October 1994 arXiv papers — page 9

Emilio Elizalde, Sergei D. Odintsov, August Romeo

Quantum gravitational corrections to the effective potential, at one-loop level and in the leading-log approximation, for scalar quantum electrodynamics with higher-derivative gravity ---which is taken as an effective theory for quantum gravity (QG)--- are calculated. We point out the appearence of relevant phenomena caused by quantum gravity, like dimension

Martin Koehler

The product of two free scalar fields on a manifold is shown to be a well defined operator valued distribution on the GNS Hilbert space of a globally Hadamard product state. Viewed as a new field all n-point distributions exist, giving a new example for a Wightman field on a manifold.

A. MacIntyre

The possible boundary conditions consistent with the integrability of the classical sine-Gordon equation are studied. A boundary value problem on the half-line $x\leq 0$ with local boundary condition at the origin is considered. The most general form of this boundary condition is found such that the problem be integrable. For the resulting system an infinite

T. Kobayashi, C. S. Lim

We study CP in orbifold models. It is found that the orbifolds always have some automorphisms as CP symmetry. The symmetries are restricted non-trivially due to geometrical structure of the orbifolds. Explicit analysis on Yukawa couplings also shows that CP is not violated in orbifold models.

Wolfgang Keil, H. -Thomas Janka, Georg Raffelt

Axial-vector interactions of neutrinos and axions with a medium are based on structure functions which cannot be calculated in simple perturbative terms for nuclear densities. We use the SN~1987A neutrino signal duration to estimate the range of allowed neutrino opacities of a supernova (SN) core. We perform numerical simulations of the evolution from the ho

J. Sirkka

Bounds of the neutral current sector parameters of the left-right symmetric model are investigated taking into account the low-energy data, LEP-data and CDF-result for the top mass $m_t=174\pm 10^{+13}_{-12}$. It is found that in the case of the minimal scalar sector with a left- and a right-handed triplet and a bidoublet Higgses the mass of the heavy neutra

D. Comelli, M. Pietroni, A. Riotto

We study the implications of a light stop for the spontaneous CP breaking at finite temperature in the Higgs sector of the Minimal Supersymmetric Standard Model with a gauge singlet. Assuming CP conservation at zero temperature, we show that the presence of a large mixing between the left- and the right-handed stops can trigger easily the spontaneous breakin

K. Enqvist, I. Vilja

We study induced nucleation by considering the accumulation rate of shrinking subcritical bubbles. We derive the probability for a collection of subcritical bubbles to form a critical bubble, and argue that this mechanism could well play a role in electroweak phase transitions if the Higgs is heavy.

S. Guellenstern, P. Gornicki, L. Mankiewicz, A. Schaefer

This program can be used to simulate polarised nucleon - nucleon collisions at high energies. Spins of colliding particles are taken into account. The program allows to calculate cross sections for various processes.

S. Guellenstern, P. Gornicki, L. Mankiewicz, A. Schaefer

Direct photon production in longitudinally polarised proton-proton collisions offers the most direct and unproblematic possibility to determine the polarised gluon distribution of a proton. This information could play a major role for improving our understanding of the nucleon structure and QCD in general. It is hoped that such experiments will be done at RH

Wolfgang Lucha, Franz F. SCHÖberl

We review some important topics related to the semirelativistic description of bound states by the spinless Salpeter equation: the special case of the Coulomb interaction, numerical approximation methods, and a way to avoid the problematic square-root operator of the relativistic kinetic energy.

J. T. Hong

We report a search for slowly moving magnetic monopoles in the cosmic radiation with the first supermodule of the MACRO detector at Gran Sasso. The absence of candidates established an upper limit on the monopole flux of $5.6\times10^{-15}\mbox{cm}^{-2}\mbox{sr}^{-1}\mbox{s}^{-1}$ at 90\% confidence level for the velocity range of $1.8\times10^{-4}<β<3\times

David Gerdes, the CDF Collaboration

Using data collected during the 1992-93 collider run at Fermilab, CDF has made measurements of correlated $b$ quark cross section where one $b$ is detected via a muon from semileptonic decay and the second $b$ is detected with secondary vertex techniques. We report on measurements of the cross section as a function of the momentum of the second $b$ and as a

David Gerdes, the CDF Collaboration

For the 1994 Tevatron collider run, CDF has upgraded the electron and photon trigger hardware to make use of shower position and size information from the central shower maximum detector. For electrons, the upgrade has resulted in a 50\% reduction in backgrounds while retaining approximately 90\% of the signal. The new trigger also eliminates the background

S. M. Carroll, D. Z. Freedman, M. E. Ortiz, D. N. Page

It is argued that states in $N=1$ supergravity that solve all of the constraint equations cannot be bosonic in the sense of being independent of the fermionic degrees of freedom. (Based on a talk given by Miguel Ortiz at the 7th Marcel Grossmann Meeting.)

P. T. Chrusciel, R. M. Wald

We prove that the domain of outer communication of a stationary, globally hyperbolic spacetime satisfying the null energy condition must be simply connected. Under suitable additional hypotheses, this implies, in particular, that each connected component of a cross-section of the event horizon of a stationary black hole must have spherical topology.

F. Bagarello, C. Trapani

The Banach space $L^p(X,μ)$, for $X$ a compact Hausdorff measure space, is considered as a special kind of quasi *-algebra (called CQ*-algebra) over the C*-algebra $C(X)$ of continuous functions on $X$. It is shown that, for $p \geq 2$, $(L^p(X,μ), C(X))$ is *-semisimple (in a generalized sense). Some consequences of this fact are derived.

Zhong Ge

This paper shows that when the Riemannian metric on a contact manifold is blown up along the direction orthogonal to the contact distribution, the corresponding harmonic forms rescaled and normalized in the $L^2$-norms will converge to Rumin&#39;s harmonic forms. This proves a conjecture in Gromov `` Carnot-Caratheodory spaces seen from within &#39;&#39;, IH

A. C. Hewson

We give a Hamiltonian based interpretation of microscopic Fermi liquid theory within a renormalization group framework. We identify the fixed point Hamiltonian of Fermi liquid theory, with the leading order corrections, and show that this Hamiltonian in mean field theory gives the Landau phenomenological theory. A renormalized perturbation theory is develope

O. Gulseren, F. Ercolessi, E. Tosatti

Recent work has raised considerable interest on the nature of thin metallic wires. We have investigated the melting behavior of thin cylindrical Pb wires with the axis along a (110) direction, using molecular dynamics and a well-tested many-body potential. We find that---in analogy with cluster melting---the melting temperature $T_m (R)$ of a wire with radiu

Yuli Nazarov

A small review on scattering approach to electric transport. Transmission distribution can be gotten from Ohm&#39;s law and/or circuit theory. Send me a postcard if you read it all and enjoy.

A. Frank, U. Reyle

The paper presents a constraint based semantic formalism for HPSG. The advantages of the formlism are shown with respect to a grammar for a fragment of German that deals with (i) quantifier scope ambiguities triggered by scrambling and/or movement and (ii) ambiguities that arise from the collective/distributive distinction of plural NPs. The syntax-semantics

John David Crawford

An amplitude equation for an unstable mode in a collisionless plasma is derived from the dynamics on the unstable manifold of the equilibrium $F_0(v)$.\\ The mode eigenvalue arises from a simple zero of the dielectric $ε_{k}(z)$; as the linear growth rate $γ$ vanishes, the eigenvalue merges with the continuous spectrum on the imaginary axis and disappears. T

Yihu Fang, Arlin Crotts

In order to carry out a systematic and thorough measurement of the HI Gunn-Peterson effect at high redshift, a quantitatively testable and repeatable procedure, in particular, a robust statistical weighting technique, is developed. It is applied to an echelle spectrum of resolution 15 km s$^{-1}$ of PKS 1937-101 with z=3.787. A weighted intensity distributio

E. F. Borra, G. Moretto, M. Wang

We discuss a family of two-mirror correctors that can greatly extend the field accessible to a fixed telescope such as a liquid mirror telescope. The performance of the corrector is remarkable since it gives excellent images in patches contained within a field greater than 45 degrees. We argue that this performance makes fixed telescopes competitive with til

J. Loveday, S. J. Maddox, G. Efstathiou, B. A. Peterson

We present clustering measurements for samples of galaxies selected by morphological type and luminosity from the recently completed Stromlo-APM Redshift Survey. Early type galaxies are clustered more strongly by a factor 3.5--5.5, than late type galaxies. Low-luminosity galaxies are clustered more weakly by a factor of $\sim 2$ than $L^*$ and brighter galax

Robert W. Nelson, John C. L. Wang, E. E. Salpeter, Ira Wasserman

Estimates indicate there may be $\simgreat 10^3$ low luminosity X-ray pulsars ($L \simless 10^{34} \rom{erg\;s^{-1}}$) in the Galaxy undergoing ``low-state&#39;&#39; wind accretion in Be/X-ray binary systems, and $\sim 10^8-10^9$ isolated neutron stars which may be accreting directly from the interstellar medium. Despite their low effective temperatures ($kT

F. De Paolis, G. Ingrosso, Ph. Jetzer, M. Roncadelli

Recent observations of microlensing events in the Large Magellanic Cloud by the MACHO and EROS collaborations suggest that an important fraction of the galactic halo is in the form of Massive Halo Objects (MHO) with mass $\sim 0.1 M_{\odot}$. We outline a scenario in which dark clusters of MHO with mass $\sim 0.1 M_{\odot}$ and $H_2$ molecular clouds form in

K. Jahn, J. Kaluzny, S. M. Rucinski

Fifteen variable stars have been discovered during four nights of monitoring of NGC 7789. It was possible to determine periods for ten of these variables. Seven objects are W UMa-type binaries, in this number five are members of the cluster. Among the remaining variables, there are three further close binaries, one delta Scuti which is a Blue Straggler in th

Yutaka Fujita, Hideo Kodama

Iron abundance distribution is now known for 12 clusters of galaxies. For some clusters (e.g. Centaurus) the observed abundance increases toward the cluster center, while for the others (e.g. Coma and Hydra-A) no significant inhomogeneity was observed. In order to understand this difference, we investigate the influence of cooling flow and turbulence produce

Valery Alexeev

We construct and prove the projectiveness of the moduli spaces which are natural generalizations to the case of surfaces of the following: 1) $M_{g,n}$, the moduli space of $n$-marked stable curves, 2) $M_{g,n}(W)$, the moduli space of $n$-marked stable maps to a variety $W$.

David Reed

Serre and Abelson have produced examples of non-homeomorphic conjugate varieties. We show that if the field of definition of a polarized projective variety coincides with its field of moduli then all of its conjugates have the same topological type. This extends the class of varieties known to posses conjugacy invariant to canonically embedded varieties. We

Victor V. Batyrev, Dimitrios I. Dais

In the revised version of the paper, we correct misprints and add some new statements.

Ngee-Pong Chang

In this paper, we perform the quantization of the nonlocal BPFTW effective action in coordinate space. The action is made local by using a conjugate set of auxiliary fields. The action summarizes the properties of quark propagation through a hot environ. The fermion propagator shows a pseudo-Lorentz invariant particle pole as well as a pair of conjugate spac

Ngee Pong Chang

< \psibarpsi > vanishing above $T_c$ indicates chiral symmetry restoration at high $T$. But is it the old $T=0$ chiral symmetry that is `restored'? In this talk, I report on the spacetime quantization of the BPFTW effective action for quarks in a hot environ. The fermion propagator is known to give a pseudo-Lorentz invariant particle pole as well as new spac

Sharon Hagopian, D0 Collaboration

Searches have been made for first generation scalar and vector leptoquarks by the D0 collaboration and for second generation scalar leptoquarks by the CDF collaboration. Lower leptoquark mass limits were set. A search for squarks and gluinos, predicted by Supersymmetric models, was made by D0 in the three or more jets plus missing Et channel. The number of e

T. C. Chan, H. F. Chau, K. S. Cheng

We study a cellular automaton model, which allows diffusion of energy (or equivalently any other physical quantities such as mass of a particular compound) at every lattice site after each timestep. Unit amount of energy is randomly added onto a site. Whenever the local energy content of a site reaches a fixed threshold $E_{c1}$, energy will be dissipated. D

K. Jahn, H. U. Schmidt

The conjecture that energy transport in sunspot penumbrae occurs through convection by an interchange of magnetic flux tubes is used in order to construct a magnetostatic model for a deep penumbra which is part of a global sunspot model. The model describes an overall mechanical equilibrium between the three stratifications: of the umbra, the penumbra, and o

Luis Masperi, Ariel Megevand

We discuss the stability of an electroweak string with axions in its core, which give to the configuration a quasi-topological property, and compare it with other modifications using instantons in the thin wall approximation.

A. A. Thoul, D. H. Weinberg

We describe an accurate, one-dimensional, spherically symmetric, Lagrangian hydrodynamics/gravity code, designed to study the effects of radiative cooling and photo-ionization on the formation of protogalaxies. The code can treat an arbitrary number of fluid shells (representing baryons) and collisionless shells (representing cold dark matter). As a test of

Berndt Mueller

This is a critical review of the various observables that have been proposed to signal the change from dense hadronic matter to a quark-gluon plasma at high temperature or baryon density. I discuss current models of quark-gluon plasma formation in relativistic heavy ion collisions and analyze the virtues and ambiguities of various signatures. [The author esp

M. S. Hussein, A. K. Kerman, C-Y Lin

The large magnitude and the sign correlation effect in the parity non-conserving resonant scattering of epithermal neutrons from $^{232}$Th is discussed in terms of a non-collective $2p-1h$ local doorway model. General conclusions are drawn as to the probability of finding large parity violation effects in other regions of the periodic table.

Kimiaki Nishida, Munetake Ichimura

Effects of the delta-isobar $(Δ)$ mixing on the spin-isospin response functions in finite nuclei are studied in the quasi-elastic region. A method to calculate the response function for a finite system composed of nucleon $(N)$ and $Δ$ is formulated in a ring approximation. It is designed to treat the $Δ$-related Landau-Migdal parameters, $g&#39;_{NΔ}$ and $

V. Chari

We define the notion of a minimal affinization of an irreducible representation of $U_q(g)$. We prove that minimal affinizations exist and establish their uniqueness in the rank 2 case.

S. Pakuliak

Some relations between different objects associated with quantum affine algebras are reviewed. It is shown that the Frenkel-Jing bosonization of a new realization of quantum affine algebra $\Uqa$ as well as bosonization of $L$-operators for this algebra can be obtained from Zamolodchikov-Faddeev algebras defined by the quantum $R$-matrix satisfying unitarity

K. N. Ilinski, G. V. Kalinin, V. V. Melezhik

We revise the sequences of SUSY for a cyclic adiabatic evolution governed by the supersymmetric quantum mechanical Hamiltonian. The condition (supersymmetric adiabatic evolution) under which the supersymmetric reductions of Berry (nondegenerated case) or Wilczek-Zee (degenerated case) phases of superpartners are taking place is pointed out. The analogue of W

M. Schaden, D. Zwanziger

It is proven that the &#34;horizon condition&#34;, which was found to characterize the fundamental modular region in continuum theory and the thermodynamic limit of gauge theory on a periodic lattice, holds for every (transverse) configuration on a finite lattice with free boundary conditions.

Edi Halyo

We investigate the dependence of the number and type of untwisted moduli on the boundary condition vectors of relistic free fermionic strings. The number of moduli is given by six minus the number of complex internal world--sheet fermions and the type of moduli is determined by the details of the world--sheet left--right asymmetry of the boundary conditions

Jens Böckenhauer

In a Fock representation, a non-surjective Bogoliubov transformation of CAR leads to a reducible representation. For the case that the corresponding Bogoliubov operator has finite corank, the decomposition into irreducible subrepresentations is clarified. In particular, it turns out that the number of appearing subrepresentations is completely determined by

Martin Cederwall, Gabriele Ferretti, Bengt E. W. Nilsson, Anders Westerberg

We study the cohomology of the Schwinger term arising in second quantization of the class of observables belonging to the restricted general linear algebra. We prove that, for all pseudodifferential operators in 3+1 dimensions of this type, the Schwinger term is equivalent to the ``twisted&#39;&#39; Radul cocycle, a modified version of the Radul cocycle aris

Martin Cederwall

This talk deals with the old problem of formulatingn a covariant quantum theory of superstrings, ``covariant&#39;&#39; here meaning having manifest Lorentz symmetry and supersymmetry. The advantages and disadvantages of several quantization methods are reviewed. Special emphasis is put on the approaches using twistorial variables, and the algebraic structure

K. Hornfeck

Recently it has been discovered that the W-algebras (orbifold of) WD_n can be defined even for negative integers n by an analytic continuation of their coupling constants. In this letter we shall argue that also the algebras WA_{-n-1} can be defined and are finitely generated. In addition, we show that a surprising connection exists between already known W-a

Matthias Burkardt

A scheme is developed which shows how one would, given a light-front Hamiltonian for QCD, extract the $Q\overline{Q}$ potential, i.e. the quantity which corresponds to the potential between two infinitely heavy quarks in a rest frame, from a light-front calculation. The resulting potential will in general depend on the direction along which the infinitely he

Eric Braaten, Agustin Nieto

The asymptotic behavior of the correlator for Polyakov loop operators separated by a large distance $R$ is determined for high temperature QCD. It is dominated by nonperturbative effects related to the exchange of magnetostatic gluons. To analyze the asymptotic behavior, the problem is formulated in terms of the effective field theory of QCD in 3 space dimen

Murray A. Moinester

Can one expect gamma rays rates from the QGP to be higher than from the hot hadronic gas phase? Xiong, Shuryak, Brown (XSB) calculate photon production from a hot hadronic gas via the reaction $π^- + ρ^0 \rightarrow π^- + γ$. They assume that this reaction proceeds through the a$_1$(1260). They also use their estimated a$_1$ radiative width to calculate the

Peter Cho, Mark Wise

Gluon fragmentation to heavy $J^{PC}=2^{-+}$ quarkonia is studied herein. We compute these D-wave states&#39; polarized fragmentation functions and find that they are enhanced by large numerical prefactors. The prospects for detecting the lowest lying $^1D_2$ charmonium state at the Tevatron are discussed.

Joseph Schechter, Anand Subbaraman

The orbitally excited heavy quark baryons are studied in the Callan Klebanov bound state model with heavy spin symmetry. First, a compact description of the large $N_c$, infinite heavy quark mass bound state wavefunctions and the collective quantization is given. In order to study the kinematical corrections due to finite masses we motivate an approximate Sc

Junko Shigemitsu

We report on recent developments and results from Lattice Gauge Theory. These include determinations of the strong coupling constant $α_s$ and the b-quark mass $M_b$ and an update on the Kaon B parameter $B_K$. Lattice results for heavy meson decay constants and semileptonic B and D meson decay form factors are reviewed. The first attempts to study the Isgur

Herbi Dreiner

We summarize two sets of signals at HERA in supersymmetric models with explicitly broken R-parity. (1) The resonant production of single squarks through an operator $L_1Q_i{ \bar D}_j$. (2) The MSSM production of a squark and a slepton followed by R-parity violating decays via the operators $L_iQ_j{\bar D}_k$. The first case allows for a very large mass reac

Mitja Rosina, Borut Bajc

The $γγ\toρ^0ρ^0\to 4 π$ reaction shows a broad &#34;resonance&#34;at 1.5 GeV with no counterpart in the $ρ^+ρ^-$ channel. This $(J^P,J_z)=(2^+,2)$, $I=0$, and $2$ resonance is considered as a candidate for a $qq\bar q\bar q$ state. We show, however, that it can also be explained by potential scattering of $ρ^0ρ^0$ via the $σ-$ exchange.

A. Pich

The interplay of QCD in $ΔS=1,2$ non-leptonic weak transitions can be rigorously analyzed, at the inclusive level, by studying the 2--point functions associated with the corresponding $ΔS=1,2$ effective Hamiltonians. The next-to-leading order calculation of these correlators shows a huge ($\gsim 100\%$) gluonic enhancement of the $|ΔI|=1/2$ channel, providin

S. Kumano

We discuss two topics in this talk. One is a brief overview of nuclear parton distributions, and the other is SU(2)-flavor-symmetry breaking in {\it nuclear} antiquark distributions. First, we show that nuclear structure functions $F_2^A(x)$ could be explained in a $Q^2$ rescaling model with parton recombination effects. Then, nuclear gluon distributions are

G. S. Bali, K. Schilling, C. Schlichter, A. Wachter

We show the running coupling as derived from the SU(3) QQ potential and discuss preliminary results on spin dependent heavy quark potentials from high statistics lattice simulations of SU(2) gauge theory. The precision suffices to study scaling properties and lattice artifacts (at short distances). We identify the Coulomb like short range interaction as a mi

A. Agodi, G. Andronico, M. Consoli

We present a critical reappraisal of the available results on the broken phase of $λ(Φ^4)_4$ theory, as obtained from rigorous formal analyses and from lattice calculations. All the existing evidence is compatible with Spontaneous Symmetry Breaking but dictates a trivially free shifted field that becomes controlled by a quadratic hamiltonian in the continuum

Robert Beig, Sascha Husa

A new class of time-symmetric solutions to the initial value constraints of vacuum General Relativity is introduced. These data are globally regular, asymptotically flat (with possibly several asymptotic ends) and in general have no isometries, but a $U(1)\times U(1)$ group of conformal isometries. After decomposing the Lichnerowicz conformal factor in a dou

Vadim V. Zhytnikov, James M. Nester

We consider the possibility of an alternative gravity theory explaining the dynamics of galactic systems without dark matter. From very general assumptions about the structure of a relativistic gravity theory we derive a general expression for the metric to order $(v/c)^2$. This allows us to compare the predictions of the theory with various experimental dat

Bernhard Leeb

In the context of Thurstons geometrisation program we address the question which compact aspherical 3-manifolds admit Riemannian metrics of nonpositive curvature. We show that non-geometric Haken manifolds generically, but not always, admit such metrics. More precisely, we prove that a Haken manifold with, possibly empty, boundary of zero Euler characteristi

F. E. Burstall, F. Pedit

We study the harmonic map equations for maps of a Riemann surface into a Riemannian symmetric space of compact type from the point of view of soliton theory. There is a well-known dressing action of a loop group on the space of harmonic maps and we discuss the orbits of this action through particularly simple harmonic maps called {\em vacuum solutions}. We s

Lian Zheng, H. A. Fertig

Using the Hartree-Fock approximation, we calculate the energy of different Wigner crystal states for the two-dimensional electron gas of a double quantum well system in a strong magnetic field. Our calculation takes interlayer hopping as well as an in-plane magnetic field into consideration. The ground The ground state at small layer separations is a one-com

Y. Trudeau, M. L. Plumer

A method for treating ferromagnetic chains coupled with antiferromagnetic interactions on an hexagonal lattice is presented in this paper. The solution of the $1D$ part of the problem is obtained by classical transfer-matrix while the coupling between the chains is processed by mean-field theory. This method is applied with success to the phase diagram and a

Rodney Price, Xuejun Zhu, S. Das Sarma, P. M. Platzman

Assuming that the phase transition between the Wigner solid and the Laughlin liquid is first-order, we compare ground-state energies to find features of the phase diagram at fixed $ν$. Rather than use the Coulomb interaction, we calculate the effective interaction in a square quantum well, and fit the results to a model interaction with length parameter $λ$

Jae Dong Noh, Doochul Kim

We investigate the interacting domain-wall model derived from the triangular-lattice antiferromagnetic Ising model with two next-nearest-neighbor interactions. The system has commensurate phases with a domain-wall density $q=2/3$ as well as that of $q=0$ when the interaction is repulsive. The $q=2/3$ commensurate phase is separated from the incommensurate ph

Ralf Steinberger

Modifiers in general, and adverbs in particular, are neglected categories in linguistics, and consequently, their treatment in Natural Language Processing poses problems. In this article, we present the dictionary information for German adverbs which is necessary to deal with word order, degree modifier scope and other problems in NLP. We also give evidence

David Carter

Many of the kinds of language model used in speech understanding suffer from imperfect modeling of intra-sentential contextual influences. I argue that this problem can be addressed by clustering the sentences in a training corpus automatically into subcorpora on the criterion of entropy reduction, and calculating separate language model parameters for each

C. I. Short, J. B. Lester

Synthetic spectra of Arcturus computed with the latest theoretical stellar atmospheres disagree strongly with both the spectral energy distribution and with the spectroscopic data for $λ< 4000$ Å, even though the stellar parameters are well constrained. We find that the discrepancy can be removed by adding a continuous absorption opacity that is approximatel

Roeland P. van der Marel

The dynamical evidence for black holes (BHs) in galactic nuclei is reviewed, with emphasis on recent improvements in spatial resolution, methods for analyzing galaxy spectra and dynamical modeling. M31, M32 and M87 are discussed in some detail.

Peter J. Kernan, Lawrence M. Krauss

We supplement \ML methods with a \MC simulation to re-investigate the SN1987A neutrino burst detection by the IMB and Kamiokande experiments. The detector simulations include background in the the latter and ``dead-time&#39;&#39; in the former. We consider simple neutrinosphere cooling models, explored previously in the literature, to explore the case for or

Vladimir V. Kisil

To study operator algebras with symmetries in a wide sense we introduce a notion of {\em relative convolution operators} induced by a Lie algebra. Relative convolutions recover many important classes of operators, which have been already studied (operators of multiplication, usual group convolutions, two-sided convolution etc.) and their different combinatio

The MACRO Collaboration, J. T. Hong

The MACRO experiment at Gran Sasso provides means for detailed studies of multiple coincident penetrating cosmic ray muons. In this paper we concentrate on the studies of the ultrahigh energy primary cosmic ray composition using muon bundle multiplicities, muon pair lateral and angular separation distributions.

Robert de Mello Koch, João P. Rodrigues

The supersymmetric collective field theory with the potential $v&#39;(x)=ωx-{η\over x}$ is studied, motivated by the matrix model proposed by Jevicki and Yoneya to describe two dimensional string theory in a black hole background. Consistency with supersymmetry enforces a two band solution. A supersymmetric classical configuration is found, and interpreted i

S. S. Kamalov, L. Tiator, C. Bennhold

A breakdown of the Impulse Approximation is studied in pion photoproduction on $^3$He at high momentum transfers. The usual DWIA formalism with Faddeev wave functions which works well for small momentum transfers deviates from experimental measurements by up to two orders of magnitude for $Q^2>6 fm^{-2}$. It is found that the explicit inclusion of two-body m

L. L. Salcedo

A definition is given, in the framework of stochastic quantization, for the dynamics of a system composed of classical and quantum degrees of freedom mutually interacting. It is found that the theory breaks reflection positivity, and hence it is unphysical. The Feynman rules for the Euclidean vacuum expectation values are derived and the perturbative renorma

Z. Berezhiani, A. Rossi

The neutrino long wavelength (just-so) oscillation is revisited as a solution to the solar neutrino problem. We consider just-so scenario in various cases: in the framework of the solar models with relaxed prediction of the boron neutrino flux, as well as in the presence of the non-standard weak range interactions between neutrino and matter constituents. We

E. V. Ferapontov, Y. Nutku

Surfaces of constant negative curvature in Euclidean space can be described by either the sine-Gordon equation for the angle between asymptotic directions, or a Monge-Ampere equation for the graph of the surface. We present the explicit form of the correspondence between these two integrable non-linear partial differential equations using their well-known pr

J. L. Friar

A summary of the XIV\underline{th} International Conference on Few-body Problems In Physics is given, with an emphasis on the important problems solved recently and the prognosis for the future of the field. Personal remarks and ``homework&#39;&#39; problem assignments are made.

Dmitrij V. Volkov

A story on how an attempt to realize W. Heizenberg idea that the neutrino might be a Goldstone particle had led in its development to the discovery of supergravity action.

Michael Bershadsky, Vladimir Sadov

In this paper we discuss the connection on a space of $N=2$ TCFT&#39;s that appears in the context of background (in)dependence. We formulate a family of {\it target space field theories} with a similar connection on it. Each theory is a gauge theory (with the gauge group being ${\cal SD}iff $ in the case of $3$-fold). It describes deformations of Kähler str

J. Fuchs, A. N. Schellekens, C. Schweigert

The set of modular invariants that can be obtained from Galois transformations is investigated systematically for WZW models. It is shown that a large subset of Galois modular invariants coincides with simple current invariants. For algebras of type B and D infinite series of previously unknown exceptional automorphism invariants are found.

S. P. Clarke, J. F. Cornwell

The conjugacy classes of the involutive automorphisms of the affine Kac-Moody algebras \Cli\ for $\ell\geq 2$ are determined using the matrix formulation of automorphisms of an affine Kac-Moody algebra.

A. A. Tseytlin

We review some recent results about exact classical solutions in string theory. In particular, we consider four dimensional extremal electric black holes which are related via dimensional reduction to the exact five dimensional fundamental string solutions. We also comment on the issue of \a&#39; corrections to non-extremal black holes. (To appear in Proceed

Z. Khviengia, H. Lu, C. N. Pope, E. Sezgin

In this paper we construct a $(2,2)$ dimensional string theory with manifest $N=1$ spacetime supersymmetry. We use Berkovits&#39; approach of augmenting the spacetime supercoordinates by the conjugate momenta for the fermionic variables. The worldsheet symmetry algebra is a twisted and truncated ``small&#39;&#39; $N=4$ superconformal algebra. The physical sp

H. Lu, C. N. Pope, K. Thielemans, X. J. Wang

In this paper, we examine the conditions under which a higher-spin string theory can be quantised. The quantisability is crucially dependent on the way in which the matter currents are realised at the classical level. In particular, we construct classical realisations for the $W_{2,s}$ algebra, which is generated by a primary spin-$s$ current in addition to

B. Rusakov

Pure gauge lattice QCD at arbitrary D is considered. Exact integration over link variables in an arbitrary D-volume leads naturally to an appearance of a set of surfaces filling the volume and gives an exact expression for functional of their boundaries. The interaction between each two surfaces is proportional to their common area and is realized by a non-l

M. M. Leite, V. O. Rivelles

We present a central extension of the $(m,n)$ super-Poincaré algebra in two dimensions. Besides the usual Poincaré generators and the $(m,n)$ supersymmetry generators we have $(m,n)$ Grassmann generators, a bosonic internal symmetry generator and a central charge. We then build up the topological gauge theory associated to this algebra. We can solve the clas

M. Kibler

Some results about non-bijective quadratic transformations generalizing the Kustaanheimo-Stiefel and the Levi-Civita transformations are reviewed in §1. The three remaining sections are devoted to new results: §2 deals with the Lie algebras under constraints associated to some Hurwitz transformations; §3 and §4 are concerned with several applications of some

Pietro Donatis, Roberto Iengo

We study the possible stationary persistent supercurrents flowing on a cylindrical sample supporting a two-dimensional charged fluid. The internal dynamics of the fluid is obtained by means of an effective theory in which the fluid self-interacts through a $U(1)$ gauge field. We find that the presence of persistent supercurrents depends on what kind of gauge

Valeri V. Dvoeglazov

The Weinberg-Tucker-Hammer equations are shown to substitute the common-used $j=1$ massless equations. Meantime, the old equations preserve their significance as a particular case. Possible consequences are discussed.

George Siopsis

We discuss the Hamiltonian formulation of the Schwinger proper-time method of calculating Green functions in gauge theories. Instead of calculating Feynman diagrams, we solve the corresponding Dyson-Schwinger equations. We express the solutions in terms of vertex operators, which consist of the zero modes of the vertex operators appearing in string theories.

G. Raffelt, A. Weiss

If axions or other low-mass pseudoscalars couple to electrons (``fine structure constant&#39;&#39; $α_a$) they are emitted from red giant stars by the Compton process $γ+e\to e+a$ and by bremsstrahlung $e+(Z,A)\to (Z,A)+e+a$. We construct a simple analytic expression for the energy-loss rate for all conditions relevant for a red giant and include axion losse

G. DOMOKOS, S. KOVESI-DOMOKOS

A class of phenomena either not contained in the Standard Model or in its perturbative treatment (multiple W/Z production, compositeness of quarks and leptons) leads to a large energy deposition in neutrino telescopes within a rather small volume. The shape of the particle distribution arising from such phenomena is estimated.