November 1997 arXiv papers — page 5

Xinmin Zhang, Tao Huang, Robert H. Brandenberger

In this paper we construct a string-like classical solution, the pion-string, in the linear sigma model. We then study the stability of the pion-string, and find that it is unstable in the parameter space allowed experimentally. We also speculate on the existance of an unstable eta-string, associated with spontaneous breakdown of the anomalous $U_A(1)$ symme

K. J. Juge, J. Kuti, C. J. Morningstar

The hybrid quarkonium states are studied using the Born-Oppenheimer expansion. The first step in this expansion is the determination of the energy levels of the gluons in the presence of a static quark-antiquark pair as a function of the quark-antiquark separation. The spectrum of such gluonic excitations is determined from first principles using lattice QCD

M. Consoli, P. M. Stevenson

We discuss the physics of the 3+1 dimensional lambda Phi^4 quantum field theory in terms of the statistical mechanics of a gas of particles (`atoms') that interact via a -1/r^3-plus-hard-core potential. The hard-core potential, delta^(3)(r), arises from the bare vertex diagram, while the attractive, long-range -1/r^3 potential is due to exchange of a par

M. C. Gonzalez-Garcia, S. M. Lietti, S. F. Novaes

We estimate the attainable limits on the coupling of a non-standard Higgs boson to two photons taking into account the data collected by the Fermilab collaborations on diphoton events. We based our analysis on a general set of dimension--6 effective operators that give rise to anomalous couplings in the bosonic sector of the Standard Model. If the coefficien

J. Bernabeu, F. J. Botella, O. Vives

We study the $γ$-Z interference in the process $e^+ e^-\to Υ\to τ^+ τ^-$ as a means to measure the neutral current coupling of the b-quark. The helicity amplitudes are calculated from resonant and background diagrams and the spin density matrix of the final state is discussed. The spin analyzer of the $τ$'s is illustrated with the decays $πν$ and $ρν\to

Bernd A. Kniehl

We study J/psi photoproduction via fragmentation at next-to-leading order in the QCD-improved parton model, using the nonrelativistic factorization formalism proposed by Bodwin, Braaten, and Lepage. We predict that measurements of J/psi photoproduction at DESY HERA should show a distinctive excess over the expectation based on the colour-singlet model at sma

A. Bialas, H. Navelet, R. Peschanski

Using the recent solution of the triple Pomeron coupling in the QCD dipole picture as a closed string amplitude with six legs, its analytical form in terms of hypergeometric functions and numerical value are derived.

A. Dobado, M. J. Herrero, S. Penaranda

A heavy supersymmetric spectrum at the Minimal Supersymmetric Standard Model is considered and the decoupling from the low energy electroweak scale is analyzed. A formal and partial proof of decoupling of supersymmetric particles in the limit where their masses are larger than the electroweak scale is performed by integrating out all the sparticles to one lo

D. de Florian, O. Sampayo, R. Sassot

We present a combined next-to-leading order QCD analysis to data on both inclusive and semi-inclusive polarized deep inelastic scattering asymmetries. Performing NLO QCD global fits with different sets of observables, we evaluate the impact of the very recent semi-inclusive results presented by SMC in the extraction of NLO polarized parton distributions.

Jochen Biebel

I give a short report on the semi-analytical approach to off-shell W pair production. In particular, I show the effects of irreducible background diagrams of the CC11 class in the differential cross-section. Further, I study the influence of potential anomalous couplings at a future linear collider and investigate the sensitivity of the forward-backward asym

J Bordes, HM Chan, J Faridani, J Pfaudler

A review is given on the recently proposed idea that air showers with energy $> 10^{20}$ eV beyond the Greisen-Zatsepin-Kuz'min cut-off may be due to neutrinos having acquired a strong interaction at these energies, as suggested by the Dualized Standard Model. Such a hypothesis is shown to be consistent with the so far known facts. Further, by linking th

J. Fleischer, M. Tentyukov, O. L. Veretin

We present a review of the Bielefeld-Dubna activities on the multiloop calculations. In the first part a C-program DIANA (DIagram ANAlyser) for the automation of Feynman diagram evaluations is presented, in the second part various techniques for the evaluation of scalar diagrams are described, based on the Taylor expansion method and large mass expansion.

R. A. Alanakyan, V. H. Grabski

In the framework of Minimal Supersymmetric Standard Model Higgs bosons production via gluino/squark loop in the processes $gu \to H^{+}d$, $gd \to H^{-}u$,$gq \to H^{0}_iq$ are studied.

Marco Aurelio Diaz

Some aspects of bilinear R-Parity violation, the simplest extension of the MSSM which does not conserve R-Parity, are reviewed in comparison with the MSSM. We put special emphasis on the effect of quantum corrections.

E. Mirkes, S. Willfahrt

Next-to-leading order QCD predictions for 1-jet and 2-jet cross sections in polarized deep inelastic scattering at HERA energies are presented. Whereas the QCD corrections to the total polarized cross section are very large, only moderate corrections are found for the dijet cross sections.

S. M. Bilenky, C. Giunti, W. Grimus

It is shown that in the two schemes with four massive neutrinos which are compatible with the results of all neutrino oscillation experiments, the probabilities of nu_e disappearance and nu_mu->nu_e appearance in long-baseline experiments are severely constrained.

P. Minkowski

We propose to use as a mathematical tool to study the mass square of the etaprime meson an infinitely heavy supplementary quark flavor Q. This is understood in the framework of QCD with one light quark flavor (or n_fl light flavors) and the gauge group SU3 colour (or SUN colour). The full system thus consists of n_fl + 1 flavors, including the infinitely hea

I. M. Dremin, V. I. Manko

Rotation of such objects as an atomic nucleus or a chromodynamical string can result in specific effects in scattering processes and multiparticle production. Secondary fragments of the rotating nucleus or of the decaying string can move like stones thrown from a sling. That would be detected as the azimuthal asymmetry of particle distributions in individual

Jiro Kodaira, Takashi Nasuno, Hiroshi Tochimura, Kazuhiro Tanaka

We investigate the nucleon's transverse spin-dependent structure function g_2(x, Q^2) in the framework of the operator product expansion and the renormalization group. We construct the complete set of the twist-3 operators for the flavor singlet channel, and give the relations among them. We develop an efficient, covariant approach to derive the anomalou

M. Maul, E. Stein, L. Mankiewicz, M. Meyer-Hermann

We review the possibility to use the renormalons emerging in the perturbation series of the twist-2 part of the nonsinglet structure functions FL, F2, F3, and g1 to make approximate predictions for the magnitude of the appertaining twist-4 corrections.

J. M. Aroca, H. Fort, Gonzalo Alvarez-Campot

The Schwinger model is studied in a finite lattice by means of the P-representation. The vacuum energy, mass gap and chiral condensate are evaluated showing good agreement with the expected values in the continuum limit.

Fermilab E706 Collaboration, L. Apanasevich

Inclusive pizero and direct-photon cross sections in the kinematic range 3.5 < pT < 12 GeV/c with central rapidities are presented for 530 and 800 GeV/c proton beams and a 515 GeV/c pi- beam incident on beryllium targets. Current Next-to-Leading-Order perturbative QCD calculations fail to adequately describe the data for conventional choices of scales. Kinem

Ru-Keng Su, Bin Wang, P. K. N. Yu, E. C. M. Young

It is shown that the classical entropy of the extremal black hole depends on two different limits procedures. If we first take the extremal limit and then the boundary limit, the entropy is zero; if we do it the other way round, we get the Bekenstein-Hawking entropy. By means of the brick wall model, the quantum entropy of scalar field in the extremal black

Yurii A. Neretin

We consider hilbert spaces of holomorphic functions in Cartan domains (in particular in ball and polydisk) and operator of restriction of holomorphic function to a submanifold in Shilov boundary. We discuss conditions when this operator exists. Using such &#39;trace theorems&#39; it is possible to construct discrete increments to spectra of some unitary repr

Liviu I. Nicolaescu

We corrected a few errors in the previous submission. These do not affect any of the topological conclusions of the earlier version. We have also included a few observations about the Casson invariant of the Brieskorn homology spheres.

Ming-Che Chang, Min-Fong Yang

The energy spectra of spin-1/2 electrons under two-dimensional magnetic field modulations are calculated beyond the one-band approximation. Our formulation is generally applicable to a modulation field with a rectangular lattice symmetry. The field distribution within a plaquette is otherwise arbitrary. The spectra being obtained are qualitatively different

A. F. Volkov, V. V. Pavlovskii

A short introduction to the theory of matrix quasiclassical Green&#39;s functions is given and possible applications of this theory to transport properties of mesoscopic superconducting-normal metal (S/N) structures are considered. We discuss a simplified version of these equations in the diffusive regime and in the case of a weak proximity effect. These equ

E. Ben-Naim, A. R. Bishop, I. Daruka, P. L. Krapivsky

We study statistical properties of a continuum model of polynuclear surface growth on an infinite substrate. We develop a self-consistent mean-field theory which is solved to deduce the growth velocity and the extremal behavior of the coverage. Numerical simulations show that this theory gives an improved approximation for the coverage compare to the previou

R. Eder, O. Rogojanu, G. A. Sawatzky

We present a theory for the single particle excitations and Fermi surface of the Kondo lattice. Thereby we construct an effective Hamiltonian describing the creation and propagation of single particle-like charge fluctuations on an `RVB-background&#39; of local singlets. The theory may be viewed as a `Fermionic version&#39; of linear spin wave theory and is

N. B. Kopnin

We predict a resonant microwave absorption on collective vortex modes in a superclean d-wave superconductor. Energies of the collective modes are multiples of the distance between the exact quantum levels of bound states in the vortex core at lower temperatures and involve delocalized states for higher temperatures. We calculate the vortex mass in a d-wave s

I. D. White, R. W. Godby, M. M. Rieger, R. J. Needs

We evaluate the electronic self-energy Sigma(E) at an Al(111) surface using the GW space-time method. This self-energy automatically includes the image potential V_{im} not present in any local-density approximation for exchange and correlation. We solve the energy-dependent quasiparticle equations to obtain surface state wavefunctions, and calculate the eff

A. O. Anokhin, M. I. Katsnelson

A model of alloy is considered which includes both quenched disorder in the electron subsystem (``alloy&#39;&#39; subsystem) and electron-phonon interaction. For given approximate solution for the alloy part of the problem, which is assumed to be conserving in Baym&#39;s sense, we construct the generating functional and derive the Eliashberg-type equations w

J. Richter, A. Voigt, J. Schulenburg, N. B. Ivanov

Ba_2Cu_3O_4Cl_2 consists of two types of copper atoms, Cu(A) and Cu(B). We study the corresponding Heisenberg model with three antiferromagnetic couplings, J_AA, J_BB and J_AB. We find interesting frustration effects due to the coupling J_AB.

Stephen W. Pierson, Oriol T. Valls

We discuss the influence of lowest Landau level (LLL) fluctuations near H_{c2}(T) on flux lattice melting in YBa$_2$Cu$_3$O$_{7-δ}$ (YBCO). We show that the specific heat step of the flux lattice melting transition in YBCO single crystals can be attributed largely to the degrees of freedom associated with LLL fluctuations. These degrees of freedom have alrea

Stavros Theodorakis

We introduce an unusual Mexican hat potential, a piecewise parabolic one, and we show that its vortex solutions can be found analytically, in contrast to the case of the standard Psi^4 field theory.

Yue Yu, Wan-Peng Tan

The most general model with a magnetic impurity coupled to hybridizing and screening channels of a conduction band is considered. The partition function of the system is asymptotically equivalent to that of the multi-component kink plasma with a weak external field. The scaling properties of the models for finite $U$ are sketched by using the Anderson-Yuval-

Keith Jahoda

This paper summarizes some cosmologically interesting measurements which are uniquely possible in the hard X-ray band and presents a mission concept capable of achieving them. The Present Epoch Plus mission will achieve a surface brightness sensitivity of better than 1% per square degree in the 2-10 keV band, and create a catalog of about 10^6 sources. About

M. S. Strickman, M. Tavani, M. J. Coe, I. A. Steele

We present the results of a multiwavelength monitoring campaign targeting the gamma-ray source 2CG 135+1 in an attempt to confirm the association of this object with the radio/Be/X-ray binary system LSI +61o 303. The campaign included simultaneous radio, optical, infrared, and hard x-ray/gamma-ray observations carried out with a variety of instruments, cover

R. Morganti, T. Oosterloo, Z. Tsvetanov

New radio continuum (8 GHz and 1.4 GHz) and HI 21 cm line observations of the Seyfert 2 galaxy IC 5063 (PKS 2048-572) were obtained with the Australia Telescope Compact Array (ATCA). The 8 GHz image reveals a linear triple structure (~4&#39;&#39;, 1.5 kpc) oriented perpendicular to the optical polarization position angle. It is aligned with the inner dust la

Anita Krishnamurthi, D. M. Terndrup, M. H. Pinsonneault, K. Sellgren

We present results of photometric monitoring campaigns of G, K and M dwarfs in the Pleiades carried out in 1994, 1995 and 1996. We have determined rotation periods for 18 stars in this cluster. In this paper, we examine the validity of using observables such as X-ray activity and amplitude of photometric variations as indicators of angular momentum loss. We

F. Y. -H. Wang, M. Ruderman, J. P. Halpern, T. Zhu

A model is proposed for the observed combination of power-law and thermal emission of keV X-rays from rotationally powered pulsars. For gamma-ray pulsars with accelerators very many stellar radii above the neutron star surface, 100 MeV curvature gamma-rays from $e^{-}$ or $e^{+}$ flowing starward out of such accelerators are converted to electron-positron pa

S. N. Zhang, W. Yu, W. Zhang

Aql X-1 is a soft X-ray transient source and emits type I X-ray bursts. A spectral state transition was observed with RXTE during its outburst decay in February and March 1997. Its 10-30 keV and 5-10 keV count rate ratio increased suddenly when its luminosity was between (4-12) E35 ergs/s, assuming a 2.5 kpc distance. Spectral fitting with a model composed o

G. A. Mamon, M. Tricottet, W. Bonin, V. Banchet

The DENIS survey is currently imaging 21334 deg^2 of the mainly southern sky in the IJK and the observations are expected to go on until mid 2000. The expectations for extragalactic and cosmological research are outlined, including a quantitative assessment of the effects of recent star formation on the measured fluxes of galaxies. The galaxy extraction is m

Jochen Greiner, Robert Schwarz, Wolfgang Wenzel

We report the discovery of a new AM Herculis binary (polar) as the optical counterpart of the soft X-ray source RX J1724.0+4114 detected during the ROSAT all-sky survey. The magnetic nature of this V~17 mag object is confirmed by low-resolution spectroscopy showing strong Balmer and HeII emission lines superimposed on a blue continuum which is deeply modulat

F. Frontera, E. Costa, L. Piro, J. M. Muller

We report high-energy spectral data of the prompt emission of GRB970228 and its X-ray afterglow. We establish that the nature of the X-ray afterglow emission is non-thermal and similar to the later portion of GRB970228. Our data can be used to discriminate different emission models of GRB afterglows. While cooling of excited compact objects can be ruled out,

R. Bender, R. P. Saglia, B. Ziegler, L. Greggio

We explore the possibility to calibrate massive cluster ellipticals as cosmological standard rods. The method is based on the Fundamental Plane relation combined with a correction for luminosity evolution which is derived from the Mg$-σ$ relation. Principle caveats and sources of major errors are briefly discussed. We apply the described procedure to nine el

Jim Bryan, Naichung Conan Leung

We prove the conjectures of Yau-Zaslow and Gottsche concerning the number curves on K3 surfaces. Specifically, let X be a K3 surface and C be a holomorphic curve in X representing a primitive homology class. We count the number of curves of geometric genus g with n nodes passing through g generic points in X in the linear system |C| for any g and n satisfyin

Vicente Muñoz

We determine the quantum cohomology of the moduli space of odd degree rank two stable vector bundles over a Riemann surface $Σ$ of any genus. This work together with dg-ga/9710029 prove that this quantum cohomology is isomorphic to the instanton Floer cohomology of the three manifold $Σ\times S^1$. (Note: There is some overlap with the previous paper: alg-ge

Terutake Abe

We classify the log del Pezzo surface (S,B) of rank 1 with no 1-,2-,3-,4-, or 6-complements with the additional condition that B has one irreducible component C which is an elliptic curve, and that C has the coefficient b in B with (1/n)floor((n+1)b)=1 for n=1,2,3,4, and 6.

Fay Dowker, Sumati Surya

The result that, for a scalar quantum field propagating on a ``trousers&#39;&#39; topology in 1+1 dimensions, the crotch singularity is a source for an infinite burst of energy has been used to argue against the occurrence of topology change in quantum gravity. We draw attention to a conjecture due to Sorkin that it may be the particular type of topology cha

Dongsheng Du, C. S. Kim, Yadong Yang

We present a new mechanism for $B^{\pm}\to η&#39; K^{\pm}$, and analyze it strictly within perturbative QCD. We find that such a new mechanism may dominate non-leptonic $B$-decays to light mesons. Within a reasonable parameter space, our prediction is in good agreement with the recent CLEO data on $B^{\pm}\to η&#39; K^{\pm}$. We conclude that there is no roo

Konrad Banaszek, Krzysztof Wodkiewicz

The recently proposed scheme for direct sampling of the quantum phase space by photon counting is discussed within the Wigner function formalism.

Andras Bodor

This paper has been withdrawn.

Phung Ho Hai

We study the Poincaré series of the quantum spaces associated to a Hecke operator, i.e., a Yang-Baxter operator satisfying the equation $(x+1)(x-q)=0$. The Poincaré series of the corresponding matrix bialgebra is also considered. Using an old result on Polyá frequency sequence, we show that the Poincaré series of quantum spaces are always rational functions

K. Kajantie, M. Karjalainen, M. Laine, J. Peisa

We study the three-dimensional U(1)+Higgs theory (Ginzburg-Landau model) as an effective theory for finite temperature phase transitions from the 1 K scale of superconductivity to the relativistic scales of scalar electrodynamics. The relations between the parameters of the physical theory and the parameters of the 3d effective theory are given. The 3d theor

Radu Ionicioiu

We investigate topology change in 3D. Using Morse theory and handle decomposition we find the set of elementary cobordisms for 3-manifolds. These are: (i) Ø<-> S^2; (ii) Σ_g <-> Σ_{g+1}; (iii) Σ_{g_1} \sqcup Σ_{g_2} <-> Σ_{g_1+g_2} and they have appealing physical interpretations, e.g. Big Bang/Big Crunch, wormhole creation/annihilation and Einstein-Rosen br

V. I. Yukalov

The question addressed in this paper is: What originates pure spin superradiance in a polarized spin system placed inside a resonator? The term &#34;pure&#34; means that no initial coherence is imposed on spins, and its appearance manifests a purely self-organized collective effect. The consideration is based on a microscopic model with dipole spin interacti

Jack Lidmar, Mats Wallin, Carsten Wengel, S. M. Girvin

We present a finite temperature Monte Carlo study of the XY-model in the vortex representation, and study its dynamical critical behavior in two limits. The first neglects magnetic field fluctuations, corresponding to the absence of screening, which should be a good approximation in high $T_c$ superconductors ($κ\to \infty$) except extremely close to the cri

Steven M. Girvin

Strongly correlated quantum systems in low dimensions often exhibit novel quantum ordering. This ordering is sometimes hidden and can be revealed only by examining new `dual&#39; types of correlations. Such ordering leads to novel collective modes and fractional quantum numbers. Examples will be presented from quantum spin chains and the quantum Hall effect.

M. Hanasz

In this paper we continue investigations of the Parker-shearing instability performing numerical simulations of the magnetic flux tube dynamics in the thin flux-tube approximation. We show that evolution of flux tubes resulting from numerical simulations is very similar to that of linear solutions if the vertical displacements are smaller than the vertical s

Norbert Straumann

These lectures provide a detailed introduction to the electro- dynamics of black holes. A simplified derivation of the basic membrane equations for stationary, axisymmetric black holes is given. The general theory is applied to idealized current generators involving rotating black holes, and we also analyse the Blandford-Znajek process for magnetic energy ex

M. Hanasz

The observed wiggles and knots in astrophysical jets as well as the curvilinear motion of radio emitting features are frequently interpreted as signatures of the Kelvin-Helmholtz (KH) instability (eg. Hardee 1987). We investigate the KH instability of a hydrodynamic jet composed of a relativistic gas, surrounded by a nonrelativistic external medium and movin

Thorsten Poeschel, Thomas Schwager, Clara Saluena

When granular material is shaken vertically one observes convection, surface fluidization, spontaneous heap formation and other effects. There is a controversial discussion in literature whether there exists a threshold for the Froude number $Γ=A_0ω_0^2/g$ below which these effects cannot be observed anymore. By means of theoretical analysis and computer sim

Marek Czachor

Nonlinear Doebner-Goldin [Phys. Rev. A 54, 3764 (1996)] gauge transformations (NGT) defined in terms of a wave function $ψ(x)$ do not form a group. To get a group property one has to consider transformations that act differently on different branches of the complex argument function and the knowledge of the value of $ψ(x)$ is not sufficient for a well define

Gary J. Feldman, Robert D. Cousins

We give a classical confidence belt construction which unifies the treatment of upper confidence limits for null results and two-sided confidence intervals for non-null results. The unified treatment solves a problem (apparently not previously recognized) that the choice of upper limit or two-sided intervals leads to intervals which are not confidence interv

Marek Czachor

Linear quantum mechanics can be regarded as a particular example of a nonlinear Nambu-type theory. Some elements of this approach are presented.

Konrad Banaszek, Krzysztof Wodkiewicz

We study the application of squeezed states in a quantum optical scheme for direct sampling of the phase space by photon counting. We prove that the detection setup with a squeezed coherent probe field is equivalent to the probing of the squeezed signal field with a coherent state. An example of the Schroedinger cat state measurement shows that the use of sq

Steve Seif, Johnny Ray Sena

Primitive representations of finite groups as well as primitive finite groups were classified in the O&#39;Nan-Scott Theorem. In this paper we classify faithful finite primitive semigroup representations. To each finite primitive representation, we associate an invariant, a finite dimensional matirix with entries in a primitive finite groups representation.

V. S. Fadin, R. Fiore, A. Flachi, M. I. Kotsky

The quark-antiquark contribution to the BFKL kernel is calculated. Using the effective vertex for the $q\bar q$ pair production in the Reggeon-Reggeon collision we find this contribution by integrating the square of this vertex over relative transverse momenta and fractions of longitudinal momenta of produced particles.

Aida X. El-Khadra, Andreas S. Kronfeld, Paul B. Mackenzie, Sinead M. Ryan

We have calculated the decay constants of B and $D$ mesons with lattice QCD. We use an $O(a)$ improved action that takes light quark actions as a starting point, tuned so that it can be directly applied at the physical masses of the $b$ and $c$ quarks. Our results are $f_B = 164 \err{+14}{-11} \pm 8$ MeV, $f_{B_s} = 185 \err{+13}{-8} \pm 9$ MeV, $f_D = 194 \

B. E. Vugmeister, H. Rabitz

The dielectric response in relaxor ferroelectrics is analyzed in the framework a model for the polarization dynamics in the presence of polar clusters. We associate the origin of polar clusters with the atoms displaced from their centro-symmerical positions even above $T_c$. Their collective hopping in multi-well potentials induced by disorder is analogous w

O. Zobay, P. Meystre

Various aspects of the phase dynamics of an atom laser scheme based on binary collisions are investigated. Analytical estimates of the influence of elastic atom-atom collisions on the laser linewidth are given, and linewidths achievable in a recently proposed atom laser scheme [Phys. Rev. A 56, 2989 (1997)] are evaluated explicitly. The extent to which a rel

Steven S. Plotkin, Peter G. Wolynes

The non-Markovian nature of polymer motions is accounted for in folding kinetics, using frequency-dependent friction. Folding, like many other problems in the physics of disordered systems, involves barrier crossing on a correlated energy landscape. A variational transition state theory (VTST) that reduces to the usual Bryngelson-Wolynes Kramers approach whe

Prasenjit Saha

This paper describes a method for quantitatively comparing an N-body model with a sample of discrete kinematic data. The comparison has two stages: (i) finding the optimum scaling and orientation of the model relative to the data; and (ii) calculating a goodness of fit, and hence assessing the plausibility of the model in vew of the data. The method derives

J. Craig Wheeler, John J. Cowan, Wolfgang Hillebrandt

Several circumstantial arguments point to the formation of the third r-process peak at A about 190, near platinum, in stars of mass of about 8-10 solar masses: 1) The delayed production of europium with respect to iron imposes a time scale that restricts the progenitor stars to less than about 10 solar masses; 2) the r-process demands a dominant robust mecha

R. G. Carlberg, H. K. C. Yee, H. Lin, M. Sawicki

The CNOC1 cluster survey measures Omega_M via Oort&#39;s method, Omega_M= M/L x j/rho_c, where M/L is the field mass-to-light ratio, j is the field luminosity density and rho_c is the closure density. A wide range of potential systematic effects are explicitly controlled by independently deriving the mean cluster mass profile (finding good agreement with the

Haruichi Washimi, Shinpei Shibata, Masao Mori

Several weeks after the explosion of supernova (SN) 1987A, the UV flash of the SN illuminated a ring-like structure in the circumstellar material at about 0.65 ly from the SN. The interaction between the stellar winds from the SN progenitor is considered to be the candidate for the formation of the circumstellar structure. In the case that the stellar winds

Vladimir M. Lipunov

The Invited Review on Joint Discussion &#34;High Energy Transients&#34; on XXIIIrd General Assembly of IAU, Kioto, 1997 is presented. The simulated rates of neutron star + neutron star, neutron star + black hole and black hole + black hole mergings are considered in relation with the problem of GRBursts origin and gravitational waves detection.

E. Brocato, V. Castellani, S. Degl&#39;Innocenti, G. Fiorentini

Theoretical expectations concerning stars as neutrino sources are presented according to detailed evaluations of the stellar evolutionary histories for an extended grid of stellar masses. Neutrino fluxes and cumulative neutrino yields are given for both `thermo-nuclear&#39; and `cooling&#39; neutrinos all over the nuclear life of the stars and along the fina

S. A. Laurent-Muehleisen, R. I. Kollgaard, R. B. Ciardullo, E. D. Feigelson

We present new spectroscopic identifications for 169 objects in the RASS-Green Bank (RGB) catalog of radio- and X-ray-emitting AGN. These data significantly increase the fraction of bright RGB objects with classifications. Specifically, we report and discuss the classification of 66 radio-loud quasars, 53 BL Lacs, 33 Broad Line Radio Galaxies, 5 Narrow Line

G. Q. Luo

An equation of state for the domain extending from hot gases to cool-dense fluids is formulated for a hydrogen-helium mixture. The physical processes take account of temperature ionization and dissociation, electron degeneracy, Coulomb coupling and pressure ionization. Pressure ionization and Coulomb coupling are studied with simple and comprehensive modelin

S. W. Mansour, T. K. Kuo

We study the effect of including flavor changing neutral currents (FCNC) in the analysis of the neutrino signal of a supernova burst. When we include the effect of the FCNC which are beyond the standard model (SM) in the study of the MSW resonant conversion, we obtain dramatic changes in the Δm^2-sin^2(2θ) probability contours for neutrino detection.

P. M. Hansen, J. A. Riera, A. Delia, E. Dagotto

The effects of spin-1 impurities introduced in dimerized antiferromagnetic spin chains are studied using Lanczos diagonalization and quantum Monte Carlo simulations. Firstly, the magnitude of the interaction between a Ni-ion replacing a Cu-ion is derived for the case study system Cu-O-Cu. Then, it is shown that the introduction of S=1 impurities leads to the

G. R. Farrar, G. Gabadadze, M. Schwetz

We propose a generalization of the Veneziano-Yankielowicz effective low-energy action for N=1 SUSY Yang-Mills theory which includes composite operators interpolating pure gluonic bound states. The chiral supermultiplet of anomalies is embedded in a larger three-form multiplet and an extra term in the effective action is introduced. The mass spectrum and mixi

Jorge Gamboa, Mikhail Plyushchay

We discuss the phenomenon of classical anomaly. It is observed for 3D Berezin-Marinov (BM), Barducci-Casalbuoni-Lusanna (BCL) and Cortes-Plyushchay-Velazquez (CPV) pseudoclassical spin particle models. We show that quantum mechanically these different models correspond to the same P,T-invariant system of planar fermions, but the quantum system has global sym

Andrew Gould, Chris Flynn, John N. Bahcall

We analyze 166 spheroid subdwarfs $(6.5<M_V<14.5)$ found in 53 fields observed with the Wide Field Camera on the {\it Hubble Space Telescope}. The fields cover 221 square arcmin over a wide range of directions. The spheroid luminosity function (LF) is inconsistent at about the 3 sigma level with the local spheroid LF of Dahn et al. even when the normalizatio

Kimball A. Milton, A. V. Nesterenko, V. V. Nesterenko

Using the mode-by-mode summation technique the zero point energy of the electromagnetic field is calculated for the boundary conditions given on the surface of an infinite solid cylinder. It is assumed that the dielectric and magnetic characteristics of the material which makes up the cylinder $(ε_1, μ_1)$ and of that which makes up the surroundings $(ε_2, μ

X. G. Wen, A. Zee

We present a simple approach to calculate the degeneracy and the structure of the ground states of non-abelian quantum Hall (QH) liquids on the torus. Our approach can be applied to any QH liquids (abelian or non-abelian) obtained from the parton construction. We explain our approach by studying a series of examples of increasing complexity. When the effecti

Edmund J Copeland, Andrew R Liddle, David Wands

We present a phase-plane analysis of cosmologies containing a barotropic fluid with equation of state $p_γ= (γ-1) ρ_γ$, plus a scalar field $ϕ$ with an exponential potential $V \propto \exp(-λκϕ)$ where $κ^2 = 8πG$. In addition to the well-known inflationary solutions for $λ^2 < 2$, there exist scaling solutions when $λ^2 > 3γ$ in which the scalar field ener

Marek Gazdzicki, Andrei Leonidov, Gunther Roland

We demonstrate that a new type of analysis in heavy-ion collisions, based on an event-by-event analysis of the transverse momentum distribution, allows us to obtain information on secondary interactions and collective behaviour that is not available from the inclusive spectra. Using a random walk model as a simple phenomenological description of initial stat

F. Guinea

Lattice distortions in which the axes are locally rotated provide an intrinsic source of frustration in anisotropic superconductors. A general framework to study this effect is presented. The influence of lattice defects and phonons in $d$ and $s+d$ layered superconductors is studied.

Ruggero Ferrari

The Quantum Hall Effect for free electrons in external periodic field is discussed without using the linear response approximation. We find that the Hall conductivity is related in a simple way to Floquet energies (associated to the Schroedinger equation in the co-moving frame). By this relation one can analyze the dependence of the Hall conductivity from th

S. Blom, H. Olin, J. L. Costa-Kramer, N. Garcia

When two metal electrodes are separated, a nanometer sized wire (nanowire) is formed just before the contact breaks. The electrical conduction measured during this retraction process shows signs of quantized conductance in units of G_0=2e^2/h. Recent experiments show that the force acting on the wire during separation fluctuates, which has been interpreted a

A. Cucchieri, T. Mendes

We present a new implementation of the Fourier acceleration method for Landau gauge fixing. By means of a multigrid inversion we are able to avoid the use of the fast Fourier transform. This makes the method more flexible, and well suited for vector and parallel machines. We study the performance of this algorithm on serial and on parallel (APE100) machines

J. Wilder, T. A. Vilgis

This paper discusses the elastic behavior of a very long crosslinked polyelectrolyte chain (Debye-Hückel chain), which is weakly charged. Therefore the response of the crosslinked chain (network) on an external constant force $f$ acting on the ends of the chain is considered. A selfconsistent variational computation of an effective field theory is employed.

Michael R. Douglas, Chris Hull

We show that in certain superstring compactifications, gauge theories on noncommutative tori will naturally appear as D-brane world-volume theories. This gives strong evidence that they are well-defined quantum theories. It also gives a physical derivation of the identification proposed by Connes, Douglas and Schwarz of Matrix theory compactification on the

JLQCD Collaboration, S. Aoki, M. Fukugita, S. Hashimoto

We present a calculation for the $K^+\toπ^+ π^0 $ decay amplitude using a quenched simulation of lattice QCD with the Wilson quark action at $β=6/g^2=6.1$. The decay amplitude is extracted from the ratio, the $K\toππ$ three-point function divided by either $K$ and $π$ meson two-point functions or $K$ meson two-point function and I=2 $ππ$ four-point function;

T. Fukuyama, K. Matsuda, H. Nishiura

Taking account of possible CP violation, we discuss about the constraints on the lepton mixing angles from the neutrinoless double beta decay and from the neutrino oscillation for the three flavour Majorana neutrinos. From the CHORUS oscillation experiment, combined with the data of neutrinoless double beta decay, we show that the large angle solution of (θ_

Jeffrey D. Scargle

I describe a new time-domain algorithm for detecting localized structures (bursts), revealing pulse shapes, and generally characterizing intensity variations. The input is raw counting data, in any of three forms: time-tagged photon events (TTE), binned counts, or time-to-spill (TTS) data. The output is the most likely segmentation of the observation into ti

N. David Mermin

In a recent article under the above title (but without the question mark) Henry Stapp presented arguments which lead him to conclude that under suitable conditions ``the truth of a statement that refers only to phenomena confined to an earlier time&#39;&#39; must ``depend on which measurement an experimenter freely chooses to perform at a later time.&#39;&#3