March 1999 arXiv papers — page 16

S. Sanvito, C. J. Lambert, J. H. Jefferson

We study the effect on CPP GMR of changing the order of the layers in a multilayer. Using a tight-binding simple cubic two band model (s-d), magneto-transport properties are calculated in the zero-temperature, zero-bias limit, within the Landauer-Buttiker formalism. We demonstrate that for layers of different thicknesses formed from a single magnetic metal a

Catherine Pepin, Alexei M. Tsvelik

We study an exactly solvable model describing a stripe consisting of a Toda array of $N$ anharmonic elastic chains sandwiched between two conducting chains. It is shown that the presence of a charge on one chain generates a gapless excitation branch (Luttinger liquid) on the other and leads to increase in the phonon frequencies.

Gabriel Kotliar

We discuss the solution of the Mott transition problem in a fully frustrated lattice with a semicircular density of states in the limit of infinite dimensions from the point of view of a Landau free energy functional. This approach provides a simple relation between the free energy of the lattice model and that of its local description in terms of an impurit

Ganpathy Murthy

A microscopic Hamiltonian theory of the FQHE, developed by Shankar and myself based on the fermionic Chern-Simons approach, has recently been quite successful in calculating gaps in Fractional Quantum Hall states, and in predicting approximate scaling relations between the gaps of different fractions. I now apply this formalism towards computing magnetoexcit

J. Heinonen, I. Koponen, J. Merikoski, T. Ala-Nissila

We present Monte Carlo simulations for the size and temperature dependence of the diffusion coefficient of adatom islands on the Cu(100) surface. We show that the scaling exponent for the size dependence is not a constant but a decreasing function of the island size and approaches unity for very large islands. This is due to a crossover from periphery domina

Ola Tageman, A. P. Singh

We consider electron transport in a ballistic multi-mode channel structure in the presence of a transversely polarized far-infrared (FIR) field. The channel structure consists of a long resonance region connected to an adiabatic widening with a potential barrier at the end. At frequencies that match the mode energy separation in the resonance region we find

L. A. Braunstein, R. C. Buceta, N. Giovambattista, A. Diaz-Sanchez

We present the microscopic equation for the growing interface with quenched noise for the model first presented by Buldyrev et al. [Phys. Rev. A 45, R8313 (1992)]. The evolution equation for the height, the mean height, and the roughness are reached in a simple way. The microscopic equation allows us to express these equations in two contributions: the conta

L. I. Glazman, F. W. J. Hekking, A. I. Larkin

We study a quantum dot connected to the bulk by single-mode junctions at almost perfect conductance. Although the average charge $e\langle N \rangle$ of the dot is not discrete, its spin remains quantized: $s=1/2$ or $s=0$, depending (periodically) on the gate voltage. This drastic difference from the conventional mixed-valence regime stems from the existenc

R. Chitra, G. Kotliar

We reconsider the Mott transition problem in the presence of long range Coulomb interactions. Using an extended DMFT, that sums an important class of diagrams absent in ordinary DMFT, we show that in the presence of Coulomb the Mott transition in two and three dimensions is discontinuous as envisioned by Mott.

C. Megan Urry

Blazar spectral energy distributions (SEDs) are double peaked and follow a self-similar sequence in luminosity. The so-called "blue" blazars, whose first SED component peaks at X-ray energies, are TeV sources, although with a relatively small fraction of their bolometric luminosities. The "red" blazars, with SED peaks in the infrared-optical range, appear to

Richard de Grijs, Robert W. O'Connell, John S. Gallagher

We present high-resolution optical and near-infrared HST observations of two adjacent regions in the fossil starburst region in M82, M82 B1 and B2. The presence of both the active and the fossil starburst in M82 provides a unique physical environment to study the stellar and dynamical evolution of star cluster systems. The cluster population in B2 is more he

P. D. Morley, C. Dib, I. Schmidt

We calculate neutrino and antineutrino scattering off electrons and nucleons in supernovae using a detailed Monte Carlo transport code incorporating realistic equations of state. The goal is to determine whether particles in a neutron star core, partially spin-aligned by the local magnetic field, can give rise to asymmetric neutrino emission via the standard

J. A. Sellwood

In this review, I discuss just three aspects of the stability and evolution of galactic discs. (1) I first review our understanding of the bar instability and how it can be controlled. Disc galaxies in which the orbital speed does not decrease much towards the centre have no difficulty avoiding bars, even when dark matter makes an insignificant contribution

J. A. Sellwood

While the total interior mass of a galaxy is reasonably well determined by a good rotation curve, the relative contributions from disk, bulge and halo are only weakly constrained by one-dimensional data. Barred galaxies are intrinsically more complicated, but provide much tighter constraints on the disk masses and support the idea that most of the mass in th

Subir Sarkar

Recent observational and theoretical developments concerning the primordial synthesis of the light elements are reviewed, and the implications for dark matter mentioned.

Gustavo Medina Tanco, Alan A. Watson

Several explanations for the existence of Ultra High Energy Cosmic Rays invoke the idea that they originate from the decay of massive particles created in the reheating following inflation. It has been suggested that the decay products can explain the observed isotropic flux of cosmic rays. We have calculated the anisotropy expected for various models of the

David S. Graff, Katherine Freese, Terry Walker, Marc Pinsonneault

If galactic halos contain stellar remnants, the infra-red flux from the remnant progenitors would contribute to the opacity of multi-TeV gamma-rays. The multi-TeV gamma-ray horizon is established to be at a redshift z>0.034 by the observation of the blazar Mkn501 . By requiring that the optical depth due to γγ---> e+ e- be less than one for a source at z=0.0

C. Chapuis, S. Corbel, P. Durouchoux, T. N. Gautier

The rapid variability of blazars in almost all wavelengths is now well established. Two days of observations were conducted at the Palomar Observatory during the nights of 25 and 26 February 1997 with the 5-meter Hale telescope, in order to search for rapid variability in the near-infrared (NIR) bands J, H, Ks for a selection of eight blazars. With the possi

K. Reif, K. Bagschik, K. S. de Boer, J. Schmoll

The "Bonn University Simultaneous CAmera" (BUSCA) is a CCD camera system which allows simultaneous direct imaging of the same sky area in four colors. The optics are designed for an f/8 beam and four 4Kx4K CCDs with 15m pixels covering a field of view of 12 arcmin x 12 arcmin at a 2m class telescope. In September 1998 BUSCA has seen "First Light&

François R. Bouchet, Richard Gispert

As Cosmic Microwave Background (CMB) measurements are becoming more ambitious, the issue of foreground contamination is becoming more pressing. This is especially true at the level of sensitivity, angular resolution and for the sky coverage of the planned space experiments MAP and PLANCK. We present in this paper an indicator of the accuracy of the separatio

Stephen Holland, Jens Hjorth

We reduced the Hubble Space Telescope Space Telescope Imaging Spectrograph images of the gamma-ray burst GRB 990123 that were obtained on 8-9 February 1999 and find V_0 = 25.36 +/- 0.10, which corresponds to a flux of 0.258 +/- 0.023 micro-Jy for the optical transient 16.644 days after the burst's peak. The probable host galaxy has V_0 = 24.25 +/- 0.07 (

A. W. Jones

The data from Cosmic Microwave Background (CMB) experiments are becoming more complex with each new experiment. A consistent way of analysing these data sets is required so that direct comparison is possible between the various experimental results. This thesis presents several techniques that can be used to analyse CMB data.

J. Knodlseder, D. Dixon, K. Bennett, H. Bloemen

We present a new algorithm, called Multiresolution Regularized Expectation Maximization (MREM), for the reconstruction of gamma-ray intensity maps from COMPTEL data. The algorithm is based on the iterative Richardson-Lucy scheme to which we added a wavelet thresholding step in order to eliminate image-noise in the reconstruction. The wavelet thresholding exp

Keiichi Wada, C. A. Norman

Using high resolution, two-dimensional hydrodynamical simulations, we investigate the evolution of a self-gravitating multi-phase interstellar medium in the central kiloparsec region of a galactic disk. We find that a gravitationally and thermally unstable disk evolves, in a self-stabilizing manner, into a globally quasi-stable disk that consists of cold (T

Etienne Parizot, Jurgen Knodlseder

We present an evolutionary model for gamma-ray line emission from superbubbles based on shock acceleration of metal-rich stellar ejecta. Application to the Orion OB1 association shows that gamma-ray lines at the detection threshold of the SPI spectrometer aboard of INTEGRAL are expected, making this region an interesting target for studies of the interaction

Arieh Konigl

There is a growing number of observational indicators for the presence of bipolar outflows in massive, young stellar objects that are still accreting mass as part of their formation process. In particular, there is evidence that the outflows from these objects can attain higher velocities and kinetic luminosities than their lower-mass counterparts. Furthermo

Arieh Konigl, Ralph E. Pudritz

We review recent observational and theoretical results on the relationship between circumstellar accretion disks and jets in young stellar objects. We then present a theoretical framework that interprets jets as accretion-powered, centrifugally driven winds from magnetized accretion disks. Recent progress in the numerical simulation of such outflows is descr

Alexander Kusenko

Several mechanisms based on neutrino oscillations can explain the observed motions of pulsars if the magnetic field in their interiors is of order 10^{14}-10^{15} G.

J. Richard Bond, Robert G. Crittenden, Andrew H. Jaffe, Lloyd Knox

The Cosmic Microwave Background (CMB) encodes information on the origin and evolution of the universe, buried in a fractional anisotropy of one part in 100,000 on angular scales from arcminutes to tens of degrees. We await the coming onslaught of data from experiments measuring the microwave sky from the ground, from balloons and from space. However, we are

Michael Blanton, Renyue Cen, Jeremiah P. Ostriker, Michael A. Strauss

The clustering of galaxies relative to the mass distribution declines with time because: first, nonlinear peaks become less rare events; second, the densest regions stop forming new galaxies because gas there becomes too hot to cool and collapse; third, after galaxies form, they are gravitationally ``debiased'' because their velocity field is the sam

Ben Moore, Tom Quinn, Fabio Governato, Joachim Stadel

We show that a universe dominated by cold dark matter fails to reproduce the rotation curves of dark matter dominated galaxies, one of the key problems that it was designed to resolve. We perform numerical simulations of the formation of dark matter halos, each containing \gsim 10^6 particles and resolved to 0.003 times the virial radius, allowing an accurat

K. M. Mertes, D. Simonian, M. P. Sarachik, S. V. Kravchenko

The response to a parallel magnetic field of the very dilute insulating two-dimensional system of electrons in silicon MOSFET's is dramatic and similar to that found on the conducting side of the metal-insulator transition: there is a large initial increase in resistivity with increasing field, followed by saturation to a value that is approximately cons

The Fermilab E791 Collaboration

Using the large hadroproduced charm sample collected in experiment E791 at Fermilab, we report the first directly measured constraint on the decay-width difference Delta Gamma for the mass eigenstates of the D0-D0bar system. We obtain our result from lifetime measurements of the decays D0 --> K-pi+ and D0 --> K-K+, under the assumption of CP invariance, whic

Hong Liu, A. A. Tseytlin

We consider SO(4) x SO(6) invariant type IIB string solution describing D3-branes superposed with D-instantons homogeneously distributed over D3-brane world-volume. In the near D3-brane horizon limit this background interpolates between AdS_5 x S^5 space in UV and flat space (with non-constant dilaton and RR scalar) in IR. Generalizing the AdS/CFT conjecture

T. J. Davidge, S. Courteau

High angular resolution optical and near-infrared images are used to investigate the central regions of the nearby Sb galaxy M81 (NGC3031). The spectral-energy distribution of the circumnuclear region, which extends out to 1.5 arcsec (~ 24 pc if μ_0 = 27.5) from the nucleus, can be modelled as a combination of an old metal-rich population and emission from h

Paolo S. Coppi, Felix A. Aharonian

The last years have seen a revolution in ground-based gamma-ray detectors. We can now detect the spectra of nearby TeV blazars like Mrk 421 and 501 out to approximately 20 TeV, and during the strongest flares, we can now follow fluctuations in these spectra on timescales close to the shortest ones likely in these objects. We point out that this represents a

S. P. Kou, J. Q. Liang, Y. B. Zhang, X. B. Wang

The crossover from thermal hopping to quantum tunneling is studied. We show that the decay rate $\Gamma$ with dissipation can accurately be determined near the crossover temperature. Besides considering the Wentzel-Kramers-Brillouin (WKB) exponent, we also calculate contribution of the fluctuation modes around the saddle point and give an extended account of

Victor Ginzburg

This is the first of a series of papers devoted to certain pairs of commuting nilpotent elements in a semisimple Lie algebra that enjoy quite remarkable properties and which are expected to play a major role in Representation theory. The properties of these pairs and their role is similar to those of the principal nilpotents. To any principal nilpotent pair

R. Folch, J. Casademunt, A. Hernandez-Machado, L. Ramirez-Piscina

We implement a phase-field simulation of the dynamics of two fluids with arbitrary viscosity contrast in a rectangular Hele-Shaw cell. We demonstrate the use of this technique in different situations including the linear regime, the stationary Saffman-Taylor fingers and the multifinger competition dynamics, for different viscosity contrasts. The method is qu

Adi Armoni, Ehud Fuchs, Jacob Sonnenschein

We study five dimensional non critical type 0 string theory and its correspondence to non supersymmetric Yang Mills theory in four dimensions. We solve the equations of motion of the low energy effective action and identify a class of solutions that translates into a confining behavior in the IR region of the dual gauge theories. In particular we identify a

R. Folch, J. Casademunt, A. Hernandez-Machado, L. Ramirez-Piscina

We present a phase-field model for the dynamics of the interface between two inmiscible fluids with arbitrary viscosity contrast in a rectangular Hele-Shaw cell. With asymptotic matching techniques we check the model to yield the right Hele-Shaw equations in the sharp-interface limit and compute the corrections to these equations to first order in the interf

Jean-Philippe Uzan, Roland Lehoucq, Jean-Pierre Luminet

Multi-connected universe models with space identification scales smaller than the size of the observable universe produce topological images of cosmic sources. We generalise to locally hyperbolic spaces the crystallographic method, aimed to detect the topology from three-dimensional catalogs of cosmological objects. Our new method is based on the constructio

Alvaro Corral, Maya Paczuski

A dynamical transition separating intermittent and continuous flow is observed in a sandpile model, with scaling functions relating the transport behaviors between both regimes. The width of the active zone diverges with system size in the avalanche regime but becomes very narrow for continuous flow. The change of the mean slope, Delta z, on increasing the d

N. F. Johnson, P. M. Hui, D. Zheng, M. Hart

We study a mixed population of adaptive agents with small and large memories, competing in a minority game. If the agents are sufficiently adaptive, we find that the average winnings per agent can exceed that obtainable in the corresponding pure populations. In contrast to the pure population, the average success rate of the large-memory agents can be greate

T. Hakioglu

The operational approach to the measurement of phase studied by Noh, Fougeres and Mandel is applied to the measurement of the state of polarization of fully polarized light. Operational counterparts of the quantum Stokes parameters are introduced and their fluctuations are examined. It is shown that if the polarized field is weak, the measured fluctuations a

Baruch Horovitz

The second peak phenomena of flux lattices in layered superconductors is described in terms of a disorder induced layer decoupling transition. For weak disorder the tilt mudulus undergoes an apparent discontinuity which leads to an enhanced critical current and reduced domain size in the decoupled phase. The Josephson plasma frequency is reduced by decouplin

W. James Stirling, Anja Werthenbach

The production of three electroweak gauge bosons in high-energy $e^+e^-$ collisions offers a window on anomalous quartic gauge boson couplings. We investigate the effect of three possible anomalous couplings on the cross sections for $W^+W^-γ$, $Z^0Z^0γ$ and $Z^0γγ$ productions at LEP2 ($\sqrt{s} = 200$ GeV) and at a future linear collider ($\sqrt{s} = 500$

Arun Kumar Pati

we envisage a novel quantum cloning machine, which takes an input state and produces an output state whose success branch can exist in a linear superposition of multiple copies of the input state and the failure branch exist in a superposition of composite state independent of the input state. We prove that unknown non-orthogonal states chosen from a set $\c

K. Dick, M. Freund, M. Lindner, A. Romanino

We study in a quantitative way CP-violating effects in neutrino oscillation experiments in the light of current and future data. Different scenarios with three and four neutrinos are worked out in detail including matter effects in long baseline experiments and it is shown that in some cases CP-violating effects could affect the analysis of a possible measur

Youichi Ohyama, Yoshiaki Taniguchi, J. E. Hibbard, William D. Vacca

We present redshift measurements of four faint galaxies around the archetypal ultraluminous infrared galaxy Arp 220. These galaxies have significantly higher redshifts ($z \sim$ 0.036 -- 0.091) than that of Arp 220 ($z \simeq 0.018$). Therefore, we conclude that they are background objects not physically related to Arp 220. Three of these faint galaxies loca

Toshihiro Matsuo, Takashi Yokono

The production of string charge during a crossing of certain oriented D-branes is studied. We compute the string charge in the system of a probe D2-brane and a background D6-brane by use of the equations of motion in the ten-dimensions. We confirm the creation of string charge as inflow from the background D6-brane.

L. A. Anchordoqui, G. E. Romero, J. A. Combi

We provide an account of the possible acceleration of iron nuclei up to energies $\sim300$ EeV in the nearby, metally-rich starburst galaxy NGC 253. It is suggested that particles can escape from the nuclear region with energies of $\sim10^{15}$ eV and then could be reaccelerated at the terminal shock of the galactic superwind generated by the starburst, avo

H. Jung, L. Jönsson, H. Küster

The measurement of forward jet cross sections has been suggested as a promising probe of new small x parton dynamics and the question is whether the new HERA data provide an indication of this. In this paper the influence of resolved photon processes has been investigated and it has been studied to what extent the inclusion of such processes in addition to n

Yi-hong Gao

We consider a version of the $AdS_{d+1}/CFT_{d}$ correspondence, in which the bulk space is taken to be the quotient manifold $AdS_{d+1} /Γ$ with a fairly generic discrete group $Γ$ acting isometrically on $AdS_{d+1}$. We address some geometrical issues concerning the holographic principle and the UV/IR relations. It is shown that certain singular structures

Mei Huang, Pengfei Zhuang, Weiqin Chao

Based on the self-consistent scheme beyond mean-field approximation in the large $N_c$ expansion, including current quark mass explicitly, a general scheme of SU(2) NJL model is developed. To ensure the quark self-energy expanded in the proper order of $N_c$, an approximate internal meson propagator is deduced, which is in order of $O(1/N_c)$. In our scheme,

Andrea Cavagna, Irene Giardina, Giorgio Parisi

We analytically compute the spectrum of the Hessian of the Hamiltonian for a system of N particles interacting via a purely repulsive potential in one dimension. Our approach is valid in the low density regime, where we compute the exact spectrum also in the localized sector. We finally perform a numerical analysis of the localization properties of the eigen

H. E. Boos, V. V. Mangazeev

This paper is a continuation of our previous work (solv-int/9903001). We obtain two more functional relations for the eigenvalues of the transfer matrices for the $sl(3)$ chiral Potts model at $q^2=-1$. This model, up to a modification of boundary conditions, is equivalent to the three-layer three-dimensional Zamolodchikov model. From these relations we deri

M. Dugic

Within the decoherence theory we investigate the physical background of the condition of the separability (diagonalizability in noncorrelated basis) of the interaction Hamiltonian of the composite system, "system plus environment". It proves that the condition of the separability may serve as a criterion for defining "system", but so that &#3

Harry Buhrman, Wim van Dam

We combine the classical notions and techniques for bounded query classes with those developed in quantum computing. We give strong evidence that quantum queries to an oracle in the class NP does indeed reduce the query complexity of decision problems. Under traditional complexity assumptions, we obtain an exponential speedup between the quantum and the clas

Jens Eggers, John R. Lister, Howard A. Stone

When two drops of radius $R$ touch, surface tension drives an initially singular motion which joins them into a bigger drop with smaller surface area. This motion is always viscously dominated at early times. We focus on the early-time behavior of the radius $\rmn$ of the small bridge between the two drops. The flow is driven by a highly curved meniscus of l

G. F. Gribakin, V. K. Ivanov, A. V. Korol, M. Yu. Kuchiev

Absolute two-photon detachment cross sections and photoelectron angular distribution are calculated for halogen negative ions within lowest-order perturbation theory. The Dyson equation method is used to obtain the outer np ground-state wave functions with proper asymptotic behavior exp (-k r), corresponding to correct (experimental) binding energies E=k^2/2

Thomas D. Cohen, Chi-Keung Chow

We show that the variance in the number of charged pions (in a suitable range of momentum space) provides a signature for the observation of a disoriented chiral condensate (D$χ$C). The signal should be observable even if multiple domains of D$χ$C form provided the average number of pions per domain is significantly large than unity. The variance of the numb

V. A. Atsarkin, A. L. Barabanov, A. G. Beda, V. V. Novitsky

The methods of investigation of Time Reversal Invariance (TRI) violation using polarized neutron beam and polarized or aligned nuclear target are briefly considered. The new method of dynamic nuclear alignment (DNA) of quadrupolar nuclei is proposed. An implementation of this method can significantly increase the number of aligned nuclei accessible for TRI v

Sheng Li, Yishi Duan

The index theorem of Euler-Poincaré characteristic of manifold with boundary is given by making use of the general decomposition theory of spin connection. We shows the sum of the total index of a vector field $ϕ$ and half the total of the projective vector field of $ϕ$ on the boundary equals the Euler-Poincaré characteristic of the manifold. Detailed discus

Jan Arthur Christophersen, Trond Stoelen Gustavsen

The purpose of this paper is to prove dimension formulas for $T^1$ and $T^2$ for rational surface singularities. These modules play an important role in the deformation theory of isolated singularities in analytic and algebraic geometry. The first may be identified as the Zariski tangent space of the versal deformation of the singularity; i.e. it is the spac

Theodore Stanford, Rolland Trapp

We observe that most known results of the form "v is not a finite-type invariant" follow from two basic theorems. Among those invariants which are not of finite type, we discuss examples which are "ft-independent" and examples which are not. We introduce (n,q)-finite invariants, which are generalizations of finite-type invariants based on Fox

Rob Kirby, Paul Melvin

Canonical framings and stable framings for the tangent bundle of a spin 3-manifold are introduced, and illustrated by a number of familiar examples. Methods for constructing canonical framings, and for comparing them with other naturally defined framings, are discussed.

Mark E. Kidwell, Theodore B. Stanford

We give an upper bound on the z-degree of the Kauffman polynomial of a link, using bridges of length greater than one which are separated in some tangle decomposition of a link diagram. We construct some examples by wiring together rational tangles.

Mika Oksanen

Using techniques developed in the revision theory of truth, I build a model for the set theory NF (New Foundations) developed by Quine in ZF, therefore proving its consistency relative to ZF. The model is essentially a term model; the sets of NF are interpreted as equivalence classes of closed stratified terms of a language that is a slight modification of t

Diane Maclagan

A boolean term order is a total order on subsets of [n]={1,...,n} such that \emptyset < alpha for all nonempty alpha contained in [n], and alpha < beta implies alpha \cup gamma < beta \cup gamma for all gamma which do not intersect alpha or beta. Boolean term orders arise in several different areas of mathematics, including Gröbner basis theory for the exter

Martin Markl

The aim of this brief note is mainly to advocate our approach to homotopy algebras based on the minimal model of an operad. Our exposition is motivated by two examples which we discuss very explicitly - the example of strongly homotopy associative algebras and the example of strongly homotopy Lie algebras. We then indicate what must be proved in order to sho

Reinhard Oehme

The general method of the reduction in the number of coupling parameters is discussed. Using renormalization group invariance, theories with several independent couplings are related to a set of theories with a single coupling parameter. The reduced theories may have particular symmetries, or they may not be related to any known symmetry. The method is more

R. D&#39;Auria, S. Ferrara amd M. A. Lledó

We consider general properties of central charges of zero branes and associated duality invariants, in view of their double role, on the bulk and on the world volume (quantum-mechanical) theory. A detailed study of the BPS condition for the mass spectrum arising from toroidal compactifications is given for 1/2, 1/4 and 1/8 BPS states in any dimensions. As a

A. Mironov

We present a review of the results on the associativity algebras and WDVV equations associated with the Seiberg-Witten solutions of N=2 SUSY gauge theories. It is mostly based on the integrable treatment of these solutions. We consider various examples of the Seiberg-Witten solutions and corresponding integrable systems and discuss when the WDVV equations ho

A. Morozov

Review of the theory of effective actions and the hypothetical origins of integrability in Seiberg-Witten theory.

I. Pesando

We quantize the type IIB GS string action on AdS3 X S3 with pure NSNS background and we show that it is equivalent to Liouville with periodic boundary condition plus free spacetime fermions.

M. Porrati, A. Starinets

Recently, it has been conjectured that supergravity solutions with two asymptotically AdS regions describe the RG flow of a 4-d field theory from a UV fixed point to an interacting IR fixed point. In this paper we lend support to this conjecture by showing that, in the UV (IR) limit, the two-point function of a minimally-coupled scalar field depends only on

F. Ferrari, I. Lazzizzera

In this work a field theoretical model is constructed to describe the statistical mechanics of an arbitrary number of topologically linked polymers in the context of the analytical approach of Edwards. As an application, the effects of the topological interactions are studied in the one loop approximation. A natural way to include in the treatment also more

V. I. Ritus

This paper discusses the symmetry of the wave field that lies to the right and left of a two-sided accelerated mirror in 1 + 1 space and satisfies a single condition on it. The symmetry is accumulated in the Bogolyubov matrix coefficients $α$ and $β$ that connect the two complete sets of solutions of the wave equations. The amplitudes of the quantum processe

G. Delfino

We consider the two-dimensional dilute q-state Potts model on its first order phase transition surface for 0<q\leq 4. After determining the exact scattering theory which describes the scaling limit, we compute the two-kink form factors of the dilution, thermal and spin operators. They provide an approximation for the correlation functions whose accuracy is i

D. Minic

We review the construction of the unitary supermultiplets of the ${\cal{N}}=8$ d=5 anti-de Sitter (AdS_5) superalgebra SU(2,2|4), which is the symmetry group of the type IIB superstring theory on $AdS_5 \times S^5$, using the oscillator method.

E. D&#39;Hoker, D. H. Phong

We summarize recent results on the construction of Lax pairs with spectral parameter for the twisted and untwisted elliptic Calogero-Moser systems associated with arbitrary simple Lie algebras, their scaling limits to Toda systems, and their role in Seiberg-Witten theory. We extend part of this work by presenting a new parametrization for the spectral curves

J. C. Montero, V. Pleitez, M. C. Rodriguez

Several left-right parity violating asymmetries in lepton-lepton scattering in fixed target and collider experiments are considered as signals for doubly charged vector bosons (bileptons).

Zoheir Aouissat

Using the concept of dynamical mappings, two symmetry conserving nonperturbative approaches are presented. The first is based on the 1/N-expansion and sorted out using Holstein-Primakoff mapping. The second consists of dynamically mapping the canonical fields into the corresponding currents. It is argued, either by comparing the Fock spaces or the observable

I. F. Ginzburg, A. Schiller

If a heavy Dirac monopole exists, the light-to-light scattering below the monopole production threshold is enhanced due to strong coupling of monopoles to photons. At the next Linear Collider with electron beam energy 250 GeV this photon pair production could be observable at monopole masses less than 2.5-6.4 TeV in the $e^+e^-$ mode or 3.7-10 TeV in the $γγ

Bing An Li

The study of a EW theory without spontaneous symmetry breaking is presented. A new symmetry breaking, axial-vector symmetry breaking, is found. M^{2}_{W}=1/2g^{2}m^{2}_{t}, m^{2}_{Z}=ρm^{2}_{W}/cos^{2} θ, and G_{F}=1/(2\sqrt{2}m^{2}_{t}) are obtained and they agree with data. It has been proved that the theory is renormalizable and unitary.

Pervez Hoodbhoy

It is shown that the amplitude for the scattering of a heavy quarkonium system from a nucleon near threshold is completely determined by the fraction of angular momentum, as well as linear momentum, carried by gluons in the nucleon. A form for the quarkonium-nucleon non-relativistic potential is derived.

Stephan Paul

This paper reviews the experimental status of heavy baryons. It covers the aspec ts of production, spectroscopy and decay presenting recent results obtained in this fi eld. It closes with an outlook on further work on and with heavy baryons and their po ssible role for other measurements.

J. M. LoSecco

Recent observations of variability in the ``atmospheric neutrino&#39;&#39; rate place constraints on possible explanations of the atmospheric neutrino anomaly. Many proposed solutions to the problem are static and can not be adapted to the temporal dependence observed. Nonatmospheric sources may be needed to explain the variations.

Charanjit Singh Aulakh

We argue that with the discovery of neutrino mass effects at Super-Kamiokande there is a clear logical chain leading from the Standard Model through the MSSM and the recently developed Minimal Left Right Supersymmetric models with a renormalizable see-saw mechanism for neutrino mass to Left Right symmetric SUSY GUTS : in particular, SO(10) and $SU(2)_L \time

Patrick Aurenche, Francois Gelis, Randy Kobes, Haitham Zaraket

We calculate the Compton and annihilation production of a soft static lepton pair in a quark-gluon plasma in the two-loop approximation. We work in the context of the effective perturbative expansion based on the resummation of hard thermal loops. Double counting is avoided by subtracting appropriate counterterms. It is found that the two-loop diagrams give

Zoltan Ligeti, Michael Luke, Aneesh V. Manohar, Mark B. Wise

The photon energy spectrum in inclusive weak radiative B -> X_s gamma decay is computed to order alpha_s^2 beta_0. This result is used to extract a value for the HQET parameter $\barΛ$ from the average <1-2E_γ/m_B>, and a value of the parameter $λ_1$ from <(1-2E_γ/m_B)^2>. An accurate measurement of <1-2E_γ/m_B> can determine the size of the nonperturbative

M. Maris, S. T. Petcov

We study in detail the threshold energy dependence of the seasonal variation effect in the energy integrated solar neutrino signal of the Super-Kamiokande detector in the case of the $ν_{e}\leftrightarrow ν_{μ,τ}$ vacuum oscillation (VO) solution of the solar neutrino problem. We show, in particular, that for the values of $Δm^2$ and $\sin^22θ$ from the VO s

Peter Boyle

We present results of simulations of the quenched quarkonium spectrum at two values of the lattice spacing and for quark masses around $m_c$ using the tadpole improved clover action. Attention is focussed on the lowest lying S and P states, and the triplet fine structure is obtained for the first time using a relativistic action.

Jochen Heitger

We present a scaling investigation of some correlation functions in $\Or(a)$ improved quenched lattice QCD. In particular, as one observable the renormalized PCAC quark mass is considered. Others are constructed such that they become the vector meson mass and the pseudoscalar meson decay constant when the volume is large. For the present discussion we remain

I. L. Bogolubsky, L. Del Debbio, V. K. Mitrjushkin

We discuss the influence of Dirac sheets and zero-momentum modes on the gauge variant photon correlators $Γ(τ;\vp)$ with $\vp\ne 0$ and $\vp =0$ in the pure gauge U(1) theory. A special attention has been paid to the $β$- and volume-dependence of this influence. Numerical simulations are performed on $12\times 6^3$ and $24\times 12^3$ lattices at different $

I. Campos, A. Feo, R. Kirchner, S. Luckmann

In a numerical Monte Carlo simulation of SU(2) Yang-Mills theory with light dynamical gluinos the low energy features of the dynamics as confinement and bound state mass spectrum are investigated. The motivation is supersymmetry at vanishing gluino mass. The performance of the applied two-step multi-bosonic dynamical fermion algorithm is discussed.

F. Abe

We present a measurement of the mass difference Delta m_d for the B0 meson and the statistical power of the b flavor tagging methods used. The measurement uses 90 (1/pb) of data from p p-bar collisions at sqrt[s] = 1.8 TeV collected with the CDF detector. An inclusive lepton trigger is used to collect a large sample of B hadron semileptonic decays. The mass

A. Castera, J. Dumarchez, C. Lachaud, F. Vannucci

An exploratory search for an anomalous energy deposition by neutrinos in a germanium crystal was performed in the CERN high energy neutrino beam. No signal was found and a limit is set at a level of about 10^-12 of the normal dE/dx for a minimum ionizing particle.

Norbert Schmitz

Recent results on neutrino oscillations and neutrino masses are presented. The most exciting news are the Super-Kamiokande measurements of atmospheric neutrinos, which show evidence for the neutrinos being massive. Various possible schemes for the neutrino masses are discussed.