October 2001 arXiv papers — page 2

Sven Moch, Peter Uwer, Stefan Weinzierl

High precision analyses of experimental data for e+ e- annihillation, such as determination of jet rates or event shape observables, call for complete next-to-next-to-leading order (NNLO) perturbative QCD predictions. In this talk, we discuss the various ingredients entering the calculation of the NNLO corrections in e+ e- annihillation.

S. Digal, P. Petreczky, H. Satz

We use recent lattice data on the heavy quark potential in order to determine the dissociation temperatures of different quarkonium states in hot strongly interacting matter. Our analysis shows in particular that certain quarkonium states dissociate below the deconfinement point.

M. B. Gay Ducati, V. P. Goncalves, C. B. Mariotto

The diffractive photoproduction of vector mesons is usually described considering the two-gluon (Pomeron) exchange, non-diagonal parton distributions and the contribution of the real part to the cross section. In this letter we analyze the diffractive photoproduction of the $Υ$ at HERA using an alternative model, the Color Evaporation Model (CEM), where the

R. Bacher

In October 2000, the third PCaPAC (PCs and Particle Accelerator Controls) workshop took place at DESY. This paper presents a summary of the workshop. The workshop reviewed existing and new PC-based accelerator control systems, from small-scale to large-scale installations. It demonstrated convincingly the advantage of modern, commercial mass-market products

A. Denner, S. Dittmaier, M. Roth, D. Wackeroth

The relevance of radiative corrections to 4f production at LEP2 and future e+e- colliders is emphasized, and their treatment in the event generator RacoonWW is briefly discussed. In particular, the non-universal corrections are compared with the signature of anomalous triple gauge-boson couplings. For 4f+gamma production the influence of anomalous quartic ga

A. A. Arkhipov

A manifestation of narrow diproton resonances in the early discovered global structure of proton-proton total cross section at low energies is discussed. It is also discussed the existence of new particle with the mass $1.833 MeV$ predicted early.

A. A. Pivovarov

Theoretical results for the cross section of heavy quark production near the threshold at NNLO of NRQCD are briefly overviewed.

K. Splittorff

The response of the QCD vacuum to quark chemical potentials on the order of the pion mass is studied within the context of chiral perturbation theory. For two colour QCD diquark condensation sets in when the baryon chemical potential becomes larger than the pion mass. This leading order result is confirmed at next to leading order. Next a set of massive spin

A. Bode, H. Panagopoulos, Y. Proestos

We calculate the 3-loop bare $β$-function of QCD, formulated on the lattice with the clover fermionic action. The dependence of our result on the number of colors $N$, the number of fermionic flavors $N_f$, and the clover parameter $c_{SW}$, is shown explicitly. A direct outcome of our calculation is the two-loop relation between the bare coupling constant $

Bernd Gehrmann, Stefan Kurth, Juri Rolf, Ulli Wolff

We study the Schrödinger functional coupling for lattice Yang-Mills theory coupled to an improved bosonic spinor field, which corresponds to QCD with minus two light flavors. This theory serves as a less costly testcase than QCD for the scaling of the coupling.

Elmar Bittner, Harald Markum, Rainer Pullirsch

This article is the written version of a talk delivered at the Bexbach Colloquium of Science 2000 and starts with an introduction into quantum chaos and its relationship to classical chaos. The Bohigas-Giannoni-Schmit conjecture is formulated and evaluated within random-matrix theory. Several examples of physical systems exhibiting quantum chaos ranging from

Sergio Caracciolo, Andrea Montanari, Andrea Pelissetto

We consider a two-dimensional $σ$-model with discrete icosahedral/dodecahedral symmetry. Using the perturbative renormalization group, we argue that this model has a different continuum limit with respect to the O(3) $σ$ model. Such an argument is confirmed by a high-precision numerical simulation.

O. Miyamura, S. Choe

Using the Nambu--Jona-Lasinio (NJL) model we study chemical potential response of the pion and kaon masses as a function of temperature and chemical potential, i.e., dm/dμ(T, μ). First, we obtain the responses assuming the vector-axial vector coupling is zero (g_V=0). Then, we include a non-zero g_V and study the effects of g_V on the responses. We find that

V. I. Kotov, A. G. Afonin, V. M. Biryukov, Y. A. Chesnokov

Bent crystal was extracting 70-GeV protons with average intensity 4*10^11 (as measured in external beamline) per spill of 1.6 s duration, in parallel to the simultaneous work of two internal targets in the accelerator ring. An additional crystal, placed in the external beamline, was deflecting a small part of the extracted beam with intensity 10^7 protons to

S. P. Barrow, representing the CLAS collaboration

The large acceptance and high multiplicity capabilities of the CLAS detector make it possible to study a wide range of previously unmeasured strange baryon production processes. Studies of the decay angular distributions of electroproduced strange baryons have yielded several interesting new results. The $Λ$(1520) electroproduction decay angular distribution

David Charlton

The current status of experimental tests of the electroweak sector of the Standard Model is reviewed.

Monica Vazquez

The substructure of jets produced in an exclusive and a charm-induced dijet sample in photoproduction and in charged and neutral current interactions has been studied with the ZEUS detector at HERA. Jets were identified using the longitudinally invariant k_T cluster algorithm in the laboratory frame. The substructure of jets has been studied in terms of the

Marek Tasevsky

The differences between quark and gluon jets are studied using LEP results on jet widths, scale dependent multiplicities, ratios of multiplicities, slopes and curvatures and fragmentation functions. It is emphasized that the observed differences stem primarily from the different quark and gluon colour factors.

The MACRO Collaboration

We describe a search method for fast moving ($β> 5 \times 10^{-3}$) magnetic monopoles using simultaneously the scintillator, streamer tube and track-etch subdetectors of the MACRO apparatus. The first two subdetectors are used primarily for the identification of candidates while the track-etch one is used as the final tool for their rejection or confirmatio

Philip J. Clark

The BaBar detector and SLAC PEP-II asymmetric e+e- collider tuned to the Y(4s) resonance has collected around 23M B0 anti-B0 pairs in year 2000. The total data sample for run 1 is 20.7fb-1, using this data we present the study of sin2beta, with samples of B0 --> J/Psi KOS, B0 --> psi(2S) K0S and B0 --> J/Psi KOL decays. The measured value is sin2beta 0.34+/-

Kirill A. Bronnikov

We discuss the global properties of static, spherically symmetric configurations of a self-gravitating real scalar field $ϕ$ in general relativity (GR), scalar-tensor theories (STT) and high-order gravity ($L=f(R)$) in various dimensions. In GR, for fields with arbitrary potentials $V(ϕ)$, not necessarily positive-definite, it is shown that the list of all p

Ath. Kehagias, M. Konstantinidou

The starting point of this paper is the introduction of a new measure of inclusion of fuzzy set A in fuzzy set B. Previously used inclusion measures take values in the interval [0,1]; the inclusion measure proposed here takes values in a Boolean lattice. In other words, inclusion is viewed as an L-fuzzy valued relation between fuzzy sets. This relation is re

K. U. Kasemir, M. Pieck, L. R. Dalesio

Being easy to learn and well suited for a self-contained desktop laboratory setup, many casual programmers prefer to use the National Instruments LabVIEW environment to develop their logic. An ActiveX interface is presented that allows integration into a plant-wide distributed environment based on the Experimental Physics and Industrial Control System (EPICS

Fedor S. Kilin

The optimal planning trajectory is analyzed on the basis of the growth model with effectiveness. The saving per capital value has to be rather high initially with smooth decrement in the future years.

K. U. Kasemir, L. R. Dalesio

The Channel Archiver has been operational for more than two years at Los Alamos National Laboratory and other sites. This paper introduces the available components (data sampling engine, viewers, scripting interface, HTTP/CGI integration and data management), presents updated performance measurements and reviews operational experience with the Channel Archiv

K. U. Kasemir, L. R. Dalesio

The Allen-Bradley ControlLogix line of pro-grammable logic controllers (PLCs) offers several in-terfaces: Ethernet, ControlNet, DeviceNet, RS-232 and others. The ControlLogix Ethernet interface module 1756-ENET uses EtherNet/IP, the ControlNet protocol, encapsulated in Ethernet packages, with specific service codes. A driver for the Experimental Physics and

Serban E. Vlad

We write the relations that characterize the simpliest timed automaton, the inertial delay buffer, in two versions: the non-deterministic and the deterministic one, by making use of the derivatives of the R->{0,1} functions.

Serban E. Vlad

The paper studies some important properties of the asynchronous (=timed) automata: the delay-insensitivity, the hazard-freedom, the semi-modularity and the technical condition of good running. Time is discrete.

Serban E. Vlad

The paper presents the differential equations that characterize an asynchronous automaton and gives their solution x:R->{0,1}x...x{0,1}. Remarks are made on the connection between the continuous time and the discrete time of the approach. The continuous and the discrete time, the linear and the branching temporal logics have the semantics depending on x and

Serban E. Vlad

The paper is concerned with defining the electrical signals and their models. The delays are discussed, the asynchronous automata - which are the models of the asynchronous circuits - and the examples of the clock generator and of the R-S latch are given. We write the equations of the asynchronous automata, which combine the pure delay model and the inertial

J. A. Fernandez-Baca, Pengcheng Dai, H. Kawano-Furukawa, H. Yoshizawa

Using inelastic neutron scattering we measured the microscopic magnetic coupling associated with the ferromagnetic (FM) clusters of the ``colossal magnetoresistance'' (CMR) compound Pr$_{0.70}$Ca$_{0.30}$MnO$_3$. When the insulating to metal (I-M) transition is induced by an external magnetic field there is a discontinuous change in the spin-wave sti

Beth Parks, Joseph Loomis, Evan Rumberger, David N. Hendrickson

We use time-domain terahertz spectroscopy to measure the position and linewidth of single photon transitions in Mn$_{12}$-acetate. This linewidth is compared to the linewidth measured in tunneling experiments. We conclude that local magnetic fields (due to dipole or hyperfine interactions) cannot be responsible for the observed linewidth, and suggest that th

E. Somfai, R. van Gastel, S. B. van Albada, W. van Saarloos

We develop a version of the vacancy mediated tracer diffusion model, which follows the properties of the physical system of In atoms diffusing within the top layer of Cu(001) terraces. This model differs from the classical tracer diffusion problem in that (i) the lattice is finite, (ii) the boundary is a trap for the vacancy, and (iii) the diffusion rate of

R. van Gastel, E. Somfai, S. B. van Albada, W. van Saarloos

We have used the indium/copper surface alloy to study the dynamics of surface vacancies on the Cu(001) surface. Individual indium atoms that are embedded within the first layer of the crystal, are used as probes to detect the rapid diffusion of surface vacancies. STM measurements show that these indium atoms make multi-lattice-spacing jumps separated by long

Michael Baake, Uwe Grimm, Max Scheffer

The investigation of colour symmetries for periodic and aperiodic systems consists of two steps. The first concerns the computation of the possible numbers of colours and is mainly combinatorial in nature. The second is algebraic and determines the actual colour symmetry groups. Continuing previous work, we present the results of the combinatorial part for p

A. O. Parry, A. J. Wood, E. Carlon, A. Drzewiński

The phase boundaries for corner wetting (filling) in square and diagonal lattice Ising models are exactly determined and show a universal shift relative to wetting near the bulk criticality. More generally, scaling theory predicts that the filling phase boundary shift for wedges and cones is determined by a universal scaling function $R_d(ψ)$ depending only

Federico Corberi, Eugenio Lippiello, Marco Zannetti

The connection between the out of equilibrium linear response function and static properties established by Franz, Mezard, Parisi and Peliti for slowly relaxing systems is analyzed in the context of phase ordering processes. Separating the response in the bulk of domains from interface response, we find that in order for the connection to hold the interface

C. Fusco, P. Gallo, A. Petri, M. Rovere

We studied the single dimer dynamics in a lattice diffusive model as a function of particle density in the high densification regime. The mean square displacement is found to be subdiffusive both in one and two dimensions. The spatial dependence of the self part of the van Hove correlation function displays as function of $r$ a single peak and signals a dram

C. Pennetta, L. Reggiani, E. Alfinito

The electromigration (EM) of metallic lines is studied in terms of competition between two percolative processes taking place in a random resistor network. The effects associated with the transport of mass and with the consequent growth of the internal stress are accounted for by stochastic generation and recovery of voids, driven by the external current. Mo

C. Pennetta, L. Reggiani, E. Alfinito, G. Trefan

The state of a 2-D random resistor network, resulting from the simultaneous evolutions of two competing biased percolations, is studied in a wide range of bias values. Monte Carlo simulations show that when the external current $I$ is below the threshold value for electrical breakdown, the network reaches a steady state with a nonlinear current-voltage chara

Minoru Takahashi, Masahiro Shiroishi

New numerical method to calculate thermodynmic Bethe ansatz equations is proposed based on Newton's method. Thermodynamic quantities of one-dimensional Hubbard model is numerically calculated and compared with high temperature expansion and numerical results of quantum transfer matrix method by Jüttner, Klümper and Suzuki. The coincidence is surprisingly

C. S. O'Hern, S. A. Langer, A. J. Liu, S. R. Nagel

We study random packings of frictionless particles at T=0. The packing fraction where the pressure becomes nonzero is the same as the jamming threshold, where the static shear modulus becomes nonzero. The distribution of threshold packing fractions narrows and its peak approaches random close-packing as the system size increases. For packing fractions within

L. Campbell, L. Hedin, J. J. Rehr, W. Bardyszewski

The interference between extrinsic and intrinsic losses in x-ray absorption fine structure (XAFS) is treated within a Green's function formalism, without explicit reference to final states. The approach makes use of a quasi-boson representation of excitations and perturbation theory in the interaction potential between electrons and quasi-bosons. These l

Y. J. Uemura

We propose a phenomenological model for high-$T_{c}$ superconductors (HTSC) assuming: (1) a microscopic phase separation between superconducting and normal-metal areas in the overdoped region; and (2) existence of a homogeneous superconducting phase only below the pseudo-gap $T^{*}$ line, which shows a sharp reduction towards $T^{*}\sim 0$ at a mildly overdo

Kevin E. Bassler, Joern Davidsen, Maya Paczuski

Current-voltage measurements of type-II superconductors are described by a coarse-grained model of superconducting vortex dynamics. We find that the power spectra of the voltage fluctuations, and the noise power, are related to the large scale morphology of the plastic flux flow. At currents corresponding to the peak in differential resistance, the flux flow

A. Andreone, G. Ausanio, E. Di Gennaro, G. Lamura

We present a study of the electrodynamic response of MgB2 pellets and thin film samples exhibiting critical temperatures ranging between 26 and 38 K. We have performed accurate measurements of the surface impedance ZS =RS+iXS as a function of the temperature and of the magnitude of the electromagnetic field. The temperature variation and the field dependence

J. B. Sokoloff

Using both a recent calculation by Bruch of the damping of the motion of a monolayer nitrogen film oscillating harmonically on a metallic surface due to Ohm's law heating and a Thomas-Fermi approximation treatment of the Ohm's law heating mechanism, which accounts for the nonzero thickness of the surface region of a metal, it is argued that this mech

N. Wang, R. N. Manchester, J. Zhang, X. J. Wu

A pulsar timing system has been operating in the 18-cm band at the Urumqi Astronomical Observatory 25-m telescope since mid-1999. Frequency resolution allowing dedispersion of the pulsar signals is provided by a 2X128X2.5 MHz filterbank/digitiser system. Observations of 74 pulsars over more than 12 months have resulted in updated pulsar periods and period de

James S. Bullock

Although the currently favored cold dark matter plus cosmological constant model (LCDM) has proven to be remarkably successful on large scales, on subgalactic scales it faces some potentially fatal difficulties; these include over-producing dwarf satellite galaxies and predicting excessive central densities in dark halos. Among the most natural cosmological

Jessica L. Rosenberg, Stephen E. Schneider

We use the HI-selected galaxy sample from the Arecibo Dual-Beam Survey (Rosenberg & Schneider 2000) to determine the shape of the HI mass function of galaxies in the local universe using both the step-wise maximum likelihood and the 1/V_tot methods. Our survey region spanned all 24 hours of right ascension at selected declinations between 8 and 29 degrees co

L. K. Townsley, P. S. Broos, G. Chartas, E. Moskalenko

We have implemented a Monte Carlo algorithm to model and predict the response of various kinds of CCDs to X-ray photons and minimally-ionizing particles and have applied this model to the CCDs in the Chandra X-ray Observatory's Advanced CCD Imaging Spectrometer. This algorithm draws on empirical results and predicts the response of all basic types of X-r

Alberto Conti, Barbara S. Ryden, David H. Weinberg

(Abridged) Motivated by forthcoming data from the Sloan Digital Sky Survey, we present a theoretical framework that can be used to interpret Principal Component Analysis (PCA) of disk galaxy properties. We use the formalism introduced by Mo, Mao, & White to compute the observable properties of galaxies in a number of model populations, varying assumptions ab

S. A. Stanford, B. P. Holden, P. Rosati, P. R. Eisenhardt

We report the discovery of an X-ray luminous galaxy cluster at z =1.11. RDCS J0910+5422 was selected as an X-ray cluster candidate in the ROSAT Deep Cluster Survey on the basis of its spatial extent in a Rosat PSPC image. Deep optical and near-IR imaging reveal a red galaxy overdensity around the peak of the X-ray emission, with a significant excess of objec

M. R. S. Hawkins

The variability of active galactic nuclei (AGN) has long held the promise of shedding light on their detailed structure, and possibly other astrophysical phenonema. Different emission mechanisms lead to different patterns of variability in flux which are in principle easily distinguishable. Recent predictions for the expected spectrum of variations for vario

S. Calchi Novati, G. Iovane, A. A. Marino, M. Auriere

We present the first results of the analysis of data collected during the 1998-99 observational campaign at the 1.3 meter McGraw-Hill Telescope, towards the Andromeda galaxy (M31), aimed to the detection of gravitational microlensing effects as a probe of the presence of dark matter in our and in M31 halo. The analysis is performed using the pixel lensing te

Victor I. Denisov, Irene P. Denisova, Sergey I. Svertilov

It was shown that according to the non-linear electrodynamics of vacuum electromagnetic rays should bend in the field of magnetic dipole. The angles of ray bending in the gravitational and magnetic fields of pulsars and magnetars were obtained. In the case of pulsars with $b\sim R\sim $ 100 km, $B_0\sim 10^{13} G$ the value of the angle of non-linear electro

Claus A. Goessl, Arno Riffeser

We present a reduction pipeline for CCD (charge-coupled device) images which was built to search for variable sources in highly crowded fields like the M31 bulge and to handle extensive databases due to large time series. We describe all steps of the standard reduction in detail with emphasis on the realisation of per pixel error propagation: Bias correction

D. Martinez-Delgado, M. A. Gomez-Flechoso, A. Aparicio

Standard cosmology predicts that dwarfs were the first galaxies to be formed in the Universe and that many of them merge afterwards to form bigger galaxies such as the Milky Way. This process would have left behind traces such as tidal debris or tidal streams in the outer halo. We report here the detection of two new tidal debris of the northern stream of th

Duilia F. de Mello, Tommy Wiklind, Marcio A. G. Maia

In order to study whether there is any correlation between nuclear activities, gas content, and the environment where galaxies reside, we have obtained optical and millimetric spectra for a well-defined sample of intermediate Hubble type spirals in dense environments and in the field. We found that these spirals in dense environments have on average: less mo

R. Bachiller, A. Fuente, M. S. N. Kumar

We present molecular line observations of the star-forming cloud around RNO6 along with a newly discovered nearby molecular cloud that we name RNO6NW. Both clouds display striking similarities in their cometary structures and overall kinematics. By using 13CO line observations, we estimate that these clouds have similar sizes (~4.5 pc) and masses (~200 solar

Martin D. Weinberg

I review the arguments for the importance of halo structure in driving galaxy evolution and coupling a galaxy to its environment. We begin with a general discussion of the key dynamics and examples of structure dominated by modes. We find that simulations with large numbers of particles (N > 1e6) are required to resolve the dynamics. Finally, I will describe

Duilia F. de Mello, Marcio A. G. Maia, Tommy Wiklind

We present optical and millimetric data for 47 intermediate Hubble type spiral galaxies located either in dense environments or in the field. We compare correlations between global parameters, such as far-infrared luminosity, blue luminosity, and total molecular gas content, with other samples of galaxies, including normal galaxies, clusters and ultraluminou

Alessandro Marconi, Marco Salvati

We follow the evolution of the Black Hole mass function in the assumption that mass accretion onto a massive BH is the powering mechanism of AGN activity. With reasonable assumptions suggested by current knowledge, it is possible to reproduce the Black Hole mass function derived from local bulges. In particular it is found that the majority of the mass in re

C. Adami, A. Mazure

We present an automated method to detect populations of groups in galaxy redshift catalogs. This method uses both analysis of the redshift distribution along lines of sight in fixed cells to detect elementary structures and a friend-of-friend algorithm to merge these elementary structures into physical structures. We apply this method to the SSRS2 galaxy red

J. J. M. in 't Zand, J. Swank, R. H. D. Corbet, C. B. Markwardt

A search for pulsations from the Be X-ray binary SAX J2239.3+6116, through observations with the Narrow Field Instruments on BeppoSAX and the Proportional Counter Array on RXTE, yielded the clear presence of a 1247 s coherent oscillation. Given the fairly high X-ray luminosity on previous occasions (up to a few times 10^36 erg/s in 2 to 28 keV), the oscillat

Michael Burton

Ecosystems are systems where energy flows and material cycles are maintained in an apparently stable, but non-equilibrium state through a process of self-regulation. Such a definition does just apply to biological systems, it can also apply to systems that involve entirely physical processes. We discuss how four systems, each operating on very different spat

R. N. Manchester, B. M. Gaensler, V. C. Wheaton, L. Staveley-Smith

The development of the radio remnant of SN 1987A has been followed using the Australia Telescope Compact Array since its first detection in 1990 August. The remnant has been observed at four frequencies, 1.4, 2.4, 4.8 and 8.6 GHz, at intervals of 4 - 6 weeks since the first detection. These data are combined with the 843 MHz data set of Ball et al. (2001) ob

D. Molteni, K. Acharya, Oleg Kuznetsov, D. Bisikalo

We demonstrate that generically an accretion disk around a compact object could have a new type of instability in that the accretion flow need not be symmetric with respect to the equatorial plane even when matter is supplied symmetrically farther out. We find that this behaviour is mainly due to interaction of outgoing matter bounced off the centrifugal bar

R. A. Ibata, G. F. Lewis, M. J. Irwin, L. Cambresy

A pole-count analysis of the infrared 2MASS survey is presented, in order to identify faint stream-like structures within the halo of the Milky Way. Selecting stars with colours consistent with M-giant stars, we find a strong over-density of sources on a stream with pole (l=95,b=13), which corresponds to the pole of the orbit of the Sagittarius dwarf galaxy.

R. A. Ibata, G. F. Lewis, M. J. Irwin

Models for the formation and growth of structure in a cold dark matter dominated universe predict that galaxy halos should contain significant substructure. Studies of the Milky Way, however, have yet to identify the expected few hundred sub-halos with masses greater than about 10^6 Msun. Here we propose a test for the presence of sub-halos in the halos of g

Chang H. Ree, Suk-Jin Yoon, Soo-Chang Rey, Young-Wook Lee

We have constructed synthetic color-magnitude diagrams (CMDs) for omega Cen and other massive globular clusters with apparently peculiar CMD morphology. Our population models, which adopt the most up-to-date input physics and parameters, show that the observed CMD of omega Cen can be reproduced by adopting (1) multimodal metallicity distribution function as

Young-Wook Lee, Soo-Chang Rey, Chang H. Ree, Jong-Myung Joo

Our recent CCD photometry (Lee et al. 1999) has shown, for the first time, that omega Cen has several distinct stellar populations, which is reminiscent of the Sagittarius dwarf galaxy. Here we present more detailed analysis of the data along with the population models. We confirm the presence of several distinct red-giant-branches (RGBs) with a red metal-ri

Soo-Chang Rey, Jong-Myung Joo, Young-Jong Sohn, Chang H. Ree

We present wide-field and high-precision BV and Ca & Stromgren by photometry of omega Centauri and its RR Lyrae stars, which represents one of the most extensive photometric surveys to date for this cluster. The member stars of omega Cen are well discriminated from foreground Galactic disk stars from the different distributions in the hk [=(Ca-b)-(b-y)] vs.

A. Alexakis, Y. Young, R. Rosner

We examine the linear stability of fluid interfaces subjected to a shear flow. Our main object is to generalize previous work to arbitrary Atwood number, and to allow for surface tension and weak compressibility. The motivation derives from instances in astrophysical systems where mixing across material interfaces driven by shear flows may significantly affe

Helmut Jerjen, Rami Rekola, Leo Takalo, Matthew Coleman

We obtained B and R-band CCD images for the dwarf elliptical (dE) galaxies DDO44, UGC4998, KK98_77, DDO71, DDO113, and UGC7356 at the NOT. Using Fourier analysis technique we measure stellar R-band surface brightness fluctuations (SBFs) and magnitudes in 29 different fields of the galaxies. Independent tip of the red giant branch distances for DDO44, KK98_77

R. Rosner, A. Alexakis, Y. Young, J. Truran

Using the results of recent work in shear instabilities in stratified fluids, we show that the resonant interaction between large-scale flows in the accreted H/He envelope of white dwarf stars and interfacial gravity waves can mix with the star's envelope with the white dwarf's surface material, leading to the enhancement of the envelope's C/O ab

James A. Harvin, Douglas R. Gies, William G. Bagnuolo,, Laura R. Penny

Double-lined spectroscopic orbital elements have recently been found for the central binary in the massive triple, delta Orionis A based on radial velocities from cross-correlation techniques applied to IUE high dispersion spectra and He I 6678 spectra obtained at Kitt Peak. The primary and secondary velocity amplitudes were found to be 94.9 +/- 0.6 km/s and

Shih-Ping Lai, Richard M. Crutcher, Jose M. Girart, Ramprasad Rao

We present the first interferometric polarization maps of the NGC2024 FIR5 molecular core obtained with the BIMA array at approximately 2 arcsec resolution. We measure an average position angle of -60+-6 degrees in the main core of FIR5 and 54+-9 degrees in the eastern wing of FIR5. The morphology of the polarization angles in the main core of FIR5 suggests

Pasquale Blasi

The universe should be dark at energies exceeding $\sim 5\times 10^{19}$ eV. This simple but solid prediction of our best known particle physics is not confirmed by observations, that seem to suggest a quite different picture. Numerous events have in fact been detected in this energy region, with spectra and anisotropy features that defy many conventional an

Scott A. Hughes, Szabolcs Marka, Peter L. Bender, Craig J. Hogan

Gravitational-wave detectors with sensitivities sufficient to measure the radiation from astrophysical sources are rapidly coming into existence. By the end of this decade, there will exist several ground-based instruments in North America, Europe, and Japan, and the joint American-European space-based antenna LISA should be either approaching orbit or in fi

A. J. M. Medved

It is often convenient to view Hawking (black hole) radiation as a process of quantum tunneling. Within this framework, Kraus and Wilczek (KW) have initiated an analytical treatment of black hole emission. Notably, their methodology incorporates the effects of a dynamical black hole geometry. In the current paper, the KW formalism is applied to the case of a

Mauricio Bellini

I study a thermodynamical approach to scalar metric perturbations during the inflationary stage. In the power-law expanding universe here studied, I find a negative heat capacity as a manifestation of superexponential growing for the number of states in super Hubble scales. The power spectrum depends on the Gibbons-Hawking and Hagedorn temperatures.

Thomas S. Levi, Marcelo Gleiser

We present a new model for a non-topological soliton (NTS) that contains interacting fermions, scalar particles and a gauge field. Using a variational approach, we estimate the energy of the localized configuration, showing that it can be the lowest energy state of the system for a wide range of parameters.

Ian Low, Aneesh V. Manohar

Goldstone's theorem states that there is a massless mode for each broken symmetry generator. It has been known for a long time that the naive generalization of this counting fails to give the correct number of massless modes for spontaneously broken spacetime symmetries. We explain how to get the right count of massless modes in the general case, and dis

S. G. Schirmer, A. I. Solomon, J. V. Leahy

We address the question of which quantum states can be inter-converted under the action of a time-dependent Hamiltonian. In particular, we consider the problem applied to mixed states, and investigate the difference between pure and mixed-state controllability introduced in previous work. We provide a complete characterization of the eigenvalue spectrum for

I. K. Baldry, K. Glazebrook, C. M. Baugh, J. Bland-Hawthorn

We present the first results on the history of star formation in the Universe based on the `cosmic spectrum', in particular, the volume-averaged, luminosity-weighted, stellar absorption line spectrum of present day galaxies from the 2dFGRS. This method is novel in that unlike previous studies it is not an estimator based on total luminosity density. The

Cheng-Wei Chiang, Jonathan L. Rosner

Cabibbo-favored nonleptonic charmed particle decays exhibit large final-state phase differences in $\bar K π$ and $\bar K^* π$ but not $\bar K ρ$ channels. It is of interest to know the corresponding pattern of final-state phases in doubly-Cabibbo-suppressed decays, governed by the $c \to d u \bar s$ subprocess. An experimental program is outlined for determ

Uchida Gen, Akihiro Ishibashi, Takahiro Tanaka

We propose an alternative inflationary universe scenario in the context of Randall-Sundrum braneworld cosmology. In this new scenario the existence of extra-dimension(s) plays an essential role. First, the brane universe is initially in the inflationary phase driven by the effective cosmological constant induced by small mismatch between the vacuum energy in

V. Barger, A. M. Gago, D. Marfatia, W. J. C. Teves

We perform a detailed analysis of the capabilities of the MINOS, ICARUS and OPERA experiments to measure neutrino oscillation parameters at the atmospheric scale with their data taken separately and in combination. MINOS will determine $Δm^2_{32}$ and $\sin^2 2θ_{23}$ to within 10% at the 99% C.L. with 10 kton-years of data. While no one experiment will dete

Carlos Herdeiro, Shinji Hirano, Renata Kallosh

We find a description of hybrid inflation in (3+1)-dimensions using brane dynamics of Hanany-Witten type. P-term inflation/acceleration of the universe with the hybrid potential has a slow-roll de Sitter stage and a waterfall stage which leads towards an N=2 supersymmetric ground state. We identify the slow-roll stage of inflation with a non-supersymmetric `

Branislav K. Nikolic, Viktor Z. Cerovski

We report on the comprehensive numerical study of the fluctuation and correlation properties of wave functions in three-dimensional mesoscopic diffusive conductors. Several large sets of nanoscale samples with finite metallic conductance, modeled by an Anderson model with different strengths of diagonal box disorder, have been generated in order to investiga

Alexander Mück, Apostolos Pilaftsis, Reinhold Rückl

We consider minimal 5-dimensional extensions of the Standard Model compactified on an $S^1/Z_2$ orbifold, in which the SU(2)$_L$ and U(1)$_Y$ gauge fields and Higgs bosons may or may not all propagate in the fifth dimension while the observable matter is always assumed to be confined to a 4-dimensional subspace. We pay particular attention to consistently qu

Katherine A. Seaton

The universal amplitude ratio $\tilde{R}_ξ$ for percolation in two dimensions is determined exactly using results for the dilute A model in regime 1, by way of a relationship with the q-state Potts model for q<4.

E. V. Bugaev, M. G. Elbakidze, K. V. Konishchev

The process of baryogenesis through the evaporation of black holes formed at the end of inflation phase is considered. The increase of black hole mass due to accretion from the surrounding radiation after the reheating is taken into account. It is shown that the influence of the accretion on the baryogenesis is important only in the case when the initial val

Pierre-Yves Casteill, Evgeny Ivanov, Galliano Valent

We construct, using harmonic superspace and the quaternionic quotient approach, a quaternionic-Kähler extension of the most general two centres hyper-Kähler metric. It possesses $U(1)\times U(1)$ isometry, contains as special cases the quaternionic-Kähler extensions of the Taub-NUT and Eguchi-Hanson metrics and exhibits an extra one-parameter freedom which d

A. A. Andrianov, P. Giacconi, R. Soldati

The possibility of a small modification of spinor Quantum Electro-Dynamics is reconsidered, in which Lorentz and CPT non-covariant kinetic terms for photons and fermions are present. The corresponding free field theory is carefully discussed. The finite one-loop parity-odd induced effective action is unambiguously calculated using the physical cutoff method,

T. R. Kallman, P. Meszaros, M. J. Rees

We present models for reprocessing of an intense flux of X-rays and gamma rays expected in the vicinity of gamma ray burst sources. We consider the transfer and reprocessing of the energetic photons into observable features in the X-ray band, notably the K lines of iron. Our models are based on the assumption that the gas is sufficiently dense to allow the m

M. R. Evans, R. A. Blythe

In these lectures we give an overview of nonequilibrium stochastic systems. In particular we discuss in detail two models, the asymmetric exclusion process and a ballistic reaction model, that illustrate many general features of nonequilibrium dynamics: for example coarsening dynamics and nonequilibrium phase transitions. As a secondary theme we shall show h

Matyas Koniorczyk, Jozsef Janszky

The group theoretical aspect of the description of passive lossless optical four-ports (beam splitters) is revisited. It is shown through an example, that this approach can be useful in understanding interferometric schemes where a low number of photons interfere. The formalism is extended to passive lossless optical six-ports, their SU(3)-theory is outlined

P. M. Nadolsky, Z. Sullivan

We apply a method proposed by members of CTEQ Collaboration to estimate the uncertainty in associated $W$-Higgs boson production at Run II of the Tevatron due to our imprecise knowledge of parton distribution functions. We find that the PDF uncertainties for the signal and background rates are of the order 3%. The PDF uncertainties for the important statisti