May 2001 arXiv papers — page 9

J. -M. Le Goff, Z. Kovacs, N. Baker, P. Brooks

CRISTAL is a distributed scientific workflow system used in the manufacturing and production phases of HEP experiment construction at CERN. The CRISTAL project has studied the use of a description driven approach, using meta- modelling techniques, to manage the evolving needs of a large physics community. Interest from such diverse communities as bio-informa

Erasmo Recami, Tonin-Zanchin, Antonino Del Popolo, Mario Gambera

In this paper we fix our attention, on hadron structure, and show that also the strong interaction strength alpha_S, ordinarily called the "(perturbative) coupling--constant square}", can be evaluated within our theory, and found to decrease (increase) as the "distance" r decreases (increases). This yields both the confinement of the hadron c

Metod Saniga

A sequence of integers generated by the number of conjugated pairs of homaloidal nets of plane algebraic curves of even order is found to provide an >exact< integer-valued match for El Naschie&#39;s primordial set of fractal dimensions characterizing transfinite heterotic string space-time.

M. Moseler, H. Hakkinen, Uzi Landman

Photoabsorption cross sections of small sodium cluster cations (Na$_n^+$, n=3,5,7 and 9) were calculated at various temperatures with the time-dependent local-density-approximation (TDLDA) in conjunction with ab initio molecular dynamics simulations, yielding spectra that agree with measured ones without ad-hoc line broadening or renormalization. Three therm

S. M. Blinder

The region very close to an electron ($r << r_0 = e^2/mc^2 \approx 2.8\times 10^{-13}$ cm) is, according to quantum electrodynamics, a seething maelstrom of virtual electron-positron pairs flashing in and out of existence. To take account of this well-established physical reality, a phenomenological representation for vacuum polarization is introduced into t

Yehea I. Ismail

A simple general relativity theory for objects moving in gravitational fields is developed based on studying the behavior of an atom in a gravitational field. The theory is applied to calculate the satellite time dilation, light deflection by the sun, and Mercury&#39;s precession with an error of less than 1%. The approach to the new theory introduced here i

S. Ciechanowicz, F. C. Khanna, E. Truhlik

Comparison of the new data for the negative muon capture in 28^Si with the recent shell model calculations using a full 1s-0d model space and the USD empirical effective interaction and the one-nucleon weak current provides the induced pseudoscalar g_P substantially smaller than the value predicted by PCAC and pion-pole dominance. We find that adding the eff

David Damanik, Daniel Lenz

We consider discrete one-dimensional Schrödinger operators with quasi-Sturmian potentials. We present a new approach to the trace map dynamical system which is independent of the initial conditions and establish a characterization of the spectrum in terms of bounded trace map orbits. Using this, it is shown that the operators have purely singular continuous

S. M. Blinder

A model is proposed for the classical electron as a point charge with finite electromagnetic self-energy. Modifications of the Reissner-Nordstrøm (spin 0) and Kerr-Newman (spin 1/2) solutions of the Einstein-Maxwell equations are derived. It is conjectured that spacetime curvature very close to the point charge deforms the electric and magnetic fields such a

Paul-Emile Paradan

We present a K-theoritic approach to the Guillemin-Sternberg conjecture, about the commutativity of geometric quantization and symplectic reduction, which was proved by Meinrenken and Tian-Zhang. Besides providing a new proof of this conjecture for the full non-abelian group action case, our methods lead to a generalisation for compact Lie group actions on m

Hans Plesner Jakobsen, Søren Jøndrup

First some old as well as new results about P.I. algebras, Ore extensions, and degrees are presented. Then quantized $n\times r$ matrices as well as quantized factor algebras of $M_q(n)$ are analyzed. The latter are the quantized function algebra of rank $r$ matrices obtained by working modulo the ideal generated by all $(r+1)\times (r+1)$ quantum subdetermi

Vincent Beffara

We define and study a family of generalized non-intersection exponents for planar Brownian motions that is indexed by subsets of the complex plane: For each $A\subset\CC$, we define an exponent $ξ(A)$ that describes the decay of certain non-intersection probabilities. To each of these exponents, we associate a conformally invariant subset of the planar Brown

Chris Judge

We study the limiting behavior of eigenfunctions/eigenvalues of the Laplacian of a family of Riemannian metrics that degenerates on a hypersurface. Our results generalize earlier work concerning the degeneration of hyperbolic surfaces.

Philippe Gaucher

We introduce a new simplicial nerve of higher dimensional automata whose homology groups yield a new definition of the globular homology. With this new definition, the drawbacks noticed with the construction of math.CT/9902151 disappear. Moreover the important morphisms which associate to every globe its corresponding branching area and merging area of execu

S. L. Dubovsky, V. A. Rubakov

We argue that any viable mechanism of gauge field localization should automatically imply charge universality on the brane. We study whether this condition is satisfied in the two known proposals aimed to localize vector field in flat bulk space. We construct a simple calculable model with confinement in the bulk and deconfinement on the brane, as in the Shi

J. Diemand, Ch. Mathys, D. Wyler

We show the instability of two self-tuning brane world models with gauge invariant linear perturbation theory. This general method confirms a known instability of the original model with vanishing bulk potential. We also show the dynamical instability of a recently proposed self-tuning &#34;smooth&#34; brane model and its limit, the Randall-Sundrum model. As

M. R. Setare

The Casimir stress on two concentric spherical shell in de Sitter background for massless scalar field is calculated. The scalar field satisfies Dirichlet boundary conditions on the spheres. The metric is written in conformally flat form to make maximum use of Minkowski space calculations. Then the Casimir stress is calculated for inside and outside of the s

C. Bizdadea, S. O. Saliu

The Lagrangian Sp(3) BRST symmetry for irreducible gauge theories is constructed in the framework of homological perturbation theory. The canonical generator of this extended symmetry is shown to exist. A gauge-fixing procedure specific to the standard antibracket-antifield formalism, that leads to an effective action, which is invariant under all the three

C. A. S. Almeida

One of the most intriguing aspects of Chern-Simons-type topological models is the fractional statistics of point particles which has been shown essential for our understanding of the fractional quantum Hall effects. Furthermore these ideas are applied to the study of high Tc superconductivity. We present here an recently proposed model for fractional spin wi

Nathan Berkovits

I review the construction of an action for open superstring field theory which does not suffer from the contact term problems of other approaches. This action resembles a Wess-Zumino-Witten action and can be constructed in a manifestly D=4 super-Poincaré covariant manner. This review is based on lectures given at the ICTP Latin-American String School in Mexi

E. A. Baltz, P. Gondolo

The anomalous magnetic moment of the muon has recently been measured to be in conflict with the Standard Model prediction with an excess of 2.6 sigma. Taking this result as a measurement of the supersymmetric contribution, we find that at 95% confidence level it imposes an upper bound of about 500 GeV on the neutralino mass and forbids higgsino dark matter.

Hai-Yang Cheng, Amarjit Soni

We have systematically investigated the semi-inclusive B decays B->MX, which are manifestations of the quark decay b->Mq, within the framework of QCD-improved factorization. These decays are theoretically clean and have distinctive experimental signatures. We focus on a class of these that do not require any form factor information and therefore may be espec

J. Manjavidze, A. Sissakian

The paper contains a description of a first attempt to understand the extremely inelastic high energy hadron collisions, when the multiplicity of produced hadrons considerably exceeds its mean value. Problems with existing model predictions are discussed. The real-time finite-temperature $S$-matrix theory is built to have a possibility to find model-free pre

I. P. Lokhtin, A. M. Snigirev

The potential of coming experiments on Large Hadron Collider (LHC) to observe the rescattering and energy loss of heavy quarks in the dense matter created in heavy ion collisions is discussed. We analyze the sensitivity of high-mass mu+mu- pairs from BBbar semileptonic decays and secondary J/Psi from single B decays to the medium-induced bottom quark energy

R. A. Schneider, T. Renk, W. Weise

We calculate the dilepton emission rate from a fireball created in an ultra-relativistic heavy-ion collision. For the partonic phase, we complement the perturbative results by a phenomenological approach based on lattice QCD results, whereas in the hadronic phase temperature and finite baryon density effects on the spectral function are considered. The resul

R. A. Schneider, W. Weise

We propose a novel quasiparticle interpretation of the equation of state of deconfined QCD at finite temperature. Using appropriate thermal masses, we introduce a phenomenological parametrization of the onset of confinement in the vicinity of the predicted phase transition. Lattice results of the energy density, the pressure and the interaction measure of pu

Wojciech Slominski, Jerzy Szwed

The electron and photon structure functions are compared. Advantages of the electron structure function are demonstrated. At very high momenta probabilistic (partonic) interpretation can be preserved despite strong $γ$-$Z$ interference. At present energies analyses of both the electron and the photon structure functions give an important test of the experime

Y. Sumino

We report new aspects of the recent theoretical progress in heavy quarkonium physics. (1) Contrary to wide beliefs, the gross structure of the bottomonium spectrum is described well by the non-relativistic boundstate theory based on perturbative QCD. (2) This leads to a new physical picture of the bottomonium states: the boundstate mass is composed mainly of

N. M. Hassan, W. R. El-Harby, R. W. El-Moualed And M. T. Hussein

The proton structure function is re-deduced from the data of deep inelastic electron-proton scattering after enhanced correction that is made due to the multiple scattering effect. The Glauber approach is used to account for the multiple scattering of electron with the quark constituents of the proton. The results are compared with the prediction of the part

J. B. Kogut, D. K. Sinclair, S. J. Hands, S. E. Morrison

We have simulated two-colour four-flavour QCD at non-zero chemical potential $μ$ for quark number. Simulations were performed on $8^4$ and $12^3 \times 24$ lattices. Clear evidence was seen for the formation of a colourless diquark condensate which breaks quark number spontaneously, for $μ> μ_c \sim m_π/2$. The transition appears to be second order. We have

Matteo Beccaria

We present an improved upper bound for the ground state energy of lattice fermion models with sign problem. The bound can be computed by numerical simulation of a recently proposed family of deformed Hamiltonians with no sign problem. For one dimensional models, we expect the bound to be particularly effective and practical extrapolation procedures are discu

Matteo Beccaria, Antonio Moro

We present a simulation algorithm for Hamiltonian fermion lattice models. A guiding trial wave function is adaptively optimized during Monte Carlo evolution. We apply the method to the two dimensional Gross-Neveu model and analyze systematc errors in the study of ground state properties. We show that accurate measurements can be achieved by a proper extrapol

Juerg Beringer

The BaBar detector at the PEP-II asymmetric B Factory at SLAC collected a sample of 23M B-anti-B pairs in the years 1999 and 2000. Using this data sample, we measure the amplitude of the time-dependent CP-violating asymmetry in neutral B decays to the CP eigenstates B0 --> J/psi K0S, B0 --> psi(2S) K0S and B0 --> J/psi K0L. We find a value of sin2beta = 0.34

G. Dissertori

A summary is given of the current status of measurements of the strong coupling constant $α_s$ performed at LEP. These include measurements from inclusive observables as well as from event shape variables. Recent results based on power law corrections are discussed.

John Krane

This article summarizes several analyses I discussed at Moriond and I attempt to maintain my speaking voice throughout. I extract several broad themes in the recent development of QCD,and emphasize how the latest results on jet physics reinforce these themes: that QCD is in a transitional stage from providing qualitative descriptions to providing true quanti

R. De Pietri, L. Lusanna, L. Martucci, S. Russo

We define the {\it rest-frame instant form} of tetrad gravity restricted to Christodoulou-Klainermann spacetimes. After a study of the Hamiltonian group of gauge transformations generated by the 14 first class constraints of the theory, we define and solve the multitemporal equations associated with the rotation and space diffeomorphism constraints, finding

M. Gasperini

We discuss the possibility that &#34;quintessential effects&#34;, recently displayed by large scale observations, may be consistently described in the context of the low-energy string effective action, and we suggest a possible approach to the problem of the cosmic coincidence based on the link between the strength of the dilaton couplings and the cosmologic

Roberto A. Sussman, Luis García Trujillo

We re-examine the Lemâitre-Tolman-Bondi (LTB) solutions with a dust source admitting symmetry centers. We consider as free parameters of the solutions the initial value functions: $Y_i$, $ρ_i$ and $\Ri$, obtained by restricting the curvature radius, $Y\equiv \sqrt{g_{θθ}}$, the rest mass density, $ρ$, and the 3-dimensional Ricci scalar of the rest frames, $\

Rolando Cardenas, I. Quiros, Rolando Bonal

In reference gr-qc/0104036 a four-dimensional effective theory of gravity embeddable in a five-dimensional &#34;distorted&#34; Randall-Sundrum brane scenario was derived. The present paper is aimed at the application of such a theory to describe physics in an open Friedmann-Robertson-Walker (Weyl-symmetric) universe. It is shown that regular bouncing univers

Ahmed Helmy

IP mobility addresses the problem of changing the network point-of-attachment transparently during movement. Mobile IP is the proposed standard by IETF. Several studies, however, have shown that Mobile IP has several drawbacks, such as triangle routing and poor handoff performance. Multicast-based mobility has been proposed as a promising solution to the abo

Krzysztof R. Apt, Eric Monfroy

We study here a natural situation when constraint programming can be entirely reduced to rule-based programming. To this end we explain first how one can compute on constraint satisfaction problems using rules represented by simple first-order formulas. Then we consider constraint satisfaction problems that are based on predefined, explicitly given constrain

B. Jackson, E. Zaremba

The dynamics of a trapped Bose-condensed gas at finite temperatures is described by a generalized Gross-Pitaevskii equation for the condensate order parameter and a semi-classical kinetic equation for the thermal cloud, solved using $N$-body simulations. The two components are coupled by mean fields as well as collisional processes that transfer atoms betwee

Stefan Wessel, Maxim Olshanii, Stephan Haas

We study magnetic field-induced three-dimensional ordering transitions in low-dimensional quantum spin liquids, such as weakly coupled, antiferromagnetic spin-1/2 Heisenberg dimers and ladders. Using stochastic series expansion quantum Monte Carlo simulations, thermodynamic response functions are obtained down to ultra-low temperatures. We extract the critic

Hitoshi Inoue

We discuss effects of $1/r^β$ type long-range (LR) interactions in a tight-binding model by utilizing the bosonization technique, renormalization group and conformal field theory (CFT). We obtain the low energy action known for Kibble&#39;s model which generates the mass gap in 3 dimension when $β=1$, the Coulomb force case. In one dimension, the dispersion

V. P. Zhukov, V. M. Silkin, E. V. Chulkov, P. M. Echenique

The frequency- and momentum-dependent dielectric function $ε{(\bf q,ω)}$ as well as the energy loss function Im[-$ε^{-1}{(\bf q,ω)}$\protect{]} are calculated for intermetallic superconductor $MgB_2$ by using two {\it ab initio} methods: the plane-wave pseudopotential method and the tight-binding version of the LMTO method. We find two plasmon modes dispersi

S. Abbet, U. Heiz, H. Hakkinen, U. Landman

The oxidation of CO on single Pd atoms anchored to MgO(100) surface oxygen vacancies is studied with temperature-programmed-reaction mass-spectrometry and infrared spectroscopy. In one-heating-cycle experiments CO$_2$, formed from O$_2$ and CO preadsorbed at 90 K, is detected at 260 K and 500 K. Ab-initio simulations suggest two reaction routes, with Pd(CO)$

E. Schachinger, J. P. Carbotte

The in-plane optical conductivity has been successfully employed to obtain information about the coupling of the charge carriers to the spin degrees of freedom in the high T_c oxides. We investigate how this inelastic scattering affects the out-of-plane charge dynamics. We consider both coherent (in-plane momentum is conserved) and incoherent (no momentum co

R. Hilfer

The paper discusses local porosity theory and its relation with other geometric characterization methods for porous media such as correlation functions and contact distributions. Special emphasis is placed on the charcterization of geometric observables through Hadwigers theorem in stochastic geometry. The four basic Minkowski functionals are introduced into

H. Scherer, Th. Weimann, A. B. Zorin, J. Niemeyer

The effect of thermal annealing on the properties of Al-AlOx-Al single electron tunneling transistors is reported. After treatment of the devices by annealing processes in forming gas atmosphere at different temperatures and for different times, distinct and reproducible changes of their resistance and capacitance values were found. According to the temperat

M. Morelle, V. Bruyndoncx, R. Jonckheere, V. V. Moshchalkov

We study the magnetic interaction between two superconducting concentric mesoscopic Al loops, close to the superconducting/normal phase transition. The phase boundary is measured resistively for the two-loop structure as well as for a reference single loop. In both systems Little-Parks oscillations, periodic in field are observed in the critical temperature

Junya Shibata, Komajiro Niizeki

We construct a coherent state path integral formalism for the one-dimensional Bloch particle within the single band model. The transition amplitude between two coherent states is a sum of transition amplitudes with different winding numbers on the two-dimensional phase space which has the same topology as that of the cylinder. Appearance of the winding numbe

T. Vukovic, I. Milosevic, M. Damnjanovic

Various properties of the energy band structures (electronic, phonon, etc.), including systematic band degeneracy, sticking and extremes, following from the full line group symmetry of the single-wall carbon nanotubes are established. The complete set of quantum numbers consists of quasi momenta (angular and linear or helical) and parities with respect to th

F. Hebert, G. G. Batrouni, R. T. Scalettar, G. Schmid

We use two Quantum Monte Carlo algorithms to map out the phase diagram of the two-dimensional hardcore boson Hubbard model with near ($V_1$) and next near ($V_2$) neighbor repulsion. At half filling we find three phases: Superfluid (SF), checkerboard solid and striped solid depending on the relative values of $V_1$, $V_2$ and the kinetic energy. Doping away

M. Damnjanovic, T. Vukovic, I. Milosevic

The friction between the walls of multi-wall carbon nanotubes is shown to be extremely low in general, with important details related to the specific choice of the walls. This is governed by a simple expression revealing that the phenomenon is a profound consequence of the specific symmetry breaking: super-slippery sliding of the incommensurate walls is a Go

L. Velazquez, F. Guzman

In the present paper are analysed the conditions for the validity of the Tsallis Statistics. The same have been done following the analogy with the traditional case: starting from the microcanonical description of the systems and analysing the scaling properties of the fundamental macroscopic observables in the Thermodynamic Limit. It is shown that the Gener

A. Chattopadhyay, S. Das Sarma, A. J. Millis

This paper has been withdrawn by the authors due to a numerical error. A revised version will be posted shortly.

M. L. Mehta, J. -M. Normand

Moments of the characteristic polynomial of a random matrix taken from any of the three ensembles, orthogonal, unitary or symplectic, are given either as a determinant or a pfaffian or as a sum of determinants. For gaussian ensembles comparing the two expressions of the same moment one gets two remarkable identities, one between an $n\times n$ determinant an

Christopher J. Miller, Robert C. Nichol, David J. Batuski

During its first ~100,000 years, the universe was a fully ionized plasma with a tight coupling by Thompson scattering between the photons and matter. The trade--off between gravitational collapse and photon pressure causes acoustic oscillations in this primordial fluid. These oscillations will leave predictable imprints in the spectra of the cosmic microwave

O. D. Toropina, M. M. Romanova, Yu. M. Toropin, R. V. E. Lovelace

This work investigates the propagation of magnetized, isolated old neutron stars through the interstellar medium. We performed axisymmetric non relativistic magnetohydrodynamic (MHD) simulations of the propagation of a non-rotating star with dipole magnetic field aligned with its velocity through the interstellar medium (ISM). Effects of rotation will be dis

Richard E. Rothschild, David Marsden, Richard E. Lingenfelter

We have shown that the interstellar media which surround the progenitors of SGRs and AXPs were unusually dense compared to the environments around most young radio pulsars. This environmental correlation argues strongly against the current magnetar model for SGRs and AXPs. We suggest instead that they are neutron stars with sub-critical magnetic fields and a

Craig L. Sarazin

Clusters of galaxies generally form by the gravitational merger of smaller clusters and groups. Major cluster mergers are the most energetic events in the Universe since the Big Bang. Some of the basic physical properties of mergers will be discussed, with an emphasis on simple analytic arguments rather than numerical simulations. Semi-analytic estimates of

R. E. Mennickent, C. Tappert

In this research note we present a time-resolved study of the Balmer emission lines of RZ Leo. From the analysis of the radial velocities we find an orbital period of 0.07651(26) d. This is in excellent agreement with the photometrically determined periods in quiescence and during the early stages of superoutburst. A comparison of the recently determined sup

Gilberto C. Gomez, Robert A. Benjamin, Donald P. Cox

We present a list of 109 pulsars with independent distance information compiled from the literature. Since the compilation of Frail & Weisberg, there are 35 pulsars with new distance estimate and 25 pulsars for which the distance or distance uncertainty have been revised. We used this data to fit a smooth, axisymmetric, two disk model of the distribution of

Asantha Cooray

It is now well known that mode-coupling effects associated with certain secondary effects generate higher order correlations in cosmic microwave background (CMB) temperature anisotropies, beyond the two-point function. In order to extract the non-Gaussian signal at the three-point level, we suggest a two-point statistic in the form of an angular power spectr

Barbara S. Ryden, Duncan A. Forbes, A. I. Terlevich

We test the hypothesis that the apparent axis ratio of an elliptical galaxy is correlated with the age of its stellar population. We find that old ellipticals (with estimated stellar ages t > 7.5 Gyr) are rounder on average than younger ellipticals. The statistical significance of this shape difference is greatest at small radii; a Kolmogorov-Smirnov test co

H. Schlattl, S. Cassisi, M. Salaris, A. Weiss

We investigate the evolution of initially metal-free, low-mass Red Giant stars through the He core flash at the tip of the Red Giant Branch. The low entropy barrier between the helium- and hydrogen-rich layers enables a penetration of the helium flash driven convective zone into the inner tail of the extinguishing H-burning shell. As a consequence, protons a

E. Bertone, A. Buzzoni

We devised a straightforward procedure to derive the atmosphere fundamental parameters of stars across the different MK spectral types by comparing mid-resolution spectroscopic observations with theoretical grids of synthetic spectra.The results of a preliminary experiment, by matching the Gunn and Stryker and Jacoby et al. spectrophotometric atlases with th

V. I. Slysh, M. A. Voronkov, I. E. Val&#39;tts, V. Migenes

We report on the first space-VLBI observations of the OH masers in two main-line OH transitions at 1665 and 1667 MHz. The observations involved the space radio telescope on board the Japanese satellite HALCA and an array of ground radio telescopes. The maps of the maser region and images of individual maser spots were produced with an angular resolution of 1

Robert E. Rutledge, Lars Bildsten, Edward F. Brown, George G. Pavlov

Using the Chandra/ACIS-I detector, we have identified an X-ray source (CXOU 132619.7-472910.8) in the globular cluster NGC 5139 with a thermal spectrum identical to that observed from transiently accreting neutron stars in quiescence. The absence of intensity variability on timescales as short as 4 seconds (< 25% rms variability) and as long as 5 years (<50%

Neil Trentham

A major recent evelopment in observational cosmology has been an accurate measurement of the luminosity distance-redshift relation out to redshifts z=0.8 from Type Ia supernova standard candles. The results have been argued as evidence for cosmic acceleration. It is well known that this assertion depends on the assumption that we know the equation of state f

D. V. Bisikalo, A. A. Boyarchuk, A. A. Kilpio, O. A. Kuznetsov

The results of three-dimensional numerical simulations of mass transfer in binaries with spiral shocks are presented. It is shown that the mass transfer rate variation disturbs the equilibrium state of accretion disk and results in formation of the blob. This dense formation moves on the disk with variable velocity. The results of our simulations show that t

P. Lundqvist, C. Kozma, J. Sollerman, C. Fransson

ISO/SWS observations of SN 1987A on day 3425 show no emission in [Fe I] 24.05 microns and [Fe II] 25.99 microns down to the limits of roughly 0.39 Jy and 0.64 Jy, respectively. Assuming a homogeneous distribution of Ti-44 inside 2000 km/s and negligible dust cooling, we have made time dependent theoretical models to estimate an upper limit on the mass of eje

K. Shimasaku, M. Fukugita, M. Doi, M. Hamabe

We investigate the photometric properties of 456 bright galaxies using imaging data recorded during the commissioning phase of the Sloan Digital Sky Survey (SDSS). Morphological classification is carried out by correlating results of several human classifiers. Our purpose is to examine the statistical properties of color indices, scale lengths, and concentra

Robert L. Kurucz

We list a few things that we do not understand about stars and that most people ignore. These are all hard problems. We can learn more cosmology by working on them to reduce the systematic errors they introduce than by trying to derive cosmological results that are highly uncertain.

J. U. Fynbo, P. Moller, B. Thomsen

We present spectroscopic observations obtained with the ESO Very Large Telecope (VLT) of seven candidate Ly-alpha emitting galaxies in the field of the radio quiet Q1205-30 at z=3.04 previously detected with deep narrow band imaging. Based on equivalent widths and limits on line ratios we confirm that all seven objects are Ly-alpha emitting galaxies. Deep im

Eugene Demler, Chetan Nayak, Hae-Young Kee, Yong Baek Kim

We discuss possible patterns of electron fractionalization in strongly interacting electron systems. A popular possibility is one in which the charge of the electron has been liberated from its Fermi statistics. Such a fractionalized phase contains in it the seed of superconductivity. Another possibility occurs when the spin of the electron, rather than its

LSND Collaboration, L. B. Auerbach, R. L. Burman, D. O. Caldwell

Charged Current reactions of $ν_e$ on $^{12}C$ have been studied using a $μ^+$ decay-at-rest $ν_e$ beam at the Los Alamos Neutron Science Center. The cross section for the exclusive reaction $^{12}C(ν_e,e^-)^{12}N_{g.s.}$ was measured to be $(8.9\pm0.3\pm0.9)\times10^{-42}$ cm$^2$. The observed energy dependence of the cross section and angular distribution

Feryal Ozel, Dimitrios Psaltis, Victoria M. Kaspi

Thermal emission from the surface of an ultramagnetic neutron star is believed to contribute significantly to the soft X-ray flux of the Anomalous X-ray Pulsars. We compare the detailed predictions of models of the surface emission from a magnetar to the observed properties of AXPs. In particular, we focus on the combination of their luminosities and energy-

C. C. Homes, Q. Li, P. Fournier, R. L. Greene

The ab-plane reflectance of a Pr2CuO4 single crystal has been measured over a wide frequency range at a variety of temperatures, and the optical properties determined from a Kramers-Kronig analysis. Above ~ 250 K, the low frequency conductivity increases quickly with temperature; the resistivity follows the form e^(E_a/k_BT), where E_a ~ 0.17 eV is much less

Gilbert Holder, Zoltan Haiman, Joseph Mohr

We show that the counts of galaxy clusters in future deep cluster surveys can place strong constraints on the matter density, Omega_m, the vacuum energy density, Omega_L, and the normalization of the matter power spectrum, sigma_8. Degeneracies between these parameters are different from those in studies of either high--redshift type Ia Supernovae (SNe), or

Emrah Kalemci, John A. Tomsick, R. E. Rothschild, Katja Pottschmidt

We investigate the timing behavior of XTE J1550-564 with the Rossi X-ray Timing Explorer (RXTE) as the source made a transition to the hard state during the decay of the 2000 outburst. We detect a high frequency QPO at 65 Hz in one observation with a fractional rms amplitude of 4.9%. This is the first time that a high frequency QPO has been detected in a tra

John A. Tomsick, Stephane Corbel, Philip Kaaret

We report on the evolution of the X-ray energy spectrum for the black hole candidate (BHC) X-ray transient XTE J1550-564 during the decay of the 2000 outburst. The Rossi X-ray Timing Explorer (RXTE) and Chandra observations span nearly five orders of magnitude in luminosity. The RXTE spectra are dominated by a power-law component and a comparatively weak sof

Matthew J. Case, Igor F. Herbut

The spherical limit of strongly commensurate dirty-bosons is studied perturbatively at weak disorder and numerically at strong disorder in two dimensions (2D). We argue that disorder is not perfectly screened by interactions, and consequently that the ground state in the effective Anderson localisation problem always remains localised. As a result there is o

David Berenstein, Robert G. Leigh

In this paper we propose a unified approach to (topological) string theory on certain singular spaces in their large volume limit. The approach exploits the non-commutative structure of D-branes, so the space is described by an algebraic geometry of non-commutative rings. The paper is devoted to the study of examples of these algebras. In our study there is

D. Cartin, G. Khanna

The presence of spiral structure in isolated galaxies is a problem that has only been partially explained by theoretical models. Because the rate and pattern of star formation in the disk must depend only on mechanisms internal to the disk, we may think of the spiral galaxy as a self-regulated system far from equilibrium. This paper uses this idea to look at

Emil T. Akhmedov, Anton A. Gerasimov, Samson L. Shatashvili

We consider the couplings of RR fields with open string sector for $Dp$-${\overline{Dp}}$ backgrounds of various $p$. Proposed approach, based on the approximation of the open string algebra by the algebra of differential operators, provides the unified description of these couplings and their interrelations.

T. Affolder

We present results of searches for diphoton resonances produced both inclusively and also in association with a vector boson (W or Z) using 100 pb^{-1} of p\bar p collisions using the CDF detector. We set upper limits on the product of cross section times branching ratio for both p\bar p\toγγ+ X and p\bar p\toγγ+ W/Z. Comparing the inclusive production to th

John McDonald

Inflation ends with the formation of a Bose condensate of inflatons. We show that in hybrid inflation models this condensate is typically unstable with respect to spatial perturbations and can fragment to condensate lumps. The case of D-term inflation is considered as an example and it is shown that fragmentation occurs if λ> 0.2g, where λis the superpotenti

Daniel Cormier, Katrin Heitmann, Anupam Mazumdar

Coupled, multi-field models of inflation can provide several attractive features unavailable in the case of a single inflaton field. These models have a rich dynamical structure resulting from the interaction of the fields and their associated fluctuations. We present a formalism to study the nonequilibrium dynamics of coupled scalar fields. This formalism s

Oleg A. Gleizer

In this paper we construct three infinite series and two extra triples of complex matrices B, C, and A=B+C of special spectral types associated to C. Simpson&#39;s classification in his paper ``Products of Matrices&#39;&#39; and a classification of multiple flag varieties with finitely many orbits of the diagonal action of the general linear group by P. Magy

Thomas Curtright, Cosmas Zachos

A concise derivation of all uncertainty relations is given entirely within the context of phase-space quantization, without recourse to operator methods, to the direct use of Weyl&#39;s correspondence, or to marginal distributions of x and p.

Mina Aganagic, Cumrun Vafa

By applying mirror symmetry to D-branes in a Calabi-Yau geometry we shed light on a $G_2$ flop in M-theory relevant for large $N$ dualities in ${\cal N}=1$ supersymmetric gauge theories. Furthermore, we derive superpotential for M-theory on corresponding $G_2$ manifolds for all A-D-E cases. This provides an effective method for geometric engineering of ${\ca

S. Pepin, Fl. Stancu

Recently it has been argued that a three-body colour confinement interaction can affect the stability condition of a three-quark system and the spectrum of a tetraquark described by any constituent quark model. Here we discuss the role of a three-body colour confinement interaction in a simple quark model and present some of its implications for the spectra

Mauro Napsuciale, Andreas Wirzba, Mariana Kirchbach

We investigate the relevance of the instanton-induced determinantal &#39;t Hooft interaction to the eta-nucleon coupling within the framework of a three-flavor linear sigma model in the OZI-rule-respecting basis. Instantons, in combination with the spontaneous breaking of chiral symmetry, are shown to provide the major mechanism for the ideal mixing between

Paul Mansfield, David Nolland

An infra-red fixed point of ${\mathcal N}=1$ super-Yang-Mills theory is believed to be dual to a solution of five-dimensional gauged ${\mathcal N}=8$ supergravity. We test this conjecture at next to leading order in the large $N$ expansion by computing bulk one-loop corrections to the anomaly coefficient $a-c$. The one-loop corrections are non-zero for all v

Lorenzo Iorio

The general relativistic gravitomagnetic clock effect consists in the fact that two point particles orbiting a central spinning object along identical, circular equatorial geodesic paths, but in opposite directions, exhibit a time difference in describing a full revolution. It turns out that the particle rotating in the same sense of the central body is slow

J. Morgenstern, Z. E. Meziani

Guided by the experimental confirmation of the validity of the Effective Momentum Approximation (EMA) in quasi-elastic scattering off nuclei, we have re-examined the extraction of the longitudinal and transverse response functions in medium-weight and heavy nuclei. In the EMA we have performed a Rosenbluth separation of the available world data on $^{40}$Ca,

E. Alfinito, G. Vitiello

In the framework of the Ginzburg-Landau harmonic potential approximation, we present a possible modeling of the time-dependence of the frequency of the order parameter mode suitable to account for the formation of correlated domains in non-instantaneous symmetry breaking phase transitions. An interesting spectrum of possibilities for the size and the life-ti

Christof Gattringer, Meinulf Göckeler, P. E. L. Rakow, Stefan Schaefer

We study spectra, localization properties and local chirality of eigenvectors of the lattice Dirac operator. We analyze ensembles of quenched SU(3) configurations on both sides of the QCD phase transition. Our Dirac operator is a systematic expansion in path length of a solution of the Ginsparg-Wilson equation. Analyzing the finite volume behavior of our obs

E. Kuulkers, J. Homan, M. van der Klis, W. H. G. Lewin

(abridged version) We report on ten type I X-ray bursts from GX 17+2 in data obtained with the RXTE/PCA in 1996--2000. Three bursts were short in duration (~10 s), whereas the others lasted for ~6-25 min. Five of the long bursts showed evidence for radius expansion of the neutron star photosphere. No correlations o f the burst properties with respect to the