August 2000 arXiv papers — page 16

Joannis Papavassiliou, Arcadi Santamaria

We study, at the one loop level, the dominant new physics contributions from extra dimensions to Z -> b,b(bar), as well as B-B(bar) and K-K(bar) mixing. We use a model with one extra dimension containing fermions which live in four dimensions, and gauge bosons and one scalar doublet propagating in five dimensions. We find that the effect of the infinite towe

C. Wetterich

The vacuum of QCD is characterized by the Higgs mechanism. Color is ``spontaneously broken'' by a quark-antiquark condensate in the octet representation. The massive gluons carry integer electric charges and are identified with the vector mesons. The fermionic excitations consist of the low mass baryon octet and a singlet. The interactions between th

K. Tuominen

This talk will discuss how to compute initial quantites in heavy ion collisions at RHIC (200 AGeV) and at LHC (5500 AGeV) using perturbative QCD (pQCD) by including the next-to-leading order (NLO) corrections and a dynamical determination of the dominant physical scale. The initial numbers are converted into final ones by assuming kinetic thermalization and

Hong Shen, Ma Luo

We study the nuclear dependences of high-$p_T$ jet cross sections in one photon and one jet production in proton-nucleus collisions. We find that there exist asymmetries between the outgoing jets and photons. A convincing reason responsible for those asymmetries are demonstrated in perturbative QCD. Significant nuclear enhancements are also found in the incl

T. Hadig

This article summarizes a talk given at the International Symposium on Multiparticle Dynamics 1999 in Providence/USA. It provides an overview on the variety of measurements of the hadronic final state in jet production for deep-inelastic scattering and photoproduction at HERA.

T. Hadig

The extraction of the parameters of perturbative QCD is one of the main tasks for the HERA experiments. Studies on the structure of the hadronic final states with jet algorithms give a direct handle on the parton density functions and the strong coupling strength over a wide kinematic range. In this article, new results of the H1 and ZEUS collaborations for

L3 Collaboration

The data collected by the L3 experiment at LEP at a centre-of-mass energy of 188.6 GeV are used to measure the W-pair production cross section and the W-boson decay branching fractions. These data correspond to an integrated luminosity of 176.8pb^-1. The total cross section for W-pair production, combining all final states, is measured to be sigma_WW = 16.24

L3 Collaboration

A search is performed for a Higgs boson produced in association with a Z boson and decaying into two photons, using the L3 data collected at LEP at a centre-of-mass energy of 189 GeV. All decay modes of the Z are considered. No signal is observed and limits on the branching fraction of the Higgs boson decay into two photons as a function of the Higgs mass ar

Sergio M. C. V. Goncalves

We study the spherically symmetric collapse of a real, minimally coupled, massive scalar field in an asymptotically Einstein-de Sitter spacetime background. By means of an eikonal approximation for the field and metric functions, we obtain a simple analytical criterion---involving the physical size and mass scales (the field's inverse Compton wavelength

Matthias Arnsdorf

After motivating why the study of asymptotically flat spaces is important in loop quantum gravity, we review the extension of the standard framework of this theory to the asymptotically flat sector based on the GNS construction. In particular, we provide a general procedure for constructing new Hilbert spaces for loop quantum gravity on non-compact spatial m

C. G. Hewitt, R. Bridson, J. Wainwright

In this paper we give, for the first time, a complete description of the dynamics of tilted spatially homogeneous cosmologies of Bianchi type II. The source is assumed to be a perfect fluid with equation of state $p = (γ-1) μ$, where $γ$ is a constant. We show that unless the perfect fluid is stiff, the tilt destabilizes the Kasner solutions, leading to a Mi

R. Klippert, H. C. Rosu, R. Ruffini

The barotropic indices and the corresponding FRW scale factors of the so-called Darboux cosmological fluids are presented in the comoving time axis, which is the natural one for the phenomenology related to the cosmological data. Some useful comments on the features of the plots are included

I. Radinschi

We calculate the energy distribution of a dyonic dilaton black hole by using the Tolman's energy-momentum complex. All the calculations are performed in quasi-Cartesian coordinates. The energy distribution of the dyonic dilaton black hole depends on the mass, electric charge, magnetic charge and asymptotic value of the dilaton. We get the same result as

I. Radinschi

We calculate the energy distribution of an anisotropic model of universe, based on the Bianchi type I metric, in the Tolman's prescription. The energy due to the matter plus gravitational field is equal to zero. This result agrees with the results of Banerjee and Sen and Xulu. Also, our result supports the viewpoint of Tryon and Rosen.

Christian J. Bordé, Jean-Claude Houard, Alain Karasiewicz

We present a second-quantized field theory of massive spin one-half particles or antiparticles in the presence of a weak gravitational field treated as a spin two external field in a flat Minkowski background. We solve the difficulties which arise from the derivative coupling and we are able to introduce an interaction picture. We derive expressions for the

Myra Spiliopoulou, Carsten Pohle

For many companies, competitiveness in e-commerce requires a successful presence on the web. Web sites are used to establish the company's image, to promote and sell goods and to provide customer support. The success of a web site affects and reflects directly the success of the company in the electronic market. In this study, we propose a methodology to

R. V. Leite, R. N. Costa Filho

The surface spin wave branches in ferromagnetic films are studied using a microscopic theory which considers both magnetic dipole-dipole and Heisenberg exchange interactions. The dipole terms are expressed in a Hamiltonian formalism, and the dipole sums are calculated in a rapidly convergent form. The Damon-Eshbach surface modes are analyzed for different di

L. L. Goncalves, M. Lopez de Haro, J. Taguena-Martinez

The kinetic Ising model on a n-isotopic chain is considered in the framework of Glauber dynamics. The chain is composed of N segments with n sites, each one occupied by a different isotope. Due to the isotopic mass difference, the n spins in each segment have different relaxation times in the absence of the interactions, and consequently the dynamics of the

Ho-Soon Yang, Michael R. Geller, W. M. Dennis

The low-frequency vibrational spectrum of an isolated nanometer-scale solid differs dramatically from that of a bulk crystal, causing the decay of a localized electronic state by phonon emission to be inhibited. We show, however, that an electron can also interact with the rigid translational motion of a nanocrystal. The form of the coupling is dictated by t

D. J. Singh, I. I. Mazin

The electronic structure of layered Sr$_{3}$Ru$_{2}$O$_{7}$ in its orthorhombic structure is investigated using density functional calculations. The band structure near the Fermi energy, consists of Ru $% t_{2g}$ states hybridized with O $p$ orbitals. The $yz$ and $xz$ bands, which are largely responsible for the nesting related antiferromagnetic spin fluctu

E. A. Jagla

A simple model of a glass former fluid, consisting of a bidisperse mixture of penetrable spheres is studied. The model shows a transition from fragile to strong behavior as temperature is reduced. This transition is driven by the competition between the two mechanisms that contribute to diffusivity in the model: collective rearrangement of particles (respons

G. F. Zharkov, V. G. Zharkov, A. Yu. Zvetkov

Self-consistent solutions of the Ginzburg-Landau system of equations, which describe the order parameter and the magnetic field distribution in a long superconducting cylinder of finite radius R, in external magnetic field H, when vortex line, carrying m flux quanta, is situated on the cylinder axis (a giant m-vortex state), are studied numerically. If the f

D. Fioravanti, G. Mussardo, P. Simon

The scaling form of the free-energy near a critical point allows for the definition of various thermodynamical amplitudes and the determination of their dependence on the microscopic non-universal scales. Universal quantities can be obtained by considering special combinations of the amplitudes. Together with the critical exponents they characterize the univ

A. N. Timoshevskii, V. A. Timoshevskii, B. Z. Yanchitsky, V. A. Yavna

Iron nitride Fe4N is studied by full-potential LAPW method. Structure parameters, electronic and magnetic properties as well as hyperfine interaction parameters are obtained. We observe perfect agreement with experimental results. Hypothetical Fe4N structure was also calculated to study the influence of disordering effects on parameters of Moessbauer spectra

Ferenc Simon, Slaven Garaj, Laszlo Forro

Recently, Arcon et al. reported ESR studies of the polymer phase (PP) of Na_{2}Rb_{0.3}Cs_{0.7}C_{60} fulleride. It was claimed that this phase is a quasi-one-dimensional metal above 45 K with a spin-gap below this temperature and has antiferromagnetic(AF) order below 15 K, that is evidenced by antiferromagnetic resonance(AFMR). For the understanding of the

L. Hufnagel, M. Weiss, A. Iomin, R. Ketzmerick

A recently found metal-insulator transition in a model for cyclotron resonance in a two-dimensional periodic potential is investigated by means of spectral properties of the time evolution operator. The previously found dynamical signatures of the transition are explained in terms of avoided band crossings due to the change of the external electric field. Th

E. Buks, M. L. Roukes

Using optical diffraction, we study the mechanical vibrations of an array of micromechanical resonators. Implementing tunable electrostatic coupling between the suspended, doubly-clamped Au beams leads to the formation of a band of collective vibrational modes within these devices. The evolution of these modes with coupling strength is clearly manifested in

M. L. Roukes

Nanoelectromechanical systems, or NEMS, are MEMS scaled to submicron dimensions. In this size regime, it is possible to attain extremely high fundamental frequencies while simultaneously preserving very high mechanical responsivity (small force constants). This powerful combination of attributes translates directly into high force sensitivity, operability at

Herbert Kroemer

Adding a high-frequency ac component to the bias field of a superlattice induces a synchronous modulation of the velocity with which the electrons traverse the Brillouin zone. In the presence of inelastic scattering, the k-space velocity modulation causes a wave-like bunching of the electrons in k-space, which in turn introduces a high-frequency component in

Doron Cohen

Energy absorption by driven chaotic systems, the theory of energy spreading and quantal Brownian motion are considered. In particular we discuss the theory of a classical particle that interacts with quantal chaotic degrees of freedom, and try to relate it to the problem of quantal particle that interacts with an effective harmonic bath.

David B. Cline

A neutrino factory storage ring can provide beams to various locations. We discuss the ICANOE detector (at LNGS) at one such site. We then describe the prospects for the use of the underground location at Carlsbad, NM for a neutrino factory detector. A brief discussion is given of a simple magnetized Fe detector of 10 50 kT for this site.

I. Szapudi

The fully general calculation of the cosmic error on N-point correlation functions and related quantities is presented. More precisely, the variance caused by the finite volume, discreteness, and edge effects is determined for {\em any} estimator which is based on a general function of N-tuples, such as multi-point correlation functions and multi-spectra. Th

Gregory Laughlin

We examine the correlation between stellar metallicity and short period planets. It appears that approximately 1% of dwarf stars in the solar neighborhood harbor short-period planets characterized by near-circular orbits and orbital periods P<20 days. However, among the most metal-rich stars (defined as having [Fe/H]>0.2 dex), it appears that the fraction in

L. Drissen, P. A. Crowther, L. J. Smith, C. Robert

A quantitative study of the Luminous Blue Variable NGC 2363-V1 in the Magellanic galaxy NGC 2366 (D = 3.44 Mpc) is presented, based on ultraviolet and optical HST/STIS spectroscopy. Contemporary WFPC2 and WHT imaging reveals a modest V-band brightness increase of ~ 0.2 mag per year between 1996 January and 1997 November, reaching V=17.4 mag, corresponding to

V. P. Reshetnikov

The disk positions for galaxies of various morphological and nuclear-activity types (normal galaxies, QSO, Sy, E/S0, low-surface brightness galaxies, etc.) on the &#34;central surface brightness - exponential scalelength&#34; plane are considered. The stellar disks are shown to form a single sequence on this plane over a wide range of surface brightnesses (μ

G. Lamer, P. Uttley, I. M. McHardy

We report on observations of the narrow line Seyfert galaxy NGC 5506 with the Rossi X-ray TIming Explorer. The observations cover a time interval of ~1000 days during which the source showed strong flux and spectral variability. The spectrum clearly shows iron fluorescence emission at 6.4 keV and significant reflection features. Both the equivalent width of

John P. Blakeslee, Alexandre Vazdekis, Edward A. Ajhar

We examine the use of surface brightness fluctuations (SBF) for both stellar population and distance studies. New V-band SBF data are reported for five Fornax cluster galaxies and combined with literature data to define a new V-band SBF distance indicator. We use new stellar population models, based on the latest Padua isochrones transformed empirically to t

Adi Nusser

We derive the asymptotic mass profile near the collapse center of an initial spherical density perturbation, $δ\propto M^{-ε}$, of collision-less particles with non-radial motions. We show that angular momenta introduced at the initial time do not affect the mass profile. Alternatively, we consider a scheme in which a particle moves on a radial orbit until i

G. L. Granato, C. G. Lacey, L. Silva, A. Bressan

Recently (Granato, Lacey, Silva et al. 2000, astro-ph/0001308) we have combined our spectrophotometric galaxy evolution code which includes dust reprocessing (GRASIL, Silva et al. 1998) with semi-analytical galaxy formation models (GALFORM, Cole et al. 1999). One of the most characteristic features of the former is that the dust is divided in two main phases

A. Meiksin, M. White

Numerical hydrodynamical simulations have proven a successful means of reproducing many of the statistical properties of the Lyman-Alpha forest as measured in high redshift quasar spectra. Pseudo-hydrodynamical methods based only on simulating the dark matter component have been claimed to yield a comparable level of success. We investigate the degree to whi

M. Kraus, E. Kruegel, C. Thum, T. Geballe

We observed the near infrared emission in the wavelength range 2.28-2.50 micron from the peculiar B[e]-star MWC349. The spectra contain besides the strong IR continuum the first overtone CO bands and most of the hydrogen recombination lines of the Pfund series, both in emission. We also modeled the spectra. The Pfund lines have a gaussian profile with a FWHM

T. Tatsuno, V. I. Berezhiani, S. M. Mahajan

It is shown that the interaction of large amplitude electromagnetic waves with a hot electron-positron (e-p) plasma (a principal constituent of the universe in the MeV epoch) leads to a bunching of mass, energy, and angular momentum in stable, long-lived structures. Electromagnetism in the MeV epoch, then, could provide a possible route for seeding the obser

The HEGRA Collaboration, F. Aharonian, A. Akhperjanian, J. Barrio

During 1997, the BL Lac object Mkn 501 went into an extraordinary state of high X-ray and TeV gamma-ray activity, lasting more than 6 months. In this paper we report on the TeV emission characteristics of the source in the subsequent years of 1998 and 1999 as measured with the Stereoscopic Cherenkov Telescope System of HEGRA (La Palma, Canary Islands). Our o

Mark A. Walker

Extreme Scattering Events are sometimes manifest in the light-curves of compact radio-quasars at frequencies of a few GHz. These events are not understood. The model which appears to offer the best explanation requires a new population of AU-sized, neutral gas clouds; these clouds would then make up a large fraction of the Galaxy&#39;s dark matter. Independe

Su-Chan Park, Doochul Kim, Jeong-Man Park

We present the systematic formalism to derive the path-integral formulation for the hard-core particle systems far from equilibrium. Writing the master equation for a stochastic process of the system in terms of the annihilation and creation operators with the mixed commutation relations, we find the Kramers-Moyal coefficients for the corresponding Fokker-Pl

F. del Aguila, J. Santiago

The Kaluza-Klein fermion excitations induce mixing between the Standard Model fermions and loss of universality. The flavour mixing not present in the Standard Model can be made to vanish aligning the Yukawa couplings and the Dirac masses of the heavy modes, but universality is only recovered when these masses go to infinity. This implies a bound on the ligh

K. A. Cummings, M. D. Borrego, J. DeBaca, J. S. Harrison

Radio frequency (RF) windows are historically a point where failure occurs in input-power couplers for accelerators. To understand more about the reliability of high power RF windows, lifetime testing was done on 700 MHz coaxial RF windows for the Low Energy Demonstration Accelerator (LEDA) project of the Accelerator Production of Tritium (APT) program. The

Tao Han, Danny Marfatia

We study the observability for a lepton flavor-changing decay of a Higgs boson $h\to μτ$ at hadron colliders. Flavor-changing couplings of a Higgs boson exist at tree level in models with multiple Higgs doublets. The $hμτ$ coupling is particularly motivated by the favorable intepretation of $ν_μ-ν_τ$ oscillation. We find that at the Tevatron Run II the uniqu

E. Nogueira, R. F. S. Andrade, S. Coutinho

The role of the geometric fluctuations on the multifractal properties of the local magnetization of aperiodic ferromagnetic Ising models on hierachical lattices is investigated. The geometric fluctuations are introduced by generalized Fibonacci sequences. The local magnetization is evaluated via an exact recurrent procedure encompassing a real space renormal

Rodolfo Gambini, Jorge Pullin

We have recently introduced an approach for studying perturbatively classical and quantum canonical general relativity. The perturbative technique appears to preserve many of the attractive features of the non-perturbative quantization approach based on Ashtekar&#39;s new variables and spin networks. With this approach one can find perturbatively classical o

Rodolfo Gambini, Jorge Pullin

We consider general relativity with a cosmological constant as a perturbative expansion around a completely solvable diffeomorphism invariant field theory. This theory is the $Λ\to\infty$ limit of general relativity. This allows an explicit perturbative computational setup in which the quantum states of the theory and the classical observables can be explici

Yaroslav Volovich

A stochastic process with self-interaction as a model of quantum field theory is studied. We consider an Ornstein-Uhlenbeck stochastic process x(t) with interaction of the form x^{(α)}(t)^4, where $α$ indicates the fractional derivative. Using Bogoliubov&#39;s R-operation we investigate ultraviolet divergencies for the various parameters $α$. Ultraviolet pro

A. D. Dolgov, S. H. Hansen, G. Raffelt, D. V. Semikoz

Cosmological and astrophysical effects of heavy (10 - 200 MeV) sterile Dirac neutrinos, mixed with the active ones, are considered. The bounds on mass and mixing angle from both supernovae and big-bang nucleosynthesis are presented.

O. Beckstein, J. E. Klepeis, G. L. W. Hart, O. Pankratov

We have carried out a first principles study of the elastic properties and electronic structure for two room-temperature stable Pt silicide phases, tetragonal alpha-Pt_2Si and orthorhombic PtSi. We have calculated all of the equilibrium structural parameters for both phases: the a and c lattice constants for alpha-Pt_2Si and the a, b, and c lattice constants

B. Maroufi, M. Nazah, M. B. Sedra

We propose a consistently algebraic formulation of the extended KP (supersymmetric) integrable -hierarchy systems. We exploit the results already established in [14] and which consist in a framework suspected to unify in a fascinating way all the possible supersymmetric KP-hierarchies and then their underlying supergravity theories . This construction leads

J. Scott Carter, Seiichi Kamada, Masahico Saito, Shin Satoh

The groups of link bordism can be identified with homotopy groups via the Pontryagin-Thom construction. B.J. Sanderson computed the bordism group of 3 component surface-links using the Hilton-Milnor Theorem, and later gave a geometric interpretation of the groups in terms of intersections of Seifert hypersurfaces and their framings. In this paper, we geometr

Anne-Christine Davis, Ian Vernon, Stephen C. Davis, Warren B. Perkins

The Friedmann equation for a positive tension brane situated between two bulk spacetimes that posses the same 5D cosmological constant, but which does not posses a Z_2 symmetry of the metric itself is derived, and the possible effects of dropping the Z_2 symmetry on the expansion of our Universe are examined; cosmological constraints are discussed. The globa

C. Alexandrou, Ph. de Forcrand, E. Follana

We study the gluon propagator in quenched lattice QCD using the Laplacian gauge which is free of lattice Gribov copies. We compare our results with those obtained in the Landau gauge on the lattice, as well as with various approximate solutions of the Dyson Schwinger equations. We find a finite value $\sim (445 \rm{MeV})^{-2}$ for the renormalized zero-momen

Luis Bento, Jose P. S. Lemos

It is shown that the interaction of helicity-1 waves of gravity and matter in a thin slab configuration produces new types of instabilities. Indeed, a transverse spin-2 helicity-1 mode interacts strongly with the shear motion of matter. This mode is unstable above a critical wavelength which reminds the Jeans wavelength but with the speed of sound interchang

M. Oertel, M. Buballa, J. Wambach

We compare two different possibilities to include meson-loop corrections in the Nambu-Jona-Lasinio model: a strict 1/N_c-expansion in next-to-leading order and a non-perturbative scheme corresponding to a one-meson-loop approximation to the effective action. Both schemes are consistent with chiral symmetry, in particular with the Goldstone theorem and the Ge

R. D&#39;Hulst, G. J. Rodgers

A microscopic model of aggregation and fragmentation is introduced to investigate the size distribution of businesses. In the model, businesses are constrained to comply with the market price, as expected by the customers, while customers can only buy at the prices offered by the businesses. We show numerically and analytically that the size distribution sca

Yoshio Koide, Ambar Ghosal

A Zee-type neutrino mass matrix model with a badly broken horizontal symmetry SU(3)_H is investigated. By putting a simple ansatz on the symmetry breaking effects of SU(3)_H for transition matrix elements, it is demonstrated that the model can give a nearly bimaximal neutrino mixing with the ratio $Δm^2_{solar}/Δm^2_{atm} \simeq \sqrt{2} m_e/m_μ=6.7 \times 1

PACS Collaboration, A. Ali Khan, S. Aoki, R. Burkhalter

We study the finite-temperature phase structure and the transition temperature of QCD with two flavors of dynamical quarks on a lattice with the temporal size $N_t=4$, using a renormalization group improved gauge action and the Wilson quark action improved by the clover term. The region of a parity-broken phase is identified, and the finite-temperature trans

Ting-Wai Chiu

By examining the analyticity of a sequence of topologically-proper lattice Dirac operators, we show that they tend to a nonlocal Dirac operator. This implies that a nonlocal lattice Dirac operator can have exact zero modes satisfying the Atiyah-Singer index theorem, in gauge backgrounds with nonzero topological charge.

S. Hayakawa, K. -I. Izawa

We investigate warped compactification with an abelian gauge theory in six dimensions. The vanishing cosmological constant in four dimensions can generically be realized with a regular metric even in a 3-brane background without fine tuning of couplings.

Abha Dev, Meetu Sethi, Daksh Lohiya

A strictly linear evolution of the cosmological expansion scale factor is a characteristic feature in several classes of alternative gravity theories as also in the standard (big-bang) model with specially chosen equations of state of matter. Such an evolution has no free parameters as far as the classical cosmological tests are concerned and should therefor

P. Banerjee, R. Shyam

We investigate the effects arising out of the $E1 - E2$ interference in the Coulomb dissociation of $^8$B at beam energies below and around 50 MeV/nucleon. The theory has been formulated within a first order semiclassical scheme of Coulomb excitation, in which both the ground state and the continuum state wave functions of $^8$B enter as inputs. We find that

2 Collaboration

Using 11.6 pb^{-1} of data collected in the energy range 0.984--1.06 GeV by CMD-2 at VEPP-2M, the cross section of the reaction e+e- to pi+pi-pi+pi- has been studied. For the first time an interference pattern was observed in the energy dependence of the cross section near the phi meson. The branching ratio of the phi to pi+pi-pi+pi- decay double suppressed

Andrew M. Childs, Isaac L. Chuang

Although the initial proposal for ion trap quantum computation made use of an auxiliary internal level to perform logic between ions, this resource is not necessary in principle. Instead, one may perform such operations directly using sideband laser pulses, operating with an arbitrary (sufficiently small) Lamb-Dicke parameter. We explore the potential of thi

Hitoshi Inamori

We propose a proof of the security of EPR-based quantum key distribution against enemies with unlimited computational power. The proof holds for a protocol using interactive error-reconciliation scheme. We assume in this paper that the legitimate parties receive a given number of single photon signals and that their measurement devices are perfect.

Bob Coecke

We introduce a definition for a &#39;hidden measurement system&#39;, i.e., a physical entity for which there exist: (i) &#39;a set of non-contextual states of the entity under study&#39; and (ii) &#39;a set of states of the measurement context&#39;, and which are such that all uncertainties are due to a lack of knowledge on the actual state of the measuremen

C. J. S. Clarke

Using a reformulation of conventional results in decoherence theory, a condition is proposed for singling out a distinguished class of histories which includes those which use the ``pointer basis&#39;&#39; of Zurek.

H. -K. Chung, K. Kirby, J. F. Babb

Absorption of radiation from the sodium dimer molecular states correlating to Na(3s)-Na(3s) is investigated theoretically. Vibrational bound and continuum transitions from the singlet X Sigma-g+ state to the first excited singlet A Sigma-u+ and singlet B Pi-u states and from the triplet a Sigma-u+ state to the first excited triplet b Sigma-g+ and triplet c P

G. A. Westenskow, L. R. Bertolini, P. T. Duffy, A. C. Paul

This paper describes the mechanical design of the downstream beam transport line for the second axis of the Dual Axis Radiographic Hydrodynamic Test (DARHT II) Facility. The DARHT-II project is a collaboration between LANL, LBNL and LLNL. DARHT II is a 20-MeV, 2000-Amperes, 2-msec linear induction accelerator designed to generate short bursts of x-rays for t

Denis V. Juriev

The quantum string field theoretic structure of interactive phenomena is discussed

Arthur C. Paul

We consider a technique to determine the initial beam conditions of the DARHT II Accelerator by measuring the beam size under three different magnetic transport settings. This may be time gated to resolve the parameters as a function of time within the 2000 nsec pulse. This technique leads to three equations in three unknowns with solution giving the acceler

J. F. Tooker, R. Bourque, D. Christiansen, J. Kamperschroer

The accelerator for the APT Project is a 100 mA CW proton linac with an output energy of 1030 MeV. A High Energy Beam Transport (HEBT) conveys the beam to a raster expander, that provides a large rectangular distribution at a target/blanket (T/B) assembly. Spallation neutrons generated by the proton beam in the T/B reacts with Helium-3 to produce tritium. Th

H. Zimmermann

New high current accelerator facilities like proposed for HIDIF or ESS require a beam with a high brilliance. These beams can not be produced by a single pass rf-linac. The increase in brightness in such a driver linac is done by several funneling stages at low energies, in which two identically bunched ion beams are combined into a single beam with twice th

Jean-Marc Bonard

An experimental study of strings, woodwinds (organ pipe, flute, clarinet, saxophone and recorder), and the voice was undertaken to illustrate the basic principles of sound production in music instruments. The setup used is simple and consists of common laboratory equipment. Although the canonical examples (standing wave on a string, in an open and closed pip

G. Carron, E. Jensen, M. Luong, A. Millich

For the CLIC two-beam scheme, a high-current, long-pulse drive beam is required for RF power generation. Taking advantage of the 3 GHz klystrons available at the LEP injector once LEP stops, a 180 MeV electron accelerator is being constructed for a nominal beam current of 3.5 A and 1.5 microsecond pulse length. The high current requires highly effective supp

S. J. Park, J. S. Oh, J. S. Bak, M. H. Cho

For the generation of picosecond (< 100 ps) electron beam pulses, we studied the RF modulation of a conventional triode electron gun. The feasibility study for this scheme has been experimentally investigated by modulating a triode gun of the Y-824 cathode-grid (KG) structure provided by the CPI Eimac, with 2.856-GHz pulsed RF generated by a solid-state ampl

J. P. Duke, A. P. Letchford, D. J. S. Findlay

Measurement of the endpoints of X-ray spectra emitted from RF cavities is a useful non-invasive technique for measuring peak voltages within the cavities. The matching of calculated X-ray spectra to measured spectra is described, with emphasis upon the endpoint region.

Theodore M. Lach

The masses of the quarks and leptons are for the most part a mystery to particle physicists. Currently there seems to be no correlation between the masses of the elementary particles. This paper is an attempt to formulate a theory that would begin to explain the relationship between the sub-nuclear particle masses.

Richard L. Hall

We study a bound system of N identical bosons interacting by model pair potentials of the form V(r) = A sgn(p)r^p + B/r^2, A > 0, B >= 0. By using a variational trial function and the `equivalent 2-body method&#39;, we find explicit upper and lower bound formulas for the N-particle ground-state energy in arbitrary spatial dimensions d > 2 for the two cases p

Joshua S. Scott

We produce neccessary and sufficient conditions for pairs of quantum minors in the quantized coordinate algebra $\Bbb{C}_q[Mat_{k \times m}]$ to quasi-commute. In addition we study the combinatorics of maximal (by inclusion) families of pairwise quasi-commuting quantum minors.

Terence Tao

We survey the interconnections between geometric combinatorics (such as the Kakeya problem), arithmetic combinatorics (such as the classical problem of determining which sets contain arithmetic progressions), oscillatory integrals (such as the Bochner-Riesz, restriction, and local smoothing problems), and the local and global well-posedness theory for non-li

Izu Vaisman

We discuss symplectic manifolds where, locally, the structure is that encountered in Lagrangian dynamics. Exemples and characteristic properties are given. Then, we refer to the computation of the Maslov classes of a Lagrangian submanifold. Finally, we indicate the generalization of this type of structures to Poisson manifolds.

Seiichi Kamada

The notion of a virtual knot introduced by L. Kauffman induces the notion of a virtual braid. It is closely related with a welded braid of R. Fenn, R. Rimanyi and C. Rourke. Alexander&#39;s and Markov&#39;s theorems for virtual knots and braids are proved. Similar results for welded knots and braids are also proved.

J. Scott Carter, Daniel Jelsovsky, Seiichi Kamada, Masahico Saito

Homomorphisms on quandle cohomology groups that raise the dimensions by one are studied in relation to the cocycle state-sum invariants of knots and knotted surfaces. Skein relations are also studied.

Ola Bratteli, Palle E. T. Jorgensen

In this paper, we study wavelet filters and their dependence on two numbers, the scale N and the genus g. We show that the wavelet filters, in the quadrature mirror case, have a harmonic analysis which is based on representations of the C^*-algebra O_N. A main tool in our analysis is the infinite-dimensional group of all maps T -> U(N) (where U(N) is the gro

E. F. Moreno, F. A. Schaposnik

We analyze the connection between Wess-Zumino-Witten and free fermion models in two-dimensional noncommutative space. Starting from the computation of the determinant of the Dirac operator in a gauge field background, we derive the corresponding bosonization recipe studying, as an example, bosonization of the U(N) Thirring model. Concerning the properties of

M. Hssaini, M. Kessabi, B. Maroufi, M. B. Sedra

Methods developed for the analysis of non-linear integrable models are used in the harmonic superspace (HS) framework. These methods, when applied to the HS, can lead to extract more information about the meaning of integrability in non-linear physical problems. Among the results obtained, we give the basic ingredients towards building in the HS language the

G. v. Gersdorff, C. Wetterich

The Kosterlitz-Thouless phase transition is described by the nonperturbative renormalization flow of the two dimensional $ϕ^4$-model. The observation of essential scaling demonstrates that the flow equation incorporates nonperturbative effects which have previously found an alternative description in terms of vortices. The duality between the linear and nonl

Klaus Behrndt, Carl Herrmann, Jan Louis, Steven Thomas

We study BPS domain wall solutions of 5-dimensional N=2 supergravity where isometries of the hypermultiplet geometry have been gauged. We derive the corresponding supersymmetric flow equations and define an appropriate c-function. As an example we discuss a domain wall solution of Freedman, Gubser, Pilch and Warner which is related to a RG-flow in a dual sup

Kimyeong Lee, Jeong-Hyuck Park

We present two equivalent five-dimensional actions for six-dimensional (N,0) N=1,2 supersymmetric theories of self-dual tensor whose one spatial dimension is compactified on a circle. The Kaluza-Klein tower consists of a massless vector and infinite number of massive self-dual tensor multiplets living in five-dimensions. The self-duality follows from the equ

P. Golumbeanu, C. Rosenzweig

The properties of heavy quark systems change if they are placed in a medium other than the low energy vacuum. In a hot Quark Gluon Plasma $J/Ψ$ particles will melt and not exist as resonant states. $Υ$&#39;s, however, because of their smaller size and the dominance of the Coulomb potential, will still form as $Q\bar Q$ bound states but their properties will

Max Tegmark, Matias Zaldarriaga, Andrew J. S. Hamilton

As experimentalists step up their pursuit of cold dark matter particles and neutrino masses, cosmological constraints are tightening. We compute the joint constraints on 11 cosmological parameters from cosmic microwave background and large scale structure data, and find that at 95% confidence, the total (cold+hot) dark matter density is h^2 Omega_dark = 0.20

Alejandro Ayala, Gabriel Pallares

We show that in the presence of large scale primordial hypermagnetic fields, it is possible to generate a large amount of CP violation to explain the baryon to entropy ratio during the electroweak phase transition within the standard model. The mechanism responsible for the existence of a CP violating asymmetry is the chiral nature of the fermion coupling to

S. J. Puglia, M. J. Ramsey-Musolf, Shi-Lin Zhu

We compute the octet baryon charge radii to O(1/Heavy^3) in heavy baryon chiral perturbation theory. We examine the effect of including the decuplet of spin-3/2 baryons explicitly. We find that it does no t improve the level of agreement between the HBchiPT and experimental values for the Sigma^- charge radius.

Eung Jin Chun, Hang Bae Kim, David H. Lyth

In an interesting class of models, non-renormalizable terms of the superpotential are responsible for the spontanteous breaking of Peccei-Quinn (PQ) symmetry as well as the generation of the $μ$ term. The flaton fields which break PQ symmetry are accompanied by flatinos, and the lightest flatino (the LSP) can be the stable, while the decay of the lightest ne