August 1996 arXiv papers — page 7

T. C. Brooks, M. E. Convery, W. L. Davis, K. W. Delsignore

We report on the progress of a search for disoriented chiral condensates (DCCs) in the far forward region at sqrt(s)=1.8 TeV. MiniMax is a small collider experiment situated at the C0 interaction region of the Tevatron and has been designed to measure the ratio of charged to neutral pions produced at eta near 4.1. The distribution of this ratio is expected t

Mark Israelit

Including torsion in the geometric framework of the Weyl-Dirac theory we build up an action integral, and obtain from it a gauge covariant (in the Weyl sense) general relativistic massive electrodynamics. Photons having an arbitrary mass, electric, and magnetic currents (Dirac's monopole) coexist within this theory. Assuming that the space-time is torsio

E. Amic, J. M. Luck, Th. M. Nieuwenhuizen

The multiple scattering of scalar waves in diffusive media is investigated by means of the radiative transfer equation. This approach, which does not rely on the diffusion approximation, becomes asymptotically exact in the regime of most interest, where the scattering mean free path $\ell$ is much larger than the wavelength $λ_0$. Quantitative predictions ar

P. Ao, Y. Tan, X. -M. Zhu

Since effectively the local contact vortex velocity dependent part of the Magnus force in a Josephson junction array is zero in the classical limit, we predict zero classical Hall effect. In the quantum limit because of the geometric phases due to the finite superfluid density at superconductor grains, rich and complex Hall effect is found in this quantum re

D. J. Thouless, P. Ao, Q. Niu

We describe an exact derivation of the total nondissipative transverse force acting on a quantized vortex moving in a uniform background. The derivation is valid for neutral boson or fermion superfluids, provided the order parameter is a complex scalar quantity. The force is determined by the one-particle density matrix far away from the vortex core, and is

Nathan Argaman

The conductance of a normal-metal mesoscopic system in proximity to superconducting electrode(s) is calculated. The normal-metal part may have a general geometry, and is described as a ``circuit'' with ``leads'' and ``junctions''. The junctions are each ascribed a scattering matrix which is averaged over the circular orthogonal ensemb

F. D. A. Aarão Reis, S. L. A. de Queiroz, Raimundo R. dos Santos

We address the issue of universality in two-dimensional disordered Ising systems, by considering long, finite-width strips of ferromagnetic Ising spins with randomly distributed couplings. We calculate the free energy and spin-spin correlation functions (from which averaged correlation lengths, $ξ^{ave}$, are computed) by transfer-matrix methods. An {\it ans

Jürgen König, Jörg Schmid, Herbert Schoeller, Gerd Schön

We study resonant tunneling through a single-level quantum dot in the presence of strong Coulomb repulsion beyond the perturbative regime. The level is either spin-degenerate or can be split by a magnetic field. We, furthermore, discuss the influence of a bosonic environment. Using a real-time diagrammatic formulation we calculate transition rates, the spect

T. B. Liverpool, S. F. Edwards

We present a statistical model of a meandering river on an alluvial plane which is motivated by the physical non-linear dynamics of the river channel migration and by describing heterogeneity of the terrain by noise. We study the dynamics analytically and numerically. The motion of the river channel is unstable and we show that by inclusion of the formation

J. P. Clerc, G. Giraud, J. M. Luck, Th. Robin

Electrical and optical properties of binary inhomogeneous media are currently modelled by a random network of metallic bonds (conductance $σ_0$, concentration $p$) and dielectric bonds (conductance $σ_1$, concentration $1-p$). The macroscopic conductivity of this model is analytic in the complex plane of the dimensionless ratio $h=σ_1/σ_0$ of the conductance

Y. Morita, M. Kohmoto, K. Maki

Using the Bogoliubov-de Gennes equation, we study quasi-particle spectra around a single vortex in a d-wave superconductor, where a magnetic field is parallel to the c-axis. In the temperature region where the Ginzburg-Landau theory is valid, we find that the local density of states preserves a circular symmetry when the symmetry of the superconducting order

N. Schultka, E. Manousakis

We study numerically the influence of the substrate (boundary conditions) on the finite--size scaling properties of the superfluid density $ρ_s$ in superfluid films of thickness $H$ within the XY model employing the Monte Carlo method. Our results suggest that the jump $ρ_s H/T_c$ at the Kosterlitz--Thouless transition temperature $T_c$ depends on the bounda

S. Murat Oztaner

In this thesis, morphological description of Turkish is encoded using the two-level model. This description is made up of the phonological component that contains the two-level morphophonemic rules, and the lexicon component which lists the lexical items and encodes the morphotactic constraints. The word grammar is expressed in tabular form. It includes the

J. Gallego, J. Zamorano, M. Rego, A. G. Vitores

A spectroscopic analysis of the whole sample of H$α$ Emission-Line Galaxies (ELGs) contained in the lists 1 & 2 of the Universidad Complutense de Madrid (UCM) objective-prism survey is presented. A significant fraction (59\%) of star-forming galaxies with low ionization or high extinction properties has been found. This kind of ELG is only incompletely detec

Zoltan Haiman, Martin Rees, Abraham Loeb

We investigate the ability of primordial gas clouds to retain molecular hydrogen (H_2) during the initial phase of the reionization epoch. We find that before the Stromgren spheres of the individual ionizing sources overlap, the UV background below the ionization threshold is able to penetrate large clouds and suppress their H_2 abundance. The consequent lac

I. M. Hook, R. G. McMahon, M. J. Irwin, C. Hazard

We present optical spectroscopic data for a complete sample of 161 S_5GHz >= 0.2 Jy, flat-spectrum radio sources. The sources were observed as part of a survey for high redshift, radio-loud quasars, and were selected for spectroscopic follow-up based on criteria of red optical colour and unresolved optical counterpart, as measured from APM scans of POSS-I pl

George Jacoby

The planetary nebula luminosity function (PNLF) technique for determining distances to galaxies now has been applied to 34 galaxies, including 6 in the Virgo cluster and 3 in the Fornax cluster. Of these, 16 galaxies are late-type or spirals and presumably contain Cepheid variables useful for verifying the PNLF method. For 7 of these galaxies, Cepheid distan

J. L. Collett, S. N. Dutta, N. W. Evans

The shape of galaxies depends on their orbital populations. These populations change through capture into and escape from resonance. Capture problems fall into distinct cases depending upon the shape of the potential well. To visualise the effective potential well for orbital capture, a diagrammatic approach to the resonant perturbation theory of Born is pre

Peter A. Thomas

I discuss the multiphase nature of the intracluster medium whose neglect can lead to overestimates of the baryon fraction of clusters by up to a factor of two. The multiphase form of the cooling flow equations are derived and reduced to a simple form for a wide class of self-similar density distributions. It is shown that steady-state cooling flows are \emph

H. Oberhummer, H. Herndl, T. Rauscher, H. Beer

Neutron--induced nucleosynthesis plays an important role in astrophysical scenarios like in primordial nucleosynthesis in the early universe, in the s--process occurring in Red Giants, and in the $α$--rich freeze--out and r--process taking place in supernovae of type II. A review of the three important aspects of neutron--induced nucleosynthesis is given: as

T. Mitsui, K. Maki, S. Orito

We calculate the solar-modulated energy spectra of cosmic-ray antiprotons ($\bar{p}$'s) from two candidate primary sources, i.e., evaporating primordial black holes and the annihilation of neutralino dark matter, as well as for the secondary $\bar{p}$'s produced by cosmic-ray interactions with interstellar gas. A large enhancement toward the solar mi

K. Coble, S. Dodelson, J. Frieman

Models of structure formation with a cosmological constant $Λ$ provide a good fit to the observed power spectrum of galaxy clustering. However, they suffer from several problems. Theoretically, it is difficult to understand why the cosmological constant is so small in Planck units. Observationally, while the power spectra of cold dark matter plus $Λ$ models

Judith G. Cohen, Lennox L. Cowie, David W. Hogg, Antoinette Songaila

We present initial results from a redshift survey carried out with the Low Resolution Imaging Spectrograph on the 10~m W. M. Keck Telescope in the Hubble Deep Field. In the redshift distribution of the 140 extragalactic objects in this sample we find 6 strong peaks, with velocity dispersions of ${\sim}400${\kms}. The areal density of objects within a particu

L. Barbieri-Viale

After the work of Bloch and Srinivas on correspondences and algebraic cycles we begin the study of a birational class of algebraic varieties determined by the property that a multiple of the diagonal is rationally equivalent to a cycle supported on proper subschemes.

R. Barlow

Two cycles on a projective variety over an algebraically closed field are shown to be rationally equivalent if and only if their difference equals a difference of complete intersections of a certain kind. Some of Bloch's conjectures for zero-cycles on surfaces can be restated more geometrically, which leads to several questions.

Philippe Fischer, Gary Bernstein, George Rhee, J. Anthony Tyson

Multiply gravitationally lensed objects with known time delays can lead to direct determinations of H$_0$ independent of the distance ladder if the mass distribution of the lens is known. Currently, the double QSO 0957+561 is the only lensed object with a precisely known time delay. The largest remaining source of systematic error in the H$_0$ determination

D. Anselmi, D. Z. Freedman, M. T. Grisaru, A. A. Johansen

We study the operator product algebra of the supercurrent J and Konishi superfield K in four-dimensional supersymmetric gauge theories. The Konishi superfield appears in the JJ OPE and the algebra is characterized by two central charges c and c' and an anomalous dimension h for K. In free field (one-loop) approximation, c~3N_v+N_χand c'~N_χ, where N_

Renyue Cen

We pay particular attention to the high end of the $\lya$ optical depth distribution of a quasar spectrum. Based on the flux distribution (Miralda-Escudé et al 1996), a simple yet seemingly cosmological model -differentiating statistic, $Δ_{τ_0}$ -- the cumulative probability of a quasar spectrum with $\lya$ optical depth greater than a high value $τ_0$ -- i

F. Niedermayer

The main strategies to reduce lattice artifacts for spin models, gauge fields, free fermions and QCD are discussed.

Andrzej Czarnecki, Johann H. Kühn

We present an analysis of two-loop mixed QCD and electroweak corrections to the decay of the Z boson into light quarks. We find that the naive factorization of QCD and electroweak corrections does not describe correctly the two-loop effects. The nonfactorizable corrections shift the width of the Z boson by approximately -0.55(3) MeV and increase the central

F. Krüger, L. M. Sehgal

The decay $b\to d e^+e^-$ has an amplitude containing comparable contributions proportional to $V_{tb}V_{td}^{*}$, $V_{cb}V_{cd}^{*}$ and $V_{ub}V_{ud}^{*}$. These pieces involve different unitarity phases produced by $c\bar{c}$ and $u\bar{u}$ loops. The simultaneous presence of different CKM phases and different dynamical phases leads to a calculable asymme

Charles A. Nelson, Michael G. Gartley

There is a simple, multi-sheet Riemann surface associated with e_q(z)&#39;s inverse function ln_q(w) for 0< q < 1. A principal sheet for ln_q(w) can be defined. However, the topology of the Riemann surface for ln_q(w) changes each time &#34;q&#34; increases above the collision point of a pair of the turning points of e_q(x). There is also a power series repr

R. Walser, J. I. Cirac, P. Zoller

A method to determine the state of a single quantized cavity mode is proposed. By adiabatic passage, the quantum state of the field is transfered completely onto an internal Zeeman sub-manifold of an atom. Utilizing a method of Newton and Young, we can determine this angular momentum state uniquely, by a finite number of magnetic dipole measurements with Ste

K. -I. Izawa, T. Yanagida

We consider a natural new inflationary model in broken supergravity based on an R symmetry. The model predicts a concrete relation between the amplitude of primordial density fluctuations and the scale of supersymmetry breaking. The observed value of the density fluctuations is obtained for the gravitino mass of order the weak scale along with a power-law sp

Wu-Pei Su, Yong-Shi Wu, Jian Yang

In this paper we propose a new assignment for mutual exclusion statistics between quasielectrons and quasiholes in the fractional quantum Hall effect. In addition to providing numerical evidence for this assignment, we show that the physical origin of this mutual statistics is a novel hard-core constraint due to correlation between the distinguishable vortex

Koichi Funakubo

We report a recent attempt to relate $CP$ violation in the electroweak theory with two Higgs doublets to the baryon asymmetry generated at the electroweak phase transition, after surveying the scenario of the electroweak baryogenesis.

Y-K Zhou

The formulation of integrable models with open boundary conditions and the functional relations of fused transfer matrices are discussed. It is shown that finite-size corrections to the transfer matrices and unitarity relations of free energies can be obtained from the functional relations. Unitarity relations of surface free energies presented in previous p

C. B. Muratov

The universal equations describing collective oscillations of the multidomain patterns of small period in an arbitrary $d$-dimensional reaction-diffusion system of the activator-inhibitor type are asymptotically derived. It is shown that not far from the instability leading to the formation of the pulsating multidomain pattern the oscillations of different d

W. Satuła, R. Wyss

A cranked mean-field model with two-body T=1 and T=0 pairing interactions is presented. Approximate projection onto good particle-number is enforced via an extended Lipkin-Nogami scheme. Our calculations suggest the simultaneous presence of both T=0 and T=1 pairing modes in N=Z nuclei. The transitions between different pairing phases are discussed as a funct

G. Q. Li, C. M. Ko, G. E. Brown

Using a relativistic transport model to describe the expansion of the fire-cylinder formed in the initial stage of heavy-ion collisions at SPS/CERN energies, we study the production of dileptons with mass below about 1 GeV from these collisions. The initial hadron abundance and their momentum distributions in the fire-cylinder are determined by following the

Mark Rudelson

Let $y$ be a random vector in \rn, satisfying $$ \Bbb E \, \tens{y} = id. $$ Let $M$ be a natural number and let $y_1 \etc y_M$ be independent copies of $y$. We prove that for some absolute constant $C$ $$ \enor{\frac{1}{M} \sum_i \tens{y_i} - id} \le C \cdot \frac{\sqrt{\log M}}{\sqrt{M}} \cdot \left ( \enor{y}^{\log M} \right )^{1/ \log M}, $$ provided tha

G. Mikhalkin

A quadric in $\R P^3$ cuts a curve of degree 6 on a cubic surface in $\R P^3$. The papers classifies the nonsingular curves cut in this way on non-singular cubic surfaces up to homeomorphism. Two issues new in the study related to the first part of the 16th Hilbert problem appear in this classification. One is the distribution of the components of the curve

A. A. Kapustnikov, A. Pashnev, A. Pichugin

A new approach to the quantization of the relativistic kink - model around the solitonic solution is developed on the ground of the collective coordinates method. The corresponding effective action is proved to be the action of the nonminimal $d=1+1$ point - particle with curvature. It is shown that upon canonical quantization this action yields the spectrum

R. Rodriguez, Y. Hosotani, J. E. Hetrick, S. Iso

We evaluate the Polyakov loop and string tension at zero and finite temperature in $QED_2.$ Using bozonization the problem is reduced to solving the Schrödinger equation with a particular potential determined by the ground state. In the presence of two sources of opposite charges the vacuum angle parameter $θ$ changes by $2π(q/e)$, independent of the number

Werner Krauth, Matthias Staudacher

In this paper we numerically demonstrate that massless two-dimensional QCD is not integrable. To this aim, we explicitly solve the &#39;t Hooft integral equation for bound states by an adaptive spline procedure, and compute the decay amplitudes. These amplitudes significantly differ from zero except in all cases in which the decay also produces a pion.

Werner Nahm

Electric-magnetic duality allows to calculate the central charges of N=2 supersymmetric theories with massless hypermultiplets as derivatives of simple modular forms. The procedure reproduces the Seiberg-Witten results for N_f=0,2,3 in a uniform way, but indicates open problems for N_f=1.

Olivier de Mirleau

In this article we note that in a number of situations the operator product and the classical action satisfy a natural compatibility condition. We consider the interest of this condition to be twofold: First, the naturality (functoriality) of the compatibility condition suggests that it be used for geometrical applications of renormalized functional integrat

M. V. Terentiev, K. N. Zyablyuk

The vacuun configuration of dual supergravity in ten dimensions with one-loop fivebrane corrections is analyzed. It is shown that the compactification of this theory with rather general conditions to six-dimensional space leads to zero value of cosmological constant.

Shijong Ryang

The self-duality of Dirichlet $3$-brane action under the $SL(2,R)$ duality transformation of type IIB superstring theory is shown in the Hamiltonian form of the path integral for the partition function by performing the direct integration with respect to the boundary gauge field. Through the integration in the phase space the canonical momentum conjugate to

J. R. Pelaez

Chiral lagrangians provide a model independent description of the strongly interacting symmetry breaking sector. In this work it is first reviewed the LHC sensitivity to the chiral parameters (in the hardest case of non-resonant low-energy WW scattering). Later it is shown how to reproduce or predict the resonance spectrum by means of dispersion theory and t

Eric Braaten

In recent years, there have been significant developments in heavy quarkonium production, both in theory and in experiment. These developments may have important implications for the use of charmonium as a probe in heavy-ion collisions. A summary of these developments is presented below. Those interested in more details are referred to a recent review articl

A. V. Kotikov, D. V. Peshekhonov

We analyse the proton and deutron data on spin dependent asymmetry $A_1(x,Q^2)$ supposing the DIS structure functions $g_1(x,Q^2)$ and $F_3(x,Q^2)$ have the similar $Q^2$-dependence.

Michael A. Doncheski, Stephen Godfrey

We investigate the discovery potential for first generation leptoquarks at the LEP and LEP200 $e^+e^-$ colliders. We consider single leptoquark production via resolved photon contributions which offers a much higher kinematic limit than the more commonly considered leptoquark pair production process. This process also has the advantage that it is independent

R. Pittau

The present status of four-fermion calculations and event generators for LEP2 physics is reviewed. Perspectives for future improvements are given.

A. J. Buras, M. Jamin, M. E. Lautenbacher

We update our 1993 analysis of the CP violating ratio $\epe$ in view of the changes in several input parameters, in particular the improved value of the top quark mass. We also investigate the strange quark mass $m_s$ dependence of $\epe$ in view of rather low values found in the most recent lattice calculations. A simple scanning of the input parameters wit

W. Bernreuther, A. Brandenburg, P. Overmann

We show that the CP-violating dipole form factors of the tau lepton can be of the order of $α/π$ in units of the length scale set by the inverse $Z$ boson mass. We propose a few observables which are sensitive to these form factors at LEP2 and higher e^+e^- collision energies.

N. V. Krasnikov

The masses of vector supermultiplet and of the Higgs supertriplet in standard supersymmetric SU(5) model are calculated. Taking into account uncertainties related with the initial coupling constants and threshold corrections we find that in supersymmetric SU(5) model the scale of the supersymmetry breaking could be up to 50 Tev. We find that in the extension

Kacper Zalewski

The new approach to decays of heavy quarkonia, based on factorization and expansions in powers of the relative velocity of the valence quarks is reviewed.

S. Lupia

The recent LEP-1.5 data on charged particle inclusive energy spectra are analyzed within the analytical QCD approach based on Modified Leading Log Approximation plus Local Parton Hadron Duality. The shape, the position of the maximum and the cumulants moments of the inclusive energy spectrum are well described within this model. The sensitivity of the result

C. Bernard, T. Blum, T. A. DeGrand, C. DeTar

We report on results from three spectrum calculations with staggered quarks: 1) a quenched calculation with the standard action for the gluons and quarks; 2) a quenched calculation with improved actions for both the gluons and quarks; and 3) a calculation with two flavors of dynamical quarks using the standard actions for the gluons and quarks.

Bas van den Heuvel

We study the non-perturbative effects of the global features of the configuration space for SU(2) gauge theory on the three-sphere. The strategy is to reduce the full problem to an effective theory for the dynamics of the low-energy modes. By explicitly integrating out the high-energy modes, the one-loop correction to the effective hamiltonian is obtained. I

F. Karsch, M. Lütgemeier, A. Patkòs, J. Rank

The non-perturbative input necessary for the determination of the ${\cal O}(g^6)$ part of the weak coupling expansion of the free energy density for SU(2) and SU(3) gauge theories is estimated. Although the perturbative information completing the contribution to this order is missing, we give arguments that the magnetic fluctuations are dominated by screened

J. Engels, F. Karsch, E. Laermann, C. Legeland

We determine the critical couplings and the critical exponents of the finite temperature transition in SU(2) and SU(3) pure gauge theory in (2+1) dimensions. We also measure Wilson loops at $T=0$ on a wide range of $β$ values using APE smearing to improve the signal. We extract the string tension $σ$ from a fit to large distances, including a string fluctuat

Hildegard Meyer-Ortmanns

The current understanding of finite temperature phase transitions in QCD is reviewed. A critical discussion of refined phase transition criteria in numerical lattice simulations and of analytical tools going beyond the mean-field level in effective continuum models for QCD is presented. Theoretical predictions about the order of the transitions are compared

G. S. Bali, U. Glassner, S. Gusken, H. Hoeber

We present first results on masses of the scalar and tensor glueballs as well as of the torelon from simulations of QCD with two light flavours of Wilson fermions. The gauge configurations of extent 16^3*32 at beta = 5.6 and kappa = 0.156, 0.157 and 0.1575 have been generated as part of the SESAM collaboration programme. The present lattice resolutions corre

Nathalie Deruelle, Joseph Katz, Jean-Philippe Uzan

We show the relation between Traschen&#39;s integral equations and the energy, and ``position of the centre of mass&#39;&#39;, of the matter perturbations in a Robertson-Walker spacetime. When the perturbations are ``localised&#39;&#39; we get a set of integral constraints that includes hers. We illustrate them on a simple example.

Alan D. Rendall

The main result of this paper is a proof that there are examples of spatially compact solutions of the Einstein-dust equations which only exist for an arbitrarily small amount of CMC time. While this fact is plausible, it is not trivial to prove. It is necessary to obtain a lower bound for the lapse function of a CMC foliation in a suitable class of inhomoge

A. S. Mel&#39;nikov

The dynamics of tilted vortex lines in Josephson-coupled layered superconductors is considered within the time-dependent Ginzburg-Landau theory. The frequency and angular dependences of the complex-valued vortex mobility $μ$ are studied. The components of the viscosity and inertial mass tensors are found to increase essentially for magnetic field orientation

Richard Sproat

We present a model of text analysis for text-to-speech (TTS) synthesis based on (weighted) finite-state transducers, which serves as the text-analysis module of the multilingual Bell Labs TTS system. The transducers are constructed using a lexical toolkit that allows declarative descriptions of lexicons, morphological rules, numeral-expansion rules, and phon

Stefanie Wachter, Bruce Margon

The intense galactic X-ray source GX 349+2 (Sco X-2) belongs to the class of persistently bright low-mass X-ray binaries called Z-sources. GX 349+2, although observed in X-rays for more than 30 years, has only recently been optically identified with a 19th mag star. Of the six known Z-sources, only two (Sco X-1 and Cyg X-2) have been studied in the optical.

J. J. Mohr, M. J. Geller, G. Wegner

We use 189 new radial velocities, an $R$ band CCD mosiac, archival X-ray images, and gas temperatures to study substructure, masses, luminosity functions, and mass-to-light ratios in A2626 and A2440. The symmetric X-ray emission from A2626 suggests a relaxed, single-component system; however, 159 redshifts reveals a complex, three component cluster at cz~17,

Rychard J. Bouwens, Joseph Silk

A constant age population of blue galaxies, postulated in the model of Gronwall & Koo (1995), seems to provide an attractive explanation of the excess of very blue galaxies in the deep galaxy counts. Such a population may be generated by a set of galaxies with cycling star formation rates, or at the other extreme, be maintained by the continual formation of

Patrick Petitjean

Absorption line systems are luminosity unbiased tracers of the spatial distribution of baryons over most of the history of the Universe. I review the importance of studying the clustering properties of the absorbers and the impact of VLT in this subject. The primary aim of the project is to track the evolution of the structures of the Universe back in time.

R. Sunyaev, E. Churazov

In many astrophysical objects an account for scattering of the X-ray fluorescent and resonance lines of iron ions by the electrons, bound in atomic and molecular hydrogen is important. Specific distortions of the scattered line profile spectrum appear in comparison with scattering by free electrons. Analysis of scattered line spectra may provide information

Raymond E. White, William C. Keel, Christopher J. Conselice

We describe the use of partially overlapping galaxies to provide direct measurements of the effective absorption in galaxy disks, independent of assumptions about internal disk structure. The non-overlapping parts of the galaxies and symmetry considerations are used to reconstruct, via differential photometry, how much background galaxy light is lost in pass

M. J. Duff

Superunification underwent a major paradigm shift in 1984 when eleven-dimensional supergravity was knocked off its pedestal by ten-dimensional superstrings. This last year has witnessed a new shift of equal proportions: perturbative ten-dimensional superstrings have in their turn been superseded by a new non-perturbative theory called {\it $M$-theory}, which

Andreas Knaebchen, Yehoshua Levinson, Ora Entin-Wohlman

We study theoretically the piezoelectric interaction of a surface acoustic wave (SAW) with a two-dimensional electron gas confined to an isolated quantum dot. The electron motion in the dot is diffusive. The electron-electron interaction is accounted for by solving the screening problem in real space. Since the screening in GaAs/AlGaAs heterostructures is st

K. Becker, M. Becker, D. R. Morrison, H. Ooguri

We derive in the SCFT and low energy effective action frameworks the necessary and sufficient conditions for supersymmetric cycles in exceptional holonomy manifolds and Calabi-Yau 4-folds. We show that the Cayley cycles in $Spin(7)$ holonomy eight-manifolds and the associative and coassociative cycles in $G_2$ holonomy seven-manifolds preserve half of the sp

L. M. Pismen

I consider a bistable reaction-diffusion system on the interface of deep fluid interacting with Marangoni flow. The method of matched asymptotic expansions is used to resolve the singularity at a sharp interface between the alternative states, and to compute the self-induced flow velocity advecting the domain boundary. It is shown that Marangoni flow serves

Naoyuki Haba

We analyze explicit CP violation in the Higgs sector of the next-to-minimal supersymmetric standard model which contains an additional gauge singlet field N. It is shown that there is no mixing among scalar and pseudoscalar Higgs fields in the two Higgs doublets, and scalar-pseudoscalar mixings could exist between two Higgs doublets and the singlet N, and be

Andrey V. Kravtsov

We have used integral two-point spatial correlation function and its second derivative to analyze the distribution of quasars in three very deep surveys published in the literature. Statistically significant ($\sim 2-3σ$) correlations were found at scales of $\sim 50-100h^{-1}$ Mpc in all of the analyzed surveys. We have used the friends-of-friends cluster a

J. Kwiecinski, S. C. Lang, A. D. Martin

We predict the rate of deep inelastic scattering (DIS) events containing an identified forward $π^0$ that is expected in the experiments at the HERA electron-proton collider, in order to see if this process can be used as an indicator of the underlying small $x$ dynamics. We determine the background due to deep inelastic events containing forward photons whi

N. R. Cooper, B. I. Halperin, Chin-Kun Hu, I. M. Ruzin

A recent theory has provided a possible explanation for the ``non-universal scaling&#39;&#39; of the low-temperature conductance (and conductivity) peak-heights of two-dimensional electron systems in the integer and fractional quantum Hall regimes. This explanation is based on the hypothesis that samples which show this behavior contain density inhomogeneiti

Dima Mozyrsky, Vladimir Privman, Steven P. Hotaling

We offer an alternative to the conventional network formulation of quantum computing. We advance the analog approach to quantum logic gate/circuit construction. As an illustration, we consider the spatially extended NOT gate as the first step in the development of this approach. We derive an explicit form of the interaction Hamiltonian corresponding to this

Valery Alexeev

Let J be the jacobian of a reduced projective curve C with nodes only. 1) We give a simple and natural definition for its many compactifications and show the connection with various other definitions appearing in the literature. 2) Among all compactifications we choose one canonical, and define a theta divisor on it. 3) We give two very explicit and simple d

Valery Alexeev, Iku Nakamura

We prove that a 1-dimnl family of abelian varieties with an ample sheaf defining principal polarization can be canonically compactified (after a finite base change) to a projective family with an ample sheaf. We show that the central fiber (P,L), which we call an SQAV, has a canonical Cartier theta divisor. We give a combinatorial definition for SQAVs and de

M. B. Plenio, V. Vedral, P. L. Knight

In this paper we show how the fault--tolerant error correction scheme recently proposed by DiVincenzo and Shor may be improved. Our scheme, unlike the earlier one, can also deal with a single error that might occur {\em during} the gate operations that are required for the implementation of the error correction and not only in--between the gates and hence pr

Anna Beliakova

Starting from the quantum group SL_q(2,C), we construct operator invariants of 3-cobordisms with spin structure, satisfying the requirements of a topological quantum field theory and refining the Reshetikhin--Turaev and Turaev--Viro models. We establish the relationship between these two refined models.

Edward P. Osipov

We continue the construction of the $:ϕ^4_4:$ quantum field theory. In this paper we consider the Wick kernel of the interacting quantum field. Using the complex structure and the Fock-Bargmann-Berezin-Segal integral representation we prove that this kernel defines a unique operator--valued generalized function on the space $\Sc^α(\R^4)$ for any $α<6/5,$ i.e

Kurt Riesselmann

The evaluation of high-energy cross sections involving the SM Higgs boson requires the use of the Higgs running coupling $λ(μ)$. Taking $μ$ to be equal to the center-of-mass energy $\sqrt{s}$ of the scattering process, the perturbative approach fails for relatively small values of the Higgs mass and coupling, $λ(\sqrt{s})\approx 2.2$. Performing an approxima

Kari Enqvist, Petteri Keränen, Jukka Maalampi, Hannes Uibo

We study the equilibration of the right-helicity states of light Dirac neutrinos in the early universe by solving the momentum dependent Boltzmann equations numerically. We show that the main effect is due to electroweak gauge boson poles, which enhance thermalization rates by some three orders of magnitude. The right-helicity states of tau neutrinos will be

Kouzou Nishida, Ikuo S. Sogami

We propose a phenomenological formula relating the Kobayashi-Maskawa matrix $V_{KM}$ and quark masses in a form $(m_d,\ m_s,\ m_b)\propto (m_u,\ m_c,\ m_t)V_{KM}$. The formula agrees with experimental data well and has an interesting geometric picture. The origin of such a formula is discussed in the standard model.

Dilip Kumar Ghosh, Sreerup Raychaudhuri, K. Sridhar

We study $t \bar t$ production in R-parity violating supersymmetry. The annihilation channel $q \bar q \rightarrow t \bar t$ gets new contributions from $t$-channel exchange of squarks or sleptons. With the data from Tevatron on $t \bar t$ production, we find that the squark- or slepton-exchange processes constrain the $B$-violating $λ&#39;&#39;$ couplings o

Walter Wilcox

A new calculation of the neutron electric form factor is described. Preliminary results for the connected part on a $20^{3}\times 32$ lattice are presented. The methods for calculating the disconnected part are briefly described.

Ph. deForcrand, M. Fujisaki, T. Hashimoto, S. Hioki

We study a coupling flow of pure QCD gauge system by using the Monte Carlo Renormalization Group method. A rough location of the renormalized trajectory in two coupling space is obtained. Also we compare 4 different actions; (a)standard Wilson, (b)Symanzik&#39;s, (c)Iwasaki&#39;s and (d)QCDTARO&#39;s. The rotational symmetry is restored better as an action g

A. A. Tseytlin

We discuss special supersymmetric extreme black holes in 4 and 5 dimensions which have regular horizons, non-zero entropy and can be interpreted as compactifications of BPS bound states of p-branes in 10 or 11 dimensions.

David Borthwick, Alejandro Uribe

We study two quantization schemes for compact symplectic manifolds with almost complex structures. The first of these is the Spin-c quantization. We prove the analog of Kodaira vanishing for the Spin-c Dirac operator, which shows that the index space of this operator provides an honest (not virtual) vector space semiclassically. We also introduce a new quant

M. Abolfath, L. Belkhir, N. Nafari

We study the quantum Hall states in the lowest Landau level for a single wide quantum well. Due to a separation of charges to opposite sides of the well, a single wide well can be modelled as an effective two level system. We provide numerical evidence of the existence of a phase transition from an incompressible to a compressible state as the electron densi

A. M. Aprelev, A. A. Lisachenko, R. Laiho, A. Pavlov

Electronic spectra of porous Si have been investigated in the region $<$4 eV below the Fermi level with specimens subjected to in situ oxygenation and thermal treatments. The significance of DOS to the photoluminescence and its degradation in porous Si is discussed. Fine structure of the photoelectron spectra is found from specimens heated in oxygen at 600 K

Valery Alexeev

1) Assuming log Minimal Model Conjecture, we give a construction of a complete moduli space of stable log pairs of arbitrary dimension generalizing directly the space M_{g,n} of pointed stable curves. Each stable pair has semi log canonical singularities. 2) We prove that a stable quasiabelian pair, defined by author and I.Nakamura as the limit of abelian va