February 1993 arXiv papers

F. Butler, H. Chen, J. Sexton, A. Vaccarino

We evaluate $f_π/ m_ρ$, $f_K/ m_ρ$, $1/f_ρ$, and $ m_ϕ/(f_ϕ m_ρ)$, extrapolated to physical quark mass, zero lattice spacing and infinite volume, for lattice QCD with Wilson quarks in the valence (quenched) approximation. The predicted $m_ϕ/(f_ϕ m_ρ)$ differs from experiment by less than its statistical uncertainty of approximately 15\%. The other three cons

S. P. de Alwis

Using an argument due to Regge and Teitelboim, an expression for the ADM mass of 2d quantum dilaton gravity is obtained. By evaluating this expression we establish that the quantum theories which can be written as a Liouville-like theory, have a lower bound to energy, provided there is no critical boundary. This fact is then reconciled with the observation m

W. Lerche

Talk given at the 26th Workshop: ``From Superstrings to Supergravity", Erice - Sicily, 5-12 December 1992. We review the superconformal properties of 2d matter coupled to gravity, and extensions thereof. Focusing on topological strings, we recall how the superconformal structure helps to provide a direct link between Liouville theory coupled to matter, a

Takayuki Hori, Masaru Kamata

The wheeler-DeWitt method is applied to the quantization of the 1 + 1 dimensional dilaton gravity coupled with the conformal matter fields. Exact solutions to the WD equations are found, which are interpreted as right(left)-moving black holes.

Fred C. Adams

For the theory of a single scalar field $φ$ with a quartic potential $V(φ)$, we find semi-analytic expressions for the Euclidean action in both four and three dimensions. The action in four dimensions determines the quantum tunneling rate at zero temperature from a false vacuum state to the true vacuum state; similarly, the action in three dimensions determi

S. Kumano

High-energy spin physics became a popular topic recently after the EMC finding for the proton's spin content. There exist unmeasured spin-dependent structure functions ($b_1$, $b_2$, $b_3$, and $b_4$) for spin-one hadrons such as the deuteron. The tensor structure function $b_1(x)$ could be measured by the proposed 15 GeV European Electron Facility. The

R. Koberle, A. Lima - Santos

Remarks about highest weight states of the underlying quantum group are corrected.

Fusun Akman

Semi-infinite cohomology is constructed from scratch as the proper generalization of finite dimensional Lie algebra cohomology. The differential d and other operators are realized as universal inner deri- vations of a completed algebra, which acts on any appropriate semi-infinite complex. In particular, d is shown to be the unique derivation satisfying the &

Stephen Godfrey, K. Andrew Peterson

We studied single $W$ boson production in high energy $eγ$ collisions and the sensitivity of various observables to the $WWγ$ gauge boson coupling. We evaluated the helicity amplitudes including the $W$ decay to final state fermions and all Feynman diagrams which give the same final state. At high energy, the non-resonant diagrams give significant contributi

P. Nath, R. Arnowitt

It is shown that in the physically interesting domain of the parameter space of SU(5) supergravity GUT, the Higgs and the Z poles dominate the LSP annihilation. Here the naive analyses on thermal averaging breaks down and formulae are derived which give a rigorous treatment over the poles. These results are then used to show that there exist significant doma

M. Ferraris, M. Francaviglia, I. Volovich

A model of two--dimensional gravity with an action depending only on a linear connection is considered. This model is a topological one, in the sense that the classical action does not contain a metric or zweibein at all. A metric and an additional vector field are instead introduced in the process of solving equations of motion for the connection. They sati

E. Christova, M. Fabbrichesi

T-odd correlations of polarizations and momenta provide a promising testing ground for new physics beyond the standard model. We estimate the contribution of the minimal supersymmetric extension of the standard model to two such observables: in the production of $t\bar{t}$, we look for a term proportional to \mbox{${\bf J}_t \cdot ({\bf p}_q \times {\bf p}_{

Dieter Brill, Kay-Thomas Pirk

Four-dimensional Euclidean spaces that solve Einstein's equations are interpreted as WKB approximations to wavefunctionals of quantum geometry. These spaces are represented graphically by suppressing inessential dimensions and drawing the resulting figures in perspective representation of three-dimensional space, some of them stereoscopically. The figure

Makoto Natsuume

The similarity between tree-level string theory scalar amplitudes, the Koba-Nielsen form ($S^{1}$) and the Virasoro-Shapiro form ($S^{2}$) suggests a natural $S^{n}$ generalization for a scalar amplitude. It is shown that the $S^{n}$ amplitude shares many essential properties of the string theory amplitudes, including $SO(n+1,1)$ conformal symmetry and linea

Juan Garcia-Bellido

Clarified certain points and related it to other work.

Wolfgang Bauer

The present status of the use of two-particle intensity interferometry as a diagnostic tool to study the space-time dynamics of intermediate energy heavy ion collisions is examined. Calculations for the two-proton and two-pion correlation functions are presented and compared to experiment. The calculations are based on the nuclear Boltzmann-Uehling-Uhlenbeck

James Sharp

Throughout this abstract let U be a fixed p-point ultrafilter and let I be the dual ideal. Grigorieff forcing is P(U)={p:omega to 2|dom(p) is an element of I} ordered by reverse inclusion. It is well known that Grigorieff forcing is proper. The main result of this paper is the following: THEOREM: Gregorieff forcing does not satisfy Axiom A. To prove this we

D. B. Uglov

The quantum bialgebra related to the Baxter's eight-vertex R-matrix is found as a quantum deformation of the Lie algebra of sl(2)-valued automorphic functions on a complex torus.

D. B. Uglov

It is shown that the Lie algebra of the automorphic, meromorphic sl(2, C) -valued functions on a torus is a geometric realization of a certain infinite-dimensional finitely generated Lie algebra. In the trigonometric limit, when the modular parameter of the torus goes to zero, the former Lie algebra goes over into the sl(2,C) -valued loop algebra, while the

Theodore J. Allen, Dennis B. Crossley

We show that the harmonic Becchi-Rouet-Stora-Tyutin method of quantizing bosonic systems with second-class constraints or first-class holomorphic constraints extends to systems having both bosonic and fermionic second-class or first-class holomorphic constraints. Using a limit argument, we show that the harmonic BRST modified path integral reproduces the cor

S. P. Sorella

A new way of solving the descent equations corresponding to the Wess-Zumino consistency conditions is presented. The method relies on the introduction of an operator $δ$ which allows to decompose the exterior space-time derivative $d$ as a $BRS$ commutator. The case of the Yang-Mills theories is treated in detail.

D. Birmingham, M. Rakowski

A class of lattice gauge theories is presented which exhibits novel topological properties. The construction is in terms of compact Wilson variables defined on a simplicial complex which models a four dimensional manifold with boundary. The case of Z2 and Z3 gauge groups is considered in detail, and we prove that at certain discrete values of the coupling pa

S. Penati, M. Pernici, D. Zanon

We consider a class of $N=2$ supersymmetric non--unitary theories in two--dimensional Minkowski spacetime which admit classical solitonic solutions. We show how these models can be twisted into a topological sector whose energy--momentum tensor is a BRST commutator. There is an infinite number of degrees of freedom associated to the zero modes of the soliton

H. Kawai, N. Kawamoto, T. Mogami, Y. Watabiki

We develop a transfer matrix formalism for two-dimensional pure gravity. By taking the continuum limit, we obtain a "Hamiltonian formalism'' in which the geodesic distance plays the role of time. Applying this formalism, we obtain a universal function which describes the fractal structures of two dimensional quantum gravity in the continuum limit

T. Fujiwara, Y. Igarashi, J. Kubo

The classical 2D cosmological model of Callan, Giddings, Harvey and Strominger possesses a global symmetry that is responsible for decoupling of matter fields. The model is quantized on the basis of the extended phase space method to allow an exhaustive, algebraic analysis to find potential anomalies. Under a certain set of reasonable assumptions we show tha

T. Fujiwara, T. Tabei, Y. Igarashi, K. Maeda

The extended phase space method of Batalin, Fradkin and Vilkovisky is applied to formulate two dimensional gravity in a general class of gauges. A BRST formulation of the light-cone gauge is presented to reveal the relationship between the BRST symmetry and the origin of $SL(2,R)$ current algebra. From the same principle we derive the conformal gauge action

Mikhail I. Dobroliubov, David Eliezer, Ian I. Kogan, Gordon W. Semenoff

We discuss the possibility for the spectrum of topologically massive quantum electrodynamics with spinor matter fields to contain unexpected and unusual stable particle excitations for certain values of the topological photon mass. The new field theoretical phenomena arising from this novel spectral structure are briefly discussed.

Gary T. Horowitz, Dean L. Welch

A black hole solution to three dimensional general relativity with a negative cosmological constant has recently been found. We show that a slight modification of this solution yields an exact solution to string theory. This black hole is equivalent (under duality) to the previously discussed three dimensional black string solution. Since the black string is

R. Arnowitt, Pran Nath

The predictions of SU(5) supergravity models with radiative breaking constrained by experimental proton decay bounds are discussed. It is shown that cosmological constraints further restrict the parameter space but can be satisfied for a wide range of parameters. It is also shown that no serious fine tuning problems (either at $M_{SUSY}$ or $M_{GUT}$) exist.

J. T. Peltoniemi, J. W. F. Valle

We present models that can reconcile the solar and atmospheric neutrino data with the existence of a hot dark matter component in the universe. This dark matter is a quasi-Dirac neutrino whose mass $m_{DM}$ arises at the one-loop level. The solar neutrino deficit is explained via nonadiabatic conversions of electron neutrino to a sterile neutrino and the atm

Sylvie Braibant, Yves Brihaye, Jutta Kunz

We construct the sphaleron for several temperature dependent effective potentials. We determine the sphaleron energy as a function of temperature and demonstrate that the sphaleron energy at a given temperature $T$ is well approximated by the sphaleron energy at temperature zero scaled by the ratio of the vacuum expectation values of the Higgs field at tempe

Jutta Kunz, Yves Brihaye

We demonstrate the level crossing phenomenon for fermions in the background field of the sphaleron barrier, by numerically determining the fermion eigenvalues along the minimal energy path from one vacuum to another. We assume that the fermions of a doublet are degenerate in mass, allowing for spherically symmetric ansätze for all of the fields, when the mix

N. Kitazawa

We study radiative corrections on $Zb{\bar b}$ vertex generated by the ETC gauge bosons, ``diagonal'' as well as sideways. Although the oblique corrections due to the ETC bosons are small in comparison with the oblique correction due to the technicolor dynamics, the non-oblique corrections result in substantial shift of contour plot in the $S$-$T$ pl

Richard W. Haymaker, Vandana Singh, Dana Browne, Jacek Wosiek

We present results from simulations on two aspects of quark confinement in the pure gauge sector. First is the calculation of the profile of the flux tube connecting a static $q \bar{q}$ pair in $SU(2)$. By using the Michael sum rules as a constraint we give evidence that the energy density at the center of the flux tube goes to a constant as a function of q

Vandana Singh, Dana Browne, Richard W. Haymaker

We calculate the electric field and the curl of the magnetic monopole current for U(1) and for SU(2) in the maximal abelian gauge in the mid- plane between a quark antiquark pair. The results can be understood as a dual Abrikosov vortex in the Ginzburg-Landau theory.

Yingcai Peng, Richard W. Haymaker

We studied SU(2) flux distributions on four dimensional euclidean lattices with one dimension very large. By choosing the time direction appropriately we can study physics in two cases: one is finite volume in the zero temperature limit, another is finite temperature in the the intermediate to large volume limit. We found that for cases of beta > beta crit t

L. P. Grishchuk

Contents: Introduction. The Present State of the Universe. What Can We Expect From a Complete Cosmological Theory? An Overview of Quantum Effects in Cosmology. Parametric (Superadiabatic) Amplification of Classical Waves. Graviton Creation in the Inflationary Universe. Quantum States of a Harmonic Oscillator. Squeezed Quantum States of Relic Gravitons and Pr

Heiko Leschhorn

We propose a lattice model to study the dynamics of a driven interface in a medium with random pinning forces. For driving forces F smaller than a threshold force F_c the whole interface gets pinned. The depinning transition can be characterized by a set of critical exponents: the static and dynamical roughness exponent, the velocity exponent defined by the

P. Fazekas, Hae-Young Kee

A multi--channel generalization of Doniach's Kondo necklace model is formulated, and its phase diagram studied in the mean--field approximation. Our intention is to introduce the possible simplest model which displays some of the features expected from the overscreened Kondo lattice. The $N$ conduction electron channels are represented by $N$ sets of pse

James Theiler, Paul S. Linsay, David M. Rubin

We consider the limitations of two techniques for detecting nonlinearity in time series. The first technique compares the original time series to an ensemble of surrogate time series that are constructed to mimic the linear properties of the original. The second technique compares the forecasting error of linear and nonlinear predictors. Both techniques are

James Theiler, Turab Lookman

The statistical precision of a chord method for estimating fractal dimension from a correlation integral is derived. The optimal chord length is determined, and a comparison is made to other estimators. These calculations use the approximation that all pairwise distances between the points are statistically independent; the adequacy of this approximation is

Rajesh R. Parwani

This is the revised version of an earlier paper with the same title.

W. Eholzer, A. Honecker, R. Huebel

In 2D conformal quantum field theory, we continue a systematic study of W-algebras with two and three generators and their highest weight representations focussing mainly on rational models. We review the known facts about rational models of W(2,\delta)-algebras. Our new rational models of W-algebras with two generators all belong to one of the known series.

S. Scherer, G. I. Poulis, H. W. Fearing

We discuss two different methods of obtaining ``effective $2 \times 2$ Hamiltonians'' of the electromagnetic interaction which include relativistic corrections. One is the standard Foldy--Wouthuysen transformation which we compare with the Hamiltonian obtained from a direct reduction of the matrix element of the interaction Hamiltonian between positi

H. W. Fearing, G. I. Poulis, S. Scherer

Two different methods of obtaining ``effective $2\times 2$ Hamiltonians'' which include relativistic corrections to nonrelativistic calculations are discussed, the standard Foldy--Wouthuysen transformation and what we call the ``direct Pauli reduction''. We wish to investigate under which circumstances the two approaches yield the same result

Thomas Jech, Jiří Witzany

A stationary subset $S$ of a regular uncountable cardinal $κ$ {\it reflects fully} at regular cardinals if for every stationary set $T \subseteq κ$ of higher order consisting of regular cardinals there exists an $α\in T$ such that $S \cap α$ is a stationary subset of $α$. {\it Full Reflection} states that every stationary set reflects fully at regular cardin

L. G. Zastavenko

We show that the Hamiltonian $ h= H_{QED}+H_2$, where $H_{QED}$ is the spinor QED Hamiltonian and $H_2$ is the positive transversal photon mass term, is unbounded from below if the electromagnetic coupling constant $e^2$ is small enough, $e^2<e^2_0 $, and the transversal photon squared mass parameter $M^2$ is not too large: $0\leq M^2<e^2l^2c$, here, $l$ is

H. Aratyn, L. A. Ferreira, J. F. Gomes, R. T. Medeiros

Bracket preserving gauge equivalence is established between several two-boson generated KP type of hierarchies. These KP hierarchies reduce under symplectic reduction (via Dirac constraints) to KdV, mKdV and Schwarzian KdV hierarchies. Under this reduction the gauge equivalence is taking form of the conventional Miura maps between the above KdV type of hiera

O. Piguet, S. P. Sorella

The proof of the non-renormalization theorem for the gauge anomaly of four-dimensional theories is extended to the case of models with a vanishing one-loop gauge beta function.

Olivier Piguet, Silvio P. Sorella

Ladders of field polynomial differential forms obeying systems of descent equations and corresponding to observables and anomalies of gauge theories are renormalized. They obey renormalized descent equations. Moreover they are shown to have vanishing anomalous dimensions. As an application a simple proof of the nonrenormalization theorem for the nonabelian g

K. Melnikov, O. Yakovlev

We have calculated part of O($α_{S}$) QCD radiative correction to the total cross-section of top&#39;s threshold production in $ e^{+}e^{-} \to t\bar t \to W^{-} b W^{+} \bar b$ reaction. We found out a curious fact: there is no O($α_{S}$) correction to the total cross-section, originated from $b \bar b , t \bar b ,\bar t b $ gluon exchange and corresponding

S. Dawson, G. Valencia

We consider the process $K_L \ra μ^\pm e^\mp ν\overlineν$ at next to leading order in chiral perturbation theory. This process occurs in the standard model at second order in the weak interaction and constitutes a potential background in searches for new physics through the modes $K_L \ra μ^\pm e^\mp$. We find that the same cut, $M_{μe}>489$~MeV, used to rem

Ulrich H. E. Hansmann, Yuko Okamoto

We apply a recently developed method, multicanonical algorithm, to the problem of tertiary structure prediction of peptides and proteins. As a simple example to test the effectiveness of the algorithm, Met-enkephalin is studied and the ergodicity problem, or multiple-minima problem, is shown to be overcome by this algorithm. The lowest-energy conformation ob

R. Brunetti, D. Guido, R. Longo

Making use of a recent result of Borchers, an algebraic version of the Bisognano-Wichmann theorem is given for conformal quantum field theories, i.e. the Tomita-Takesaki modular group associated with the von Neumann algebra of a wedge region and the vacuum vector concides with the evolution given by the rescaled pure Lorentz transformations preserving the we

Vladimir G. Pestov

For every operator space $X$ the $C^\ast$-algebra containing it in a universal way is residually finite-dimensional (that is, has a separating family of finite-dimensional representations). In particular, the free $C^\ast$-algebra on any normed space so is. This is an extension of an earlier result by Goodearl and Menal, and our short proof is based on a cri

G. G. Batrouni, B. Larson, R. T. Scalettar, J. Tobochnik

We use Quantum Monte Carlo to evaluate the conductivity $σ$ of the 2--dimensional disordered boson Hubbard model at the superfluid-bose glass phase boundary. At the critical point for particle density $ρ=0.5$, we find $σ_{c}=(0.45 \pm 0.07) σ_{Q}$, where $σ_{Q}= e_{*}^{2} / h$ from a finite size scaling analysis of the superfluid density. We obtain $σ_{c}=(0

Arnon Dar, Ari Laor, Abraham Loeb

We show that recent $γ$-ray observations of the Small Magellanic Cloud with EGRET rule out a universal cosmic ray flux only at energies below $\approx 10$ GeV, while the observed diffuse X-ray and $γ$-ray background radiations have already ruled out, by more than three orders of magnitude, a universal extragalactic cosmic ray flux identical to that observed

E. Cappellaro, M. Turatto, Benetti, D. Yu. Tsvetkov

We present new estimates of the observed rates of SNe determined with the {\em control time} method applied to the files of observations of two long term, photographic SN searches carried out at the Asiago and Sternberg Observatories. Our calculations are applied to a galaxy sample extracted from RC3, in which 65 SNe have been discovered. This relatively lar

R. Schiavilla, R. B. Wiringa, J. Carlson

In simple models of the nuclear charge operator, measurements of the Coulomb sum and the charge form factor of a nucleus directly determine the proton-proton correlations. We examine experimental results obtained for few-body nuclei at Bates and Saclay using models of the charge operator that include both one- and two-body terms. Previous analyses using one-

D. Wesolowski, Y. Hosotani, C. -L. Ho

Intertwined multiple Chern-Simons gauge fields induce matrix statistics among particles. We analyse this theory on a torus, focusing on the vacuum structure and the Hilbert space. The theory can be mimicked, although not completely, by an effective theory with one Chern-Simons gauge field. The correspondence between the Wilson line integrals, vacuum degenera

Wei-Min Zhang, Avaroth Harindranath

In the canonical light-front QCD, the elimination of unphysical gauge degrees of freedom leads to a set of boundary integrals which are associated with the light-front infrared singularity. We find that a consistent treatment of the boundary integrals leads to the cancellation of the light-front linear infrared divergences. For physical states, the requireme

Ll. Ametller, A. Bramon, E. Massó

The rare $π^0 \to e^+e^-$ and $η\to μ^+μ^-$ decays are calculated in different schemes, which are seen to be essentially equivalent to and produce the same results as conventional Vector-Meson Dominance. We obtain the theoretical predictions $B(π^0 \to e^+e^-) = (6.41 \pm 0.19)\times 10^{-8}$ and $B(η\to μ^+μ^-) = (1.14 +0.06 -0.03) \times 10^{-5}$ in agreem

E. Christova, M. Fabbrichesi

The minimal supersymmetric extension of the standard model allows for some of the coupling strengths to be complex parameters. The presence of such imaginary phases can lead to violations of time reversal invariance, which can be tested if correlations in products of an odd number of polarizations and momenta are measured and found to be different from zero.

Frank Cuypers, Geert Jan van Oldenborgh, Reinhold Rückl

We study the occurrence of final states with only an electron-positron pair and missing transverse momentum as a signal of \susy\ in photon-photon collisions. Suitable high energy photon beams may be provided at linear colliders by back-scattering laser beams on electron beams. The final states considered represent a typical signature for the production and

Doron Gepner

RSOS models based on the Lie algebras $B_m$, $C_m$ and $D_m$ are derived from the braiding of conformal field theory. This gives the first systematic derivation of these models earlier described by Jimbo et al. The general two field Boltzmann weights associated to any RCFT are described, giving in particular the off critical thermalized Boltzmann weights. Cr

David Seibert, Tanguy Altherr

The dilepton mass distribution from pre-equilibrium matter in ultrarelativistic nuclear collisions is indistinguishable from a thermally produced distribution.

S. Drozdz, S. Nishizaki, J. Speth, J. Wambach

A statistical analysis of the spectrum of two particle - two hole doorway states in a finite nucleus is performed. On the unperturbed mean-field level sizable attractive correlations are present in such a spectrum. Including particle-hole rescattering effects via the residual interaction introduces repulsive dynamical correlations which generate the fluctuat

Yuri Latushkin, Stephen Montgomery-Smith

We present a spectral mapping theorem for semigroups on any Banach space $E$. From this, we obtain a characterization of exponential dichotomy for nonautonomous differential equations for $E$-valued functions. This characterization is given in terms of the spectrum of the generator of the semigroup of evolutionary operators.

Alan Kostelecky, Malcolm Perry

We derive a class of solutions to the string sigma-model equations for the closed bosonic string. The tachyon field is taken to form a constant condensate and the beta-function equations at one-loop level are solved for the evolution of the metric and the dilaton. The solutions represent critical string theories in arbitrary dimensions. The spectrum of the s

David N. Yetter, Louis Crane

We show that the construction of Ocneanu, which yields 1 for any 4D manifold, is not identical to our construction, which gives different numbers for different manifolds.

Karl Yee, Myron Bander

The equations of motion for the position and spin of a classical particle coupled to an external electromagnetic and gravitational potential are derived from an action principle. The constraints insuring a correct number of independent spin components are automatically satisfied. In general the spin is not Fermi-Walker transported nor does the position follo

O. Bergman, G. Lozano

We perform a perturbative analysis of the Aharonov-Bohm problem to one loop in a field-theoretic formulation, and show that contact interactions are necessary for renormalizability. In general, the classical scale invariance of this problem is broken quantum mechanically. There exists however a critical point for which this anomaly disappears.

Michael Freeman, Peter West

A general formalism for covariant $W_3$ string scattering is given. It is found necessary to use screening charges that are constructed from the $W_3$ fields including ghosts. The scattering amplitudes so constructed contain within them Ising model correlation functions and agree with those found previously by the authors. Using the screening charge and a pi

Genya Levin, Chung-I Tan

A unified treatment of high energy collisions in QCD is presented. Using a probabilistic approach, we incorporate both perturbative (hard) and non-perturbative (soft) components in a consistent fashion, leading to a ``Heterotic Pomeron&#34;. As a Regge trajectory, it is nonlinear, approaching 1 in the limit $t\rightarrow -\infty$.

Eric Braaten, Kingman Cheung, Tzu Chiang Yuan

In decays of the $Z^0$, the dominant mechanism for the direct production of charmonium states is the decay of the $Z^0$ into a charm quark or antiquark followed by its fragmentation into the charmonium state. We calculate the fragmentation functions describing the splitting of charm quarks into S-wave charmonium states to leading order in the QCD coupling co

John HUTH, Michelangelo MANGANO

We review the status of QCD tests in high energy p-pbar collisions. Contents: i) Introduction ii) QCD in Hadronic Collisions iii) Jet Production iv) Heavy Flavour Production v) W and Z Production vi) Direct Photons.

M. A. G. Aivazis, Wu-Ki Tung, Fredrick Olness

We have performed a QCD next-to-leading order (NLO) calculation for Deep Inelastic Scattering (DIS) retaining the full parton and hadron mass dependencies. We find that the gluon initiated contributions to DIS processes, such as charm production, are {\it comparable} in magnitude ({\it i.e.}, $30\%$ to $100\%$) to the ``leading-order&#39;&#39; (LO) sea-quark

Arcadi Santamaria

We present a method to find the number of real and imaginary observable parameters coming from the Yukawa sector in an arbitrary gauge theory. The method leads naturally to a classification of Yukawa couplings according to their symmetries and suggests a new parametrization of masses and mixings that is useful to study the behaviour of Yukawa couplings under

V. Eletsky, P. Ellis, J. Kapusta

The contribution of Lorentz non-scalar operators to finite temperature correlation functions is discussed. Using the local duality approach for the one-pion matrix element of a product of two vector currents, the temperature dependence of the average gluonic stress tensor is estimated in the chiral limit to be $\langle{\bf E}^2 +{\bf B}^2\rangle_{T}=\frac{π^

V. L. Eletsky, B. L. Ioffe

The recent experimental data on $D^{+}-D^{0}$ and $D^{\ast\, +}-D^{\ast\,0}$ mass differences are used as inputs in the QCD sum rules to obtain new estimates on the mass difference of light quarks and on the difference of their condensates: $m_d -m_u =3\pm 1\, MeV$, $\langle\bar{d}d\rangle -\langle\bar{u}u\rangle = -(2.5\pm 1)\cdot 10^{-3}\langle\bar{u}u\ran

V. L. Eletsky, B. L. Ioffe

Current correlators in QCD at a finite temperature $T$ are considered from the viewpoint of operator product expansion. It is stressed that at low $T$ the heat bath must be represented by hadronic, and not quark-gluon states. A possibility to express the results in terms of $T$-dependent resonance masses is discussed. It is demonstrated that in order $T^2$ t

K. A. Peterson, Stephen Godfrey

We study the potential for using $eγ$\ collisions produced by backscattered laser photons to investigate WW$γ$\ couplings. We present results for Next Linear Collider energies of 500 GeV and 1 TeV. We find that where statistics allow, off W mass shell results can be quite important, complementing on W mass shell results from this and other studies. It is sho

N. Kitazawa, T. Kurimoto

We construct an effective Lagrangian which describes interactions of heavy and light hadrons utilizing the chiral flavor symmetry for light quarks and heavy quark symmetry. For both light and heavy sector we include pseudo scalars, vectors and baryons in the Lagrangian. Heavy hadron decays are discussed as application of our formalism. The $D_s$ decay consta

S. Borgani, P. Coles, L. Moscardini, M. Plionis

We perform a detailed investigation of the statistical properties of the projected distribution of galaxy clusters obtained in Cold Dark Matter (CDM) models with both Gaussian and skewed primordial density fluctuations. We use N-body simulations to construct a set artificial Lick maps. An objective cluster--finding algorithm is used to identify clusters of d

P. Coles, L. Moscardini, F. Lucchin, S. Matarrese

We investigate the evolution of the skewness of the distribution of density fluctuations in CDM models with both Gaussian and non--Gaussian initial fluctuations. We show that the method proposed by Coles \& Frenk (1991), which uses the skewness of galaxy counts to test the hypothesis of Gaussian primordial density fluctuations, is a potentially powerful prob

L. Danese, L. Toffolatti, A. Franceschini, J. M. Martin-Mirones

The information content of the autocorrelation function (ACF) of intensity fluctuations of the X-ray background (XRB) is analyzed. The tight upper limits set by ROSAT deep survey data on the ACF at arcmin scales imply strong constraints on clustering properties of X-ray sources at cosmological distances and on their contribution to the soft XRB. If quasars h

M. C. Bento, O. Bertolami, P. V. Moniz, J. M. Mourao

A relevant reference ([14]) has been added.

David J. Summers

We calculate the subprocess q qbar --> t tbar H which contributes to the signal for detection of a light `intermediate mass&#39; Higgs boson at the LHC and SSC in the isolated lepton and two isolated photons mode. This enhances the gg --> t tbar H signal by about 10% at the SSC and 25% at the LHC. We also calculate the q qbar --> t tbar gamma gamma irreducib

Nicholas B. Tufillaro

A new class of ``toy models'' for subaqueous bedform formation are proposed and examined. These models all show a similar mechanism of wavelength selection via bedform unification, and they may have applications to bedform stratigraphy. The models are also useful for exploring general issues of pattern formation and complexity in stochastically driven far fr

E. J. O. Gavin, H. Leeb, H. Fiedeldey

We show how the two-body potential may be uniquely determined from n-body spectra where the hypercentral approximation is valid. We illustrate this by considering an harmonic oscillator potential which has been altered by changing the energy or normalisation constant of the ground state of the n-body system and finding how this modifies the two-body potentia

G. E. Brown, J. Wambach

The recent (p,n) polarization transfer experiments at LAMPF are explained in terms of a dropping rho-meson mass in the medium.

Geoffrey Dixon

Intended for mathematical physicists interested in applications of the division algebras to physics, this article highlights some of their more elegant properties with connections to the theories of Galois fields and quadratic residues.

Francisco C. Alcaraz, Michel Droz, Malte Henkel, Vladimir Rittenberg

The master equation describing non-equilibrium one-dimensional problems like diffusion limited reactions or critical dynamics of classical spin systems can be written as a Schrödinger equation in which the wave function is the probability distribution and the Hamiltonian is that of a quantum chain with nearest neighbor interactions. Since many one-dimensiona

Raffaele Caracciolo, Marco A. R-Monteiro

By considering a set of $N$ anyonic oscillators ( non-local, intrinsic two-dimensional objects interpolating between fermionic and bosonic oscillators) on a two-dimensional lattice, we realize the $SU_q(N)$ quantum algebra by means of a generalized Schwinger construction. We find that the deformation parameter $q$ of the algebra is related to the anyonic sta

C. M. Hull

Lectures given at the Trieste Summer School, 1992. These notes are an update of my review article &#34;Classical and Quantum W-Gravity&#34;, preprint QMW-92-1, published in in &#34;Strings and Symmetries 1991&#34;, with some extra material on W-geometry, W-symmetry in conformal field theory and W-strings.

Renata Kallosh, Tomas Ortin

We present axion-dilaton black-hole and multi-black-hole solutions of the low-energy string effective action. Under $SL(2,R)$ electric-magnetic duality rotations only the ``hair&#34; (charges and asymptotic values of the fields) of our solutions is transformed. The functional form of the solutions is duality-invariant. Axion-dilaton black holes with zero ent

M. Jeżabek, J. H. Kühn

A critical assessment of the available calculations of the top quark width is presented. QCD corrections, the finite mass of the $b$ quark and the effect of the $W$ width are included as well as the electroweak corrections. The relative importance of these corrections is demonstrated for the realistic range of top masses. For the QCD corrected decay rate we

S. Wycech, A. M. Green

Estimates are made of the signals to be expected in the production of the exotic atoms Pionium ($π^+π^-$), Kaonium ($K^+K^-$) and also $K^+π^-$ in pp, pd and $e^+e^-$ reactions. Such experiments are now being undertaken or contemplated at CELSIUS, COSY, Indiana and SATURNE.

A. D. Dolgov, I. Z. Rothstein

In this paper we reconsider recently derived bounds on $MeV$ tau neutrinos, taking into account previously unaccounted for effects. We find that, assuming that the neutrino life-time is longer than $O(100~sec)$, the constraint $N_{eff}<3.6$ rules out $ν_τ$ masses in the range $0.5~(MeV)<m_{ν_τ}<35~(MeV)$ for Majorana neutrinos and $0.74~(MeV)<m_{ν_τ}<35~(MeV

Alan Stange, Scott Willenbrock

We calculate the correction to $\qbq\to\tbt$ of order $\gmm$. This correction, proportional to the square of the Higgs-boson Yukawa coupling to the top quark, arises from loops of Higgs bosons and the scalar component of virtual vector bosons. The Yukawa correction to the total \tbt\ production cross section at the Fermilab Tevatron in the standard Higgs mod