November 1995 arXiv papers — page 6

G. Amelino-Camelia, L. Griguolo, D. Seminara

The radiation from the black holes of a 1+1-dimensional chiral quantum gravity model is studied. Most notably, a non-trivial dependence on a renormalization parameter that characterizes the anomaly relations is uncovered in an improved semiclassical approximation scheme; this dependence is not present in the naive semiclassical approximation.

A. A. Gvozdev, N. V. Mikheev, L. A. Vassilevskaya

A brief overview of the recent measurements of the branching ratio of the rare $K_L^0 \to μ^+ μ^-$ decay in the context of their agreement with the Standard Model (SM) is given. It is shown that KEK result well correlates with the SM and B-physics, whereas the BNL results are in conflict with the SM with the heavy top quark.

Eric W. Hirschmann, Douglas M. Eardley

We examine the gravitational collapse of a non-linear sigma model in spherical symmetry. There exists a family of continuously self-similar solutions parameterized by the coupling constant of the theory. These solutions are calculated together with the critical exponents for black hole formation of these collapse models. We also find that the sequence of sol

Eugene Lerman, Susan Tolman

In the first part of the paper, we build a foundation for further work on Hamiltonian actions on symplectic orbifolds. Most importantly we prove the orbifold versions of the abelian connectedness and convexity theorems. In the second half, we prove that compact symplectic orbifolds with completely integrable torus actions are classified by convex simple rati

D. Barbosa, J. G. Bartlett, A. Blanchard, J. Oukbir

We consider the Sunyaev-Zel'dovich (SZ) effect as a probe of Omega_o: Using a self-consistent modeling of X-ray clusters, we examine the dependence of both the mean Compton y parameter and the SZ source counts on Omega_o. These quantities increase with decreasing Omega_o due to the earlier epoch of structure formation in low-density cosmogonies; the resu

Rosemary F. G. Wyse

What the future holds for the stellar populations of the Milky Way Galaxy may (optimistically) be predicted by study of their past histories, as written in the chemical abundance distributions, angular momentum distributions, velocity dispersion tensor, ages and spatial structure of their constituent older stars.

R. Srianand

We present the results of reanalysis of low z Mg II absorption line sample compiled by SS92. The conditions on cloud parameters to produce N(Fe II)>N(Mg II) are obtained using photoionization models and curve of growth. Properties of Mg II absorbers with W(Fe II)/W(MgII) (definded as R) >and< 0.5 are analysed separately. Contrary to the whole Mg II sample, t

Boguslaw Broda

The paper contains a talk given by the author at the Banach Center in Spring 1995. It recapitulates author&#39;s approach to construction of topological invariants of the Reshetikhin-Turaev-Witten type of 3- and 4-dimensional manifolds in the framework of SU(2) Chern-Simons gauge theory and its hidden (quantum) gauge symmetry.

D. Boyanovsky, M. D&#39;attanasio, H. J. de Vega, R. Holman

The reheating stage in post-inflationary cosmologies is reanalyzed. New techniques from non-equilibrium quantum field theory allow a consistent derivation of the equation of motion including the non-linearity of the dynamics. These offer a rationale for the elementary theory of reheating based on single particle decay which is seen to be valid only in the li

M. A. Yusuf, P. Hoodbhoy

Withdrawn; originally put in incomplete form without permission

Debajyoti Choudhury, Subir Sarkar

We consider the hypothesis that the recently reported anomaly in the time structure of signals in the KARMEN experiment is due to the production of a light photino (or Zino) which decays radiatively due to violation of $R$-parity. Such a particle is shown to be consistent with all experimental data and with cosmological nucleosynthesis. There are difficultie

Camillo Imbimbo, Sunil Mukhi

A very elementary model of a single positive hermitian random matrix coupled to an external matrix is defined and studied. Expanding the exact effective action around its classical solution leads to the ``quantum Penner action&#39;&#39;, from which a rich structure of correlation functions is obtained. These are shown to be equal to the all-orders perturbati

H. Itoyama, A. Morozov

Interpretation of exact results on the low-energy limit of $4d$ $N=2$ SUSY YM in the language of $1d$ integrability theory is reviewed. The case of elliptic Calogero system, associated with the flow between $N=4$ and $N=2$ SUSY in $4d$, is considered in some detail.

D. W. Murray, O. P. Sushkov

A calculation of the spin-wave polarization operator is very important for the analysis of the magnetic structure of high temperature superconductors. We analyze the significance of the incoherent part of the spin-wave polarization operator within the framework of the t-J model. This part is calculated analytically for small doping with logarithmic accuracy.

Leonard Susskind

Consistency of the Bekenstein bound on entropy requires the physical dimensions of particles to grow with momentum as the particle is boosted to transplanckian energies. In this paper the problem of particle growth in heterotic string theory is mapped into a problem involving the properties of BPS saturated black holes as the charge is increased. Explicit ca

Christopher King, Andrzej Lesniewski

We define a large class of quantum sources and prove a quantum analog of the asymptotic equipartition property. Our proof relies on using local measurements on the quantum source to obtain an associated classical source. The classical source provides an upper bound for the dimension of the relevant subspace of the quantum source, via the Shannon-McMillan noi

D. P. McNabb, G. Baldsiefen, L. A. Bernstein, J. A. Cizewski

The $^{174}$Yb($^{29}$Si,5n) reaction at 148 MeV with thin targets was used to populate high-angular momentum states in $^{198}$Po. Resulting $γ$ rays were observed with Gammasphere. A weakly-populated superdeformed band of 10 $γ$-ray transitions was found and has been assigned to $^{198}$Po. This is the first observation of a SD band in the $A \approx 190$

E. Abdalla, F. M. de Carvalho Filho

We obtain a Quantum Electrodynamics in 2+1 dimensions by applying a Kaluza--Klein type method of dimensional reduction to Quantum Electrodynamics in 3+1 dimensions rendering the model more realistic to application in solid-state systems, invariant under translations in one direction. We show that the model obtained leads to an effective action exhibiting an

Fernando Quevedo

The status of gaugino condensation in low-energy string theory is reviewed. Emphasis is given to the determination of the efective action below condensation scale in terms of the 2PI and Wilson actions. We illustrate how the different perturbative duality symmetries survive this simple nonperturbative phenomenon, providing evidence for the believe that these

Vladimir O. Soloviev

It is shown how to extend the formal variational calculus in order to incorporate integrals of divergences into it. Such a generalization permits to study nontrivial boundary problems in field theory on the base of canonical formalism.

A. Das, R. Amorim, C. Wotzasek

We study the soldering of two Siegel chiral bosons into one scalar field in a gravitational background.

M. Reuter

The renormalization of the Chern-Simons parameter is investigated by using an exact and manifestly gauge invariant evolution equation for the scale-dependent effective average action.

Hiroaki Kanno

In cohomological field theory we can obtain topological invariants as correlation functions of BRS cohomology classes. A proper understanding of BRS cohomology which gives non-trivial results requires the equivariant cohomology theory. Both topological Yang-Mills theory and topological string theory are typical examples of this fact. After reviewing the role

Kazuo Fujikawa

After a brief historical comment on the study of BRS(or BRST) symmetry , we discuss the quantization of gauge theories with Gribov copies. A path integral with BRST symmetry can be formulated by summing the Gribov-type copies in a very specific way if the functional correspondence between $τ$ and the gauge parameter $ω$ defined by $τ(x) = f( A_μ^ω(x))$ is ``

N. Kitazawa, T. Yanagida

In technicolor theories a large radiative correction to the Zbb vertex generally emerges, because of the large top quark mass and SU(2)_L gauge symmetry. The correction can give us an explanation for the deviation of the experimental value of R_b from the standard model prediction. However, generally the T parameter becomes unacceptably large. We show that i

Amol S. Dighe, Isard Dunietz, Harry J. Lipkin, Jonathan L. Rosner

The strange $B$ meson $B_s \equiv \bar b s$ and its charge-conjugate $\bar B_s \equiv b \bar s$ are expected to mix with one another in such a way that the mass eigenstates $B_s^H$ (``heavy&#39;&#39;) and $B_s^L$ (``light&#39;&#39;) may have a perceptible lifetime difference of up to 40\%, with the CP-even eigenstate being shorter-lived. A simple transversit

T. M. Aliev, D. A. Demir, E. Iltan, N. K. Pak

The radiative decays $ B^{*} (D^{*})\to B(D) γ$ are investigated in the framework of light cone QCD sum rules. The transition amplitude and decay rates are estimated.It is shown that our results on branching ratios of D meson decays are in good agreement with the existing experimental data.

H. Khan, P. Hoodbhoy

Bound-state corrections to $J/ψ$ production from almost real photons are calculated in the colour-singlet model. A systematic, gauge-invariant, theory of hard quarkonium processes is used upto $O(v^2)$, where $v$ is the relative velocity of the quarks. The internal structure of the meson is characterised by two parameters, $ε_B/M$ and $\nabla^2 ϕ(0)/M^2 ϕ(0)

Michael Krämer, Eric Laenen

In two-photon collisions at LEP2 and a future $e^+e^-$ linear collider heavy quarks (mainly charm) will be pair-produced rather copiously. The production via direct and resolved photons can be distinguished experimentally via a remnant-jet tag. We study correlations of the heavy quarks at next-to-leading order in QCD in the direct channel, which is free from

A. Brandenburg, D. Müller, O. V. Teryaev

We consider the production of muon pairs from the scattering of pions on longitudinally polarized protons. We calculate the cross section and the single spin asymmetry for this process, taking into account pion bound state effects. We work in the kinematic region where the photon has a large longitudinal momentum fraction, which allows us to treat the bound

Paolo Cea, Luigi Tedesco

We discuss the finite temperature generalized Gaussian effective potential. We put out a very simple relation between the thermal corrections to the generalizedGaussian effective potential and those of the effective potential. We evaluate explicitly the second order thermal corrections in the case of the selfinteracting scalar field in one spatial dimension.

T. S. Biro

We have found in numerical simulations that the chaoticity of the classical hamiltonian lattice SU(2) gauge theory is reduced in the presence of static charges at the same total energy. The transition from strongly to weakly chaotic behavior is rather sudden at a critical charge strength.

T. M. Aliev, D. A. Demir, E. Iltan, N. K. PAK

Using the experimental upper bound on the neutron EDM and experimental result on $b\rightarrow sγ$ branching ratio we have calculated CP asymmetry and $Γ^{2HDM}(b\rightarrow s{\it{l^{+}l^{-}}})/Γ^{SM}(b\rightarrow s{\it{l^{+}l^{-}}})$. It is shown that in the invariant dilepton mass $q^{2}$ region $(m_{ψ&#39;}^{2}+0.2\; GeV^{2})<\;q^{2}<\;m^{2}_{b}$ the CP a

Jose Julio Lozano Bahilo

This thesis presents a study of the decays $τ\rightarrow eν\overlineν$ identified after a selection of $τ^+τ^-$ events produced in $e^+e^-$ collisions at LEP. These collisions, predominantly mediated by a $Z^0$ boson, offer a good laboratory for the study of weak current parameters. Moreover, the decays of the tau lepton, which proceed via a $W$ boson, incre

A. Lopez-Pinto, A. Tiemblo, R. Tresguerres

The correspondence between the linear multiplicity-free unirreps of SL(4, R) studied by Ne&#39;eman and {S}ija{c}ki and the non-linear realizations of the affine group is worked out. The results obtained clarify the inclusion of spinorial fields in a non-linear affine gauge theory of gravitation.

David Garfinkle, Steven G. Harris

What restrictions are there on a spacetime for which the Ricci curvature is such as to produce convergence of geodesics (such as the preconditions for the Singularity Theorems) but for which there are no singularities? We answer this question for a restricted class of spacetimes: static, geodesically complete, and globally hyperbolic. The answer is that, in

A. Barrat, R. Burioni, M. Mézard

In this letter we present a dynamical study of the structure of metastable states (corresponding to TAP solutions) in a mean-field spin-glass model. After reviewing known results of the statical approach, we use dynamics: starting from an initial condition thermalized at a temperature between the statical and the dynamical transition temperatures, we are abl

W. Ziegler, D. Poilblanc, R. Preuss, W. Hanke

Using a generalized T-matrix description which, in principle, exactly includes Coulomb correlations and potential scattering events, resonant and bound impurity states are discussed. Like in the non-interacting case, the effects of the scattering potential can be divided into different partial wave channels, exploiting the symmetry of the underlying lattice.

H. -B. Schüttler, C. -H. Pao

Based on recently proposed anti-ferromagnetic spin fluctuation exchange models for $d_{x^2-y^2}$-superconductors, we show that coupling to harmonic phonons {\it{cannot}} account for the observed isotope effect in the cuprate high-$T_c$ materials, whereas coupling to strongly anharmonic multiple-well lattice tunneling modes {\it{can}}. Our results thus point

L. Yin, S. Chakravarty

Spectral anomaly for interacting Fermions is characterized by the spectral function $A([k-k_F],ω)$ satisfying the scaling relation $A(Λ^{y_1} [k-k_F],Λ^{y_2}ω)= Λ^{y_A}A([k-k_F],ω)$, where $y_1$, $y_2$, and $y_A$ are the exponents defining the universality class. For a Fermi liquid $y_1=1$, $y_2=1$, $y_A=-1$; all other values of the exponents are termed anom

E. Baron, P. H. Hauschildt, A. Mezzacappa

Modeling the atmospheres of SNe~Ia requires the solution of the NLTE radiative transfer equation. We discuss the formulation of the radiative transfer equation in the co-moving frame. For characteristic velocities larger than about 2000 km/s, the effects of advection on the synthetic spectra are non-negligible, and hence should be included in model calculati

Corinne Charbonnel

The observations of carbon isotopic ratios in evolved stars suggest that non standard mixing is acting in low mass stars as they are ascending the red giant branch. We propose a simple consistent mechanism, based on the most recent developments in the description of rotation-induced mixing by Zahn (1992), which simultaneously accounts for the low $^{12}$C/$^

Max Tegmark, Dieter Hartmann, Michael Briggs, Jon Hakkila

We tighten previous upper limits on gamma ray burst repetition by analyzing the angular power spectrum of the BATSE 3B catalog of 1122 bursts. At 95% confidence, we find that no more than 2% of all observed bursts can be labeled as repeaters, even if no sources are observed to repeat more than once. If a fraction f of all observed bursts can be labeled as re

J. I. Katz, L. M. Canel

We report evidence from the 3B Catalogue that short (T_90 < 10 s) and long (T_90 > 10 s) GRB represent different populations and processes: Their spectral behavior is qualitatively different, with short bursts harder in the BATSE range, but chiefly long bursts detected at higher photon energies; \langle V/V_max \rangle = 0.385 \pm 0.019 for short GRB but \la

M. Farhoudi

We seek an analogy of the mathematical form of the alternative form of Einstein&#39;s field equations for Lovelock&#39;s field equations. We find that the price for this analogy is to accept the existence of the trace anomaly of the energy-momentum tensor even in classical treatments. As an example, we take this analogy to any generic second order Lagrangian

L. E. Saltini, A. Zadra

We propose a graphic method to derive the classical algebra (Dirac brackets) of non-local conserved charges in the two dimensional supersymmetric non-linear $O(N)$ sigma model. As in the purely bosonic theory we find a cubic Yangian algebra. We also consider the extension of graphic methods to other integrable theories.

Ludwik Dabrowski, Preeti Parashar

h-deformation of (graded) Hopf algebra of functions on supergroup GL(1|1) is introduced via a contration of GL_q (1|1). The deformation parameter h is odd (grassmann). Related differential calculus on h-superplane is presented.

Denis V. Juriev

This paper is a compact overview of the heuristic approach to the recently elaborated octonionic binocular mobilevision.

Hisakazu Minakata, Berndt Muller

We discuss the effect of strong electromagnetic fields on chiral orientation in the framework of the linear $σ$ model. Based on lessons we learn from computation of the effective potential at one loop, we argue that the chiral U(1) anomaly dominates chiral disorientation driven by electromagnetism. We show that the anomaly effect induces a quasi-instantaneou

Stefano Forte

We review recent developments in the theory and phenomenology of polarized structure functions. We summarize recent experimental data on the proton and deuteron structure function $g_1$, and their impact on the understanding of polarized sum rules. Specifically, we discuss how accurate measurements of the singlet and nonsinglet first moment of $g_1$ test per

V. Antonelli, S. Bertolini, M. Fabbrichesi, E. I. Lashin

We compute the isospin $I= 0$ and 2 amplitudes for the decay of a kaon into two pions by estimating the relevant hadronic matrix elements in the chiral quark model. The results are parametrized in terms of the quark and gluon condensates and of the constituent quark mass $M$. The latter is a parameter characteristic of the model, that we restrict by matching

A. G. Akeroyd

Higgs bosons with negligible couplings to fermions can arise in various non--minimal Higgs sectors. We show that such a particle could be discovered during the current run at the Tevatron, and would be evidence against a minimal supersymmetric Higgs sector.

Alexander Moroz

The Dirac Hamiltonian with the Aharonov-Bohm potential provides an example of a non-Fredholm operator for which all spectral asymmetry comes entirely from the continuous spectrum. In this case one finds that the use of standard definitions of the resolvent regularized, the heat kernel regularized, and the Witten indices misses the contribution coming from th

Gabor Vattay

We show, that the canonical invariant part of $\hbar$ corrections to the Gutzwiller trace formula and the Gutzwiller-Voros spectral determinant can be computed by the Bohr-Sommerfeld quantization rules, which usually apply for integrable systems. We argue that the information content of the classical action and stability can be used more effectively than in

R. Ansari

EROS (Expérience de Recherche d&#39;Objets Sombres) has been monitoring the luminosity of 4 million stars in the Large Magellanic Cloud in order to search for gravitational microlensing by unseen objects in the galactic halo. We present here the results from 3 years of EROS Schmidt plates data. Two stars exhibit light curves that are consistent with a sizeab

Laszlo Feher, Izumi Tsutsui

The Toda lattice defined by the Hamiltonian $H={1\over 2} \sum_{i=1}^n p_i^2 + \sum_{i=1}^{n-1} ν_i e^{q_i-q_{i+1}}$ with $ν_i\in \{ \pm 1\}$, which exhibits singular (blowing up) solutions if some of the $ν_i=-1$, can be viewed as the reduced system following from a symmetry reduction of a subsystem of the free particle moving on the group $G=SL(n,\Real )$.

H. Aoki, H. Kawai, J. Nishimura, A. Tsuchiya

We consider correlation functions of operators and the operator product expansion in two-dimensional quantum gravity. First we introduce correlation functions with geodesic distances between operators kept fixed. Next by making two of the operators closer, we examine if there exists an analog of the operator product expansion in ordinary field theories. Our

Z. Bern, A. G. Morgan

We show, for previously uncalculated examples containing a uniform mass in the loop, that it is possible to obtain complete massive one-loop gauge theory amplitudes solely from unitarity and known ultraviolet or infrared mass singularities. In particular, we calculate four-gluon scattering via massive quark loops in QCD. The contribution of a heavy quark to

Ehab Malkawi, Tim Tait

The possibility of an anomalous coupling between the top and charm quarks and the gluon field is explored in a model-independent way using an effective Lagrangian that is gauge-invariant under a non-linear realization of SU(3)$_{C} \times$ SU(2$)_{L} \times$ U(1$)_{Y}$. Even for the current 200 $pb^{-1}$ of integrated luminosity at the Tevatron, the new phys

M. Zyskin

We consider a real manifold of dimension 3 or 4 with Minkovsky metric, and with a connection for a trivial GL(n,C) bundle over that manifold. To each light ray on the manifold we assign the data of paralel transport along that light ray. It turns out that these data are not enough to reconstruct the connection, but we can add more data, which depend now not

Wei Lu, Xue Qian Li, Haiming Hu

Two spin-dependent structure functions $\hat g_1$ and $\hat g_2$ for the inclusive spin-half baryon production in electron-positron annihilation are studied in the context of QCD factorization as well as in the naive quark parton model. As a result, it is found that the sum of $\hat g_1$ and $\hat g_2$ is related to $\hat h_1$ and $\hat g_T$, two quark fragm

D. Levi, R. Yamilov

A modification of the symmetry approach for the classification of integrable differential-difference equations of the form $$ u_{n,t} = f_n(u_{n-1}, u_n, u_{n+1}), $$ where $n$ is a discrete integer variable, is presented (the well-known Volterra and Toda equations can be written in this form). If before, in the framework of the symmetry approach, only equat

V. Vedral, A. Barenco, A. Ekert

Quantum computers require quantum arithmetic. We provide an explicit construction of quantum networks effecting basic arithmetic operations: from addition to modular exponentiation. Quantum modular exponentiation seems to be the most difficult (time and space consuming) part of Shor&#39;s quantum factorising algorithm. We show that the auxiliary memory requi

Jiye Yu

We construct a smoothly bounded pseudoconvex domain such that every boundary point has a p.s.h. peak function but some boundary point admits no (local) holomorphic peak function.

Rulin Xiu

We determine the dilaton and moduli vacuum expectation values using the one-loop effective potential and topological constraints. A new ingredient of this analysis is that we use a dilaton Kähler potential that includes renormalization effects to all loops. We find that the dilaton vacuum expectation value is related to certain topological properties of the

Thomas Thiemann

In the present article we display a new constructive quantum field theory approach to quantum gauge field theory, utilizing the recent progress in the integration theory on the moduli space of generalized connections modulo gauge transformations. That is, we propose a new set of Osterwalder Schrader like axioms for the characteristic functional of a measure

Giovanni Felder, Alexander Varchenko

We give three formulas for meromorphic eigenfunctions (scattering states) of Sutherland&#39;s integrable N-body Schroedinger operators and their generalizations. The first is an explicit computation of the Etingof-Kirillov traces of intertwining operators, the second an integral representation of hypergeometric type, and the third is a formula of Bethe ansat

Pierre van Baal

We review the global issues associated to gauge fixing ambiguities and their consequence for glueball spectroscopy. To avoid infrared singularities the theory is formulated in a finite volume. The examples of a cubic and spherical geometry will be discussed in some detail. Our methods are not powerful enough to study the infinite volume limit, but the result

Renata Kallosh, Andrei Linde

Until now all known static multi black hole solutions described BPS states with charges of the same sign. Such solutions could not be related to flat directions in the space of BPS states. The total number of such states could not spontaneously increase because of the charge conservation. We show that there exist static BPS configurations which remain in equ

B. Machet

I study the scalar representations of the electroweak group of the Standard Model, with a special emphasis on their chiral properties and on their behaviour by the discrete symmetries P and CP. A gauge theory for J=0 mesons naturally springs out, together with a new approach to the question of the electroweak violation of CP. When acting in the 4-dimensional

S. Moretti, W. J. Stirling

In Ref.~\cite{paper} we calculated all the experimentally relevant branching ratios of the Higgs bosons of the Minimal Supersymmetric Standard Model, paying particular attention to the contributions from below--threshold decays. Unfortunately, an error in one of the subroutines of the {\tt FORTRAN} code we used was affecting the computation of the off--shell

Ann E. Nelson

We propose a simple and natural model of dynamical supersymmetry breaking, which could be used as a mechanism for spontaneous supersymmetry breaking in a gravitationally coupled hidden sector. The gaugino masses in the visible sector are naturally of the same size as the squark, slepton, and gravitino masses.

Tomislav Prokopec, Robert Brandenberger, Anne C. Davis, Mark Trodden

Based on a study of {\it charge,} (C), {\it parity} (P) and {\it time reversal} (T) symmetries we show how a CP violating network of defects in the early Universe may bias baryon number production. A static network, even though it violates CP, respects CPT and hence does not bias baryon number production. On the other hand, the {\it ordering dynamics\/} of d

T. Gousset, B. Pire

We review the theory of hard exclusive reactions in QCD.

A. Djouadi, M. Spira, P. M. Zerwas

We present an update of the branching ratios for Higgs decays in the Standard Model and the Minimal Supersymmetric extension of the Standard Model. In particular, the decays of the Higgs particles to quark and gluon jets are analyzed and the spread in the theoretical predictions due to uncertainties of the quark masses and the QCD coupling is discussed.

Paul H. Frampton, Otto C. W. Kong

It is shown how to use as horizontal symmetry the dicyclic group $Q_6 \subset SU(2)$ in a supersymmetric unification $SU(5)\otimes SU(5)\otimes SU(2)$ where one $SU(5)$ acts on the first and second families, in a horizontal doublet, and the other acts on the third. This can lead to acceptable quark masses and mixings, with an economic choice of matter superm

A. Djouadi, J. Kalinowski, P. M. Zerwas

We summarize the dominant decay modes of the neutral and charged Higgs bosons in the Minimal Supersymmetric extension of the Standard Model. While two--body decays are in general dominating, the branching ratios for three--body decays of the heavy scalar, pseudoscalar and charged Higgs bosons can be large below the thresholds if top quarks, $W/Z$ bosons or h

H. B. Nielsen, A. V. Novikov, V. A. Novikov, M. I. Vysotsky

We consider the bounds for the values of higgs mass $M_H$ and of the mass of the extra quarks and leptons $M_{extra}$ derived from the stability of vacuum and from the absence of Landau pole in Higgs potential. We find that in the case of the absence of new physics up to the GUT scale the bounds for the mass of the 4th generation are so restrictive that the

P. Maris

In (2+1)-dimensional QED with a Chern-Simons term, we study dynamical breaking of chiral symmetry, using the Dyson--Schwinger equation for the fermions. There is a region in parameter space were dynamical chiral symmetry breaking occurs, just as in pure QED3 (without Chern--Simons term); outside this region, this chiral symmetry breaking solution does not ex

Keisuke Fujii, Mihoko M. Nojiri, Toshifumi Tsukamoto

The lighter scalar tau lepton $\sti$ may be the lightest scalar lepton and therefore would be found earlier in future collider experiments. We point out the impact of the measurement of the mass and the mixing angle of $\st$ to discriminate the models of SUSY breaking. Furthermore, the measurement of the polarization of $τ$ lepton($P_τ$) from the decaying $\

Masayasu Harada, Francesco Sannino, Joseph Schechter

Motivated by the 1/Nc expansion, we present a simple model of pion-pion scattering as a sum of a `current-algebra&#39; contact term and resonant pole exchanges. The model preserves crossing symmetry as well as unitarity up to 1.2 GeV. Key features include chiral dynamics, vector meson dominance, a broad low energy scalar (sigma) meson and a `Ramsauer-Townsen

Yoshiharu Kawamura

Starting from non-minimal supergravity theory with unified gauge symmetry, we obtain the low-energy effective theory by taking the flat limit and integrating out the superheavy fields in a model-independent manner. The scalar potential has extra non-universal contributions to soft supersymmetry breaking terms which can give an impact on phenomenological stud

Pankaj Jain, Bernard Pire, John P. Ralston

Color transparency is the proposal that under certain circumstances the strong interactions can be reduced in magnitude. We give a comprehensive review of the physics, which hinges on the interface of perturbative QCD with non--perturbative strong interactions. Color transparency is complementary to {\it nuclear filtering}, which is the conversion of quark w

Thomas Thiemann

In this article we summarize and describe the recently found transforms for theories of connections modulo gauge transformations associated with compact gauge groups. Specifically, we put into a coherent picture the so-called loop transform, the inverse loop transform, the coherent state transform and finally the Wick rotation transform which is the appropri

R. Jackiw

(from the talk:) I shall here speak on gravity in (1+1)-dimensional space-time --- lineal gravity. The purpose of studying lower dimensional theories, and specifically lower dimensional gravity, is to gain insight into difficult conceptional issues, which are present and even more opaque in the physical (3+1)-dimensional world. Perhaps lessons learned in the

Masafumi Seriu

We investigate the back-reaction effect of the quantum field on the topological degrees of freedom in (2+1)-dimensional toroidal universe, ${\cal M} \simeq T^2\times {\bf R}$. Constructing a homogeneous model of the toroidal universe, we examine explicitly the back-reaction effect of the Casimir energy of a massless, conformally coupled scalar field, with a

Susan Tolman

An important question with a rich history is the extent to which the symplectic category is larger than the Kaehler category. Many interesting examples of non-Kaehler symplectic manifolds have been constructed. However, sufficiently large symmetries can force a symplectic manifold to be Kaehler. In this paper, we solve several outstanding problems by constru

Iwan Jensen, Anthony J. Guttmann

We have derived long series expansions of the percolation probability for site, bond and site-bond percolation on the directed triangular lattice. For the bond problem we have extended the series from order 12 to 51 and for the site problem from order 12 to 35. For the site-bond problem, which has not been studied before, we have derived the series to order

Miguel A. Martin-Delgado, German Sierra

We present two new analytic formulations of the Density Matrix Renormalization Group Method. In these formulations we combine the block renormalization group (BRG) procedure with Variational and Fokker-Planck methods. The BRG method is used to reduce the lattice size while the latter are used to construct approximate target states to compute the block densit

Alexander Altland, Yuval Gefen, Gilles Montambaux

The Thouless energy, $\Ec$ characterizes numerous quantities associated with sensitivity to boundary conditions in diffusive mesoscopic conductors. What happens to these quantities if the disorder strength is decreased and a transition to the ballistic regime takes place? In the present analysis we refute the intuitively plausible assumption that $\Ec$ loses

David L. O&#39;Brien, Paul A. Pearce, Roger E. Behrend

In a previous paper, we introduced reflection equations for interaction-round-a-face (IRF) models and used these to construct commuting double-row transfer matrices for solvable lattice spin models with fixed boundary conditions. In particular, for the Andrews-Baxter-Forrester (ABF) models, we derived special functional equations satisfied by the eigenvalues

A. Bäcker, H. R. Dullin

The periodic orbits of the strongly chaotic cardioid billiard are studied by introducing a binary symbolic dynamics. The corresponding partition is mapped to a topological well-ordered symbol plane. In the symbol plane the pruning front is obtained from orbits running either into or through the cusp. We show that all periodic orbits correspond to maxima of t

Juan Garcia-Bellido

Open Inflation has recently been suggested as a possible way out of the age crisis caused by observations of a large rate of expansion of the universe, in conflict with the existence of very old globular clusters. It proposes that our local patch of the universe originated in a quantum tunneling event, with the formation of a single bubble within which our u

Siqin Huang, R. G. Carlberg

The infall of a satellite galaxy onto a galactic disk generally brings in angular momentum that is not aligned with the axis of the disk. The main dynamical issues addressed are what fraction of the orbital angular momentum of the satellite and the associated energy is added to the disk, as opposed to being left in the halo, and whether the absorbed fraction

Abraham Loeb

I calculate the contribution of Bremsstrahlung emission from Lyman-alpha absorption clouds to the brightness of the microwave sky. The calculation is based only on the assumption that the clouds below the Lyman-limit are in photoionization equilibrium with a UV background radiation, and avoids any uncertainty about the clumpiness of the gas. I predict a mini

J. C. Lombardi, F. A. Rasio, S. L. Shapiro

We report the results of new SPH calculations of parabolic collisions between two main-sequence stars in a globular cluster. Such collisions are directly relevant to the formation of blue stragglers. In particular, we consider parent stars of mass $M/M_{TO}=0.2,0.5,0.75$, and $1$, where $M_{TO}$ is the cluster turnoff mass (typically about $0.8\,M_\odot$). L

A. Tomita, F. E. Nakamura, T. Takata, K. Nakanishi

The fraction of star-forming galaxies in rich clusters of galaxies increases rapidly with the redshift. This is interpreted as the result of a rapid evolution of cluster galaxies, though its mechanism is not yet clear. One hypothesis is that if galaxies run into the dense intracluster medium (ICM) regions, starbursts can be induced due to compression of mole

Misha Verbitsky

This article contains a compression of results from alg-geom/9501001, with most proofs omitted. We prove that every two points of the connected moduli space of holomorphically symplectic manifolds can be connected with so-called ``twistor lines&#39;&#39; -- projective lines holomorphically embedded to the moduli space and corresponding to the hyperkähler str

E. S. Martynov, B. V. Struminsky

It is shown that in a supercritical pomeron model the contribution of the tirple-pomeron diagrams violates the unitarity bound for cross-section even with account of the multiple pomeron exchanges between the initial hadrons. Asymptotic behaviour of the single diffractive dissoci\-ation cross-section is calculated in the approximation where every pomeron in

G. Grignani, G. Semenoff, P. Sodano, O. Tirkkonen

We compute the effective action and correlators of the Polyakov loop operator in the Schwinger model at finite temperature and discuss the realization of the discrete symmetries that occur there. We show that, due to nonlocal effects of massless fermions in two spacetime dimensions, the discrete symmetry which governs the screening of charges is spontaneousl