-lattice relaxation rate (1/T1) measurements detect a gap in the electronic structure, most likely related to singlet-triplet excitations of the Jahn-Teller distorted (JT

Jairo Sinova, A. H. MacDonald, S. M. Girvin

We present a Hartree-Fock study of the competition between disorder and interactions in quantum Hall ferromagnets near $ν=1$. We find that the ground state at $ν=1$ evolves with increasing interaction strength from a quasi-metallic paramagnet, to a partially spin-polarized ferromagnetic Anderson insulator, and to a fully spin-polarized ferromagnet with a cha

W. Lu, K. D. Maranowski, A. J. Rimberg

We have developed a novel system consisting of a superconducting single-electron transistor (S-SET) coupled to a two-dimensional electron gas (2DEG), for which the dissipation can be tuned in the immediate vicinity of the S-SET. Within linear response, the S-SET conductance varies nonmonotonically with increasing 2DEG impedance. We find good agreement betwee

Sadhan K. Adhikari, Paulsamy Muruganandam

The effects of a sudden increase and decrease of the interatomic interaction and harmonic-oscillator trapping potential on vortices in a quasi two-dimensional rotating Bose-Einstein condensate are investigated using the mean-field Gross-Pitaevskii equation. Upon increasing the strength of interaction suddenly the condensate enters a nonstationary oscillating

K. Takeda, I. Ichinose

In the previous paper, we studied the random-mass Dirac fermion in one dimension by using the transfer-matrix methods. We furthermore employed the imaginary vector potential methods for calculating the localization lengths. Especially we investigated effects of the nonlocal but short-range correlations of the random mass. In this paper, we shall study effect

M. Letz, W. Mannstadt, M. Brinkmann, E. Moersen

The microscopic mechanism beyond the optical anisotropy of an ionic crystal which occurs for short wavelengths is investigated. The electron-hole, two particle propagator and its analytical behaviour close to the band edge of the one particle continuum plays a major role for the mechanism of this optical anisotropy. Especially for an ionic crystal the two pa

Jairo Sinova, Alvaro Núñez, John Schliemann, A. H. MacDonald

We present a simple model for the electron-phonon interactions between the energy subbands in polyacene field-effect transistors and the vibrations of the crystal. We introduce a generalized Su-Schrieffer-Heeger model, arguing that the strongest electron-phonon interactions in these systems originate from the dependence of inter-molecule hopping amplitudes o

Francesco Guerra, Fabio L. Toninelli

We present a simple strategy in order to show the existence and uniqueness of the infinite volume limit of thermodynamic quantities, for a large class of mean field disordered models, as for example the Sherrington-Kirkpatrick model, and the Derrida p-spin model. The main argument is based on a smooth interpolation between a large system, made of N spin site