January 1996 arXiv papers — page 3

Gabriel Lopes Cardoso, Dieter Lüst, Thomas Mohaupt

In this talk we summarise our recent results on perturbative and non-perturbative monodromies in four-dimensional heterotic strings with $N=2$ space-time supersymmetry, and we compare our results with the rigid $SU(2)$ $N=2$ Yang-Mills monodromies.

P. Di Vecchia, A. Lerda, L. Magnea, R. Marotta

We describe a set of methods to calculate gauge theory renormalization constants from string theory, all based on a consistent prescription to continue off shell open bosonic string amplitudes. We prove the consistency of our prescription by explicitly evaluating the renormalizations of the two, three and four-gluon amplitudes, and showing that they obey the

Mikhail S. Plyushchay

The minimal bosonization of supersymmetry in terms of one bosonic degree of freedom is considered. A nontrivial relationship of the construction to the Witten supersymmetric quantum mechanics is illustrated with the help of the simplest $N=2$ SUSY system realized on the basis of the ordinary (undeformed) bosonic oscillator. It is shown that the generalizatio

Ariel R. Zhitnitsky

We present some generic arguments demonstrating that an effective Lagrangian $L_{eff}$ which, by definition, contains operators $O^n$ of arbitrary dimensionality in general is not convergent, but rather an asymptotic series. It means that the behavior of the far distant terms has a specific factorial dependence $L_{eff}\sim \sum_n \frac{c_n O^n}{M^{n}},~c_n\

P. F. Harrison, D. H. Perkins, W. G. Scott

We investigate the possible influence of the MSW effect on the expectations for the solar neutrino experiments in the maximal mixing scenario suggested by the atmospheric neutrino data. A direct numerical calculation of matter induced effects in the Sun shows that the naive vacuum predictions are left completely undisturbed in the particular case of maximal

Abdellatif Abada

In the framework of the product ansatz as an approximation for the two-baryon system we review in details the derivation of the isoscalar nucleon-nucleon spin orbit potential coming from the sixth order term of the extended Skyrme model. We show that the sixth order term contributes with a positive sign, as is the case for the Skyrme term, contrary to the cl

Ja. V. Burdanov, G. V. Efimov, S. N. Nedelko, S. A. Solunin

The model of induced quark currents formulated in our recent paper (Phys. Rev. D51, 176) is developed. The model being a kind of nonlocal extension of the bosonization procedure is based on the hypothesis that the QCD vacuum is realized by the (anti-)self-dual homogeneous gluon field. This vacuum field provides the analytical quark confinement. It is shown t

F. Buccella, M. Lusignoli, A. Pugliese

A global previous analysis of two-body nonleptonic decays of $D$ mesons has been extended to the decays involving light scalar mesons. The allowance for final state interaction also in nonresonant channels provides a fit of much improved quality and with less symmetry breaking in the axial charges. We give predictions for about 50 decay branching ratios yet

Marco Laveder

The NOMAD experiment has been designed to search for neutrino-tau appearance in the CERN wide-band neutrino beam . The detector is now completed and has been further improved. All subdetectors are working well. The experiment, where the search for oscillation is based on kinematical criteria, will reach the sensitivity dm2 > 0.7 eV2 for maximal mixing and dm

Tung-Mow Yan, Hai-Yang Cheng, Hoi-Lai Yu

We study the properties of Cabibbo-Kobayashi-Maskawa (CKM) favored semileptonic decays of mesons and baryons containing a heavy quark at the point of no recoil. We first use a diagrammatic analysis to rederive the result observed by earlier authors that at this kinematic point the $B$ meson decays via $b\to c$ transitions can only produce a $D$ or $D^*$ meso

Ciprian Dariescu, Marina-Aura Dariescu

Based on Brodsky-Lepage approach, the nonleptonic $B$ meson decay branching ratio is derived in terms of three parameters and is geometrically analysed as the 3-surface embedded in the 4-dimensional (abstract) Euclidean space generated by the three parameters and $BR$. Investigating its 2-dimensional sections, we find ranges for these parameters imposed by a

T. Kon, T. Kobayashi, S. Kitamura

We investigate the $e^+p \to μ^+ X$ event with high transverse momenta observed at HERA (H1) and show that this event could be interpreted as a signature of the single production of the scalar top quark in a supersymmetric model with $R$-parity breaking interactions. The event topology of the H1 event is rather characteristic and in fact it can be simulated

James Simone

Heavy-meson semileptonic decays calculations on the lattice are reviewed. The focus is upon obtaining reliable matrix elements. Errors that depend upon the lattice spacing, $a$, are an important source of systematic error. Full $O(a)$ improvement of matrix elements for arbitrary-mass four-component quarks is discussed. With improvement, bottom-quark matrix e

Ioannis Kouletsis

We discuss the issue initiated by Kuchař {\it et al}, of replacing the usual Hamiltonian constraint by alternative combinations of the gravitational constraints (scalar densities of arbitrary weight), whose Poisson brackets strongly vanish and cast the standard constraint-system for vacuum gravity into a form that generates a true Lie algebra. It is shown th

Katsutaro Shimizu

We show an equivalence between Dirac quantization and the reduced phase space quantization. The equivalence of the both quantization methods determines the operator ordering of the Hamiltonian. Some examples of the operator ordering are shown in simple models.

Ciprian Dariescu

Motivated by the recent wave of investigations on plane domain wall spacetimes with nontrivial topologies, the present paper deals with (probably) the most simple source field configuration which can generate a spatially planary symmetric static spacetime, namely a minimally coupled massless scalar field that depends only upon a spacelike coordinate, $z$. It

Stefan Scheidl

The two-dimensional XY-model with random phase-shifts on bonds is studied. The analysis is based on a renormalization group for the replicated system. The model is shown to have an ordered phase with quasi long-range order. This ordered phase consists of a glass-like region at lower temperatures and of a non-glassy region at higher temperatures. The transiti

Erik Luijten, Henk W. J. Blöte

According to renormalization theory, Ising systems above their upper critical dimensionality d_u = 4 have classical critical behavior and the ratio of magnetization moments Q = <m^2>^2 / <m^4> has the universal value 0.456947... However, Monte Carlo simulations of d = 5 Ising models have been reported which yield strikingly different results, suggesting that

I. V. Krive, P. Sandström, R. I. Shekhter, M. Jonson

The Aharonov-Bohm effect in a one-dimensional (1D) ring containing a gas of fractionally charged excitations is considered. It is shown that the low temperature behavior of the system is identical to that of free electrons with (integer) charge $e$. This is a direct consequence of the fact that the total charge in the ring is quantized in units of the electr

Yusuke Kato, Yoshio Kuramoto

We show by microscopic calculation that thermodynamics of the multicomponent Sutherland model is equivalent to that of a free particle system with fractional exclusion statistics at all temperatures. The parameters for exclusion statistics are given by the strength of the repulsive interaction, and have both intra- and inter-species components. We also show

M. G. Higgins, R. N. Henriksen

A new model for the high-energy emission from pulsars is developed by considering charged particle motion in the fields of a spinning, highly magnetised and conducting sphere in vacuum. A generally applicable approximation to the particle motion in strong fields is developed and applied to the numerical modelling, and the radiation emitted by curvature emiss

Stephen L. Adler

I point out that the results stated in the recent articles on photon splitting by Wunner, Sang, and Berg and by Wentzel, Berg, \& Wunner directly contradict an earlier analytic and numerical calculation that I performed of the same process using Schwinger&#39;s proper time method, for strong magnetic fields and general energies below the pair production thre

Peter H. Hauschildt, France Allard, David R. Alexander, Andreas Schweitzer

The atmospheres of M stars are dominated by a small number of very strong molecular compounds (H$_2$O, TiO, H$_2$, CO, VO). Most of the hydrogen is locked in molecular H$_2$, most of the carbon in CO; and H$_2$O, TiO and VO opacities define a pseudo-continuum covering the entire flux distribution of these stars. The optical ``continuum&#39;&#39; is due to Ti

L. J. Smith, M. Pettini, D. L. King, R. W. Hunstead

Observations of absorption lines in the spectra of distant QSOs offer a new approach for tracking the evolution of normal galaxies from early epochs to the present day. The damped Ly alpha systems are particularly suitable for measuring the properties of what are likely to be the progenitors of present-day luminous galaxies. We have recently concluded a long

Jane C. Charlton, Peter Anninos, Yu Zhang, Michael Norman

We perform a double line of sight (DLOS) analysis of the Lyman-alpha forest structures that form and evolve in cosmological N-body/hydrodynamic simulations. Pairs of simulated spectra, extracted from lines of sight separated by distances from D=12.5kpc up to 800kpc, and a ``control sample&#39;&#39; of unrelated lines of sight, are analyzed at redshifts 3, 2,

Pawel Gajer

It is well known that degree two Deligne cohomology groups can be identified with groups of isomorphism classes of holomorphic line bundles with connections. There is also a geometric description of degree three Deligne cohomology, due to J-L. Brylinski and P. Deligne, in terms of gerbes with connective structures and curvings. This paper gives a geometric i

E. K. Sklyanin, T. Takebe

The eigenvectors of the Hamiltionians of the XYZ Gaudin model are constructed by means of the algebraic Bethe Ansatz. The construction is based on the quasi-classical limit of the corresponding results for the inhomogeneous higher spin eight vertex model.

Christopher A. Perez, Alexander S. Silbergleit, Robert V. Wagoner, Dana E. Lehr

We generalize previous calculations to a fully relativistic treatment of adiabatic oscillations which are trapped in the inner regions of accretion disks by non-Newtonian gravitational effects of a black hole. We employ the Kerr geometry within the scalar potential formalism of Ipser and Lindblom, neglecting the gravitational field of the disk. This approach

J. R. Cudell, K. Kang, S. K. Kim

The Donnachie-Landshoff fit of total cross sections has now become a standard reference for models of total, elastic and diffractive cross-sections. Adopting their philosophy that simple-pole exchanges should account for all data to present energies, we assess the uncertainties on their fits. Our best estimate for the pomeron intercept is $1.096^{+0.012}_{-0

Christian Wieczerkowski

We compute the renormalized trajectory of $ϕ^4_4$-theory by perturbation theory in a running coupling. We introduce an iterative scheme without reference to a bare action. The expansion is proved to be finite to every order of perturbation theory.

Victor T. Kim, Grigorii B. Pivovarov

New effective Feynman-like rules are defined for inclusive multijet cross sections in the multi-Regge regime. The solution of the BFKL equation is used as a starting point. The resulting rules involve conformal weight and rapidity as a momentum and a coordinate respectively and are translation invariant in the coordinates. We use the effective rules to calcu

Maxim Nazarov

We study the image of the universal $R$-matrix for the Yangian $Y(gl_N)$ with respect to the evaluation homomorphism of $Y(gl_N)$ to the enveloping algebra $U(gl_N)$. We use the fusion procedure as defined by I. Cherednik. As a corollary we get a generalization of the classical Capelli identity.

Yuri Makeenko, Iouri Chepelev

We consider matrix-model representations of the meander problem which describes, in particular, combinatorics for foldings of closed polymer chains. We introduce a supersymmetric matrix model for describing the principal meander numbers. This model is of the type proposed by Marinari and Parisi for discretizing a superstring in D=1 while the supersymmetry is

F. Csikor, Z. Fodor, J. Hein, A. Jaster

The finite temperature phase transition in the SU(2) Higgs model at a Higgs boson mass $M_H \simeq 34$ GeV is studied in numerical simulations on four-dimensional lattices with time-like extensions up to $L_t=5$. The effects of the finite volume and finite lattice spacing on masses and couplings are studied in detail. The errors due to uncertainties in the c

Alon E. Faraggi

I discuss the calculation of the heavy generation masses in the superstring derived standard-like models. The top quark Yukawa coupling is obtained from a cubic level mass term while the bottom quark and tau lepton mass terms are obtained from nonrenormalizable terms. The calculation of the heavy fermion Yukawa couplings is outlined in detail in a specific t

Howard E. Haber

Recent refinements of the phenomenology of Higgs bosons in the Standard Model and the Minimal Supersymmetric Standard Model are reviewed.

Carlton M. Caves, Christopher A. Fuchs

Quantum information refers to the distinctive information-processing properties of quantum systems, which arise when information is stored in or retrieved from nonorthogonal quantum states. More information is required to prepare an ensemble of nonorthogonal quantum states than can be recovered from the ensemble by measurements. Nonorthogonal quantum states

S. G. Bondarenko, V. V. Burov, M. Beyer, S. M. Dorkin

The calculation of the magnetic moment of the deuteron in the framework of the Bethe--Salpeter approach is performed. The relativistic corrections are calculated analytically and estimated numerically. It is shown that the main contributions are due to partial waves with positive energies and $P$--waves. A comparison with the non-relativistic schemes of calc

R. Shyam, I. J. Thompson, A. K. Dutt-Mazumder

The Coulomb dissociation method to obtain the astrophysical S-factor, $S_{17}(0)$, for the $^7$Be($p,γ)^8$B reaction at solar energies is investigated by analysing the recently measured data on the breakup reaction $^{208}$Pb$(^8$B,$^7$Be$~p)^{208}$Pb at 46.5 MeV/A beam energy. Breakup cross sections corresponding to E1, $E2$ and $M1$ transitions are calcula

M. Beyer, G. Röpke, A. Sedrakian

The three--nucleon scattering problem in a nuclear medium is considered within the Faddeev technique. In particular the deuteron break--up cross section that governs the formation and the break--up reactions of deuterons (NNN <-> Nd) in a nuclear environment is calculated at finite temperatures and densities. A significant enhancement of the in--medium break

V. S. Uma Maheswari

Strutinsky&#39;s averaging(SA) method is applied to multiquark droplets to systematically extract the smooth part of the exact quantal energy and thereby the shell correction energies. It is shown within the bag model that the semi-phenomenological density of states expression given upto curvature order is almost equivalent to the SA method. A comparative st

K. Chadan, André Martin, J. Stubbe

We establish the asymptotic behaviour of the ratio $h^\prime(0)/h(0)$ for $λ\rightarrow\infty$, where $h(r)$ is a solution, vanishing at infinity, of the differential equation $h^{\prime\prime}(r) = iλω(r) h(r)$ on the domain $0 \leq r <\infty$ and $ω(r) = (1-\sqrt{r} K_1(\sqrt{r}))/r$. Some results are valid for more general $ω$&#39;s.

C. Emmrich, H. Römer

Hamiltonians whose symbols are not simply real valued, but matrix or, more generally, endomorphism valued functions appear in many places in physics, examples being the Dirac equation, multicomponent wave equations like electrodynamics in media, and Yang-Mills theories, and the Born-Oppenheimer approximation in molecular physics. The aim of this paper is to

Shin&#39;ichi Nojiri

We clarifies the group theoretical structure of $N=1$ and $N=2$ two-form supergravity, which is classically equivalent to the Einstein supergravity. $N=1$ and $N=2$ two-form supergravity theories can be formulated as gauge theories. By introducing two Grassmann variables $θ^A$ ($A=1,2$), we construct the explicit representations of the generators $Q^i$ of th

Joakim Hallin, Per Liljenberg

We solve the Schwinger model on a circle by first finding the explicit groundstate functional(s). Having done this, we give the structure of the Hilbert space and derive bosonization formulae in this formalism.

Michio Jimbo, Tetsuji Miwa

An integral solution to the quantum Knizhnik-Zamolodchikov ($q$KZ) equation with $|q|=1$ is presented. Upon specialization, it leads to a conjectural formula for correlation functions of the XXZ model in the gapless regime. The validity of this conjecture is verified in special cases, including the nearest neighbor correlator with an arbitrary coupling const

G. K. Leontaris

In the four dimensional free fermionic formulation of the heterotic string, a semi-realistic $SU(4)\times SU(2)_L \times SU(2)_R$ model is proposed with three fermion generations in $(4,2,1)+(\bar 4,1,2)$ representations. The gauge symmetry of the model breaks to the standard gauge group using a higgs pair in the $(4,1,2)+(\bar 4,1,2)$ representations. The m

G. G. Ross, N. Chamoun

We use QCD sum rules to determine the twist-two non-singlet operator matrix elements and fixed x structure functions paying particular regard to the estimate of the errors. Particularly for the matrix element determination, we find large uncertainties due to radiative and higher dimension contributions. We consider the origin of these large corrections and c

P. Ernstrom, P. Hoyer, M. Vanttinen

Quarkonium production at a given large p_T is dominated by parton fragmentation: a parton which is produced with transverse momentum p_T/z fragments into a quarkonium state which carries a fraction z of the parton momentum. Since parton production cross sections fall steeply with p_T, high z fragmentation is favored. However, quantum number constraints may r

Howard E. Haber

The Standard Model does not provide a very good fit to the most recent precision electroweak data from LEP, due primarily to the observed branching ratios for $Z$ decay to $b\bar b$ and $c\bar c$. The possibility that an extension of the Standard Model with low-energy supersymmetry can improve the agreement between data and theory is considered.

Charles Hellaby, Tevian dray

We contrast the two approaches to ``classical&#34; signature change used by Hayward with the one used by us (Hellaby and Dray). There is (as yet) no rigorous derivation of appropriate distributional field equations. Hayward&#39;s distributional approach is based on a postulated modified form of the field equations. We make an alternative postulate. We point

Daksh Lohiya, Annu Batra, Sameer Mehra, Shobhit Mahajan

This article reports on emergence of structures in a class of alternative theories of gravity. These theories do not have any horizon, flatness, initial cosmological singularity and (possibly) quantization problems. The model is characterised by a dynamically induced gravitational constant with a ``wrong&#39;&#39; sign corresponding to repulsive gravitation

Andrey Krakovsky

We analyze the energy band structure of a two-dimensional electron gas in a periodic magnetic field of a longitudinal antiferromagnet by considering a simple exactly solvable model. Two types of states appear: with a finite and infinitesimal longitudinal mobility. Both types of states are present at a generic Fermi surface. The system exhibits a transition t

R. Rajaraman, S. L. Sondhi

We introduce a new field theory for studying quantum Hall systems. The quantum field is a modified version of the bosonic operator introduced by Read. In contrast to Read&#39;s original work we do {\em not} work in the lowest Landau level alone, and this leads to a much simpler formalism. We identify an appropriate canonical conjugate field, and write a Hami

Andrey Krakovsky, J. K. Percus

We calculate the quasiparticle effective mass for the electron gas in two and three dimensions in the metallic region. We employ the single particle scattering potential coming from the Sjölander-Stott theory and enforce the Friedel sum rule by adjusting the effective electron mass in a scattering calculation. In 3D our effective mass is a monotonically decr

Michel J. P. Gingras, David A. Huse

As a simplified model of randomly pinned vortex lattices or charge-density waves, we study the random-field XY model on square ($d=2$) and simple cubic ($d=3$) lattices. We verify in Monte Carlo simulations, that the average spacing between topological defects (vortices) diverges more strongly than the Imry-Ma pinning length as the random field strength, $H$

Remi Monasson, Riccardo Zecchina

The study of the distribution of volumes associated to the internal representations of learning examples allows us to derive the critical learning capacity ($α_c=\frac{16}π \sqrt{\ln K}$) of large committee machines, to verify the stability of the solution in the limit of a large number $K$ of hidden units and to find a Bayesian generalization cross--over at

German Sierra, Miguel A. Martin-Delgado

We propose that the valence bonds forming the ground state of the 2D-AF Heisenberg model on a square lattice may rotate under the effect of the antiferromagnetic background. To test this idea we apply a real space renormalization group approach to construct a rotating-valence-bond ground state anstaz. Our results are analytic and valid for any value of the s

Michael P. Morrissey, Eugene I. Shakhnovich

We propose a new and effective means for designing stable and fast-folding polypeptide sequences using a cumulant expansion of the molecular partition function. This method is unique in that $T_{Z}$, the ``cumulant design temperature&#39;&#39; entered as a parameter in the design process, is predicted also to be the optimal folding temperature. The method wa

Sutapa Mukherji, Somendra M. Bhattacharjee, A. Baumgärtner

Using a finite size scaling form for reunion probability, we show numerically the existence of a binding-unbinding transition for Directed polymers with random interaction. The cases studied are (A1) two chains in 1+1 dimensions, (A2) two chains in 2+1 dimensions and (B) three chains in 1+1 dimensions. A similar finite size scaling form for fluctuation estab

France Allard, Peter H. Hauschildt

We have calculated a grid of more than 700 model atmospheres valid for a wide range of parameters encompassing the coolest known M~dwarfs, M~subdwarfs and brown dwarf candidates: $1500\le \teff \le 4000\,$K, $3.5\le \log(g)\le 5.5$, and $-4.0\le { [M/H]}\le +0.5$. Our equation of state includes 105 molecules and up to 27 ionization stages of 39 elements. In

Peter H. Hauschildt, E. Baron, Sumner Starrfield, France Allard

The atmospheres of novae at early times in their outbursts are very extended, expanding shells with low densities. Models of these atmospheres show that NLTE effects are very important and must be included in realistic calculations. We have, therefore, been improving our atmospheric studies by increasing the number of ions treated in NLTE. One of the most im

Peter H. Hauschildt, E. Baron

We describe our implementation of an extremely detailed model atom of singly ionized iron for NLTE computations in static and moving astrophysical plasmas. Our model atom includes 617 levels, 13675 primary permitted transitions and up to 1.2 million secondary transitions. Our approach guarantees that the total iron opacity is included at the correct waveleng

Marc Kamionkowski, Nicolaos Toumbas

Matter with an equation of state $p=-ρ/3$ may arise in certain scalar field theories, and the energy density of this matter decreases as $a^{-2}$ with the scale factor $a$ of the Universe. In this case, the Universe could be closed but still have a nonrelativistic-matter density $Ω_0<1$. Furthermore, the cosmic microwave background could come from a causally

Eduard Masso

The general arguments for baryonic and galactic dark matter are presented. Limits coming from a variety of theoretical considerations and observations are discussed. The surviving candidates for galactic baryonic dark matter seem most likely to be in the form of compact objects and could be in one of two mass windows: either in the brown dwarf regime or in t

Dan Kiselman, Mats Carlsson

We study the formation of B I lines in a grid of cool stellar model atmospheres without the assumption of local thermodynamic equilibrium (LTE). The non-LTE modelling includes the effect of other lines blending with the B I resonance lines. Except for the cases where the B I lines are very strong, the departures from LTE relevant for the resonance lines can

Arjun Berera

An energetic justification of a thermal component during inflation is given. The thermal component can act as a heat reservoir which induces thermal fluctuations on the inflaton field system. We showed previously that such thermal fluctuations could dominate quantum fluctuations in producing the initial seeds of density perturbations. A Langevin-like rate eq

M. K. Banerjee, J. Milana

We present the results for the electric dipole amplitude for $γN \to π^0 N$ at threshold at the $O(p^2)$ level in SU$_f$(3) chiral perturbation theory. We find that the SU$_f$(3) results differ only slightly from the SU$_f$(2) results. At the $O(p^3)$ level one encounters new, unknown counterterms to fix which one is likely to need the threshold photoproduct

Andrea Begliuomini, Luciano Bracci

We study the evolution of a wave packet impinging onto a one dimensional potential barrier. The transmission and reflection times discussed in the literature for stationary states do not correspond to the times required for the emergence of a transmitted or a reflected packet. We propose new definitions for the interaction (dwell) time and the transmission a

G. Altarelli, N. Di Bartolomeo, F. Feruglio, R. Gatto

We show that the reported anomalies in $R_b$ and $R_c$ can be interpreted as the effect of a heavy vector boson \zprime\ universally coupled to $u$- and $d$-type quarks separately and nearly decoupled from leptons. This extra vector boson could then also naturally explain the apparent excess of the jet rate at large transverse momentum observed at CDF.

O. Richard, S. Vauclair, C. Charbonnel, W. A. Dziembowski

We have computed new solar models using the same stellar evolution code as described in Charbonnel, Vauclair and Zahn (1992). This code, originating from Geneva, now includes the computation of element segregation for helium and 12 heavier isotopes. It may also include any type of mixing of the stellar gas, provided this mixing may be parametrized with an ef

Bjoern Andreas

The sequence of intertwined T-S-T duality transformations acting on the 4D static uncharged black hole leads to a new black hole background with horizon and singularity exchanged. It is shown that this space-time is extendible too. In particular we will see that a string moving into a black hole is dual to a string leaving a white hole. That offers the possi

Adel Bilal

These are notes based on a lecture given at the Cargese summer school 1995. I describe evidence that the (two-dimensional) integrable chiral Gross-Neveu model might remain integrable when coupled to gravity. The results presented here were obtained in collaboration with Ian Kogan.

D. F. Wang, James T. Liu

We examine the ground state and excitations of the one dimensional extended Hubbard model with long range interaction. The ground state wavefunctions and low lying excitations are given explicitly in the form of a Jastrow product of two body terms. This results motivates an asymptotic Bethe-ansatz for the model. We present evidence that this solution is in f

Tim R. Morris

In a recent Letter (K.Halpern and K.Huang, Phys. Rev. Lett. 74 (1995) 3526), certain properties of the Local Potential Approximation (LPA) to the Wilson renormalization group were uncovered, which led the authors to conclude that $D>2$ dimensional scalar field theories endowed with {\sl non-polynomial} interactions allow for a continuum of renormalization gr

Reginald T. Cahill, Susan M. Gunner

The Global Colour Model (GCM) of QCD is a very successful model. Not only is it formally derivable from QCD but under various conditions it reduces to the NJL model and also to Chiral Perturbation Theory, and to other models. Results presented include the effective gluon propagator, the difference between constituent and exact quark propagators, various meso

Redouane Fakir

Gravitational waves, although generally associated with extremely microscopic effects, can displace by hundreds of kilometers the pulsar interstellar scintillation patterns that bathe the Earth. The combination of the pulsar and the interstellar medium acts as a kiloparsec-long, nature-provided gravity wave amplifier. We show how an effective scheme for the

V. I. Manko

The Schrödinger cat male and female states are discussed. The Wigner and Q--functions of generalized correlated light are given. Linear transformator of photon statistics is reviewed.

Tommaso Calarco

The relation between the restricted path integral approach to quantum measurement theory and the commonly accepted von Neumann wavefunction collapse postulate is presented. It is argued that in the limit of impulsive measurements the two approaches lead to the same predictions. The example of repeated impulsive quantum measurements of position performed on a

Charilaos Aneziris

I briefly discuss a method of obtaining distinct classes of topologically equivalent knots by developing appropriate computer programs.

Sergey Arkhipov

In this paper we develop a new homology theory of associative algebras called semiinfinite cohomology in a derived category setting. We show that in the case of small quantum groups the zeroth semiinfinite cohomology of the trivial module is closely related to the conformal blocks&#39; spaces. We provide a description of the semiinfinite cohomology spaces of

S. A. Rakityansky, S. A. Sofianos, M. Braun, V. B. Belyaev

The position and movement of poles of the amplitude for elastic eta-meson scattering off the light nuclei d, t, ^3He, and ^4He are studied. It is found that, within the existing uncertainties for the elementary eta-N interaction, all these nuclei can support a quasi-bound state. The values of the eta-nucleus scattering lengths corresponding to the critical e

James J. Griffin

The experimental detection of the sharp lines of the \ee Puzzle is viewed as a struggle against Doppler broadening. Gedanken experiments which are realistic in zeroth order of detail are analyzed to show that the ORANGE and EPOS/I geometries select narrower slices of a Doppler broadened line than spherically inclusive (APEX and EPOS/II --like) apparati. Roug

V. G. Kovalevich, P. Osland, Ya. M. Shnir, E. A. Tolkachev

The effective Lagrangian of QED coupled to dyons is calculated. The resulting generalization of the Euler-Heisenberg Lagrangian contains non-linear $P$- and $T$-nonivariant (but $C$ invariant) terms corresponding to the virtual pair creation of dyons. As examples, the amplitudes for photon splitting and photon coalescence are calculated.

Siddhartha Sen

It was recently conjectured by D. Page that if a quantum system of Hilbert space dimension $nm$ is in a random pure state then the average entropy of a subsystem of dimension $m$ where $m \leq n$ is $ S_{mn} = \sum^{mn}_{k=n+1}(1/k) - (m-1)/2n$. In this letter this conjecture is proved.

C. P. Natividade, H. Boschi-Filho

The problem of a harmonic oscillator coupling to an electromagnetic potential plus a topological-like (Chern-Simons) massive term, in two-dimensional space, is studied in the light of the symplectic formalism proposed by Faddeev and Jackiw for constrained systems.

Jamil Daboul

I show that a usual propagator cannot be defined for the pseudo-diffusion equation of the Q-functions. Instead, a forward-backward propagator is defined, which motivated a generalization of Cahill-Glauber interpolating operator. Our generalized operator ${\bf Q}(p,q;σ_p^{-1},σ_q)$ depends on two squeezing parameters $σ_p$ and $σ_q$, and is shown to obey a ge

A. N. Vall, S. E. Korenblit, V. M. Leviant, A. B. Tanaev

The solutions of Heisenberg equations and two-particles eigenvalue problems for nonrelativistic models of current-current fermion interaction and $N, Θ$ model are obtained in the frameworks of dynamical mapping method. The equivalence of different types of dynamical mapping is shown. The connection between renormalization procedure and theory of selfadjoint

H. Shiomi

Induced tensor charge of the nucleon $g_T$, which originates from G-parity violation, is evaluated from QCD sum rules. We find that $g_T/g_A$ with $g_A$ being the axial charge is $ -$0.0152 $\pm$ 0.0053 which is proportional to u-d quark mass difference. This result is small compared to preliminary analysis of the experiment, but is consistent with the estim

Valerie Halyo, Edi Halyo

We argue that dilaton supersymmetry breaking in string derived supergravity requires an effective superpotential which is not separable as a function of the dilaton times a function of the moduli. We show that in a simple model with hidden sector matter condensation and a dilaton independent term one can easily obtain $|F_S| \not=0$. For a wide range of real

Tomislav Prokopec, Robert Brandenberger, Anne-Christine Davis

We investigate whether baryogenesis is possible at a second order electroweak phase transition. We find that under rather general conditions, the departure from thermal equilibrium is suppressed by the expansion rate of the Universe, and hence baryon production is also suppressed by the expansion rate. We conclude that if no additional sources of departure f

Chia-Hung V. Chang, Darwin Chang, Wai-Yee Keung

We propose two minimal extensions of Standard Model, both of which can easily accommodate the recent puzzling observations about the excess in $R_b$, the deficit in $R_c$ and the discrepancy in the low energy and high energy determinations of $α_{s}$. Each model requires three additional heavy vectorial fermions in order to resolve the puzzles. The current p

C. Muñoz

We study the structure of the soft SUSY-breaking terms obtained from 4-D Strings under the assumption of dilaton/moduli dominance in the process of SUSY breaking. We first analyze in detail the dilaton-dominated limit because of its finiteness properties and phenomenological predictivity, and second, we consider the new features appearing when several moduli

Jiri Chyla

The idea of ``dynamically&#39;&#39; generated parton distribution functions, based on regular initial conditions at low momentum scale, is reanalyzed with particular emphasize paid to its compatibility with the factorization mechanism. Basic consequences of this approach are discussed and compared to those of the conventional approach, employing singular ini

J. M. Butterworth, J. R. Forshaw, T. Sjostrand, J. K. Storrow

At HERA, the large flux of almost real photons accompanying the electron beam leads to the copious photoproduction of jets. Regions of small momentum fractions $x$ of the incoming particles are explored, where the density of partons is high. As a result, the probability for more than one hard partonic scattering occurring in a single $γp$ collision could bec

S. Simula

The space-like elastic form factor of heavy-light pseudoscalar mesons is investigated within a light-front constituent quark model in order to evaluate the Isgur-Wise form factor. The relativistic composition of the constituent quark spins is properly taken into account using the Melosh rotations, and various heavy-meson wave function are considered, includi

T. Hotta, K. -I. Izawa, T. Yanagida

We consider strongly interacting supersymmetric gauge theories which break dynamically the GUT symmetry and produce the light Higgs doublets naturally. Two models we proposed in the previous articles are reanalyzed as two phases of one theory and are shown to have desired features. Furthermore, employing nonabelian duality proposed recently by Seiberg, we st

Masaharu Tanabashi, Akiya Miyamoto, Ken-ichi Hikasa

We discuss the sensitivity of the $e^+ e^- \rightarrow W^+ W^-$ cross section at a future $e^+ e^-$ collider with $\sqrt{s}=500$GeV to the non-decoupling effects of a techni-$ρ$ like vector resonance. The non-decoupling effects are parametrized by the chiral coefficients of the electroweak chiral perturbation theory. We define renormalization scale independe

S. Groote, J. G. K&#34;orner, M. M. Tung

We calculate one-loop radiative QCD corrections to the three polarized and unpolarized structure functions that determine the beam-quark polar angle dependence of the alignment (or longitudinal) polarization of light and heavy quarks produced in e^+e^- annihilations. We present analytical and numerical results for the alignment polarization and its polar ang

T. C. Awes

Results on the target mass dependence of proton and pion pseudorapidity distributions and of their azimuthal correlations in the target rapidity range $-1.73 \le η\le 1.32$ are presented. The data have been taken with the Plastic-Ball detector set-up for 4.9 GeV p + Au collisions at the Berkeley BEVALAC and for 200 $A\cdot$GeV/$c$ p-, O-, and S-induced react