May 1999 arXiv papers — page 16

James J. Kelly

We propose an effective current operator for nucleon electromagnetic knockout that incorporates spinor distortion and density-dependent nucleon form factors using an effective momentum approximation. This method can be used in a coordinate-space approach with either relativistic or nonrelativistic optical potentials and overlap functions. We studied these ef

Gordon Slade

This paper surveys the results of recent collaborations with Eric Derbez and with Takashi Hara, which show that intergrated super-Brownian excursion (ISE) arises as the scaling limit of both lattice trees and the incipient infinite percolation cluster, in high dimensions. A potential extension to oriented percolation is also mentioned.

Chongying Dong, Kiyokazu Nagatomo

The vertex operator algebra M(1)^+ is the fixed point set of free bosonic vertex operator algebra M(1) under the -1 automorphism. All irreducible modules for M(1)^+ are classified in this paper for all ranks.

C. -L. Chai, F. Oort

We show that for any family of curves over a base scheme of finite type over the prime field $\mathbb F_p$ such that the monodromy is ``maximal'', there exist infinitely many closed points of the base scheme such that the Jacobian of fibre is absolutely simple.

Alexander Rashkovskii

We study the masses charged by $(dd^cu)^n$ at isolated singularity points of plurisubharmonic functions $u$. It is done by means of the local indicators of plurisubharmonic functions. As a consequence, bounds for the masses are obtained in terms of the directional Lelong numbers of $u$, and the notion of the Newton number for a holomorphic mapping is extende

Carlos Ortiz

In functional analysis it is of interest to study the following general question: Is the uniform version of a property that holds in all Banach spaces also valid in all Banach spaces? Examples of affirmative answers to the above question are the host of proofs of almost-isometric versions of well known isometric theorems. Another example is Rosenthal's u

N. Z. Iorgov, A. U. Klimyk

The aim of this paper is to announce the results on irreducible nonclassical type representations of the nonstandard q-deformations U'_q(so_n), U_q(iso_n) and U'_q(so_{n,1}) of the universal enveloping algebras of the Lie algebras so(n,C), iso_n and so_{n,1} when q is a real number (the algebra U'_q(so_{n,1}) is a real form of the algebra U'_

P. B. A. Lecomte, V. Yu. Ovsienko

Let $M$ be a smooth manifold, $\cal S$ the space of polynomial on fibers functions on $T^*M$ (i.e., of symmetric contravariant tensor fields). We compute the first cohomology space of the Lie algebra, $Vect(M)$, of vector fields on $M$ with coefficients in the space of linear differential operators on $\cal S$. This cohomology space is closely related to the

H. Aratyn, L. A. Ferreira, A. H. Zimerman

In this paper we construct explicitly an infinite number of Hopfions (static, soliton solutions with non-zero Hopf topological charges) within the recently proposed 3+1-dimensional, integrable and relativistically invariant field theory. Two integers label the family of Hopfions we have found. Their product is equal to the Hopf charge which provides a lower

Dean Lee, Nathan Salwen

We derive several results concerning non-perturbative renormalization in the spherical field formalism. Using a small set of local counterterms, we are able to remove all ultraviolet divergences in a manner such that the renormalized theory is finite and translationally invariant. As an explicit example we consider massless phi^4 theory in four dimensions.

C. P. Martin, D. Sanchez-Ruiz

The one-loop renormalization of a general chiral gauge theory without scalar and Majorana fields is fully worked out within Breitenlohner and Maison dimensional renormalization scheme. The coefficients of the anomalous terms introduced in the Slavnov-Taylor equations by the minimal subtraction algorithm are calculated and the asymmetric counterterms needed t

Vladimir Skalozub, Alexander Zaslavsky

The vortex-like solution to the non-linear field equations in a two-dimensional SU(2) gauge theory with the Chern-Simons mass term is found at high temperature. It is derived from the effective Lagrangian including the leading order finite temperature corrections. The discovered field configuration possesses the finite energy and the quantized magnetic flux.

G. Papadopoulos

We propose a method to investigate the conservation of brane charges at the intersection of two or more branes using the Thom classes of their normal bundles. In particular we find a relation between the charge of the branes involved in the configuration and the charge of the defects on the branes due to the intersection. We also explore the applications of

S. G. Rajeev

We solve a long-standing problem in particle physics: that of deriving the Deep Inelastic structure functions of the proton from the fundamental theory of strong interactions, Quantum ChromoDynamics (QCD). In the Bjorken limit, the momenta of the constituents of the proton (the partons) can be assumed to be in a two-dimensional plane in Minkowski space: a di

Yuuichirou Shibusa

We compute part of the superfield in terms of the component fields of 11-dimensional on-shell supergravity by using `Gauge completion' in 2nd-order formalism. The result is the same as was derived recently in 1.5-order formalism by B. de Wit, K. Peeters and J. Plefka. We use 2nd-order formalism because in order to hold $κ$-invariance generally 2nd-order

Gysbert Zwart

The Born-Infeld theory of a toroidal D3-brane has an SL(5,Z) U-duality symmetry. We investigate how this symmetry is reflected in the supersymmetry algebra. We propose an action of the group on the gauge theory fields in the BPS sector by introducing an extra field together with an additional symmetry, and argue for the U-invariance of the degeneracies of th

Joao Correia, Troels Harmark

As a test of the conjectured QCD/supergravity duality, we consider mass gaps in the supergravity construction of QCD_2. We find a mass gap in the dual field theory both when using non-rotating and rotating black D2-branes as backgrounds in the supergravity construction of QCD_2. So, since pure QCD_2 does not have a mass gap, the dual field theory of the supe

Theodora Ioannidou, Paul Sutcliffe

The moduli space of charge k SU(2) BPS monopoles is diffeomorphic to the moduli space of degree k rational maps between Riemann spheres. In this note we describe a numerical algorithm to compute the monopole fields and energy density from the rational map. The results for some symmetric examples are presented.

M. Beneke, G. Buchalla, M. Neubert, C. T. Sachrajda

We show that, in the heavy quark limit, the hadronic matrix elements that enter $B$ meson decays into two light mesons can be computed from first principles, including `non-factorizable' strong interaction corrections, and expressed in terms of form factors and meson light-cone distribution amplitudes. The conventional factorization result follows in the

I. Antoniadis, K. Benakli, M. Quiros

The realization of low (TeV) scale strings usually requires the existence of large (TeV) extra dimensions where gauge bosons live. The direct production of Kaluza-Klein excitations of the photon and Z-boson at present and future colliders is studied in this work. At the LEPII, NLC and Tevatron colliders, these Kaluza-Klein modes lead to deviations from the s

A. Gall, J. Gasser, V. E. Lyubovitskij, A. Rusetsky

The pi+pi- atom decays -in the ground state - predominantly into two neutral pions. We present a general expression for the corresponding decay width in the framework of QCD (including photons). It contains all terms at leading and next-to-leading order in isospin breaking. The result allows one to evaluate the combination |a_0-a_2| of pi-pi S-wave scatterin

G. P. Salam

I give a brief presentation of recent results on the equivalence of BFKL and CCFM small-x final states, and discuss their implications for phenomenology.

J. Kwiecinski, A. D. Martin, A. M. Stasto

In this talk we would like to present recent calculations of the cross sections for the ultrahigh energy neutrinos interacting with nucleons. We briefly present the framework of unifed BFKL/DGLAP equations which resums all the leading log(1/x) effects as well as the subleading terms. The few free parameters which specify the input parton distributions are de

Romuald A. Janik, Maciej A. Nowak, Gabor Papp, Ismail Zahed

Inspired by recent lattice calculations, we model certain aspects of the $θ$-vacuum using a matrix model with gaussian weights. The vacuum energy exhibits a cusp at $θ<π$ that is sensitive to both the accuracy of the numerical analysis and the maximum density of winding modes present in a finite volume.

F. E. Close, G. A. Schuler

The detailed dependences of central meson production on the azimuthal angle phi, t and the meson J^P are shown to be consistent with the hypothesis that the soft Pomeron transforms as a non-conserved vector current. Further tests are proposed. This opens the way for a quantitative description of q-qbar and glueball production in p p -> p M p.

S. Prelovsek, S. Fajfer, P. Singer

Flavour changing neutral current (FCNC) transitions $c\to uγ$ and $c\to ul^+l^-$ are very rare in the standard model and present an interesting probe for the physics beyond it. We study long distance contamination to these short distance processes in different hadron decays. As the most suitable probe for $c\to uγ$ transition we propose $B_c\to B_u^*γ$ decay

T. G. Steele, Fang Shi, V. Elias

QCD Laplace sum-rules for light-quark I=0,1 scalar currents are used to investigate candidates for the lightest $q\bar q$ scalar mesons. The theoretical predictions for the sum-rules include instanton contributions which split the degeneracy between the I=0 and I=1 channels. The self-consistency of the theoretical predictions is verified through a Hölder ine

Vladimir Skalozub, Michael Bordag

The spontaneous vacuum magnetization at finite temperature is investigated in SU(2) gluodynamics within a consistent effective potential approach including the one-loop and the correlation correction contributions. To evaluate the latter ones the high temperature limits of the polarization operators of charged and neutral gluon fields in a covariantly consta

A. Halprin, H. B. Kim

We point out that equivalence principle violations, while not dynamically equivalent, produce the same kinematical effects as Lorentz invariance violations for particle processes in a constant gravitational potential. This allows us to translate many experimental bounds on Lorentz invariance violations into bounds on equivalence principle violations. The mos

Th. Seidensticker

We discuss the program EXP used to automate the successive application of asymptotic expansions to Feynman diagrams. We focus on the generation of the relevant subgraphs and the determination of the topologies for the remaining integrals. Both tasks can be solved by using backtracking-type recursive algorithms. In addition, an application of EXP is presented

W. Janke, D. Johnston

The KPZ formula shows that coupling central charge less than one spin models to 2D quantum gravity dresses the conformal weights to get new critical exponents, where the relation between the original and dressed weights depends only on the central charge. At the discrete level the coupling to 2D gravity is effected by putting the spin models on annealed ense

H. Banerjee, Asit K. De

By an explicit calculation of the continuum limit of the triangle graph amplitude in lattice QED we show that in the axial Ward identity the ABJ anomaly exactly cancels the pseudoscalar density term in the limit of infinite fermion mass $m$. The result, a reflection of decoupling of the heavy fermion, provides a convenient framework for computing the flavor-

Fabrizio Palla

The latest ALEPH measurements on heavy flavours are presented. In particular the measurements of V_ub, the B(b -> s gamma) and a study on the width difference between mass eigenstates in the B_s system are presented.

James E. Lidsey

A discrete symmetry of the four-dimensional string effective action is employed to derive spatially homogeneous and inhomogeneous string cosmologies from vacuum solutions of general relativity that admit two commuting spacelike Killing vectors. In particular, a tilted Bianchi type V cosmology is generated from a vacuum type VI_h solution and a plane wave sol

Stephen F. Bush

This research concentrates on the design and analysis of an algorithm referred to as Virtual Network Configuration (VNC) which uses predicted future states of a system for faster network configuration and management. VNC is applied to the configuration of a wireless mobile ATM network. VNC is built on techniques from parallel discrete event simulation merged

Marcelo J. Rozenberg, R. Chitra, G. Kotliar

We study the second order finite temperature Mott transition point in the fully frustrated Hubbard model at half filling, within Dynamical Mean Field Theory. Using quantum Monte Carlo simulations we show the existence of a finite temperature second order critical point by explicitly demonstrating the existence of a divergent susceptibility as well as by find

C. Schonenberger, A. Bachtold, C. Strunk, J. -P. Salvetat

We report equilibrium electric resistance R and tunneling spectroscopy dI/dV measurements obtained on single multiwall nanotubes contacted by four metallic Au fingers from above. At low temperature quantum interference phenomena dominate the magnetoresistance. The phase-coherence and elastic-scattering lengths are deduced. Because the latter is of order of t

P Raychaudhuri, A E P de Araujo, F L A Machado, A K Nigam

We report the magnetoresistance measurements of a highly oriented La0.55Ho0.15Sr0.3MnOz film on LaAlO3 substrate. The film has a metal-insulator transition around 200 K and shows pronounced thermomagnetic history effect in its transport properties below 45 K at 7 Tesla. The irreversibility temperature shifts to lower temperatures when the field is reduced. T

X. G. Feng, Dragana Popovic, S. Washburn

We study the effect of the disorder on the metallic behavior of a two-dimensional electron system in silicon. The temperature dependence of conductivity $σ(T)$ was measured for different values of substrate bias, which changes both potential scattering and the concentration of disorder-induced local magnetic moments. We find that the latter has a much more p

Kresimir Josic, C. Eugene Wayne

We study the dynamics of a finite chain of diffusively coupled Lorenz oscillators with periodic boundary conditions. Such rings possess infinitely many fixed states, some of which are observed to be stable. It is shown that there exists a stable fixed state in arbitrarily large rings for a fixed coupling strength. This suggests that coherent behavior in netw

A. N. Omelyanchouk, Malek Zareyan

The macroscopic quantum interference effects in ballistic Josephson microstructures are investigated. The studied system consists of four bulk superconductors (terminals) which are weakly coupled through the mesoscopic rectangular normal metal (two dimensional electron gas). We show that nonlocal electrodynamics of ballistic systems leads to specific current

Jae-Kwon Kim

Using a novel finite size scaling Monte Carlo method, we calculate the four, six and eight point renormalized coupling constants defined at zero momentum in the symmetric phase of the three dimensional Ising system. The results of the 2D Ising system that were directly measured are also reported. Our values of the six and eight point coupling constants are s

Biplab Chattopadhyay, A. N. Das

We consider the interlayer pair-tunneling model for layered cuprates, including an effective single particle hopping along the c-axis. A phenomenological suppression of the c-axis hopping matrix element, by the pseudogap in cuprate superconductors, is incorporated. At optimal doping, quantities characteristic to the superconducting state, such as the transit

Paul N. Walker, Gilles Montambaux, Yuval Gefen

We discuss some recent results on the statistics of the Coulomb Blockade in disordered quantum dots containing spinless interacting fermions using the self-consistent Hartree-Fock approximation. We concentrate on the regime r_s >~1, with finite dimensionless conductance g. We present significantly different results for the cases of a Coulomb and a nearest-ne

D. G. Austing, S. Sasaki, S. Tarucha, S. M. Reimann

Addition energy spectra at 0 T of circular and ellipsoidally deformed few-electron vertical quantum dots are measured and compared to results of model calculations within spin-density functional theory. Because of the rotational symmetry of the lateral harmonic confining potential, circular dots show a pronounced shell structure. With the lifting of the sing

S. Schinzer, S. Köhler, G. Reents

We examine the step dynamics in a 1+1 dimensional model of epitaxial growth based on the BCF-theory. The model takes analytically into account the diffusion of adatoms, an incorporation mechanism and an Ehrlich-Schwoebel barrier at step edges. We find that the formation of mounds with a stable slope is closely related to the presence of an incorporation mech

Cristian F. Moukarzel, Marcio Argollo de Menezes

It was recently claimed that on d-dimensional small-world networks with a density p of shortcuts, the typical separation s(p) ~ p^{-1/d} between shortcut-ends is a characteristic length for shortest-paths{cond-mat/9904419}. This contradicts an earlier argument suggesting that no finite characteristic length can be defined for bilocal observables on these sys

T. Valla, A. V. Fedorov, P. D. Johnson, S. L. Hulbert

In a high-resolution photoemission study of a Mo(110) surface state various contributions to the measured width and energy of the quasiparticle peak are investigated. Electron-phonon coupling, electron-electron interactions and scattering from defects are all identified mechanisms responsible for the finite lifetime of a valence photo-hole. The electron-phon

Arnd Bäcker, Roman Schubert

We study eigenstates of chaotic billiards in the momentum representation and propose the radially integrated momentum distribution as useful measure to detect localization effects. For the momentum distribution, the radially integrated momentum distribution, and the angular integrated momentum distribution explicit formulae in terms of the normal derivative

Y. Ashkenazy, L. P. Horwitz

A relativistic charged particle moving in a uniform magnetic field and kicked by an electric field is considered. Under the assumption of small magnetic field, an iterative map is developed. We consider both the case in which no radiation is assumed and the radiative case, using the Lorentz-Dirac equation to describe the motion. Comparison between the non-ra

J. Stein, Z. Barkat, J. C. Wheeler

The previous analysis of the convective Urca neutrino loss process in degenerate, convective, quasi-static, carbon-burning cores by Barkat and Wheeler omitted specific consideration of the role of the kinetic energy flux. The arguments of Barkat and Wheeler that steady-state composition gradients exist are correct, but chemical equilibrium does not result in

Yaron Sheffer, David L. Lambert

A single-epoch low resolution GHRS spectrum of the eclipsing binary Epsilon Aurigae was obtained while the secondary was orbiting towards eclipse by the primary. The detected emission line profiles have the appearance of double- peaked emission with a stronger red component at a radial velocity of +108 km/s, and a weaker blue emission bump at ca. -92 km/s. W

Douglas P. Finkbeiner, Marc Davis, David J. Schlegel

We present predicted full-sky maps of submillimeter and microwave emission from the diffuse interstellar dust in the Galaxy. These maps are extrapolated from the 100 micron emission and 100/240 micron flux ratio maps that Schlegel, Finkbeiner, & Davis (1998; SFD98) generated from IRAS and COBE/DIRBE data. Results are presented for a number of physically plau

Graca Rocha, Radoslaw Stompor, Ken Ganga, Bharat Ratra

We use Python I, II, and III cosmic microwave background anisotropy data to constrain cosmogonies. We account for the Python beamwidth and calibration uncertainties. We consider open and spatially-flat-Lambda cold dark matter cosmogonies, with nonrelativistic-mass density parameter Omega_0 in the range 0.1--1, baryonic-mass density parameter Omega_B in the r

O. Forni, N. Aghanim

Non-gaussianity represents the statistical signature of physical processes such as turbulence. It can also be used as a powerful tool to discriminate between competing cosmological scenarios. A canonical analysis of non-gaussianity is based on the study of the distribution of the signal in the real (or direct) space (e.g. brightness, temperature). This work

N. Aghanim, O. Forni

In a first paper (Forni & Aghanim 1999), we developed several statistical discriminators to test the non-gaussian nature of a signal. These tests are based on the study of the coefficients in a wavelet decomposition basis. In this paper, we apply them in a cosmological context, to the study of the nature of the Cosmic Microwave Background (CMB) anisotropies.

Sergei A. Levshakov, Wilhelm W. Kegel

We consider the deconvolution of the thermal and the turbulent profiles for a pair of ions with different atomic weights under the condition that the lines are formed in an absorbing medium with fluctuating density and velocity fields. Our method is based on the entropy-regularized minimization (ERM) procedure. From synthetic spectra we found that the CII an

P. Blasi, S. Colafrancesco

We calculate the flux of radio, hard X-ray and UV radiation from clusters of galaxies as produced by synchrotron emission and Inverse Compton Scattering of electrons generated as secondaries in cosmic ray interactions in the intracluster medium. Both the spatial distribution of cosmic rays due to their diffusion and the spatial distribution of the intraclust

Robert Fender, Stephane Corbel, Tasso Tzioumis, Vince McIntyre

We have observed the black hole candidate X-ray binary GX 339-4 at radio wavelengths before, during and after the 1998 high/soft X-ray state transition. We find that the radio emission from the system is strongly correlated with the hard X-ray emission and is reduced by a factor > 25 during the high/soft state compared to the more usual low/hard state. At th

Andrew Gould

I investigate the prospects for using the Space Interferometry Mission (SIM) to measure the masses of nearby stars from their astrometric deflection of more distant sources, as originally suggested by Paczynski and by Miralda-Escude. I derive an analytic expression for the total observing time T_tot required to measure the masses of a fixed number of stars t

T. Belloni, M. Mendez, M. van der Klis, W. Lewin

We report the results of observations with the Rossi X-ray Timing Explorer of the black-hole candidate GX 339-4 during the state transition of 1998. We find that both the X-ray spectrum and the characteristic of the time variability after the transition are typical of a high/soft state. We cannot exclude that the source went through an Intermediate State bef

Hartmut Schulz, Stefanie Komossa

We review theoretical and observational arguments favoring a scenario in which a typical massive black hole (MBH) is formed in the merger core of colliding disk systems at high z during the build-up of a spheroid. Low-mass (~ 10^{5-6} M_sun) seed black holes are assumed to have been formed earlier. The most massive black holes giving rise to the most luminou

H. B. Ann, I. Hwang

We have conducted near-infrared (J- and H-band) surface photometry for two early type barred galaxies, NGC 3412 and NGC 3941. The bulges of NGC 3412 and NGC 3941 show isophotal twists which indicate that they are triaxial. NGC 3412 has a very short bar and its bulge is more centrally concentrated than that of NGC 3941. The unusually short bar and the central

Sungsoo S. Kim, Hyung Mok Lee

Tidal captures can produce objects that are observationally and dynamically important in dense stellar systems. Recent discoveries of compact young clusters in and out of the Galaxy have prompted the studies of dynamics of star clusters with a large range in stellar masses. The tidal interactions between high and low mass stars are found to be rather frequen

N. A. Inogamov, R. A. Sunyaev

Disk accretion onto a slowly rotating neutron star with a weak magnetic field $H < 3\times 10^8$ gauss is considered in a wide range of luminosities $1/100 < L/L_{edd} < 1,$ where $L_{edd}$ is the Eddington luminosity. We construct a theory for the deceleration of rotation and the spread of matter over the stellar surface in the shallow-water approximation.

N. Langer, A. Heger, S. Wellstein, F. Herwig

We present the first evolutionary models of intermediate mass stars up to their thermal pulses which include effects of rotation on the stellar structure as well as rotationally induced mixing of chemical species and angular momentum. We find a significant angular momentum transport from the core to the hydrogen-rich envelope and obtain a white dwarf rotatio

Finn Larsen, Emil Martinec

The decoupling limit of the D1-D5 system compactified on T^4\times S^1 has a rich spectrum of U(1) charged excitations. Even though these states are not BPS in the limit, BPS considerations determine the mass and the semiclassical entropy for a given charge vector. The dependence of the mass formula on the compactification moduli situates the symmetric orbif

Matthias Doerrzapf, Beatriz Gato-Rivera

The Kac determinant for the Topological N=2 superconformal algebra is presented as well as a detailed analysis of the singular vectors detected by the roots of the determinants. In addition we identify the standard Verma modules containing `no-label&#39; singular vectors (which are not detected directly by the roots of the determinants). We show that in stan

Leonard Parker, Alpan Raval

We show that the vacuum energy of a free quantized field of very low mass can significantly alter the recent expansion of the universe. The effective action of the theory is obtained from a non-perturbative sum of scalar curvature terms in the propagator. We numerically investigate the semiclassical Einstein equations derived from it. As a result of non-pert

G. C. Branco, D. Emmanuel-Costa, R. Gonzalez Felipe

A simple Ansatz for the quark mass matrices is considered, based on the assumption of a power structure for the matrix elements and the requirement of maximal predictability. A good fit to the present experimental data is obtained and the position of the vertex of the unitarity triangle, i.e. (\barρ,\barη), is predicted.

F. A. Chishtie, V. Elias, V. A. Miransky, T. G. Steele

We address whether Padé-summations of the $\bar{MS}$ QCD $β$-function for a given number of flavours exhibit an infrared-stable fixed point, or alternatively, an infrared attractor of a double valued couplant as noted by Kogan and Shifman for the case of supersymmetric gluodynamics. Below an approximant-dependent flavour threshold $(6 \leq n_f \leq 8)$, we f

M. Perez-Victoria

Radiative corrections arising from the axial coupling of charged fermions to a constant vector b_μcan induce a Lorentz- and CPT-violating Chern-Simons term in the QED action. We calculate the exact one-loop correction to this term keeping the full b_μdependence, and show that in the physically interesting cases it coincides with the lowest-order result. The

D. Quesada, R. Peña, C. Trallero-Giner

All the new layer perovskite superconductors seem to show a phenomenon of symmetry mixing with repect to the order parameter. An analysis of the different alternative of mixing and how far could them be presented is carried out. For the particular case of s+id symmetry of the gap, the temperature dependence of the specific heat ($C_{es}$) and the thermodynam

G. Baym, H. Heiselberg

Motivated by forthcoming experiments at RHIC and LHC, we study event-by-event fluctuations in ultrarelativistic heavy-ion collisions in participant nucleon as well as thermal models. The calculated physical observables, including multiplicity, kaon to pion ratios, and transverse momenta agree well with recent NA49 data at the SPS, and indicate that such stud

Stanislaw Mrowczynski

The Phi-measure of event-by-event fluctuations in high-energy heavy-ion collisions corresponds to the second moment of the fluctuating quantity distribution of interest. It is shown that the measure based on the third moment preserves the properties of Phi but those related to the higher moments do not. In particular, only the second and third moment measure

Nils A. Tornqvist

The linear sigma model with broken U3xU3 is compared with data on the lightest scalar and pseudoscalar mesons. When 5 of the 6 parameters are fixed by the pseudoscalar masses and decay constants one finds that, already at the tree level, a reasonable description for the 4 scalar masses, mixing and up to 8 tri-linear couplings of lightest scalars, taken as a0

Riccardo Barbieri, Alessandro Strumia

We obtain the bounds on all the gauge invariant, flavour symmetric, CP-even operators of dimension 6 that can affect the electroweak precision tests. For the preferred Higgs mass of about 100 GeV, their minimal scales range from 2 to 10 TeV. Depending on the individual operator, these limits are often significantly stronger than those quoted in the literatur

L. G. Wang, P. Kratzer, M. Scheffler, N. Moll

We study the energetics of island formation in Stranski-Krastanow growth within a parameter-free approach. It is shown that an optimum island size exists for a given coverage and island density if changes in the wetting layer morphology after the 3D transition are properly taken into account. Our approach reproduces well the experimental island size dependen

X. Gonze, M. Scheffler

Specific matrix elements of exchange and correlation kernels in time-dependent density-functional theory are computed. The knowledge of these matrix elements not only constraints approximate time-dependent functionals, but also allows to link different practical approaches to excited states, either based on density-functional theory, or on many-body perturba

T. K. Komatsubara

The current status of the experimental study of the rare kaon decay K^+ \to \pi^+ \nu \bar\nu at Brookhaven National Laboratory (BNL) by the E787 and E949 collaborations is reported.

Robert L. Dewar, Carmen I. Ciubotariu

Particle motion in a cylindrical multiple-cusp magnetic field configuration is shown to be highly (though not completely) chaotic, as expected by analogy with the Sinai billiard. This provides a collisionless, linear mechanism for phase randomization during monochromatic wave heating. A general quasilinear theory of collisionless energy diffusion is develope

Tudor Stanescu, Ivar Martin, Philip Phillips

We study here the onset of charge density wave instabilities in quantum Hall systems at finite temperature for Landau level filling $\nu>4$. Specific emphasis is placed on the role of disorder as well as an in-plane magnetic field. Beyond some critical value, disorder is observed to suppress the charge density wave melting temperature to zero. In addition, w

R. Radhakrishnan, A. Kundu, M. Lakshmanan

We propose an integrable system of coupled nonlinear Schrodinger equations with cubic-quintic terms describing the effects of quintic nonlinearity on the ultra-short optical soliton pulse propagation in non-Kerr media. Lax pair, conserved quantities and exact soliton solutions for the proposed integrable model are given. Explicit form of two-solitons are use

J. C. Retamal, E. S. Guerra

We consider the problem of quantum decoherence in cavity QED devices and investigate the possibility to preserve a Schroedinger cat as a coherent superposition along the time.

Stefano Liberati, Matt Visser, Francesco Belgiorno, Dennis Sciama

In a companion paper [quant-ph/9904013] we have investigated several variations of Schwinger&#39;s proposed mechanism for sonoluminescence. We demonstrated that any realistic version of Schwinger&#39;s mechanism must depend on extremely rapid (femtosecond) changes in refractive index, and discussed ways in which this might be physically plausible. To keep th

F. Brau

We propose a new approach to calculate perturbatively the effects of a particular deformed Heisenberg algebra on energy spectrum. We use this method to calculate the harmonic oscillator spectrum and find that corrections are in agreement with a previous calculation. Then, we apply this approach to obtain the hydrogen atom spectrum and we find that splittings

A. C. de la Torre, A. Daleo

The formalism of quantum mechanics is presented in a way that its interpretation as a classical field theory is emphasized. Two coupled real fields are defined with given equations of motion. Densities and currents associated to the fields are found with their corresponding conserved quantities. The behavior of these quantities under a galilean transformatio

A. C. de la Torre

Two types of particles, A and B with their corresponding antiparticles, are defined in a one dimensional cyclic lattice with an odd number of sites. In each step of time evolution, each particle acts as a source for the polarization field of the other type of particle with nonlocal action but with an effect decreasing with the distance: A -->...\bar{B} B \ba

Martin S. Altschul, Brett D. Altschul

Working from the Schroedinger&#39;s Cat paradigm, a series of experiments are constructed. The Bedford-Wang experiment is examined, and the ambiguity in its meaning is addressed. We eliminate this ambiguity by abandoning the idea of the triggering event, replacing the two-state system with a mirror that undergoes wave packet spreading. This creates an experi

S. R. Beane, M. Malheiro, D. R. Phillips, U. van Kolck

Compton scattering on the deuteron is studied in the framework of baryon chiral perturbation theory to third order in small momenta, for photon energies of order the pion mass. The scattering amplitude is a sum of one- and two-nucleon mechanisms with no undetermined parameters. Our results are in good agreement with existing experimental data, and a predicti

E. S. Letzter

We study certain filtrations of indecomposable injective modules over classical Lie superalgebras, applying a general approach for noetherian rings developed by Brown, Jategaonkar, Lenagan, and Warfield. To indicate the consequences of our analysis, suppose that $g$ is a complex classical simple Lie superalgebra and that $E$ is an indecomposable injective $g

E. S. Letzter

Let $A \subset H$ be a finite centralizing extension of noetherian Hopf algebras, and let $X$ denote the group of characters of $H$ that restrict to the augmentation map on $A$. Our main results provide necessary and sufficient conditions for the fibers of the canonical surjection from $spec H$ onto $spec A$ to coincide with the $X$-orbits in $spec H$. In pa

K. R. Goodearl, E. S. Letzter

Let $A$ denote the commutative polynomial ring in $n$ variables, over an algebraically closed field $k$, and let $R$ denote the standard multiparameter quantization of $A$ determined by a multiplicatively antisymmetric $n\times n$ matrix $(q_{ij})$. In this paper we prove, when -1 cannot be multiplicatively generated by the $q_{ij}$, that the primitive spect

Leonid Polterovich, Karl Friedrich Siburg

We study the asymptotic behaviour of 1-parameter subgroups with respect to Hofer&#39;s metric when the underlying symplectic manifold is an open surface of infinite area. We prove that, depending on the topology of the level sets of the Hamiltonian H, the distance either is bounded or behaves asymptotically linear. Moreover, the slope can be calculated expli

János Kollár, Endre Szabó

The aim of this note is to give simple proofs of some results of Reichstein and Youssin (math.AG/9903162) about the behaviour of fixed points of finite group actions under rational maps. Our proofs work in any characteristic. We also give a short proof of the Nishimura lemma.

Pavol Severa

An afinne-invariant view of generating functions of symplectic transformations of an affine symplectic space is discussed. More generally, it works for symmetric symplectic spaces. The note is completely elementary, but it yields some nice pictures.

C. A. Berenstein, A. Yger

In previous work of the authors and their collaborators (see Progress in Math, vol. 114, Birkäuser, 1993) it was shown how the equivalence of several constructions of residue currents associated to complete intersection families of (germs of) holomorphic functions in ${\bf C}^n$ could be profitably used to solve algebraic problems like effective versions of

John M. Sullivan

For decades, the sphere eversion has been a classic subject for mathematical visualization. The 1998 video &#34;The Optiverse&#34; shows geometrically optimal eversions created by minimizing elastic bending energy. We contrast these minimax eversions with earlier ones, including those by Morin, Phillips, Max, and Thurston. The minimax eversions were automati

Atsushi Moriwaki

In this short note, we will show that the metric of Deligne&#39;s pairing is continous.

I. L. Buchbinder, A. Yu. Petrov

We study a holomorphic effective potential $W_{eff}(Φ)$ in chiral superfield model defined in terms of arbitrary kählerian potential $K(\barΦ,Φ)$ and arbitrary chiral potential $W(Φ)$. Such a model naturally arises as an ingredient of low-energy limit of superstring theory and it is called here the general chiral superfield model. Generic procedure for calcu