July 1995 arXiv papers — page 8

C. Adam

We derive a systematic procedure of computing the vacuum functional and fermion condensate of the massive Schwinger model via a perturbative expansion in the fermion mass. We compute numerical results for the first nontrivial order.

WA89 Collaboration

We present the measurement of the lifetime of the Omega_c we have performed using three independent data samples from two different decay modes. Using a Sigma- beam of 340 GeV/c we have obtained clean signals for the Omega_c decaying into Xi- K- pi+ pi+ and Omega- pi+ pi- pi+, avoiding topological cuts normally used in charm analysis. The short but measurabl

Don N. Page

Quantum mechanics may be formulated as {\it Sensible Quantum Mechanics} (SQM) so that it contains nothing probabilistic except conscious perceptions. Sets of these perceptions can be deterministically realized with measures given by expectation values of positive-operator-valued {\it awareness operators}. Ratios of the measures for these sets of perceptions

Ken-ichi Nakao

We investigate a quasi-local energy naturally introduced by Kodama's prescription for a spherically symmetric space-time with a positive cosmological constant $Λ$. We find that this quasi-local energy is well behaved inside a cosmological horizon. However, when there is a scalar field with a long enough Compton wavelength, the quasi-local energy diverges

Anthony Zee, Edouard Brézin

We prove that in random matrix theory there exists a universal relation between the one-point Green's function $G$ and the connected two- point Green's function $G_c$ given by \vfill $ N^2 G_c(z,w) = {\part^2 \over \part z \part w} \log (({G(z)- G(w) \over z -w}) + {\rm {irrelevant \ factorized \ terms.}} $ This relation is universal in the sense tha

E. Ben-Naim, P. L. Krapivsky

We investigate the kinetics of many-species systems with aggregation of similar species clusters and annihilation of opposite species clusters. We find that the interplay between aggregation and annihilation leads to rich kinetic behaviors and unusual conservation laws. On the mean-field level, an exact solution for the cluster-mass distribution is obtained.

J. Jaklic, P. Prelovsek

Charge and spin response in the planar $t-J$ model at finite temperatures are investigated numerically, in the regime corresponding to cuprates at intermediate doping. We show that the local spin correlation function is $T$-independent, leading to $χ&#39;&#39;(ω<J) \propto \tanh (ω/2 T)$. The current correlation function $C(ω)$ appears to be $T$- as well as

E. Orignac, T. Giamarchi

We consider the effect of weak nonmagnetic disorder on two chains of interacting fermions (with and without spins) coupled by interchain hopping. For the spinless case, interchain hopping increases localization for repulsive interactions but {\it stabilizes} the s-wave superconducting phase for attractive interactions. For the case with spin, the d-wave phas

M. Ichioka, N. Hayashi, N. Enomoto, K. Machida

The vortex core structure in a d-wave superconductor is analyzed on the basis of the quasi-classical Eilenberger theory beyond the Ginzburg-Landau framework. The current and magnetic field distributions around an isolated vortex break circular symmetry seen in s-wave pairing and show four-fold symmetry, reflecting the internal degrees of freedom in d-wave pa

Rachel A. Pildis, Joel N. Bregman, James M. Schombert

Compact groups of galaxies appear to be extremely dense, making them likely sites of intense galaxy interaction, while their small populations make them relatively simple to analyze. In order to search for optical interaction tracers such as diffuse light and galaxy tidal features in Hickson compact groups (HCGs), we carried out deep photometry in three filt

Michał J. Chodorowski, François R. Bouchet

We calculate the kurtosis of a large-scale density field which has undergone weakly non-linear gravitational evolution from arbitrary non-Gaussian initial conditions. It is well known that the weakly evolved {\twelveit skewness} is equal to its initial value plus the term induced by gravity, which scales with the rms density fluctuation in precisely the same

G. Bono, F. Caputo, M. Marconi

Convective pulsating models with Y=0.24, stellar mass M=0.65Mo, 0.75Mo, under selected assumptions about luminosities and effective temperatures, are used together with stellar atmosphere computations to get the predicted dependence of RR Lyrae instability strip on stellar mass in the observative plane MV, B-V. The comparison with observed variables belongin

Francois Englert, Laurent Houart, Paul Windey

The coupling of a string to gravity allows for Schwarzschild black holes whose entropy to area relation is $S=(A/4)(1-4μ)$, where $μ$ is the string tension. This departure from the A/4 universality results from a string instanton generating a black hole with smaller entropy at a temperature exceeding the Hawking value. The temperature is sensitive to the pre

Petr Horava

We present a string theory that reproduces the large-$N$ expansion of two dimensional Yang-Mills gauge theory on arbitrary surfaces. First, a new class of topological sigma models is introduced, with path integrals localized to the moduli space of harmonic maps. The Lagrangian of these harmonic topological sigma models is of fourth order in worldsheet deriva

Anirban Kundu, Biswarup Mukhopadhyaya

We have investigated some phenomenological aspects of an $SU(2)\times U(1)$ scenario where scalars belonging to arbitrary representations of $SU(2)$ are involved in electroweak symmetry breaking. The resulting interaction terms are derived. Some constraints are obtained on the arbitrary scalar sector from the requirement of tree-level unitarity in longitudin

Wolfgang Ehehalt, Wolfgang Cassing

We formulate a covariant transport approach for high energy nucleus-nucleus collisions where the real part of the nucleon selfenergies is fitted to nuclear matter properties which are evaluated on the basis of a NJL-type Lagrangian for the quark degrees of freedom. The parameters of the quark-model Lagrangian are fixed by the Gell-Mann, Oakes and Renner rela

M. Girardi, D. Fadda, G. Giuricin, F. Mardirossian

Using a large and well-controlled sample of clusters of galaxies, we investigate the relation between cluster velocity dispersions and X-ray temperatures of intra-cluster gas. In order to obtain a reliable estimate of the total velocity dispersion of a cluster, independent of the level of anisotropies in galaxy orbits, we analyze the integrated velocity disp

A. D. Martin

We give a brief overview of the perturbative QCD description of the proton deep-inelastic structure function F2(x, Q2) at small x. We discuss GLAP and BFKL approaches, and then we review progress towards a more unified treatment.

Tomohiro Mitsumori, Nobuo Noda, Kazuharu Koide, Hiroaki Kouno

A mean free path of nucleon moving through nuclear matter with kinetic energy of more than 100MeV is formulated based on the bare vertex nuclear Schwinger-Dyson (BNSD) method in the Walecka model. The self-energy which is derived from the higher order diagrams more than the forth order includes the Feynman part of propagator of energetic nucleon and grows up

Reginald T. Cahill, Susan M. Gunner

An often used mass formula for Nambu-Goldstone (NG) bosons in QCD, such as the pions, involves the condensate $<\overline{q}q>$, $f_π$ and the quark current masses. We argue, within the context of the Global Colour Model to QCD, that this expression is wrong. Analysis of the interplay between the Dyson-Schwinger equation for the constituent quark effect and

John C. Baez

Starting from a Lie group G whose Lie algebra is equipped with an invariant nondegenerate symmetric bilinear form, we show that 4-dimensional BF theory with cosmological term gives rise to a TQFT satisfying a generalization of Atiyah&#39;s axioms to manifolds equipped with principal G-bundle. The case G = GL(4,R) is especially interesting because every 4-man

Jerzy Lukierski, Pierre Minnaert, Marek Mozrzymas

We consider new class of classical r-matrices for D=3 and D=4 conformal Lie algebras. These r-matrices do satisfy the classical Yang-Baxter equation and as two-tensors belong to the tensor product of Borel subalgebra. In such a way we generalize the lowest order of known nonstandard quantum deformation of sl(2) to the Lie algebras sp(4) = so(5) and sl(4) = s

J. Rayford Nix, Peter Moller

We discuss recent developments in macroscopic-microscopic mass models, including the 1992 finite-range droplet model, the 1992 extended-Thomas-Fermi Strutinsky-integral model, and the 1994 Thomas-Fermi model, with particular emphasis on how well they extrapolate to new regions of nuclei. We also address what recent developments in macroscopic-microscopic mas

H. Kouno, T. Mitsumori, N. Noda, K. Koide

The volume coefficient $K$(=incompressibility of the nuclear matter), the Coulomb coefficient $K_c$, and the volume-symmetry coefficient $K_{vs}$ of the nucleus incompressibility are studied in the framework of the relativistic mean field theory, with aid of the scaling model. It is found that $K= 300\pm 50$MeV is necessary to account for the empirical value

B. E. MacGibbon, G. Garino, M. A. Lucas, A. M. Nathan

The Compton scattering cross section on the proton has been measured at laboratory angles of 90$^\circ$ and 135$^\circ$ using tagged photons in the energy range 70--100 MeV and simultaneously using untagged photons in the range 100--148~MeV. With the aid of dispersion relations, these cross sections were used to extract the electric and magnetic polarizabili

Akikazu Hashimoto, Igor R. Klebanov

We apply light-cone quantization to a $1+1$ dimensional supersymmetric field theory of large N matrices. We provide some preliminary numerical evidence that when the coupling constant is tuned to a critical value, this model describes a 2+1 dimensional non-critical superstring.

Brandon Carter, David Langlois

We give a class of explicit solutions for the stationary and cylindrically symmetric vortex configurations for a ``cool&#39;&#39; two-component superfluid (i.e. superfluid with an ideal gas of phonons). Each solution is characterized only by a set of (true) constants of integration. We then compute the effective asymptotic contribution of the vortex to the s

Brandon Carter, David Langlois

The natural relativistic generalisation of Landau&#39;s two constituent superfluid theory can be formulated in terms of a Lagrangian $L$ that is given as a function of the entropy current 4-vector $s^ρ$ and the gradient $\nablaφ$ of the superfluid phase scalar. It is shown that in the ``cool&#34; regime, for which the entropy is attributable just to phonons

Jean-Bernard Zuber

It is shown that graphs that generalize the ADE Dynkin diagrams and have appeared in various contexts of two-dimensional field theory may be regarded in a natural way as encoding the geometry of a root system. After recalling what are the conditions satisfied by these graphs, we define a bilinear form on a root system in terms of the adjacency matrices of th

Z. Maassarani, S. Wallon

The Hamiltonian derived by Bartels, Kwiecinski and Praszalowicz for the study of high-energy QCD in the generalized logarithmic approximation was found to correspond to the Hamiltonian of an integrable $XXX$ spin chain. We study the odderon Hamiltonian corresponding to three sites by means of the Bethe Ansatz approach. We rewrite the Baxter equation, and con

M. Pernici, M. Raciti, F. Riva

We give a new proof of the renormalizability of a class of matter field theories on a space-time lattice; in particular we consider $ϕ^4$ and massive Yukawa theories with Wilson fermions. We use the Polchinski approach to renormalization, which is based on the Wilson flow equation; this approach is substantially simpler than the BPHZ method, applied to the l

Noureddine Mohammedi

A dual action is obtained for a general non-abelian and non-supersymmetric gauge theory at the classical level. The construction follows steps similar to those used in pure abelian gauge theory. As an example we study the spontaneously broken SO(3) gauge theory and show that the electric and the magnetic fields get interchanged in the dual theory.

T. V. Duong, E. Keith, Hisashi Kikuchi, Ernest Ma

If the standard electroweak gauge model is extended to include two or more Higgs doublets, there may be a neutral Higgs boson $h$ which is light (with a mass of say 10 GeV) but the $hZZ$ coupling is suppressed so that it has so far escaped experimental detection. However, the effective $hhZZ$ coupling is generally unsuppressed, hence the decay of Z into two

E. Akhmedov, M. Lindner, E. Schnapka, J. W. F. Valle

We study left-right symmetric models which contain only fermion and gauge boson fields and no elementary scalars. The Higgs bosons are generated dynamically through a set of gauge- and parity-invariant 4-fermion operators. It is shown that in a model with a composite bi-doublet and two triplet scalars there is no parity breaking at low energies, whereas in t

P. A. Henning, M. Blasone

Within the framework of generalized free field theory at nonzero temperature we address the problem of current conservation. The formalism of thermo field dynamics is used to derive a conserved and thermodynamically consistent physical current operator. Consequences for the calculation of photon emission rates from a hot plasma are considered briefly.

J. Bartels

Nonsinglet contributions to the $g_1(x,Q^2)$ structure function are calculated in the double-logarithmic approximation of perturbative QCD in the region $x \ll 1$. Double logarithmic contributions of the type $(α_s \ln ^2 (1/x))^k$ which are not included in the GLAP evolution equations are shown to give a stronger rise at small-x than the extrapolation of th

Fermilab E791 Collaboration

We report the results of a search for the flavor-changing neutral-current decays $D^+\rightarrow π^+ μ^+ μ^-$ and $D^+\rightarrow π^+ e^+ e^-$ in data from Fermilab charm hadroproduction experiment E791. No signal above background is found, and we obtain upper limits on branching fractions, $B(D^+\rightarrow π^+ μ^+ μ^-) < 1.8 \times 10^{-5}$ and $B(D^+\righ

Philip A. Carinhas

Gott recently has constructed a spacetime modeled by two infinitely long, parallel cosmic strings which pass and gravitationally interact with each other. For large enough velocity, the spacetime will contain closed timelike curves. An explicit construction of the solution for a scalar field is presented in detail and a proof for the existence of such a solu

Denis V. Juriev

Dynamical inverse problem of representation theory, which has its origin in a classical paper of E.P.Wigner on a determination of commutation relations of quantum mechanical quantities by the quantum dynamical equations, is illustrated on the simplest examples.

A. Degtyarev, S. Finashin

A correspondence between different $Pin$-type structures on a compact surface and quadratic (linear) forms on its homology is constructed. Addition of structures is defined and expressed in terms of these quadratic forms.

Dror Orgad, Shimon Levit

Long range Coulomb interaction between the edges of a Hall bar changes the nature of the gapless edge excitations. Instead of independent modes propagating in opposite directions on each edge as expected for a short range interaction one finds elementary excitations living simultaneously on both edges, i.e. composed of correlated density waves propagating in

François R. Bouchet, Avery Meiksin

We present a novel technique for calculating \Lya forest correlations based on cell counts. It is applied to the line lists from 7 QSOs observed at high resolution ($Δv<25\kms$). Two spectra (Q0055$-$259 and Q0014$+$813) appear to be sufficiently free of biases to obtain meaningful estimates. We find for both positive correlations, with a maximum of $0.5-1$,

François R. Bouchet, Richard Gispert, Jean-Lou Puget

COBRAS/SAMBA is a second generation satelitte dedicated to mapping at high resolution and sensitivity the anisotropies of the Cosmic Microwave Background (CMB). This mission is in the assessment study phase (A) at ESA, with a decision expected mid 1996, for a launch around 2003.

Ted Pyne, Carl R. Gwinn, Mark Birkinshaw, T. Marshall Eubanks

Gravitational waves affect the observed direction of light from distant sources. At telescopes, this change in direction appears as periodic variations in the apparent positions of these sources on the sky; that is, as proper motion. A wave of a given phase, traveling in a given direction, produces a characteristic pattern of proper motions over the sky. Com

Tohsuke Urabe

We study the Gauss map and the dual variety of a real-analytic immersion of a connected compact real-analytic manifold into a sphere or into a hyperbolic space. The dual variety is defined to be the set of all normal directions of the immersion. First, we show that the image of the Gauss map characterizes the manifold. Also we show that the dual variety char

J. Gluza, M. Zralek

We examine the e-e- -> W-W- lepton number violating process in the frame of the Standard Model with additional right-handed neutrino singlets. We give results in the framework of the `see-saw&#39; as well as other models, where there is no relation between neutrino masses and the mixing matrix elements. The cross section for the `see-saw&#39; models is negli

Sudhakar Panda, Shibaji Roy

The full cohomology ring of the Lian-Zuckerman type operators (states) in ${\hat c_M}<1$ Neveu-Schwarz-Ramond (NSR) string theory is argued to be generated by three elements $x$, $y$ and $w$ in analogy with the corresponding results in the bosonic case. The ground ring generators $x$ and $y$ are non-invertible and belong to the Ramond sector whereas the high

Robert M. Konik

In this report we compute the boundary states (including the boundary entropy) for the boundary sine-Gordon theory. From the boundary states, we derive both correlation and partition functions. Through the partition function, we show that boundary sine-Gordon maps onto a doubled boundary Ising model. With the current-current correlators, we calculate for fin

G. Eilam, A. Ioannissian, R. R. Mendel, P. Singer

We estimate the long distance (LD) contribution to the magnetic part of the $s \to dγ$ transition using the Vector Meson Dominance approximation $(V=ρ,ω,ψ_i)$. We find that this contribution may be significantly larger than the short distance (SD) contribution to $s \to dγ$ and could possibly saturate the present experimental upper bound on the $Ω^-\to Ξ^-γ$

Marco Picco

We present results of a numerical simulation of the 3-state Potts model with random bond, in two dimension. In particular, we measure the critical exponent associated to the magnetization and the specific heat. We also compare these exponents with recent analytical computations.

Ajit Srivastava, Michael Stone

We report on numerical solutions of the Gross-Pitaevskii equation for two-dimensional flow of a superfluid condensate through a small orifice. Above a critical velocity of about $30\%$ of the speed of sound, cavitation occurs in the throat of the orifice. The cavitating bubbles form the cores of singly quantized vortices which detach from the boundary and ar

Kai T. Hansen

We present here a new method which applies well ordered symbolic dynamics to find unstable periodic and non-periodic orbits in a chaotic system. The method is simple and efficient and has been successfully applied to a number of different systems such as the Hénon map, disk billiards, stadium billiard, wedge billiard, diamagnetic Kepler problem, colinear Hel

Andreas Steffens

Given a smooth complex projective variety $X$ and an ample line bundle $L$ on $X$. Fix a point $x\in X$. We consider the question, are there conditions which guarantee the maxima of the Seshadri constant of $L$ at $x$, i.e $\eps(L,x)=\root n \of {L^n}$? We give a partial answer for surfaces and find examples where the answer to our question is negative. If $

Randall D. Kamien

I describe new phases of a chiral liquid crystal with nematic and hexatic order. I find a conical phase, similar to that of a cholesteric in an applied magnetic field for Frank elastic constants $K_2>K_3$. I discuss the role of fluctuations in the context of this phase and the possibility of satisfying the inequality for sufficiently long polymers. In additi

S. Kar, J. Maharana, H. Singh

The S-duality invariance of the equations of motion of four dimensional string effective action with cosmological constant, $Λ$, is studied. It is demonstrated that the S-duality symmetry of the field equations are broken for nonzero $Λ$. The ``naturalness&#39;&#39; hypothesis is invoked to argue that $Λ$ should remain small since exact S-duality symmetry wi

Yong-Wan Kim, Young-Jai Park, Yongduk Kim

The symplectic formalism is fully employed to study the gauge-invariant CP$^1$ model with the Chern-Simons term. We consistently accommodate the CP$^1$ constraint at the Lagrangian level according to this formalism.

Dirk Ferus, Franz Pedit

In this paper we study maps (curved flats) into symmetric spaces which are tangent at each point to a flat of the symmetric space. Important examples of such maps arise from isometric immersions of space forms into space forms via their Gauss maps. Further examples are found in conformal geometry, e.g. the curved flats obtained from isothermic surfaces and c

Linda Keen, Janina Kotus

We study the dynamics of the tangent family z -> lambda tan z for lambda complex and give a complete classification of their stable behavior. We also characterize the the hyperbolic components and give a combinatorial description their deployment in the parameter plane.

Elias Kiritsis, Costas Kounnas

Exact superstring solutions are constructed in 4-D space-time, with positive curvature and non-trivial dilaton and antisymmetric tensor fields. The full spectrum of string excitations is derived as a function of moduli fields $T^{i}$ and the scale $μ^2=1/(k+2)$ which is induced by the non-zero background fields. The spectrum of string excitations has a non-z

Stefano Moretti

Both the reducible and irreducible backgrounds to the Higgs production channel \eehz\ at a Next Linear Collider (NLC) are studied, for the Standard Model (\sm) Higgs boson in the intermediate-mass range. A phenomenological analysis that does not exploit any form of tagging on the Higgs decay products is assumed.

Lisa Randall

Flat directions are a generic feature of supersymmetric theories. They are of cosmological interest because they can lead to coherent production of scalars. In the early universe such flat directions could be dangerous due to the potentially large energy density and the late decay of the associated scalars when they have only $1/M_p$ couplings (Polonyi probl

Joannis Papavassiliou, Kostas Philippides, Ken Sasaki

We show that in the framework of the pinch technique the universal part of the $ρ$ parameter can be meaningfully defined, beyond one loop. The universal part so obtained satisfies the crucial requirements of gauge-independence, finiteness, and process-independence, even when subleading contributions of the top quark are included. The mechanism which enforces

Thomas Reisz

The critical properties of renormalizable O(N) field models are determined by means of the high order ($\geq 18$) behaviour of convergent linked cluster series on finite temperature lattices. It is shown that those models become weakly coupled at the phase transition. The critical exponents agree to those of the corresponding superrenormalizable 3-dimensiona

Yakov Rutman, Mario Feingold, Yshai Avishai

We investigate the localization of electrons hopping on quasi-1D strips in the presence of random magnetic field. In the weak-disorder region, by perturbative analytical techniques, we derive scaling laws for the localization length, $ξ$, of the form $ ξ\propto \frac{1}{w^η}$, where $w$ is the size of magnetic disorder and the exponent $η$ assumes different

M. Alford, W. Dimm, G. P. Lepage, G. Hockney

We demonstrate that lattice QCD calculations can be made $10^3$--$10^6$ times faster by using very coarse lattices. To obtain accurate results, we replace the standard lattice actions by perturbatively-improved actions with tadpole-improved correction terms that remove the leading errors due to the lattice. To illustrate the power of this approach, we calcul

Cumrun Vafa, Edward Witten

Based on a simple adiabatic argument and by considering the heterotic string counterpart of certain symmetries of Type II superstrings such as $(-1)^{F_L}$ and orientation reversal, we construct orbifold candidates for dual pairs of heterotic and Type II string theories with $N=2$ and $N=1$ supersymmetry. We also analyze from a similar point of view the ${\r

Jordi Comellas, Jose I. Latorre, Josep Taron

We explore some of the constraints imposed by positivity of the QCD measure (Weingarten&#39;s inequalities) on the parameters defining chiral perturbation theory. We find, in particular, that $2 m_q (μ)\leq B_0(μ) Z(μ)$. The use of further properties of the exact fermion propagator yields information on some higher order parameters.

J. Gegelia, N. Kiknadze

Some considerations showing that renormalizable theories with consistent perturbative theries can not be nonperturbatively finite (in terms of bare parameters) are provided. Accordingly any fundamental unified theory has to be either non renormalizable or order by order finite.

A. Vidaurre, A. Perez, H. Sivak, J. Bernabeu

The emissivity for the neutrino pair synchrotron radiation in strong magnetic fields has been calculated both analytically and numerically for high densities and moderate temperatures, as can be found in neutron stars. Under these conditions, the electrons are relativistic and degenerate. We give here our results in terms of an universal function of a single

Alexander Vilenkin

After reviewing the general ideas of quantum cosmology (Wheeler-DeWitt equation, boundary conditions, interpretation of $ψ$), I discuss how these ideas can be tested observationally. Observational predictions differ for different choices of boundary conditions. With tunneling boundary conditions, $ψ$ favors initial states that lead to inflation, while with H

P. K. Townsend

The ten or eleven dimensional origin of central charges in the N=4 or N=8 supersymmetry algebra in four dimensions is reviewed: while some have a standard Kaluza-Klein interpretation as momenta in compact dimensions, most arise from $p$-form charges in the higher-dimensional supersymmetry algebra that are carried by $p$-brane `solitons&#39;. Although $p=1$ i

Gianni Blatter, Vadim Geshkenbein, Anatoli Larkin, Henrik Nordborg

We determine the position and shape of the melting line in a layered superconductor taking the electromagnetic coupling between layers into account. In the limit of vanishing Josephson coupling we obtain a new generic reentrant low-field melting line. Finite Josephson coupling pushes the melting line to higher temperatures and fields and a new line shape $B_

Benoit Bellet, Philippe Garcia, Frederic Geniet, Marcus B. Pinto

We use a nonperturbative variational method to investigate the phase transition of the Gross-Neveu model. It is shown that the variational procedure can be generalized to the finite temperature case. The large N result for the phase transition is correctly reproduced.

Avinash Dhar, Gautam Mandal, Spenta R. Wadia

We propose a new formulation of the space-time interpretation of the $c=1$ matrix model. Our formulation uses the well-known leg-pole factor that relates the matrix model amplitudes to that of the 2-dimensional string theory, but includes fluctuations around the fermi vacuum on {\sl both sides} of the inverted harmonic oscillator potential of the double-scal

Nicola Maggiore, Olivier Piguet, Sylvain Wolf

The complete renormalization procedure of a general N=1 supersymmetric gauge theory in the Wess-Zumino gauge is presented, using the regulator free ``algebraic renormalization&#39;&#39; procedure. Both gauge invariance and supersymmetry are included into one single BRS invariance. The form of the general nonabelian anomaly is given. Furthermore, it is explai

H. -T. Janka, W. Keil, G. Raffelt, D. Seckel

In the hot and dense medium of a supernova (SN) core, the nucleon spins fluctuate so fast that the axial-vector neutrino opacity and the axion emissivity are expected to be significantly modified. Axions with $m_a\alt10^{-2}\,{\rm eV}$ are not excluded by SN~1987A. A substantial transfer of energy in neutrino-nucleon ($νN$) collisions is enabled which may al

F. Bonechi, R. Giachetti, R. Maciocco, E. Sorace

We show that bicovariant bimodules as defined by Woronowicz are in one to one correspondence with the Drinfeld quantum double representations. We then prove that a differential calculus associated to a bicovariant bimodule of dimension n is connected to the existence of a particular (n+1)--dimensional representation of the double. An example of bicovariant d

Takao Fujita

Let $M$ be a submanifold of ${\Bbb P}^N$ of dimension $n>2$. Suppose that $(M,{\Cal O}_M(1))\cong{\Bbb P}({\Cal E}),{\Cal O}(1))$ for some vector bundle ${\Cal E}$ on a surface $S$. Then $N\ge 2n-1$ by Barth-Lefschetz Theorem. We are interested in the case $N=2n-1$. In 1994 Ionescu and Toma gave a classification of the cases where $S$ is not of general type.

Nicholas D. Socci, José Nelson Onuchic

Using Monte Carlo dynamics and the Monte Carlo Histogram Method, the simple three-dimensional 27 monomer lattice copolymer is examined in depth. The thermodynamic properties of various sequences are examined contrasting the behavior of good and poor folding sequences. The good (fast folding) sequences have sharp well-defined thermodynamic transitions while t

R. Akhoury, V. I. Zakharov

We consider $1/Q$ corrections to hard processes in QCD where Q is a large mass scale, concentrating on shape variables in $e^{+}e^{-}$ annihilation. While the evidence for such corrections can be and has been established by means of the renormalon technique, theory can be confronted with experiment only after clarifying the properties of the corresponding no

Anne van Otterlo, Mikhail Feigel&#39;man, Vadim Geshkenbein, Gianni Blatter

We present a microscopic derivation of the equation of motion for a vortex in a superconductor. A coherent view on vortex dynamics is obtained, in which {\it both} hydrodynamics {\it and} the vortex core contribute to the forces acting on a vortex. The competition between these two provides an interpretation of the observed sign change in the Hall angle in s

Craig A. Tracy, Harold Widom

For a particular class of integral operators $K$ we show that the quantity \[\ph:=\log \det (I+K)-\log \det (I-K)\] satisfies both the integrated mKdV hierarchy and the sinh-Gordon hierarchy. This proves a conjecture of Zamolodchikov.

Samuel L. Braunstein, Carlton M. Caves, G. J. Milburn

The quantum-mechanical framework in which observables are associated with Hermitian operators is too narrow to discuss measurements of such important physical quantities as elapsed time or harmonic-oscillator phase. We introduce a broader framework that allows us to derive quantum-mechanical limits on the precision to which a parameter---e.g., elapsed time--

Michael F. Schatz, Stephen J. VanHook, William D. McCormick, J. B. Swift

Experiments with shadowgraph visualization reveal a subcritical transition to a hexagonal convection pattern in thin liquid layers that have a free upper surface and are heated from below. The measured critical Marangoni number (84) and observation of hysteresis (3%) agree with theory. In some experiments, imperfect bifurcation is observed and is attributed

Stephen J. Vanhook, Michael F. Schatz, William D. McCormick, J. B. Swift

Laboratory studies reveal a deformational instability that leads to a drained region (dry spot) in an initially flat liquid layer (with a free upper surface) heated uniformly from below. This long-wavelength instability supplants hexagonal convection cells as the primary instability in viscous liquid layers that are sufficiently thin or are in microgravity.

L. Zamick, M. Fayache, D. C. Zheng

In shell model calculations for the yrast even spin states of 50Cr, the static quadrupole moments of the low spin states 2+_1 and 4+_1 are negative but those of the high spin states 10+_1, 12+_1 and 14+_1 are positive. Even spin states beyond the single j shell limit, J_max=14, again have negative moments. While the B(E2)&#39;s for the J -> J-2 transitions a

D. C. Zheng, B. R. Barrett, J. P. Vary, W. C. Haxton

Large-basis shell model studies of low-lying excitations in light nuclei from 4He to 7Li have been performed with a multi-valued G-matrix effective interaction, as recently suggested by Haxton et al.. Calculations were performed relative to the vacuum (``no core&#34;) using very large, separable model spaces containing all excitations with unperturbed energi

A. W. Thomas, K. Saito

The study of charge symmetry violation in nuclear physics is a potentially enormous subject. Through a few topical examples we aim to show that it is not a subject of peripheral interest but rather goes to the heart of our understanding of hadronic systems.

Richard Kaye

This is a list of the typographic and other errors that occur in `Automorphisms of first-order structures&#39;, by R. W. Kaye and H. D. Macpherson (eds), Oxford University Press, 1994.

J. Böckenhauer

The highest weight modules of the chiral algebra of orthogonal WZW models at level one possess a realization in fermionic representation spaces; the Kac-Moody and Virasoro generators are represented as unbounded limits of even CAR algebras. It is shown that the representation theory of the underlying even CAR algebras reproduces precisely the sectors of the

F. De Jonghe, A. J. Macfarlane, K. Peeters, J. W. van Holten

The non-relativistic dynamics of a spin-1/2 particle in a monopole field possesses a rich supersymmetry structure. One supersymmetry, uncovered by d&#39;Hoker and Vinet, is of the standard type: it squares to the Hamiltonian. In this paper we show the presence of another supersymmetry which squares to the Casimir invariant of the full rotation group. The geo

Stefan K. Kehrein

The spectrum of critical exponents of the $N$--vector model in $4-\eps$~dimensions is investigated to the second order in~$\eps$. A generic class of one--loop degeneracies that has been reported in a previous work is lifted in two--loop order. One-- and two--loop results lead to the conjecture that the spectrum possesses a remarkable hierarchical structure:

D. C. Cabra, K. D. Rothe, F. A. Schaposnik

Integrability of Quantum Chromodynamics in 1+1 dimensions has recently been suggested by formulating it as a perturbed conformal Wess-Zumino-Witten Theory. The present paper further elucidates this formulation, by presenting a detailed BRST analysis.

H. J. Weber, K. Bodoor

Spin-flavor fractions of quarks in the proton and several hyperons are obtained from their lowest order chiral fluctuations involving Goldstone bosons. SU(3) flavor breaking, relativistic effects and the axial anomaly are included. The validity of the Karl-Sehgal formulas for magnetic moments is studied as well.

M. M. Guzzo, O. L. P. Peres, V. Pleitez, R. Zukanovich Funchal

We point out that the usual experimental upper bounds on the ``tau-neutrino mass&#39;&#39; do not apply if neutrino mixing is considered. The suppression of the population of the tau decay spectrum near the end-point, caused by mixing, may be compensated by an enhancement due to a resonant mechanism of hadronization. It is necessary therefore to analyse the

G. Couture, H. König

We calculate the contribution of second generation scalar leptoquarks to the anomalous magnetic moment of the muon (AMMM). In the near future, E-821 at Brookhaven will reduce the experimental error on this parameter to $Δa_μ^{\rm exp}<4\times 10^{-10}$, an improvement of 20 over its current value. With this new experimental limit we obtain a lower mass limit

Stefan Herrlich, Ulrich Nierste

We have calculated the short distance QCD coefficient η_3 of the effective |ΔS|=2-hamiltonian in the next-to-leading order. Since now all coefficients η_1, η_2 and η_3 are known beyond the leading log approximation, one can achieve a much higher precision in the theoretical analysis of ε_K. The measured value for ε_K$ yields a lower bound on each of |V_{cb}|

L. Clavelli, P. W. Coulter

Going beyond the theta function approximation we discuss supersymmetric unification of gauge couplings with exact decoupling of light and heavy particles at energy scales below their masses. We find that the Minimal SUSY model is strongly disfavored while the Missing Doublet Model survives with GUT scale masses rising into the $10^{18}$ GeV region.

B. Dutta, S. Nandi

We investigate how the Fritzsch ansatz for the quark mass matrices can be modified in the least possible way to accommodate the observed large top quark mass and the measured values of the CKM elements. As one of the solutions, we find that the \{23\} and the \{32\} elements of the up quark mass matrix are unequal. The rest of the assumptions are same as in

Vittorio Del Duca

In this talk I report on some work done in collaboration with Jochen Bartels and Mark Wüsthoff on forward-jet inclusive production in DIS in the small-$x_{bj}$ limit. We work in the HERA lab frame and examine the jet production rate and the lepton-jet azimuthal-angle correlation at small values of $x_{bj}$.