September 1995 arXiv papers — page 3

George Gasper

These lecture notes were written for a mini-course that was designed to introduce students and researchers to {\it $q$-series,} which are also called {\it basic hypergeometric series} because of the parameter $q$ that is used as a base in series that are ``{\it over, above or beyond}'' the {\it geometric series}. We start by considering $q$-extension

G W Gibbons, D A Rasheed

The most general Lagrangian for non-linear electrodynamics coupled to an axion $a$ and a dilaton $ϕ$ with $SL(2,\mbox{\elevenmsb R})$ invariant equations of motion is $$ -\half\left(\nablaϕ\right)^2 - \half e^{2ϕ}\left(\nabla a\right)^2 + \fraction{1}{4}aF_{μν}\star F^{μν} + L_{\rm inv}(g_{μν},e^{-\frac{1}{2}ϕ}F_{ρσ}) $$ where $L_{\rm inv}(g_{μν},F_{ρσ})$ is

Wilson Oliveira, Jorge Ananias Neto

We apply The Batalin-Tyutin constraint formalism of converting a second class system into a first class system for the rotational quantisation of the SU(2) Skyrme model. We obtain the first class constraint and the Hamiltonian in the extended phase space. The vacuum functional is constructed and evaluated in the unitary gauge and a multiplier dependent gauge

Wei Chen

We examine the thermal behavior of a relativistic anyon system, dynamically realized by coupling a charged massive spin-1 field to a Chern-Simons gauge field. We calculate the free energy (to the next leading order), from which all thermodynamic quantities can be determined. As examples, the dependence of particle density on the anyon statistics and the anyo

Denis Bernard

We describe applications of (perturbed) conformal field theories to two-dimensional disordered systems. We present various methods of study~: (i) {\it A direct method} in which we compute the explicit disorder dependence of the correlation functions for any sample of the disorder. This method seems to be specific to two dimensions. The examples we use are di

koji Harada, Atsushi Okazaki, Masa-aki Taniguchi

We investigate mesons in the bosonized massive Schwinger model in the light-front Tamm-Dancoff approximation in the strong coupling region. We confirm that the three-meson bound state has a few percent fermion six-body component in the strong coupling region when expressed in terms of fermion variables, consistent with our previous calculations. We also disc

Jim McCarthy

I summarize some recent results obtained in collaboration with P.~Bouwknegt and K.~Pilch on the spectrum of physical states in $\cW_3$ gravity coupled to $c=2$ matter. In particular, it is shown that the algebra of operators corresponding to physical states -- defined as a semi-infinite (or BRST) cohomology of the $\cW_3$ algebra -- carries the structure of

Peter Bouwknegt, Jim McCarthy, Krzysztof Pilch

The noncritical $4D$ $\cW_3$ string is a model of $\cW_3$ gravity coupled to two free scalar fields. In this paper we discuss its BRST quantization in direct analogy with that of the $2D$ (Virasoro) string. The physical operators form a BV-algebra. We model this BV-algebra on that of the polyderivations of a commutative ring on six variables with a quadratic

M. Quirós

We review various effective potential methods which have been useful to compute the Higgs mass spectrum and couplings of the minimal supersymmetric standard model. We compare results where all-loop next-to-leading-log corrections are resummed by the renormalization group, with those where just the leading-log corrections are kept. Pole masses are obtained fr

R. Sekhar Chivukula

In this talk I discuss theories of dynamical electroweak symmetry breaking, with emphasis on the implications of a heavy top-quark on the weak-interaction $ρ$ parameter.

V. P. Gusynin, I. A. Shovkovy

The derivative expansion of the one-loop effective Lagrangian in QED$_4$ is considered. The first term in such an expansion is the famous Schwinger result for a constant electromagnetic field. In this paper we give an explicit expression for the next term containing two derivatives of the field strength $F_{μν}$. The results are presented for both fermion an

Aida X. El-Khadra

Recent theoretical progress in calculations of the spectrum and decays of charmonium is reviewed. Traditionally, our understanding of charmonium was based on potential models. This is now being replaced by first principles.

V. P. Gusynin, A. H. Hams, M. Reenders

We study chiral symmetry breaking in $\rm QED_3$ with $N_f$ flavors of four-component fermions. A closed system of Schwinger-Dyson equations for fermion and photon propagators and the full fermion-photon vertex is proposed, which is consistent with the Ward-Takahashi identity. A simplified version of that set of equations is reduced (in nonlocal gauge) to th

E. Gabrielli, A. Masiero, L. Silvestrini

We consider supersymmetric extensions of the standard model with general non-universal soft breaking terms. We analyse in a model-independent way the constraints on these terms at the electroweak energy scale coming from gluino mediated flavour (F) changing neutral current and CP-violating processes. We have computed the complete $ΔF=1$ and $ΔF=2$ effective

K. Adel, F. J. Ynduráin

We use recently evaluated radiative and nonperturbative corrections to production of heavy quarks by a vector current to give very precise theoretical calculations of the high energy ($t^{1/2}\geq \sqrt{2}$ GeV) imaginary part of the photon vacuum polarization function, ${\rm Im}Π(t)$. This allows us to improve the corresponding contributions to the muon (or

I. M. Dremin

The solution of QCD equations for generating functions of multiplicity distributions reveals new peculiar features of cumulant moments oscillating as functions of their rank. This prediction is supported by experimental data on $e^{+}e^{-}, hh, AA$ collisions. Evolution of the moments at smaller phase space bins leads to intermittency and fractality. The exp

Chris Michael, Hugh Shanahan, UKQCD collaboration

We present results for the masses and decay constants of the light mesons in quenched QCD using the standard gluon action and a tadpole--improved SW--clover fermionic action to reduce discretisation errors. The calculation has been carried out at fixed volume and three lattice spacings corresponding to $\beta=5.7$, $6.0$ and $6.2$. We make comparisons with t

Philippe de Forcrand

I review recent progress on algorithms for calculating quark propagators and for simulating full QCD.

Philippe de Forcrand, Seyong Kim

We measure the topological susceptibility by cooling with an over-improved action. In contrast with usual cooling, large instantons survive over-improved cooling {\em indefinitely}. By varying the parameter of the over-improved cooling action, we measure the instanton size distribution.

Artan Boriçi, Philippe de Forcrand

We study improved variants of Lüscher's algorithm, including the cases of staggered fermions and finite density.

M. Göckeler, R. Horsley, E. -M. Ilgenfritz, H. Oelrich

The lower moments of the unpolarized and polarized deep-inelastic structure functions of the nucleon are calculated on the lattice. The calculation is done with Wilson fermions and for three values of the hopping parameter $κ$, so that we can perform the extrapolation to the chiral limit. Particular emphasis is put on the renormalization of lattice operators

F. Abe

We present a measurement of $σ\cdot B(W \to e ν)$ and $σ\cdot B(Z^0 \to e^+e^-)$ in proton - antiproton collisions at $\sqrt{s} =1.8$ TeV using a significantly improved understanding of the integrated luminosity. The data represent an integrated luminosity of 19.7 pb$^{-1}$ from the 1992-1993 run with the Collider Detector at Fermilab (CDF). We find $σ\cdot

Andrew Chamblin

Recently, there have been several applications of differential and algebraic topology to problems concerned with the global structure of spacetimes. In this paper, we derive obstructions to the existence of spin-Lorentz and pin-Lorentz cobordisms and we show that for compact spacetimes with non-empty boundary there is no relationship between the homotopy typ

Ian D. Lawrie, Richard J. Epp

The classical and quantum dynamics of simple time-reparametrization- invariant models containing two degrees of freedom are studied in detail. Elimination of one ``clock'' variable through the Hamiltonian constraint leads to a description of time evolution for the remaining variable which is essentially equivalent to the standard quantum mechanics of

David Hochberg

The thermal properties of black holes in the presence of quantum fields can be revealed through solutions of the semi-classical Einstein equation. We present a brief but self-contained review of the main features of the semi-classical back reaction problem for a black hole in the microcanonical ensemble. The solutions, obtained for conformal scalars, massles

J. Hwang

In a class of generalized Einstein's gravity theories we derive the equations and general asymptotic solutions describing the evolution of the perturbed universe in unified forms. Our gravity theory considers general couplings between the scalar field and the scalar curvature in the Lagrangian, thus includes broad classes of generalized gravity theories

Sudhansu S. Mandal, V. Ravishankar

We show that neutron scattering and Raman scattering experiments can unambiguously determine a composite fermion parameter, viz., the effective number of Landau Levels filled by the composite fermions. For this purpose, one needs partially polarized or more preferably unpolarized quantum Hall states. We further find that spin correlation function acts as an

M. Franz, C. Kallin, P. I. Soininen, A. J. Berlinsky

We discuss the physics of the vortex state in a $d$-wave superconductor, using the phenomenological Ginzburg-Landau theory, where many novel phenomena arise from the small admixture of the $s$-wave component induced by spatial variations in the dominant $d$-wave. Properties of an isolated vortex and of the Abrikosov vortex lattice are studied by means of ana

D. Averin, A. Bardas

Starting from the quasiclassical equations for non-equilibrium Green's functions we derive a simple kinetic equation that governs ac Josephson effect in a superconducting quantum point contact at small bias voltages. In contrast to existing approaches the kinetic equation is valid for voltages with arbitrary time dependence. We use this equation to calcu

Henrik Kajueter, Gabriel Kotliar

We derive a new perturbation scheme for treating the large d limit of lattice models at arbitrary filling. The results are compared with exact diagonalization data for the Hubbard model and found to be in good agreement.

I. Ispolatov, P. Krapivsky

The kinetics of irreversible annihilation of charged particles performing overdamped motion induced by long-range interaction force, $F(r)\sim r^{-λ}$, is investigated. The system exhibits rich kinetic behaviors depending on the force exponent $λ$. In one dimension we find that the densities decay as $t^{-1/(2+λ)}$ and $t^{-1/(1+2λ)}$ when $λ>1$ and $1/2<λ<1

Ulrich Weiss, Reinhold Egger, Maura Sassetti

The temperature-dependent nonlinear conductance for transport of a Luttinger liquid through a barrier is calculated in the nonperturbative regime for $g=1/2-ε$, where $g$ is the dimensionless interaction constant. To describe the low-energy behavior, we perform a leading-log summation of all diagrams contributing to the conductance which is valid for $|ε| <<

Vladimir Dotsenko, Marco Picco, Pierre Pujol

We study the spin-spin and energy-energy correlation functions for the 2D Ising and 3-states Potts model with random bonds at the critical point. The procedure employed is the renormalisation group approach of the perturbation series around the conformal field theories representing the pure models. For the Ising model, we obtain a crossover in the amplitude

N. R. Claughton, R. Raimondi, C. J. Lambert

We examine transport properties of superconducting hybrid mesoscopic structures, in both the diffusive and ballistic regimes. For diffusive structures, analytic results from quasi-classical theory are compared with predictions from numerical, multiple-scattering calculations performed on small structures. For all structures, the two methods yield comparable

Tomi Ohtsuki, Yoshiyuki Ono

The level statistics in the two dimensional disordered electron systems in magnetic fields (unitary ensemble) or in the presence of strong spin-orbit scattering (symplectic ensemble) are investigated at the Anderson transition points. The level spacing distribution functions $P(s)$&#39;s are found to be independent of the system size or of the type of the po

Herbert H. H. Homeier, Sebastian Rast, Hartmut Krienke

The solution of the Ornstein-Zernike equation with various closure approximations is studied. This problem is rewritten as an integral equation that can be solved iteratively on a grid. The convergence of the fixed point iterations is relatively slow. We consider transformations of the sequence of solution vectors using non-linear sequence transformations, s

Thomas Quinn, Neal Katz, George Efstathiou

It has been argued that a UV photoionizing background radiation field suppresses the formation of dwarf galaxies, and may even inhibit the formation of larger galaxies. In order to test this, we present gas-dynamical simulations of the formation of small objects in a CDM universe with and without a photoionizing background. The objects are selected from a co

R Benton Metcalf, Joseph Silk

It has been proposed that the MACHOs in our galaxy could be clumped in globular cluster--like associations or RAMBOs (robust associations of massive baryonic objects) (Moore \& Silk 1995). Here we investigate the effect such clustering has on the microlensing of stars in the Large Magellanic Cloud. We find that the lensing in a one square degree field could

Peter. J. Kernan, Glenn D. Starkman, Tammay Vachaspati

We reanalyze the effect of magnetic fields in BBN, incorporating several features which were omitted in previous analyses. We find that the effects of coherent magnetic fields on the weak interaction rates and the electron thermodynamic functions (\rhoe, \Pe, and \drhoedt ) are unimportant in comparison to the contribution of the magnetic field energy densit

R. M. Campbell, J. Lehar, B. E. Corey, I. I. Shapiro

We present hybrid maps of the A and B images of 0957+561 from each of four sessions of 6 cm VLBI observations that span the six-year interval 1987-1993. The inner- and outer-jets are clearly detected, and confirm the structures reported previously. There is no evidence of change in the separation between the core and inner-jet components, so the prospect of

Juan Antonio Miralles, Kenneth A. Van Riper

The equation of state of an ideal Fermi gas is expressed in terms of Fermi-Dirac integrals. We give formulae for evaluation the Fermi-Dirac integrals of orders 1/2, 3/2, and 5/2 and their derivatives in various limits of non- and extreme degeneracy and relativity. We provide tables and a Fortran subroutine for numerical evaluation of the integrals and deriva

Enrico Arrigoni

We study the spin and charge phase diagram of a three-legs ladder (at zero temperature) as a function of fermion density and of transverse single-particle hopping by means of a Renormalization-Group analysis rigorously controlled in the weak-coupling limit. Periodic boundary conditions in the direction transverse to the ladder produce frustrated magnetic exc

Daniel M. Kaplan

Studies of CP violation, for 30 years focused primarily on the neutral K meson, are on the threshold of a new era as experiments approach Standard-Model sensitivities in decays of beauty, charm, and hyperons. The array of heavy-quark experiments approved and planned at Fermilab may lead to a significant breakthrough in the next five to ten years.

Stephen H. Shenker

We suggest that some of the remarkable results on stringy dynamics which have been found recently indicate the existence of another dynamical length scale in string theory that, at weak coupling, is much shorter than the string scale. This additional scale corresponds to a mass $\sim m_{\rm s}/g_{\rm s}$ where $m_{\rm s}$ is the square root of the string ten

Paul Federbush

In line with a previous paper, a gauge-invariant regularization is developed for the Weyl determinant of a Euclidean gauged chiral fermion. We restrict ourselves to gauge configurations with the $A$ field going to zero at infinity in Euclidean space; and thus restrict gauge transformations to those with $U$ the identity at infinity. For each finite cutoff on

M. Beneke, I. Z. Rothstein

We calculate the $α_s$ corrections to the transverse polarization fraction of $ψ^\prime$&#39;s produced at the Tevatron. If the `$ψ^\prime$-anomaly&#39; is explained by gluon fragmentation into a colour octet Fock component of the $ψ^\prime$, the $ψ^\prime$&#39;s should be $100\%$ transversely polarized at leading order in $α_s$, up to spin symmetry breaking

S. Elitzur, A. Forge, A. Giveon, E. Rabinovici

We derive the exact effective superpotential in 4d, N=1 supersymmetric SU(2) gauge theories with $N_A$ triplets and $2N_f$ doublets of matter superfields. We find the quantum vacua of these theories; the equations of motion (for $N_A=1$) can be reorganized into the singularity conditions of an elliptic curve. From the phase transition points to the Coulomb b

Parthasarathi Majumdar

Generically coupled neutral scalar bosons and chiral fermions are shown, in the eikonal kinematical limit, to be described by a reduced (free field) theory with N=1 {\it on-shell} supersymmetry. {\it Charged} scalars and spinors turn out to be described in the eikonal limit by a reduced interacting theory with a modified and restricted on-shell N=1 supersymm

Kazuo Fujikawa

An index relation $dim\ ker\ a - dim\ ker\ a^{\dagger} = 1$ is satisfied by the creation and annihilation operators $a^{\dagger}$ and $a$ of a harmonic oscillator. Implications of this analytic index on the possible form of the phase operator are discussed. A close analogy between the present phase operator problem and chiral anomaly in gauge theory, which i

M. Gasperini

I report recent studies on the evolution of perturbations in the context of the ``pre-big-bang&#34; scenario typical of string cosmology, with emphasis on the formation of a stochastic background of relic photons and gravitons, and its possible direct/indirect observable consequences. I also discuss the possible generation of a thermal microwave background b

J. Kambor, C. Wiesendanger, D. Wyler

Using extended Khuri-Treiman equations, we evaluate the final state interactions due to two-pion rescatterings to the decays $η\to π^0 π^+ π^-$ and $η\to π^0 π^0 π^0$. As subtraction to the dispersion relation we take the one-loop chiral perturbation theory result of Gasser and Leutwyler. The calculated corrections are moderate and amount to about $14\%$ in

David B. Kaplan, Martin J. Savage

We show that nuclear interactions are SU(4) symmetric at leading order in chiral perturbation theory in the large-N limit of QCD. The nucleons and delta resonances form a 20-dimensional representation of SU(4) and we show how Wigner&#39;s supermultiplet symmetry SU(4)_{sm}, under which the nucleons transform as a 4-dimensional representation, follows as an a

A. K. Motovilov

Explicit representations for the Faddeev components of the three-body T-matrix continued analytically into unphysical sheets of the energy Riemann surface are formulated. According to the representations, the T-matrix in unphysical sheets is explicitly expressed in terms of its components taken in the physical sheet only. The representations for the T-matrix

C. Ford, L. O&#39;Raifeartaigh

Using canonical quantization we find the Virasoro centre for a class of conformally-invariant interacting Wess-Zumino-Witten theories. The theories have a group structure similar to that of Toda theories (both abelian and non-abelian) but the usual Toda constraints on the coupling constants are relaxed and the theories are not necessarily integrable. The gen

J. J. M. Verbaarschot

Recently, the Columbia group obtained the valence quark mass dependence of the chiral condensate for lattice QCD simulations with dynamical fermions for a series of couplings close to the critical temperature. In this letter we show that the data for temperatures below $T_c$ and sufficiently small valence quark masses can be rescaled to fall on a universal c

Ivan K. Kostov

We give a sequence of equivalent formulations of the $ADE$ and $\hat A\hat D\hat E$ height models defined on a random triangulated surface: random surfaces immersed in Dynkin diagrams, chains of coupled random matrices, Coulomb gases, and multicomponent Bose and Fermi systems representing soliton $τ$-functions. We also formulate a set of loop-space Feynman r

U. Ornik, M. Plumer, A. Timmermann, R. W. Weiner

We study single- and double-inclusive spectra of thermal photons, produced in heavy-ion collisions at $\sqrt{s}=200$ AGeV within a realistic space-time framework which combines the Parton-Cascade-Model and 3-dimensional hydrodynamics (HYLANDER). This allows also for the first time to take into account pre-equilibrium effects for photon production. A rapid de

C. A. Piguet, D. F. Wang, C. Gruber

The Hofstadter problem is studied on hexagonal lattice. We first establish a relation between the spectra for the hexagonal lattice and for its dual he triangular lattice. Following the idea of Faddeev and Kashaev, we then obtain the Bethe-ansatz equations for this system.

R. Fux, D. Friedli

We present a 3D N-body simulation of the Milky Way including 4*10^5 star- and dark-like particles and 2*10^4 gas particles, initially distributed according to an axisymmetric, observationally constrained, mass model. The whole system is self-gravitating and the gas hydrodynamics is solved using the SPH method. The simulation leads to the spontaneous formatio

Rachel Jeannerot

We have built a supersymmetric SO(10) model consistent with cosmological observations. The model gives rise to a false vacuum hybrid inflationary scenario which solves the monopole problem. We argue that this type of inflationary scenario is generic in supersymmetric SO(10) model, and arises naturally from the theory. Neither any external field nor any exter

W. Broniowski, G. Ripka, E. Nikolov, K. Goeke

We analyze the analytic structure of meson propagators in the Nambu--Jona-Lasinio model with a proper-time regulator. We show that the regulator produces unphysical complex singularities. As a result the naive use of the Wick rotation is no longer allowed. Formulas involving integration over mesonic momenta, such as meson-loop contributions or dispersion rel

M. Pitkänen

TGD predicts the existence of color octet excitations of ordinary leptons forming &#39;leptohadrons&#39; as their color singlet bound states. There is some evidence on the existence of leptohadrons: the production of anomalous $e^+e^-$ pairs in heavy ion collisions, Karmen anomaly, the anomalously high decay rate of ortopositronium (Op) and anomalous product

Laurent Lellouch

Lattice results, kinematical constraints and QCD dispersion relations are combined for the first time to derive model-independent bounds for QCD form factors and corresponding rates. To take into account the error bars on the lattice results we develop a general formalism which ascribes well-defined statistical properties to these bounds. We concentrate on $

Suzhou Huang, Marcello Lissia

We discuss the interpretation of Euclidean correlation functions at finite temperature ($T$) and their relationship with the corresponding real-time Green&#39;s functions. The soluble 2+1 dimensional Gross-Neveu model in the large-$N$ limit is used throughout as a working example. First, the real-time bound state, identified as an elementary excitation at fi

Drazen Adamovic, Antun Milas

We investigate vertex operator algebras $L(k,0)$ associated with modular-invariant representations for an affine Lie algebra $A_1 ^{(1)}$ , where k is &#39;admissible&#39; rational number. We show that VOA $L(k,0)$ is rational in the category $\cal O$ and find all irreducible representations in the category of weight modules.

A. P. Isaev

We show that the Faddeev-Pyatov SL_q(N) differential algebra is a subalgebra of the GL_q(N) differential algebra constructed by Schupp, Watts and Zumino.

S. Majid

This is an introduction for algebraists to the theory of algebras and Hopf algebras in braided categories. Such objects generalise super-algebras and super-Hopf algebras, aswell as colour-Lie algebras. Basic facts about braided categories C are recalled, the modules and comodules of Hopf algebras in such categories are studied,the notion of `braided -commuta

R. Nojarov, Amand Faessler, M. Dingfelder

Important $E2$ contributions to the $(e,e^{\prime})$ cross sections of low-lying orbital $M1$ excitations are found in heavy deformed nuclei, arising from the small energy separation between the two excitations with $I^πK = 2^+1$ and 1$^+1$, respectively. They are studied microscopically in QRPA using DWBA. The accompanying $E2$ response is negligible at sma

N. N. Nikolaev, B. G. Zakharov

The current status of the theory of and the experimental evidence for color transparency are reviewed. The problems with interpretation of quasielastic scattering on nuclei are discussed to some detail.

Peter G. Casazza, Ole Christensen

Aldroubi has shown how one can construct any frame $\gtu$ starting with one frame $\ftu $,using a bounded operator $U$ on $l^2(N)$. We study the overcompleteness of the frames in terms of properties of $U$. We also discuss perturbation of frames in the sense that two frames are ``close&#39;&#39; if a certain operator is compact. In this way we obtain an equi

Peter G. Casazza, Ole Christensen

We prove that a Hilbert space frame $\fti$ contains a Riesz basis if every subfamily $\ftj , J \subseteq I ,$ is a frame for its closed span. Secondly we give a new characterization of Banach spaces which do not have any subspace isomorphic to $c_0$. This result immediately leads to an improvement of a recent theorem of Holub concerning frames consisting of

Peter Bouwknegt, Krzysztof Pilch

We summarize some recent results obtained in collaboration with J. McCarthy on the spectrum of physical states in $W_3$ gravity coupled to $c=2$ matter. We show that the space of physical states, defined as a semi-infinite (or BRST) cohomology of the $W_3$ algebra, carries the structure of a BV-algebra. This BV-algebra has a quotient which is isomorphic to t

A. Yu. Alekseev, C. Klimcik, A. A. Tseytlin

A pair of conformal sigma models related by Poisson-Lie T-duality is constructed by starting with the O(2,2) Drinfeld double. The duality relates the standard SL(2,R) WZNW model to a constrained sigma model defined on SL(2,R) group space. The quantum equivalence of the models is established by using a path integral argument.

Andrei Dubikovsky

A set of integral relations for rotational and translational zero modes in the vicinity of the classical soliton solution are derived from the particle-like properties of the latter. The validity of these all relations is considered for a number of soliton models in 2+1- and 3+1-dimensions.

Q-Han Park, H. J. Shin

It is shown that the McCall-Hahn theory of self-induced transparency in coherent optical pulse propagation can be identified with the complex sine-Gordon theory in the sharp line limit. We reformulate the theory in terms of the deformed gauged Wess-Zumino-Witten sigma model and address various new aspects of self-induced transparency.

Peter Bouwknegt, Jim McCarthy, Krzysztof Pilch

The noncritical $D=4$ $W_3$ string is a model of $W_3$ gravity coupled to two free scalar fields. In this paper we discuss its BRST quantization in direct analogy with that of the $D=2$ (Virasoro) string. In particular, we calculate the physical spectrum as a problem in BRST cohomology. The corresponding operator cohomology forms a BV-algebra. We model this

Rainer Dick

The dilaton in three dimensions does not roll. Witten&#39;s conjecture that duality between theories in three and four dimensions solves the cosmological constant problem thus may also solve the dilaton problem in string theory.

R. Engel, J. Ranft

Photon-photon collisions are investigated in the framework of the two-component Dual Parton Model. The model is shown to agree well to hadron production data from hadron-hadron and photon-hadron collisions. The multiparticle production in hadron-hadron, photon-hadron and photon-photon collisions as predicted by the model is compared. Strong differences are o

S. Richardson, C. Picciotto

The decay $K_L \to γν\barν$ is analyzed within the standard model. Short-distance contributions are found to dominate, yielding a branching ratio of $\sim 0.7 \times 10^{-11}$. We examine the possibility that non-standard model effects might be observed at higher rates. As an example, we calculate the branching ratio for the process mediated by neutral horiz

Michael Martin Nieto

Using the vehicle of resolving an apparent paradox, a discussion of quantum interference is presented. The understanding of a number of different physical phenomena can be unified, in this context. These range from the neutral kaon system to massive neutrinos, not to mention quantum beats, Rydberg wave packets, and neutron gravity.

Bing An Li

In terms of an effective chiral theory of mesons it is shown quantitatively that in the limit of $m_{q}=0$, the masses of $ρ$, $ω$, $K^{*}(892)$, $m_ϕ$, $a_{1}$, $f_{1}(1286)$, $K_{1}(1400)$, and $f_{1}(1510)$ mesons originate from dynamical chiral symmetry breaking.

Moo-Sung Bae, Judith A. McGovern

Baryon magnetic moments are calculated in the colour-dielectric model with pion and kaon loops. The only free parameter of the model is determined from the nucleon isoscalar radius, and all SU(3) symmetry breaking, including that in the quark sector, is determined by mesonic masses and decay constants. Good agreement with experiment is obtained for the ratio

F. M. L. Almeida, J. H. Lopes, J. A. Martins Simões, A. J. Ramalho

We discuss the possibility of detecting heavy spin-3/2 leptons at LEP2 and NLC energies. The angular distributions of primary ordinary leptons are shown to be a good measure to discriminate between a heavy spin-3/2 lepton and a similar nonstandard spin-1/2 signal.

B. Kopeliovich, B. Povh

A new scaling variable is introduced in terms of which nuclear shadowing in deep-inelastic scattering is universal, i.e. independent of $A$, $Q^2$ and $x$. This variable can be interpreted as a measure of the number of gluons probed by the hadronic fluctuations of a virtual photon during their lifetime. The shadowing correction grows at small $x$ substantial

B. Bajc, S. Fajfer, R. J. Oakes

We investigate Cabibbo suppressed $D^{0}$, $D^{+}$ and $D^{+}_{s}$ radiative weak decays in order to find the best mode to test $c\to u γ$ decay. Combining heavy quark effective theory and the chiral Lagrangian approach we determine the decay widths. We calculate $Γ(D^{0}\to ρ^{0}/ωγ)/ Γ(D^{0}\to {\bar K}^{*0} γ)$ previously proposed to search for possible N

Timo Holopainen, Jukka Maalampi, Jukka Sirkka, Iiro Vilja

The damping rate and free path of neutrinos in the singlet Majoron model have been calculated including both finite temperature and symmetry breaking effects. The behaviour of right- and left-handed fermions are found inherently different. While the damping rates of the left-handed leptons are essentially model independent, e.g. directly applicable to the St

B. Z. Kopeliovich, J. Nemchik

The standard first-order inelastic correction (IC) well known in the pre-QCD era, causes a rising $Q^2$-dependence of nuclear transparency in the quasielastic electron scattering, $A(e,e&#39;p)A&#39;$, at moderate $Q^2$, similar to what is supposed to be the onset of color transparency (CT). Although IC is a part of the whole pattern of CT, it contains no ex

Marina-Aura Dariescu, C. Dariescu

Working in a perturbative QCD model approach, we obtain the essential form factor of the radiative transition $B \rightarrow V^{*} γ$ and estimate the branching ratio $BR(B \rightarrow K^{*} γ)$. The results are determined by a parameter expressing the momentum distribution in the $B$ - meson wave function. Our estimations are compared to other theoretical p

Peter Cho

Color-octet contributions to quarkonia production at LEP are studied herein. The short distance formation of heavy quark-antiquark pairs in color-octet configurations via gluon fragmentation processes is significantly enhanced relative to the creation of color-singlet pairs via heavy quark fragmentation. But the subsequent long distance hadronization of thes

A. Donini, V. Gimenez, G. Martinelli, C. T. Sachrajda

We apply a recently introduced non-perturbative renormalization method to two types of lattice operators: the $ΔS=2$ four fermion operator and the heavy-light static axial current, which are relevant for the physics of $K$ and $B$ mesons respectively. The results of the non-perturbative calculations of the renormalization constants are compared with the corr

J. L. Alonso, A. Tarancón, H. G. Ballesteros, L. A. Fernández

We study several antiferromagnetic formulations of the O(3) spin model in three dimensions by means of Monte Carlo simulations. We discuss about the vacua properties and analyze the phase transitions. Using Finite Size Scaling analysis we conclude that all phase transitions found are of first order

C. Bernard T. Blum, C. DeTar, Steven Gottlieb, Urs M. Heller

Previous work at $6/g^2=5.7$ with quenched staggered quarks is extended with new calculations at 5.85 and 6.15 on lattices up to $32^3\times 64$. These calculations allow a more detailed study of extrapolation in quark mass, finite volume and lattice spacing than has heretofore been possible. We discuss how closely the quenched spectrum approaches that of th

Biplab Bhawal, S. V. Dhurandhar

We describe how the six planned detectors (2 LIGOs, VIRGO, GEO, AIGO, TAMA) can be used to perform coincidence experiments for the detection of broadband signals from either coalescing compact binaries or burst sources. We make comparisons of the achievable sensitivities of these detectors under different optical configurations and find that a meaningful coi

A. Criscuolo, H. Quevedo, H. Waelbroeck

We use the polygon representation of 2+1--dimensional gravity to explicitly carry out the canonical quantization of a universe with the topology of a torus. The mapping-class-invariant wave function for a quantum &#39;&#39;big bounce&#39;&#39;, is reminiscent of the interference patterns of linear gratings. We consider the ``problem of time&#39;&#39; of quan

Arkadiusz Blaut, Jerzy Kowalski-Glikman

In this paper we discuss the quantum potential approach of Bohm in the context of quantum cosmological model. This approach makes it possible to convert the wavefunction of the universe to a set of equations describing the time evolution of the universe. Following Ashtekar et.\ al., we make use of quantum canonical transformation to cast a class of quantum c

Andrew Chamblin

We derive the topological obstructions to the existence of non-Cliffordian pin structures on four-dimensional spacetimes. We apply these obstructions to the study of non-Cliffordian pin-Lorentz cobordism. We note that our method of derivation applies equally well in any dimension and in any signature, and we present a general format for calculating obstructi

Silvio J. Rabello

A field theory with generalized statistics in one space dimension is introduced. The statistics enters the scene through the coupling of the matter fields to a statistical gauge field, as it happens in the Chern-Simons theory in two dimensions. We study the particle-hole excitations and show that the long wave length physics of this model describes a gas obe

A. Barrat, R. Burioni, M. Mézard

We study the out of equilibrium dynamics of several models exhibiting aging. We attempt at identifying various types of aging systems using a phase space point of view: we introduce a trial classification, based on the overlap between two replicas of a system, which evolve together until a certain waiting time, and are then totally decoupled. We investigate

Erwin Frey, Franz Schwabl

We review our current understanding of the critical dynamics of magnets above and below the transition temperature with focus on the effects due to the dipole--dipole interaction present in all real magnets. Significant progress in our understanding of real ferromagnets in the vicinity of the critical point has been made in the last decade through improved e

Ralf K. Heilmann, Jian-Sheng Wang, Robert H. Swendsen

We investigate the three-state antiferromagnetic Potts model on a simple cubic lattice with a cluster flipping Monte Carlo simulation algorithm in the temperature region below the transition into disorder at T_{c1}. We find both the well established broken-sublattice-symmetry (BSS) phase at low temperature and a new, rotationally symmetric phase at higher te