September 1994 arXiv papers — page 7

Kimyeong Lee

We consider the dynamics of vortex strings and sound waves in superfluids in the phenomenological Landau-Ginzburg equation. We first derive the vortex equation where the velocity of a vortex is determined by the average fluid velocity and the density gradient near the vortex. We then derive the effective action for vortex strings and sound waves by the dual

Hidetoshi Fukuyama, Masao Ogata

It is shown that the energy $(\varepsilon)$ and momentum $(k)$ dependences of the electron self-energy function $ Σ(k, \varepsilon + i0) \equiv Σ^{R}(k, \varepsilon) $ are, $ {\rm Im} Σ^{R} (k, \varepsilon) = -a\varepsilon^{2}|\varepsilon - ξ_{k}|^{- γ(k)} $ where $a$ is some constant, $ξ_{k} = \varepsilon(k)-μ, \varepsilon(k)$ being the band energy, and the

Philip Phillips

I show here how the algebraic scaling of the Kondo temperature in a Luttinger liquid can be understood simply from the condition for the existence of the singlet (or triplet) bound state.

Frail, Kulkarni, Hurley, Fishman

We report on the results of a search for the radio counterpart to the bright gamma-ray burst of March 1, 1994. Using the Dominion Radio Astrophysical Observatory Synthesis Telescope sensitive, wide-field radio images at 1.4 GHz and 0.4 GHz were made of a region around GRB940301. A total of 15 separate radio images were obtained at each frequency, sampling a

Mark A. O'Dell, Peter M. Panagi, Martin A. Hendry, Andrew Collier-Cameron

We present statistically robust observational evidence which imposes new limits on dynamo saturation in young solar-type stars. These are inferred from the increasing amplitude of the V-band optical flux with rotation, caused by the filling of the disc with surface spots in a non-axisymmetric pattern. Assuming spot coverage acts as a tracer of the total magn

Clifford V. Johnson

A description is given of how to construct $(0,2)$ supersymmetric conformal field theories as coset models. These models may be used as non--trivial backgrounds for Heterotic String Theory. They are realised as a combination of an anomalously gauged Wess--Zumino--Witten model, right--moving supersymmetric fermions, and left--moving current algebra fermions.

R. Kallosh, T. Ortin

Extreme magnetic dilaton black holes are promoted to exact solutions of heterotic string theory with unbroken supersymmetry. With account taken of alpha' corrections this is accomplished by supplementing the known solutions with SU(2) Yang-Mills vectors and scalars in addition to the already existing Abelian U(1) vector field. The solution has a simple analy

HongSheng Zhao, David N. Spergel, R. Michael Rich

We compute the predicted optical depth and duration distribution of microlensing events towards Baade's window in a model composed of a Galactic disk and a bar. The bar model is a self-consistent dynamical model built out of individual orbits that has been populated to be consistent with the COBE maps of the Galaxy and kinematic observations of the Bulge

Shahn Majid

$*$-structures on quantum and braided spaces of the type defined via an R-matrix are studied. These include $q$-Minkowski and $q$-Euclidean spaces as additive braided groups. The duality between the $*$-braided groups of vectors and covectors is proved and some first applications to braided geometry are made.

Gil Gat, Alpan Raval, Rashmi Ray

The effective action for Q.E.D in external magnetic field is constructed using the method of inhomogeneity expansion. We first treat the non-relativistic case where a Chern-Simons like term is generated. We then consider the full relativistic theory and derive the effective action for the $A_μ$ fields. In the non-relativistic case we also add a 4-fermi type

Lynne H. Orr, W. J. Stirling

Top pairs produced at the Tevatron may be accompanied by extra jets due to radiation of soft gluons. Whether these jets should be included in top momentum reconstruction depends on the source of the gluons, which can be radiated off the initial partons, the final state $b$ quarks, or the intermediate top quarks. We compute soft gluon distributions and discus

Oleg A. Fonarev

We consider self-interacting scalar fields coupled to gravity. Two classes of exact solutions to Einstein's equations are obtained: the first class corresponds to the minimal coupling, the second one to the conformal coupling. One of the solutions is shown to describe a formation of a black hole in a cosmological setting. Some properties of this solution

Daniel Cangemi

In 1+1 dimensions, the Wheeler-DeWitt equation cannot be imposed owing to an anomaly in its commutator with the diffeomorphism constraint. A similar obstruction prevents also a semiclassical definition of a WKB local time. (Talk given at the 7th Marcel Grossman Meeting on General Relativity, Stanford, July 28, 1994.)

Shahn Majid

We give an overview of a new kind symmetry in physics which exists between observables and states and which is made possible by the language of Hopf algebras and quantum geometry. It has been proposed by the author as a feature of Planck scale physics. More recent work includes corresponding results at the semiclassical level of Poisson-Lie groups and at the

Shahn Majid

We recall the abstract theory of Hopf algebra bicrossproducts and double cross products due to the author. We use it to develop some less-well known results about the quantum double as a twisting, as an extension and as $q$-Lorentz group.

Charilaos Aneziris

We discuss the possibility of the existence of finite algorithms that may give distinct knot classes. In particular we present two attempts for such algorithms which seem promising, one based on knot projections on a plane, the other on placing knots on a cubic lattice.

Frédéric Bidegain, Georges Pinczon

Using duality and topological theory of well behaved Hopf algebras (as defined in [2]) we construct star-product models of non compact quantum groups from Drinfeld and Reshetikhin standard deformations of enveloping Hopf algebras of simple Lie algebras. Our star-products act not only on coefficient functions of finite-dimensional representations, but actuall

Moshé Flato, Daniel Sternheimer

We first review the introduction of star products in connection with deformations of Poisson brackets and the various cohomologies that are related to them. Then we concentrate on what we have called ``closed star products" and their relations with cyclic cohomology and index theorems. Finally we shall explain how quantum groups, especially in their rece

M. Flato, D. Sternheimer

This short summary of recent developments in quantum compact groups and star products is divided into 2 parts. In the first one we recast star products in a more abstract form as deformations and review its recent developments. The second part starts with a rapid presentation of standard quantum group theory and its problems, then moves to their completion b

M. Hage Hassan, M. Kibler

A bibliography on the Hurwitz transformations is given. We deal here, with some details, with two particular Hurwitz transformations, viz, the $\grq \to \grt$ Kustaanheimo-Stiefel transformation and its $\grh \to \grc$ compact extension. These transformations are derived in the context of Fock-Bargmann-Schwinger calculus with special emphasis on angular mome

Masoud Mohazzab

Based on the mechanism of cusp production on long cosmic strings, the baryon asymmetry caused by cusp annihilation has been calculated. The result is compatible with observation and stronger than the results from loops.

S. U. Ji, S. J. Sin

In the previous work, we investigated the rotation curves of galaxies assuming that the dark matter consists of ultra light boson appearing in $'$late time phase transition' theory. Generalizing this work, we consider the effect of visible matter and classify the types of rotation curves as we vary the fraction of the mass and extention of visible ma

Y. K. Lau

The objectivity of black hole entropy is discussed in the particular case of a Schwarzchild black hole. Using Jaynes' maximum entropy formalism and Euclidean path integral evaluation of partition function, it is argued that in the semiclassical limit when the fluctutation of metric is neglected, the black hole entropy of a Schwarzchild black hole is equa

M. S. Ferreira, R. B. Muniz, J. d'Albuquerque e Castro, D. M. Edwards

The effects on the exchange coupling in magnetic trilayers due to the presence of a spin-independent potential well are investigated. It is shown that within the RKKY theory no bias nor extra periods of oscillation associated with the depth of the well are found, contrary to what has been claimed in recent works. The range of validity of the RKKY theory is a

John J. Neumann, David Seibert, George Fai

We use a boost-invariant one-dimensional (cylindrically symmetric) fluid dynamics code to calculate thermal photon production in the central rapidity region of S+Au and Pb+Pb collisions at SPS energy ($\sqrt{s}=20$ GeV/nucleon). We assume that the hot matter is in thermal equilibrium throughout the expansion, but consider deviations from chemical equilibrium

Glenn D. Starkman, David N. Spergel

We estimate the event rate for excitation of atomic transition by photino-like dark matter. For excitations of several eV, this event rate can exceed naive cross-section by many orders of magnitude. Although the event rate for these atomic excitation is smaller than that of nuclear recoil off of non-zero spin nuclei, the photons emitted by the deexcitation a

Ziwei Lin, Miklos Gyulassy

The pre-equilibrium contribution to open charm production in nuclear collisions at $\sqrt{s}=200$ AGeV is calculated using three different models for the correlations between momentum and space-time coordinates. Ideal (Bjorken) correlation between the rapidity $y$ and space-time rapidity $η$ of mini-jet gluons suppresses greatly the pre-equilibrium yield and

F. Bonechi, N. Ciccoli, R. Giachetti, E. Sorace

After a preliminary review of the definition and the general properties of the homogeneous spaces of quantum groups, the quantum hyperboloid qH and the quantum plane qP are determined as homogeneous spaces of Fq(E(2)). The canonical action of Eq(2) is used to define a natural q-analog of the free Schro"dinger equation, that is studied in the momentum and

P. A. Blaga, O. Moritsch, M. Schweda, T. Sommer

The BRST transformations for gravity in Ashtekar variables are obtained by using the Maurer-Cartan horizontality conditions. The BRST cohomology in Ashtekar variables is calculated with the help of an operator $δ$ introduced by S.P. Sorella, which allows to decompose the exterior derivative as a BRST commutator. This BRST cohomology leads to the differential

Dirk H. Rischke, Miklos Gyulassy

Correlators of magnetic and electric field energy density are investigated for SU($N_c$) gauge theory at high temperatures $T$. At separations $z\leq 2/T$ the correlators are shown to be dominated by a power--law behavior even for finite gluon screening masses. This continuum behavior is well approximated on current $4\times 16^3$--lattices in the perturbati

Lee Mosher

This document is a practical guide to computations using an automatic structure for the mapping class group of a once-punctured, oriented surface $S$. We describe a quadratic time algorithm for the word problem in this group, which can be implemented efficiently with pencil and paper. The input of the algorithm is a word, consisting of ``chord diagrams'&

T. Hatsuda, H. Kuratsuji

We propose a dynamical mechanism to induce gauge fields in four dimensional space-time from a single scalar field or a spinor field in higher dimensions. The Born-Oppenheimer treatment of the extra dimensions is an essential ingredient in our approach. A possible applications of the idea to low dimensional condensed matter systems and high temperature field

Michael Grady

It is proposed that an event that constitutes a quantum measurement corresponds to the spontaneous breaking of a symmetry in the measuring device over time.

S. Hyun, Y. -S. Song, J. H. Yee

By calculating the response function, we study the Hawking radiation of massless Dirac fields in the (2+1)-dimensional black hole geometry. We find that the response function has Planck distributions, with the temperature that agrees with the previous results obtained for the scalar field cases. We also find the Green's functions in (2+1)-dimensional Ein

K. Ohta, H. Suzuki

We construct wave functions and Dirac operator of spin $1/2$ fermions on quantum four-spheres. The construction can be achieved by the q-deformed differential calculus which is manifestly $SO(5)_q$ covariant. We evaluate the engenvalue of the Dirac operator on wave functions of the spinors and show that we can define the chiral fermions in such a way that th

G. Moore

Contribution to the Proceedings of the International Congress of Mathematicians 1994. We review recent developments in the physics and mathematics of Yang-Mills theory in two dimensional spacetimes. This is a condensed version of a forthcoming review by S. Cordes, G. Moore, and S. Ramgoolam.

Marcus T. Grisaru, Marcia E. Wehlau

We present a complete solution of the constraints for two-dimensional, N=2 supergravity in N=2 superspace. We obtain explicit expressions for the covariant derivatives in terms of the vector superfield $H^m$ and, for the two versions of minimal (2,2) supergravity, a chiral or twisted chiral scalar superfield $ϕ$.

Robin G. Stuart

A Mathematica implementation of the program LERG-I is presented that performs the reduction of tensor integrals, encountered in one-loop Feynman diagram calculations, to scalar integrals. The program was originally coded in REDUCE and in that incarnation was applied to a number of problems of physical interest.

Felix Schlumpf

A relativistic constituent quark model is used to calculate the semileptonic beta decay of nucleons and hyperons. The parameters of the model, namely, the constituent quark mass and the confinement scale, are fixed by a previous calculation of the magnetic moments of the baryon octet within the same model. We discuss the momentum dependence of the form facto

I. I. Balitsky, V. M. Braun

We consider the instanton-induced cross section for production of a gluon jet with large transverse momentum in QCD and point out that Mueller's corrections corresponding to the rescattering of hard quanta are likely to remove contributions of large instantons, making this cross section well defined. Some speculations about possible phenomenological sign

Toby Falk, Keith A. Olive, Mark Srednicki

We calculate the relic density of very heavy, stable scalar neutrinos in the minimal supersymmetric standard model. We include all two-body final states, as well as the effects of co-annihilation with scalar electrons. We find that the sneutrino relic density is in the cosmologically interesting region $0.1\ltwidΩ_{\sn}h^2\ltwid 1.0$ for $550\gev\ltwid\msn\l

Rajesh Parwani, Claudio Coriano`

We elaborate on the computation of the pressure of thermal quantum electrodynamics, with massless electrons, to the fifth ($e^5$) order. The calculation is performed within the Feynman gauge and the imaginary-time formalism is employed. For the $e^4$ calculation, the method of Sudakov decomposition is used to evaluate some ultraviolet finite integrals which

A. Blotz, M. Praszalowicz, K. Goeke

Baryonic correlation functions are calculated within an effective chiral quark model motivated by the instanton liquid model of QCD. Using a flavour SU(3) symmetry for the local four-quark interaction and taking rotational zero modes for the quantization into account low-energy hadronic observables are in surprising agreement with experimental data. (Talk pr

Izumi Joichi, Masahiro Yamaguchi

We study properties of the Polonyi field in the renormalizable hidden sector in supergravity models. It is shown that radiative corrections induce a sizable coupling of the Polonyi field to gravitinos as well as raise its mass to an intermediate scale. We find it serves a solution of the Polonyi problem and show that the gravitino abundance produced by the P

Z. Bern, L. Dixon, D. C. Dunbar, D. A. Kosower

We identify a large class of one-loop amplitudes for massless particles that can be constructed via unitarity from tree amplitudes, without any ambiguities. One-loop amplitudes for massless supersymmetric gauge theories fall into this class; in addition, many non-supersymmetric amplitudes can be rearranged to take advantage of the result. As applications, we

Cai-Dian Lü, Jing-Liang Hu, Chong-Shou Gao

We find some errors in previous calculation of leading log QCD corrections to $b \to sγ$ decay, which include corrections from $m_{top}$ to $M_W$ in addition to corrections from $M_{W}$ to $m_b$. The inclusive decay rate is found to be enhanced more than previous calculations. At $m_t=170$GeV, the running from $m_{top}$ to $M_W$ results in 13\% enhancement,

Lajos Diosi

The usual composition rule of independent systems, as applied to decoherent histories or to linearly positive histories, requires (at least) medium decoherence and, consequently, a second constraint for the linearly positive histories of Goldstein and Page. Other plausible classical features, valid for medium decoherence, seem anyhow to be missed by linear p

Franz Embacher

It is argued heuristically -- using an ${\bf S}^3 \times {\bf S}^6$ minisuperspace model -- that there might be a fundamental quantum gravity effect stabilizing internal spaces with non-vanishing Ricci curvature.

Jongsu Kim, Claude LeBrun, Massimiliano Pontecorvo

Let (M,J) be a compact complex 2-manifold which which admits a Kaehler metric for which the integral of the scalar curvature is non-negative. Also suppose that M does not admit a Ricci-flat Kähler metric. Then if M is blown up at sufficiently many points, the resulting complex surface admits Kaehler metrics with scalar curvature identically equal to zero.

Claude LeBrun

Let Z be a compact complex (2n+1)-manifold which carries a {\em complex contact structure}, meaning a codimension-1 holomorphic sub-bundle D of TZ which is maximally non-integrable. If Z admits a Kähler-Einstein metric of positive scalar curvature, we show that it is the Salamon twistor space of a quaternion-Kähler manifold (M^{4n}, g). If Z also admits a se

B. S. Helmkamp, D. A. Browne

We study the quantum chaotic dynamics of an initially well-localized wave packet in a cosine potential perturbed by an external time-dependent force. For our choice of initial condition and with $\hbar$ small but finite, we find that the wave packet behaves classically (meaning that the quantum behavior is indistinguishable from that of the analogous classic

De Siena, M. Zannetti

The structure of the gaussian auxiliary field approximation in the theory of phase ordering kinetics is analysed with the aim of placing the method within the context of a systematic theory. While we are unable to do this for systems with a scalar order parameter, where the approximation remains uncontrolled, a systematic development about the gaussian appro

A. M. Tsvelik

Non-perturbative results are obtained for multipoint correlation functions of the model of (2 + 1)-dimensional relativistic fermions in a random static non-Abelian gauge potential. The results indicate that the replica symmetry remains unbroken. We calculate the diffuson propagator and show that DC-conductivity for this model is finite. ||

D. Yoshioka, H. Kato

The persistent current in three-dimensional mesoscopic rings is investigated numerically. The model is tight-binding one with random site-energies and interaction between electrons. The Hartree-Fock approximation is adopted for the interaction between electrons, and models with up to $3\times 4\times 40$ sites are investigated. It is shown that the long-rang

N. Elstner, R. L. Glenister, R. R. P. Singh, A. Sokol

We study scaling behavior in 2D, S=1/2 and S=1 Heisenberg antiferromagnets using the data on full q-dependences of the equal time structure factor and the static susceptibility, calculated through high temperature expansions. We also carry out comparisons with a model of two coupled S=1/2 planes with the interlayer coupling tuned to the T=0 critical point. W

Cyrus F. Nourani

Techniques are presented for defining models of computational linguistics theories. The methods of generalized diagrams that were developed by this author for modeling artificial intelligence planning and reasoning are shown to be applicable to models of computation of linguistics theories. It is shown that for extensional and intensional interpretations, mo

Wolfgang Menzel

Spoken language applications in natural dialogue settings place serious requirements on the choice of processing architecture. Especially under adverse phonetic and acoustic conditions parsing procedures have to be developed which do not only analyse the incoming speech in a time-synchroneous and incremental manner, but which are able to schedule their resou

Guohong Xu

We have developed a gravity solver based on combining the well developed Particle-Mesh (PM) method and TREE methods. It is designed for and has been implemented on parallel computer architectures. The new code can deal with tens of millions of particles on current computers, with the calculation done on a parallel supercomputer or a group of workstations. Ty

S. E. Church, P. D. Mauskopf, P. A. R. Ade, M. J. Devlin

We have searched for mm-wave emission from compact objects in two fields, each approximately 1 square degree in size, taken from regions of the sky in which degree-scale structure in the Cosmic Background Radiation (CBR) has recently been reported. The observations were made at frequency of 4.7~cm^-1 and with an angular resolution of 1.7' using the Sunya

Xingming Chen, Ronald E. Taam

The global nonlinear time-dependent evolution of the inertial-acoustic mode instability in accretion disks surrounding black holes has been investigated. The viscous stress is assumed to be proportional to the gas pressure only, i.e.\,, $τ= - αp_g$. It is found that an oscillatory instability exists in the inner regions of disks ($r < 10 r_g$, where $r_g$ is

Marek A. Abramowicz, Xingming Chen, Shoji Kato, Jean-Pierre Lasota

We show that most of hot, optically thin accretion disk models which ignore advective cooling are not self-consistent. We have found new types of optically thin disk solutions where cooling is dominated by radial advection of heat. These new solutions are thermally and viscously stable.

Yakov Karpishpan

The reciprocity law for abelian differentials of first and second kind is generalized to higher-dimensional varieties. It is shown that $H^1(V)$ of a polarized variety $V$ is encoded in the Laurent data along a curve germ in $V$, with the polarization form on $H^1(V)$ corresponding to the {\em one-dimensional} residue pairing. This associates an {\em extende

Yi Hu, Wei-Ping Li

In this article, we study the variation of the Gieseker and Uhlenbeck compactifications of the moduli spaces of Mumford-Takemoto stable vector bundles of rank 2 by changing polarizations. Some {\it canonical} rational morphisms among the Gieseker compactifications are proved to exist and their fibers are studied. As a consequence of studying the morphisms fr

K. M. Benson, A. V. Manohar, M. Saadi

We describe flux tubes and their interactions in a low energy sigma model induced by $SU(\NF) \goto SO(\NF)$ flavor symmetry breaking in $SO(N_c)$ QCD. Gauge confinement manifests itself in the low energy theory through flux tube interactions with unscreened sources. The flux tubes which mediate confinement also illustrate an interesting ambiguity in definin

Leo Kadanoff, Detlef Lohse, Jane Wang, Roberto Benzi

This is a paper about multi-fractal scaling and dissipation in a shell model of turbulence, called the GOY model. This set of equations describes a one dimensional cascade of energy towards higher wave vectors. When the model is chaotic, the high-wave-vector velocity is a product of roughly independent multipliers, one for each logarithmic momentum shell. Th

J. K. Jain, T. Kawamura

We demonstrate the formation of composite fermions in two-dimensional quantum dots under high magnetic fields. The composite fermion interpretation provides a simple way to understand several qualitative and quantitative features of the numerical results obtained earlier in exact diagonalization studies. In particular, the ground states are recognized as com

V. V. Kiselev

Using a specific scheme of the QCD sum rules for heavy quarkonium in the leading approximation over the inverse heavy quark mass, one gets the estimate of the difference between the masses of the heavy meson and heavy quark $\bar Λ= 0.59\pm 0.02$ GeV.

Jacob D. Bekenstein

I review various proposals for the nature of black hole entropy and for the mechanism behind the operation of the generalized second law. I stress the merits of entanglement entropy {\tenit qua\/} black hole entropy, and point out that, from an operational viewpoint, entanglement entropy is perfectly finite. Problems with this identification such as the mult

G. J. Gounaris, J. Layssac, J. E. Paschalis, F. M. Renard

We compute the helicity amplitudes for boson-boson scattering at high energy due to the operators $Ø_{BΦ}$, $Ø_{WΦ}$ and $Ø_{UB}$, and we derive the corresponding unitarity bounds. Thus, we provide relations between the couplings of these operators and the corresponding New Physics thresholds, where either unitarity is saturated or new degrees of freedom are

Johan Bijnens, Joaquim Prades

The $B_K$ parameter is discussed in the general context of calculating beyond the factorization approximation for hadronic matrix elements. A variant of the $1/N_c$ method of Bardeen et al. is used. We present calculations within a low energy approach and a calculation within the Nambu--Jona-Lasinio model. Matching with the QCD behaviour and dependence on no

Mikhail S. Volkov, Dmitri D. Gal&#39;tsov

An analytical proof of the existence of negative modes in the odd--parity perturbation sector is given for all known non-abelian Einstein--Yang--Mills black holes. The significance of the normalizability condition in the functional stability analysis is emphasized. The role of the odd--parity negative modes in the sphaleron interpretation of the Bartnik--McK

Denis Juriev

The principal scheme of the secondary image synthesis in electronic computer photography is described. The crucial role of the Clebsch-Gordan coefficient calculus is pointed out.

J. Soffer

We derive new positivity constraints on the spin-dependent structure functions of the nucleon. These model independent results reduce conside\-rably their domain of allowed values, in particular for the chiral-odd parton distribution $h_1 (x)$.

Yusuke Kato, Yoshio Kuramoto

An elementary theory is presented for solving the Sutherland model with arbitrary internal symmetry such as SU($ν$) or a supersymmetry SU($ν, μ$). The ground state wave function and all the energy levels are derived. One starts with solving a variant of the model with distinguishable particles, and then (anti)symmetrizes the solution. The theory is also appl

Tsukasa Tada, Shozo Uehara

We investigate the CGHS model through numerical calculation. The behavior of the mass function, which we introduced in our previous work as a ``local mass&#39;&#39;, is examined. We found that the mass function takes negative values, which means that the amount of Hawking radiation becomes greater than the initial mass of the black hole as in the case of the

Sangyong Jeon

Hydrodynamic transport coefficients may be evaluated from first principles in a weakly coupled scalar field theory at arbitrary temperature. In a theory with cubic and quartic interactions, the infinite class of diagrams which contribute to the leading weak coupling behavior are identified and summed. The resulting expression may be reduced to a single linea

S. W. Hawking, Gary T. Horowitz, Simon F. Ross

We clarify the relation between gravitational entropy and the area of horizons. We first show that the entropy of an extreme Reissner-Nordström black hole is $zero$, despite the fact that its horizon has nonzero area. Next, we consider the pair creation of extremal and nonextremal black holes. It is shown that the action which governs the rate of this pair c

V. Yu. Dobretsov, V. D. Efros, Bin Shao

The method of integral transforms is first applied for studying the $^3$He longitudinal response functions. The transforms are calculated from localized bound-state-type solutions to an inhomogenous Schrödinger-type three-body equation. Several versions of local $s$-wave spin-dependent potentials supplemented with a singlet $p$-wave potential and with the pr

Ursula Carow-Watamura, Satoshi Watamura

With the aim to construct a dynamical model with quantum group symmetry, the $q$-deformed Schrödinger equation of the harmonic oscillator on the $N$-dimensional quantum Euclidian space is investigated. After reviewing the differential calculus on the $q$-Euclidian space, the $q$-analog of the creation-annihilation operator is constructed. It is shown that it

Jonathan L. Feng

If new particles are discovered, it will be important to determine if they are the supersymmetric partners of standard model bosons and fermions. Supersymmetry predicts relations among the couplings and masses of these particles. We discuss the prospects for testing these relations at a future $e^+e^-$ linear collider with measurements that exploit the avail

M. Baillargeon, G. Belanger, F. Boudjema

We address the problem of how to extract the signal of a Higgs within the intermediate mass range at a photon-photon collider that has a wide energy spectrum. All backgrounds from two-jets production are included: direct, so-called resolved and twice-resolved as well as single $Z$ and $W$ production. Uncertainties in the evaluation of the QCD-initiated proce

P. Kroll

Recent improvements of the hard scattering picture for the large $p_{\perp}$ behaviour of electromagnetic form factors, namely the inclusion of both Sudakov corrections and intrinsic transverse momentum dependence of the hadronic wave function, are reviewed. On account of these improvements the perturbative contributions to the pion&#39;s and the nucleon&#39

Carl E. Carlson, J. Milana

Many known models, which generally use a factorization hypothesis, give a poor account of the decays B into J/psi + K(*). Usually there is a free overall factor, which is fit to the data, so that tests of the models rely upon ratios. The models tend to give too much K* compared to K and too much transverse polarization compared to longitudinal. Our microscop

J. G. Körner, K. Melnikov, O. Yakovlev

In this note we report some model-independent bounds involving transition form factors for $ \Omb \rightarrow \Omc $ and $ \Omb \rightarrow \Omc ^* $ and the nonperturbative matrix elements of the $ \Omb $ system. They are derived by using operator product expansion (OPE) in Heavy Quark Effective Theory .

A. D. Martin, R. G. Roberts, W. J. Stirling

To obtain improved parton densities of the proton, we present a new global analysis of deep-inelastic and related hard scattering data including, in particular, the recent measurements of F2 at HERA, of the asymmetry of the rapidity distributions of W+- production at the FNAL pbar p collider and of the asymmetry in Drell-Yan production in pp and pn collision

S. Furui, A. M. Green, B. Masud

Energies of four-quark systems calculated by the static quenched SU(2) lattice Monte Carlo method are analyzed in $2\times 2$ bases for square, rectangle, tilted rectangle, linear and quadrilateral geometry configurations and in $3\times 3$ bases for a non-planar geometry configuration. For small interquark distances, a lattice effect is taken into account b

D. Giulini, C. Kiefer

We discuss some subtleties which arise in the semiclassical approximation to quantum gravity. We show that integrability conditions prevent the existence of Tomonaga-Schwinger time functions on the space of three-metrics but admit them on superspace. The concept of semiclassical time is carefully examined. We point out that central charges in the matter sect

Bertrand I. Halperin

The past few years have produced major advances in our understanding of the quantum Hall effects---quantized and unquantized. Theories based on a mathematical transformation, where the electrons are replaced by a set of fermions interacting with a Chern-Simons gauge field, have been useful for explaining and predicting observations at even-denominator fillin

Jun Zang, Joseph L Birman, Zhao-Bin Su

We develop a theory for the total optical secondary emission from a 1D interacting electron system modelled as a Tomonaga-Luttinger liquid. We separate the emission into two parts which may originate in {\em hot luminescence} (HL) and {\em Raman Scattering} (RS) respectively when we neglect the {\em interference} effect. We find a peak around $Δω= v_f |q|$ i

D. Z. Liu, X. C. Xie, S. Das Sarma, S. C. Zhang

Using a finite-size scaling method, we calculate the localization properties of a disordered two-dimensional electron system in the presence of a random magnetic field. Below a critical energy $E_c$ all states are localized and the localization length $ξ$ diverges when the Fermi energy approaches the critical energy, {\it i.e.} $ξ(E)\propto |E-E_c|^{-ν}$. We

T. Ala-Nissila, E. Granato, K. Kankaala, J. M. Kosterlitz

We present results of numerical studies of the two dimensional XY model with four and eight fold symmetry breaking fields. This model has recently been shown to describe hydrogen induced reconstruction on the W(100) surface. Based on mean-field and renormalization group arguments,we first show how the interplay between the anisotropy fields can give rise to

Ralf Steinberger

In `free word order&#39; languages, every sentence is embedded in its specific context. Among others, the order of constituents is determined by the categories `theme&#39;, `rheme&#39; and `contrastive focus&#39;. This paper shows how to recognise and to translate these categories automatically on a sentential basis, so that sentence embedding can be achieve

Renyue Cen, Jordi Miralda-Escude, Jeremiah P. Ostriker, Michael Rauch

If gravitational clustering is a hierarchical process, the present large-scale structure of the galaxy distribution implies that structures on smaller scales must have formed at high redshift. We simulate the formation of small-scale structure (average cell mass: $Δ\bar m_b=10^{4.2}$M$_\odot$) and the evolution of photoionized gas, in the specific case of a

Victor D. Efros, Winfried Leidemann, Giuseppina Orlandini

We propose to calculate inelastic response functions from the inversion of their integral transform with a Lorentz kernel. The transform can be obtained using bound-state type methods. Thus one does not need to solve the much more complicated continuum problem with many open channels. Contrary to other integral transforms considered in the literature, the in

Stefano Forte, Richard D. Ball

We review a formalism that includes the effects of nonperturbative U(1) symmetry breaking on the QCD evolution of nonsinglet structure functions. We show that a strong scale dependence is generated in an intermediate energy range $0.5 \lsim Q^2 \lsim 5$~GeV$^2$ for all values of $x$. We show that this explains naturally the observed violation of the Gottfrie

A. M. Tsvelik

We establish the equivalence between the problem of a solitary potential scatterer in a Luttinger liquid of spinless repulsive fermions and an anisotropic Kondo model where the value of the impurity spin id determined by the scaling dimension of the scattering potential. The Bethe ansatz is used to derive non-perturbative expressions for the capacitance and

L. T. Handoko, T. Morozumi Pages, :, 19 pages

We study the implications of a vector-like quark, especially a down-type vector-like quark in $b \rightarrow s(d) γ$ including the neutral Higgs in the calculation. After analyzing some possible constraints for the mixing, the contribution may be significant for the $b \rightarrow d γ$, but not for the $b \rightarrow s γ$. We also find that the FCNC among or

Mannque Rho

The role of chiral symmetry in nuclear physics is summarized. The topics treated are the chiral bag model for nucleon structure resulting from large $N_c$ QCD, the pion cloud in chiral perturbation theory for low-energy electroweak nuclear response functions, ``swelled hadrons&#34; in nuclear matter, chiral symmetry restoration in terms of the Georgi vector

C. R. Hagen

The general theory of a massless fermion coupled to a massive vector meson in two dimensions is formulated and solved to obtain the complete set of Green&#39;s functions. Both vector and axial vector couplings are included. In addition to the boson mass and the two coupling constants, a coefficient which denotes a particular current definition is required fo

M. Bianchi, F. Fucito, M. Martellini, G. C. Rossi

We show that the classical equations of motion of the low-energy effective field theory describing the massless modes of the heterotic (or type I) string admit two classes of supersymmetric self--dual backgrounds. The first class, which was already considered in the literature, consists of solutions with a (conformally) flat metric coupled to axionic instant