December 1993 arXiv papers — page 2

Esteban Calzetta, B. L. Hu

We continue our earlier investigation of the backreaction problem in semiclassical gravity with the Schwinger-Keldysh or closed-time-path (CTP) functional formalism using the language of the decoherent history formulation of quantum mechanics. Making use of its intimate relation with the Feynman-Vernon influence functional (IF) method, we examine the statist

B. L. Hu, Andrew Matacz

The quantum Brownian motion paradigm provides a unified framework where one can see the interconnection of some basic quantum statistical processes like decoherence, dissipation, particle creation, noise and fluctuation. We treat the case where the Brownian particle is coupled linearly to a bath of time dependent quadratic oscillators. While the bath mimics

B. L. Hu, Yuhong Zhang

We derive the uncertainty relation for a quantum open system comprised of a Brownian particle interacting with a bath of quantum oscillators at finite temperature. We examine how the quantum and thermal fluctuations of the environment contribute to the uncertainty in the canonical variables of the system. We show that upon contact with the bath (assumed ohmi

Chuck Yeung, Rashmi Desai

A laser focussed onto a semiconductor film can create a disordered lamellae pattern of coexisting molten-solid regions. We present a continuum model based on the higher reflectivity of the molten regions. For large latent heat, this model becomes equivalent to a model of block copolymers. The characteristic wavenumber of the lamellae is that marginally stabl

A. Kogut, C. Lineweaver, G. F. Smoot, C. L. Bennett

We present a determination of the cosmic microwave background dipole amplitude and direction from the COBE Differential Microwave Radiometers (DMR) first year of data. Data from the six DMR channels are consistent with a Doppler-shifted Planck function of dipole amplitude Delta T = 3.365 +/-0.027 mK toward direction (l,b) = (264.4 +/- 0.3 deg, 48.4 +/- 0.5 d

Leonardo Castellani

We present a general method to deform the inhomogeneous algebras of the $B_n,C_n,D_n$ type, and find the corresponding bicovariant differential calculus. The method is based on a projection from $B_{n+1}, C_{n+1}, D_{n+1}$. For example we obtain the (bicovariant) inhomogeneous $q$-algebra $ISO_q(N)$ as a consistent projection of the (bicovariant) $q$-algebra

Eduardo de Rafael

The basic ideas and some recent developments of the chiral perturbation theory approach to hadron dynamics at low-energies are reviewed. (Invited talk at the HADRON'93 Conference Como, Italy June 1993.)

M. Fukuma, N. Ishibashi, H. Kawai, M. Ninomiya

We propose a new type of gauge in two-dimensional quantum gravity. We investigate pure gravity in this gauge, and find that the system reduces to quantum mechanics of loop length $l$. Furthermore, we rederive the $c\!=\!0$ string field theory which was discovered recently. In particular, the pregeometric form of the Hamiltonian is naturally reproduced.

H-T. Sato

We discuss a generalization of the quantum group $\su$ to the $q$-Virasoro algebra in two-dimensional electrons system under uniform magnetic field. It is shown that the integral representations of both algebras are reduced to those in a (1+1)-dimensional fermion. As an application of the quantum group symmetry, we discuss a model of quantum group current on

S. Drozdz, S. Nishizaki, J. Wambach

The influence of background states with increasing level of complexity on the strength distribution of the isoscalar and isovector giant quadrupole resonance in $^{40}$Ca is studied. It is found that the background characteristics, typical for chaotic systems, strongly affects the fluctuation properties of the strength distribution. In particular, the small

S. A. Gurvitz, A. S. Rinat

We study the response of a nucleus composed of nucleons and confined quarks. Assuming dynamics implied by a non-relativistic cluster model, we prove that the total response is a convolution of the responses of, respectively, a nucleus with interacting point-nucleons and an isolated nucleon with confined quarks. Defining as an intermediary structure functions

E. Pace, G. Salme, A. S. Rinat

We show the equivalence of a previously derived exact expression for the response of a non-relativistic system with harmonic forces and an infinite sum of weighted $δ$-functions corresponding to the spectrum. We forward arguments, indicating that the Gersch-Rodriguez-Smith $1/q$-expansion of the response does not converge and prove that this expansion is an

P. J. Dortmans, L. Canton, G. Pisent, K. Amos

Sturmian eigenstates specified by stationary scattering boundary conditions are particularly useful in contexts such as forming simple separable two nucleon t matrices, and are determined via solution of generalised eigenvalue equation using real and symmetric matrices. In general, the spectrum of such an equation may contain complex eigenvalues. But to each

L. Canton, G. Cattapan

We derive the dynamical equations which consistently couple the four--body ($π$NNN) system to the underlying three--nucleon system. Our treatment can be considered the proper generalization of the Afnan--Blankleider equations for the coupled NN--$π$NN system. The resulting connected--kernel equation resembles in structure the Yakubovskii--Grassberger--Sandha

Marius Junge

We give a positive solution for the hyperplane conjecture of quotient spaces F of $L_p$, where $1<p\kll\infty$. \[ vol(B_F)^{\frac{n-1}{n}} \kl c_0 \pl p&#39; \pl \sup_{H \p hyperplane} vol(B_F\cap H) \pl.\] This result is extended to Banach lattices which does not contain $\ell_1^n$&#39;s uniformly. Our main tools are tensor products and minimal volume rati

Marius Junge

It is well known in Banach space theory that for a finite dimensional space $E$ there exists a constant $c_E$, such that for all sequences $(x_k)_k \subset E$ one has \[ \summ_k \noo x_k \rrm \kl c_E \pl \sup_{\eps_k \pm 1} \noo \summ_k \eps_k x_k \rrm \pl .\] Moreover, if $E$ is of dimension $n$ the constant $c_E$ ranges between $\sqrt{n}$ and $n$. This imp

N. Mohammedi

We present a systematic approach to constructing current algebras based on non-semi-simple groups. The Virasoro central charges corresponding to these current algebras are not, in general, given by integer numbers. The key point in this construction is that the bilinear form appearing in the current algebra can be different from the bilinear form used to rai

S. Okubo

Jordan as well as related triple systems have been used to find several solutions of the Yang-Baxter equation, which are of rational as well as trigonometric type.

S. Okubo

We first reformulate para-statistics in terms of Lie-super triple systems. In this way, we reproduce various new kinds of para-statistics discovered recently by Palev in addition to the standard one. Also, bosonic and fermionic operators may not necessarily commute with each other.

S. G. Rajeev, G. Sparano, P. Vitale

We study a canonical quantization of the Wess--Zumino--Witten (WZW) model which depends on two integer parameters rather than one. The usual theory can be obtained as a contraction, in which our two parameters go to infinity keeping the difference fixed. The quantum theory is equivalent to a generalized Thirring model, with left and right handed fermions tra

C. Gomez, G. Sierra

We define a new mathematical structure ( graph quantum group) which combines the tower of algebras associated with a graph ${\cal G}$ and the structure of a Hopf algebra {\cal A}. In this structure Ocneanu&#39;s string operators become Hopf algebra intertwiners. We present some examples of graph quantum groups.

H. Osborn

Recently obtained results for two and three point functions for quasi-primary operators in conformally invariant theories in arbitrary dimensions {\absit d} are described. As a consequence the three point function for the energy momentum tensor has three linearly independent forms for general {\absit d} compatible with conformal invariance. The corresponding

M. Boyce, P. J. S. Watson

A Monte Carlo model for nuclear matter using a many body $SU_c(3)$ string flip potential, with fixed colour, is investigated. The potential is approximated by considering colour singlet flux tube formations that connect only three quarks at a time. The model is compared with a similar string flip model, proposed by Horowitz and Piekarewicz \cite{kn:HorowitzI

Tadashi Kon, Toshihiko Nonaka

\def\nle{{\stackrel{<}{\sim}}} We examine a possibility for existence of a light supersymmetric partner of the top quark (stop) with mass 15 $\sim$ 16 GeV in the framework of the minimal supergravity GUT model. Such light stop could explain the slight excess of the high $p_{T}$ cross section of the $D^{*\pm}$-meson production in two-photon process at TRISTAN

P. Ball

We calculate finite mass corrections to leptonic decay constants in HQET using QCD sum rules. The results are given to two--loop accuracy including renormalization group analysis. The contribution of unknown two--loop anomalous dimension matrix--elements is estimated. We find that the $1/m_Q$ corrections to $f_P$, the decay constant of a pseudoscalar meson,

Kazunori Takenaga

The oblique parameters $S$ and $T$ are studied in electroweak theory with two massless Higgs doublets. The effect of quadratic dependence on the charged Higgs mass in the parameter $T$ could be cancelled. %when mass differences between the charged and neutral scalars %become large. The constraint on the charged Higgs mass from the parameter $T$ is not so str

Greg Kilcup

We give a preliminary report on the hadron spectrum on an ensemble of quenched lattices at $β$ values of 6.0, 6.2 and 6.4, using staggered fermions and collaborators Rajan Gupta and Steve Sharpe. Because of the relatively small number of configurations we pay marginally more attention to the question of statistics than in previous analyses. We are unable to

X. G. Wu, J. K. Jain

We investigate the spectrum of interacting electrons at arbitrary filling factors in the limit of vanishing Zeeman splitting. The composite fermion theory successfully explains the low-energy spectrum {\em provided the composite fermions are treated as hard-core}.

J. K. Jain, X. G. Wu

We consider the ``fractional quantum Hall atom&#34; in the vanishing Zeeman energy limit, and investigate the validity of Hund&#39;s maximum-spin rule for interacting electrons in various Landau levels. While it is not valid for {\em electrons} in the lowest Landau level, there are regions of filling factors where it predicts the ground state spin correctly

Menke U. Ubbens, Patrick A. Lee

We analyze the phase diagram of single and bi-layer cuprates using the gauge-field description of the t-J model. For $T>T_{\text{BE}}$ the in-plane fermion-pairing order parameter $Δ_{\scriptscriptstyle\parallel}$ is eliminated by gauge field fluctuations, leading us to predict the absence of a spin-gap phase in single-layer cuprates. For bi-layer cuprates t

P. Andreani, S. Cristiani, F. Lucchin, S. Matarrese

{}From three quasar samples with a total of 1038 objects in the redshift range $1.0 ÷2.2$ we measure the variance $σ^2$ of counts in cells of volume $V_u$. By a maximum likelihood analysis applied separately on these samples we obtain estimates of $σ^2(\ell)$, with $\ell \equiv V_u^{1/3}$. The analysis from a single catalog for $\ell = ~40~h^{-1}$ Mpc and fr

Rosemary A. Mardling

A self-consistent, adiabatic model for the {\it long-time} behaviour of tidal capture binaries is presented. It is shown that most capture orbits behave chaotically, with the eccentricity following a quasi-random walk between the values of $\appless 1$ and some lower limit associated with the periastron separation at capture. If dissipation is taken into acc

Rosemary A. Mardling

A self-consistent model for binary evolution devised by Gingold \& Monaghan (1980) is used to show that two distinctly different types of behaviour are possible for close eccentric binaries. The model is based on a linear adiabatic normal mode analysis of the problem, which allows detailed examination of the transfer of energy from the orbit to the tides. We

Fay Dowker, Jerome P. Gauntlett, Steven B. Giddings, Gary T. Horowitz

Classical solutions describing charged dilaton black holes accelerating in a background magnetic field have recently been found. They include the Ernst metric of the Einstein-Maxwell theory as a special case. We study the extremal limit of these solutions in detail, both at the classical and quantum levels. It is shown that near the event horizon, the extrem

M. Cadoni, S. Mignemi

We discuss both classical and semiclassical properties of extremal black holes in theories where the dilaton and a modulus field are present. We find that the corresponding 2-dim geometry is asymptotically anti-de Sitter rather then asymptotically flat as in the purely dilatonic case. This fact has many important consequences, which we analyze at length, bot

Eli Hawkins

A simple self gravitating system --- a thin spherical shell of charged pressureless matter --- is naively quantized as a test case of quantum gravitational collapse. The model is interpreted in terms of an inner product on the positive energy states. An S-matrix is constructed describing scattering between negatively and positively infinite radius.

Israel Vainsencher

For each $1\leq n\leq6$ we present formulas for the number of $n-$nodal curves in an $n-$dimensional linear system on a smooth, projective surface. This yields in particular the numbers of rational curves in the system of hyperplane sections of a generic $K3-$surface imbedded in \p{n} by a complete system of curves of genus $n$ as well as the number {\bf17,6

Domenico Giulini

This paper contains an introduction into Ashtekar&#39;s reformulation of General Relativity in terms of connection variables. To appear in &#34;Canonical Gravity - From Classical to Quantum&#34;, ed. by J. Ehlers and H. Friedrich, Springer Verlag (1994).

Chetan Nayak, Frank Wilczek

We construct models of excitations about a Fermi surface that display calculable deviations from Fermi liquid behavior in the low-energy limit. They arise as a consequence of coupling to a Chern-Simons gauge field, whose fluctations are controlled through a ${1\over{k^x}}$ interaction. The Fermi liquid fixed point is shown to be unstable in the infrared for

R. Emparan, M. A. Valle Basagoiti

We show how macroscopic manifestations of $P$ (and $T$) symmetry breaking can arise in a simple system subject to Aharonov-Bohm interactions. Specifically, we study the conductivity of a gas of charged particles moving through a dilute array of flux tubes. The interaction of the electrons with the flux tubes is taken to be of a purely Aharonov-Bohm type. We

M. A. G. Aivazis, John C. Collins, Fredrick I. Olness, Wu-Ki Tung

A unified QCD formulation of leptoproduction of massive quarks in charged current and neutral current processes is described. This involves adopting consistent factorization and renormalization schemes which encompass both vector-boson-gluon-fusion (flavor creation) and vector-boson-massive-quark-scattering (flavor excitation) production mechanisms. It provi

M. A. G. Aivazis, Fredrick I. Olness, Wu-Ki Tung

Existing calculations of heavy quark production in charged-current and neutral current lepton-hadron scattering are formulated differently because of the artificial distinction of ``light&#39;&#39; and ``heavy&#39;&#39; quarks made in the traditional approach. A proper QCD formalism valid for a wide kinematic range from near threshold to energies much higher

Vassilis Koulovassilopoulos, R. Sekhar Chivukula

In this paper we consider the phenomenology of a ``non-standard&#39;&#39; Higgs Boson in longitudinal gauge-Boson scattering. First, we present a composite Higgs model (based on an $SU(4)/Sp\,(4)$ chiral-symmetry breaking pattern) in which there is a non-standard Higgs Boson. Then we explore, in a model-independent way, the phenomenology of such a non-standa

Ali Mostafazadeh

The line bundles which arise in the holonomy interpretations of the geometric phase display curious similarities to those encountered in the statement of the Borel-Weil-Bott theorem of the representation theory. The remarkable relation of the geometric phase to the classification of complex line bundles provides the necessary tools for establishing the relev

Shahn Majid, Ulrich Meyer

We clarify the relation between the approach to $q$-Minkowski space of Carow-Watamura et al. with an approach based on the idea of $2\times 2$ braided Hermitean matrices. The latter are objects like super-matrices but with Bose-Fermi statistics replaced by braid statistics. We also obtain new R-matrix formulae for the $q$-Poincare group in this framework.

V. V. Bazhanov, B. Nienhuis, S. O. Warnaar

Zamolodchikov found an integrable field theory related to the Lie algebra E$_8$, which describes the scaling limit of the Ising model in a magnetic field. He conjectured that there also exist solvable lattice models based on E$_8$ in the universality class of the Ising model in a field. The dilute A$_3$ model is a solvable lattice model with a critical point

E. Bergshoeff, E. Sezgin

Closed super (p+2)-forms in target superspace are relevant for the construction of the usual super p-brane actions. Here we construct closed super (p+1)-forms on a {\it worldvolume superspace}. They are built out of the pull-backs of the Kalb-Ramond super (p+1)-form and its curvature. We propose a twistor-like formulation of a class of super p-branes which c

Christopher T. Hill, Stephen J. Parke

The production cross--section and distributions of the top quark are sensitive to new physics, e.g., the $t\overline{t}$ system can be a probe of new resonances or gauge bosons that are strongly coupled to the top quark, in analogy to Drell--Yan production. The existence of such new physics is expected in dynamical electroweak symmetry breaking schemes, and

K. G. Chetyrkin, O. V. Tarasov

We find the effective neutral current in the heavy top quark limit up to and including the terms of order $α_s^3$. The result is then employed to compute the correction of the same order to the axial part of the Z decay rate into hadrons ($\G^h_Z$) induced by the top-bottom quark mass splitting. The calculations confirm the prediction made in a previous work

Kei-ichi Kondo, Akihiro Shibata, Masaharu Tanabashi, Koichi Yamawaki

Based on the ladder Schwinger-Dyson equation, we investigate phase struc- ture of the gauged Yukawa model possessing a global $SU(2)_L \times SU(2)_R$ symmetry and an unbroken (vector-like) gauge symmetry. We show that even when we tune the squared mass of the scalar boson in the Lagrangian to be positive, there still exists the dynamical chiral symmetry bre

J. O. Eeg, I. Picek

We present a new contribution to the $K_L\rightarrow γγ$ amplitude, which is ${\cal{O}}(p^4)$ within the counting rules of chiral perturbation theory. This direct (non-pole) amplitude, obtained from short-distance $s \rightarrow d γ$ quark diagrams of order $e G_F α_s/π$, and similar $s \rightarrow d γγ$ diagrams, can account for about half of the experiment

David E. Kahana, Sidney H. Kahana

A model for composite electroweak bosons is re-examined to establish approximate ranges for the initial predictions of the top and Higgs masses. Higher order corrections to this $4$-fermion theory at a high mass scale where the theory is matched to the Standard Model have little effect, as do wide variations in this scale. However, including all one loop evo

Aida X. El-Khadra

The status of determinations of $\al_s$ from quarkonia using lattice QCD is reviewed. We compare the results with those obtained from perturbative QCD.

W. Kalau, M. Walze

We derive an action for gravity in the framework of non-commutative geometry by using the Wodzicki residue. We prove that for a Dirac operator $D$ on an $n$ dimensional compact Riemannian manifold with $n\geq 4$, $n$ even, the Wodzicki residue Res$(D^{-n+2})$ is the integral of the second coefficient of the heat kernel expansion of $D^{2}$. We use this resul

P. E. T. Jorgensen, L. M. Schmitt, R. F. Werner

We consider the problem of representing in Hilbert space commutation relations of the form $$ a_ia_j^*=δ_{ij}{\bold1} + \sum_{k\ell}T_{ij}^{k\ell} a_\ell^*a_k \quad,$$ where the $T_{ij}^{k\ell}$ are essentially arbitrary scalar coefficients. Examples comprise the $q$-canonical commutation relations introduced by Greenberg, Bozejko, and Speicher, and the twis

Oleg Starykh, George Reiter

Starting from the $CP^{N-1}$ model description of the thermally disordred phase of the $D=2$ quantum antiferromagnet, we examine the interaction of the Schwinger-boson spin-1/2 mean-field excitations with the generated gauge (chirality) fluctuations in the framework of the 1/N expansion. This interaction dramatically supresses the one-particle motion, but en

Kazuo Hida

The magnetic properties of the ferromagnetic-ferromagnetic-antiferromagnetic trimerized spin-1/2 Heisenberg chain are studied theoretically. The high temperature susceptibilty and the ground state saturation magnetic field are calculated and the exchange energies of the trimer compound 3CuCl${}_2\cdot$2dx are determined. The magnetization curve is obtained b

R. Hlubina

We consider spinless electrons in two dimensions with the bare spectrum $ε({\bf p})=|p_x|+|p_y|$. In momentum space, the interactions among electrons have a finite range $q_0$, which is small compared to the Fermi momentum. A golden rule calculation of the electron lifetime indicates a breakdown of the Landau Fermi liquid in the model. At the one-loop level

N. B. Volkov, A. M. Iskoldsky

A set of equations according to which the conducting medium consists of two fluids - laminar and vortex, has been obtained in the present paper by transforming MHD equations. In a similar way, an electronic fluid is assumed to consist of a laminar and a vortex fluid. This system allows one to study the formation and the dynamics of large-scale hydrodynamic f

Frederick H. Willeboordse, Kunihiko Kaneko

It is shown that a coupled map model for open flow may exhibit spatial chaos and spatial quasiperiodicity with temporal periodicity. The locations of these patterns, which cover a substantial part of parameter space, are indicated in a comprehensive phase diagram. In order to analyze the encountered phenomena, a novel class of spatial maps is introduced whic

Charles D. Dermer, Reinhard Schlickeiser

Compton scattering of external radiation by nonthermal particles in outflowing blazar jets is dominated by accretion-disk photons rather than scattered radiation to distances $\sim 0.01-0.1$ pc from the central engine for standard parameters, thus clarifying the limits of validity of the model by the present authors and the model of Sikora, Begelman, \& Rees

A. Weiss, R. F. Peletier, F. Matteucci

There are strong indications from recent papers (e.g. Worthey et al. 1992) that the abundance ratio of Mg/Fe, and consequently also O/Fe in giant elliptical galaxies is not solar. The line strengths of two Fe lines at 5270 and 5335 A are weaker than one expects from the strength of the Mg b line if [Mg/Fe] = 0. We have synthesized absorption line indices to

Philippe Jetzer, Eduard Masso

Recently the French EROS collaboration and the American-Australian MACHO collaboration have reported the observation of altogether three possible microlensing events by monitoring over several years the brightness of millions of stars in the Large Magellanic Cloud. For each of these events, assuming they are due to microlensing, we compute the most likely ma

J. P. Norris, R. J. Nemiroff, J. D. Scargle, C. Kouveliotou

If gamma-ray bursters are at cosmological distances - as suggested by their isotropic distribution on the sky and by their number-intensity relation - then the burst profiles will be stretched in time, by an amount proportional to the redshift, 1 + $z$. We have tested data from the {\it Compton} Gamma Ray Observatory&#39;s Burst and Transient Source Experime

K. Behrndt, S. Foerste

We obtain cosmological four dimensional solutions of the low energy effective string theory by reducing a five dimensional black hole, and black hole--de Sitter solution of the Einstein gravity down to four dimensions. The appearance of a cosmological constant in the five dimensional Einstein--Hilbert action produces a special dilaton potential in the four d

L. Turban, F. Igloi, B. Berche

We consider semi-infinite two-dimensional layered Ising models in the extreme anisotropic limit with an aperiodic modulation of the couplings. Using substitution rules to generate the aperiodic sequences, we derive functional equations for the surface magnetization. These equations are solved by iteration and the surface magnetic exponent can be determined e

Matthias Neubert

Using a combination of the operator product and heavy quark expansions, we resum the leading nonperturbative contributions to the inclusive photon spectrum in $B\to X_s\,γ$ decays. The shape of the spectrum is determined by a universal structure function, which describes the distribution of the light-cone momentum of the $b$-quark inside the $B$-meson. The m

J. Resag, D. Schütte

We give a derivation of the particle-hole RPA equations for an interacting multi-fermion system by applying the instantaneous approximation to the amputated two-fermion propagator of the system. In relativistic field theory the same approximation leads from the fermion-antifermion Bethe-Salpeter equation to the Salpeter equation. We show that RPA equations a

Yuval Gefen, Daniel Braun, Gilles Montambaux

The weak field average magnetic susceptibility of square shaped mesoscopic conductors is studied within a semiclassical framework. Long semiclassical trajectories are strongly affected by static disorder and differ sharply from those of clean systems. They give rise to a large linear paramagnetic susceptibility which is disorder independent and in agreement

F. Iglói, I. Peschel, L. Turban

The phase transitions and critical properties of two types of inhomogeneous systems are reviewed. In one case, the local critical behaviour results from the particular shape of the system. Here scale-invariant forms like wedges or cones are considered as well as general parabolic shapes. In the other case the system contains defects, either narrow ones in th

Nicola Manini, Erio Tosatti, Assa Auerbach

The ground state energy shifts and excitation spectra of charged buckminsterfullerene C$_{60}^{n-}$, $n=1,\ldots 5$ are calculated. The electron--vibron Hamiltonian of Part I is extended to include all $A_g$ and $H_g$ modes with experimentally determined frequencies and theoretically estimated coupling constants. Complex splitting patterns of $H_g$ vibration

Assa Auerbach, Nicola Manini, Erio Tosatti

A simple model for electron-vibron interactions on charged buckminsterfullerene C$_{60}^{n-}$, $n=1,\ldots 5$, is solved both at weak and strong couplings. We consider a single $H_g$ vibrational multiplet interacting with $t_{1u}$ electrons. At strong coupling the semiclassical dynamical Jahn-Teller theory is valid. The Jahn-Teller distortions are unimodal f

Adam F. Falk, Elizabeth Jenkins, Aneesh V. Manohar, Mark B. Wise

Recently, Neubert has suggested that a certain class of nonperturbative corrections dominates the shape of the electron spectrum in the endpoint region of semileptonic $B$ decay. Perturbative QCD corrections are important in the endpoint region. We study the effects of these corrections on Neubert&#39;s proposal. The connection between the endpoint of the el

W. Melendez, C. J. Horowitz

The longitudinal response function $R(q,w)$\ of nuclear matter is calculated in a semiclassical quark model. The model has a many- body string-flip potential that confines quarks into hadrons and avoids color van der Waals forces. Molecular dynamics simulations are used to calculate $R(q,w)$\ in one space dimension for a variety of momentum transfers $q$\ an

J. Barcelos-Neto, S. M. de Souza

We study the symplectic quantization of Abelian gauge theories in $2+1$ space-time dimensions with the introduction of a topological Chern-Simons term.

Dean F. Miller

Four-dimensional quantum electrodynamics has been formulated on a hypercubic Minkowski finite-element lattice. The equations of motion have been derived so as to preserve lattice gauge invariance and have been shown to be unitary. In addition, species doubling is avoided due to the nonlocality of the interactions. The model is used to investigate the lattice

E. Elizalde, S. Leseduarte, S. D. Odintsov

We discuss the phase structure (in the $1/N$-expansion) of the Nambu-Jona-Lasinio model in curved spacetime with non-trivial topology ${\cal M}^3 \times {\rm S}^1$. The evaluation of the effective potential of the composite field $\barψ ψ$ is presented in the linear curvature approximation (topology is treated exactly) and in the leading order of the $1/N$-e

J. Anandan

It is shown that from the expectation values of obervables, which can be measured for a single system using protective measurements, the linear structure, inner product, and observables in the Hilbert space can be reconstructed. A universal method of measuring the wave function of a single particle using its gravitational field is given. Protective measureme

Igor V. Kanatchikov

The analogue of the Poisson bracket for the De Donder-Weyl (DW) Hamiltonian formulation of field theory is proposed. We start from the Hamilton- Poincaré-Cartan (HPC) form of the multidimensional variational calculus and define the bracket on the differential forms over the space-time (=horizontal forms). This bracket is related to the Schouten-Nijenhuis bra

Taejin Lee, Phillial Oh

We construct a classical action for a system of $N$ point-like sources which carry SU(2) non-Abelian charges coupled to non-Abelian Chern-Simons gauge fields, and develop a quantum mechanics for them. Adopting the coherent state quantization and solving the Gauss&#39; constraint in an appropriately chosen gauge, we obtain a quantum mechanical Hamiltonian giv

Sergey V. Shabanov

The role of a physical phase space structure in a classical and quantum dynamics of gauge theories is emphasized. In particular, the gauge orbit space of Yang-Mills theories on a cylindrical spacetime (space is compactified to a circle) is shown to be the Weyl cell for a semisimple compact gauge group, while the physical phase space coincides with the quotie

Masaru Nagura, Katsuyuki Sugiyama

We discuss a K3 and torus from view point of &#34;mirror symmetry&#34;. We calculate the periods of the K3 surface and obtain the mirror map, the two-point correlation function, and the prepotential. Then we find there is no instanton correction on K3 (also torus), which is expected from view point of Algebraic geometry.

Ryuichi Nakayama

A two-loop (cylinder) amplitude of the 2d pure gravity theory is obtained in the proper-time gauge ($g_{00}=1$, $g_{01}=g_{10}=0$) in the continuum formulation. The constraint $T_{01}=0$ is solved and used to reduce the problem of field theory to that of quantum mechanics. This reduction can also be proved by using a conformal Ward identity. The amplitude de

K. S. Babu, Kazuo Fujikawa, Atsushi Yamada

In left-right symmetric models, large contributions to the decay amplitude $b \rightarrow s+ γ$ can arise from the mixing of the $W_L$ and $W_R$ gauge bosons as well as from the charged Higgs boson. These amplitudes are enhanced by the factor $\mt/\mb$ compared to the contributions in the standard model. We use the recent CLEO results on the radiative $B$ de

V. Barger, E. Mirkes, J. Ohnemus, R. J. N. Phillips

Events with a leptonic W-decay plus jets should contain top-quark signals, but a QCD W+jets background must be separated. We compare transverse W-momentum, jet multiplicity, and b-tagging separation criteria, and find that the main background after tagging comes from mistagging. We illustrate how to extract the mass m_t via event reconstructions and how to c

A. P. Kostyuk, A. P. Kobushkin, N. M. Chepilko, T. Okazaki

We present a detailed discussion of the breathing mode quantization in the Skyrme model and demonstrate that the chiral angle of the hedgehog soliton is strongly affected by the breathing motion.

James T. Liu

The 331 model, an extension of the standard electroweak theory to $SU(3)_L\times U(1)_X$, naturally predicts three families of quarks and leptons via the requirement of anomaly cancellation. This is accomplished by making one of the quark families transform differently from the other two, thus leading to flavor changing neutral currents. Using experimental i

N. I. Kochelev

It is shown, that the hard component of quarks distribution functions induced by instantons gives the essential contribution to hard diffractive processes. We predict large polarization effects in these processes.

Michel Talon

These lectures present some basic facts in field theory necessary to understand the quantum theory of the Standard Model of weak and electromagnetic interactions.

Debajyoti Choudhury, Frank Cuypers

We analyze the influence of anomalous gauge couplings in the reaction $e^- \: e^- \longrightarrow e^- \: W^- \: ν_e$ at a 500 GeV linear collider. The limits imposed by this process on deviations from the standard model of electro-weak interaction, are competitive with those inferred from other high energy experiments. Furthermore, the allowed domain in the

V. Bernard, N. Kaiser, Ulf-G. Meißner

We derive novel low--energy theorems for single pion production off nucleons through the isovector axial current. We find that the $k^2$-dependence of the multipole $L_{0+}^{(+)}$ at threshold is given by the nucleon scalar form factor, namely $σ(k^2-M_π^2 ) /(3 πM_πF_π)$. The relation to PCAC results for soft pions including electroweak form factors is also

Stefan Sint

In a series of publications [\ref{LNWW},\ref{Schroedinger}], Lüscher et al. have demonstrated the usefulness of the Schrödinger functional in pure SU(2) and SU(3) gauge theory. In this paper, it is shown how their formalism can be extended to include fermions. In the framework of Wilson&#39;s lattice QCD, we define the Schrödinger functional by making use of

M. Hasenbusch, K. Rummukainen, K. Pinn

We propose an effective transfer-matrix method that allows a measurement of tunnelling correlation lengths that are orders of magnitude larger than the lattice extension. Combining this method with a particularly efficient implementation of the multimagnetical algorithm we were able to determine the interface tension of the 3D Ising model close to criticalit

Kevin Cahill

Wilson loops have been measured at strong coupling, $β=0.5$, on a $12^4$ lattice in a noncompact simulation of pure SU(2) in which random compact gauge transformations impose a kind of lattice gauge invariance. The Wilson loops suggest a confining potential.

T. Damour, S. Deser, J. McCarthy

We analyze the radiative aspects of nonsymmetric gravity theory to show that, in contrast to General Relativity, its nonstationary solutions cannot simultaneously exhibit acceptable asymptotic behavior at both future and past null infinity: good behavior at future null infinity is only possible through the use of advanced potentials with concomitant unphysic

R. J. Gooding, N. M. Salem, A. Mailhot

We provide an explanation of the spin-freezing transition recently observed by Chou et al. (Phys. Rev. Lett. 71, 2323 (1993)) in La_{2-x}Sr_x CuO_4 for x <= 0.02. We propose that topological excitations of the 2D Heisenberg quantum antiferromagnet having non-coplanar transverse components have a pair-interaction energy that qualitatively and quantitatively a

A. Martin-Rodero, F. J. Garcia-Vidal, A. Levy-Yeyati

We present a microscopic theory for the d.c. Josephson effect in model mesoscopic constrictions. Our method is based on a non-equilibrium Green function formalism which allows for a self-consistent determination of the order parameter profile along the constriction. The various regimes defined by the different length scales (Fermi wavelength $λ_F$, coherence

Vladimir Privman

This short review covers a wide selection of topics from a multidisciplinary area of dynamics of nonequilibrium systems in physics, chemistry, biology. Theoretical models of colloid particle and protein deposition and adhesion at surfaces, accompanied by relaxation processes, of reaction kinetics with and without diffusion, of phase coarsening and nucleation

Alessandro Fortunelli, Anna Painelli

Whereas the t-J model has gained wide popularity among physicists as a model for high-T_C superconductivity, its physical origin is not at all clear. In this communication we show that the Hubbard model with occupation-dependent hopping (t_1-t_2-t_3-U model), recently proposed to account for the relaxation of doubly-occupied orbitals, reduces, in a physicall

Vladimir V. Usov

Radiation of both the outer gaps and the neutron star surface is considered for a Vela-like pulsar near the death line. It is shown that if such a pulsar is close enough to the death line, its optical, UV and X-ray emission has to increase. Using results of this consideration, it is argued that Geminga is not a close relative of Vela-like pulsars. The outer