September 1994 arXiv papers — page 5

M. B. Voloshin

The current theoretical understanding of processes involving many weakly interacting bosons in the Standard Model and in model theories is discussed. In particular, such processes are associated with the baryon and lepton number violation in the Standard Model. The most interesting domain where the multiplicity of bosons is larger than the inverse of small c

Gerald B. Cleaver

I discuss how effective grand unified theories requiring adjoint Higgs fields for breaking to the standard model can be contained within string theory. Initial findings are presented in a search for and classification of effective three generation SO(10) SUSY-GUT models built using the free-fermionic string approach. Based on talk presented at PASCOS '94

As. Abada

We review recent lattice computations relevant for $D$ and $B$ decays. Decay constants $f_{D,D_s}$, $f_{B,B_s}$, $D\rightarrow K (K^*)$, $B\rightarrow \pi , \rho$ semi-leptonic form factors together with the slope of the Isgur-Wise function calculations are presented. Some recent results of $B\rightarrow K^* \gamma$ form factors will be given. $1/M$ correcti

S. Peris

By using effective field theory techniques for the standard model, we discuss the issue of what $μ$ scale is the appropriate one in the QCD corrections to the large-$\mt$ electroweak contributions to $Δr$. This needs the construction of an effective field theory below the top quark. We argue that, while matching corrections do verify the simple prescription

Andrew P. Bassom, Peter A. Clarkson

In this paper we derive a number of exact solutions of the discrete equation $$x_{n+1}x_{n-1}+x_n(x_{n+1}+x_{n-1})= {-2z_nx_n^3+(η-3δ^{-2}-z_n^2)x_n^2+μ^2\over (x_n+z_n+γ)(x_n+z_n-γ)},\eqno(1)$$ where $z_n=nδ$ and $η$, $δ$, $μ$ and $γ$ are constants. In an appropriate limit (1) reduces to the fourth \p\ (PIV) equation $${\d^2w\over\d z^2} = {1\over2w}\left({

William Y. C. Chen, Vance Faber, Emanuel Knill

The cycle prefix network is a Cayley coset digraph based on sequences over an alphabet which has been proposed as a vertex symmetric communication network. This network has been shown to have many remarkable communication properties such as a large number of vertices for a given degree and diameter, simple shortest path routing, Hamiltonicity, optimal connec

Michael Hawrylycz

An expression in the exterior algebra of a Peano space yielding Pappus' Theorem was originally given by Doubilet, Rota, and Stein. Motivated by an identity of Rota, we give an identity in a Grassmann-Cayley algebra of step 3, involving joins and meets alone, which expresses the Theorem of Pappus.

Emanuel Knill

Let G be a graph with vertices V and edges E. Let F be the union-closed family of sets generated by E. Then F is the family of subsets of V without isolated points. Theorem: There is an edge e belongs to E such that |{U belongs to F | e belongs to U}| =< 1/2|F|. This is equivalent to the following assertion: If H is a union-closed family generated by a famil

Emanuel Knill

Let H = (H,V) be a hypergraph with edge set H and vertex set V. Then hypergraph H is invertible iff there exists a permutation pi of V such that for all E belongs to H(edges) intersection of(pi(E) and E)=0. H is invertibility critical if H is not invertible but every hypergraph obtained by removing an edge from H is invertible. The degree of H is d if |{E be

Vance Faber, Mark Goldberg, Emanuel Knill, Thomas Spencer

Given a set $V$, a subset $S$, and a permutation $π$ of $V$, we say that $π$ permutes $S$ if $π(S) \cap S = \emptyset$. Given a collection $\cS = \{V; S_1,\ldots , S_m\}$, where $S_i \subseteq V ~~(i=1,\ldots ,m)$, we say that $\cS$ is invertible if there is a permutation $π$ of $V$ such that $π(S_i) \subseteq V-S_i$. In this paper, we present necessary and

Ira Gessel, Wayne Goddard, Walter Shur, Herbert S. Wilf

On an $r\times (n-r)$ lattice rectangle, we first consider walks that begin at the SW corner, proceed with unit steps in either of the directions E or N, and terminate at the NE corner of the rectangle. For each integer $k$ we ask for $N_k^{n,r}$, the number of {\em ordered\/} pairs of these walks that intersect in exactly $k$ points. The number of points in

Douglas R. Anderson, Francis X. Connolly, Hans J. Munkholm

We define an unreduced version of the e-controlled lower $K$-theoretic groups of Ranicki and Yamasaki, and Quinn. We show that the reduced versions of our groups coincide (in the inverse limit and its first derived, $\lim^1$) with those of Ranicki and Yamasaki. We also relate the controlled groups to the continuously controlled groups of Anderson and Munkhol

G. Lopes Cardoso, D. Lust, Thomas Mohaupt

We discuss the spontaneous supersymetry breaking within the low-energy effective supergravity action of four-dimensional superstrings. In particular, we emphasize the non-universality of the soft supersymmetry breaking parameters, the $μ$-problem and the duality symmetries.

A. Abdesselam, V. Rivasseau

Combinatoric formulas for cluster expansions have been improved many times over the years. Here we develop some new combinatoric proofs and extensions of the tree formulas of Brydges and Kennedy, and test them on a series of pedagogical examples.

Alexei Morozov, Luc Vinet

A representation of the group element (also known as ``universal ${\cal T}$-matrix&#39;&#39;) which satisfies $Δ(g) = g\otimes g$, is given in the form $$ g = \left(\prod_{s=1}^{d_B}\phantom.^>\ {\cal E}_{1/q_{i(s)}}(χ^{(s)}T_{-i(s)})\right) q^{2\vecϕ\vec H} \left(\prod_{s=1}^{d_B}\phantom.^<\ {\cal E}_{q_{i(s)}}(ψ^{(s)} T_{+i(s)})\right)$$ where $d_B = \fra

Hitoshi Nishino

We consider the effect of curved two-dimensional space-time on Witten&#39;s $N=2$ supersymmetric sigma models interpolating Calabi-Yau hypersurfaces to Landau-Ginzburg models. In order for the former models to have significant connection to superstring theory, only the $N=(1,1)$ or $N=(1,0)$ part of the total $N=(2,2)$ world-sheet supersymmetry is made local

Alexander Molev

New systems of Laplace (Casimir) operators for the orthogonal and symplectic Lie algebras are constructed. The operators are expressed in terms of paths in graphs related to matrices formed by the generators of these Lie algebras with the use of some properties of the noncommutative symmetric functions associated with a matrix. The decomposition of the Sklya

Wolfgang Bl&#34;umel, Ulrich Heinz

The pion multiplicity distribution is widely believed to reflect the statistical aspects of $\bar{p}p$ annihilation at rest. We try to reproduce it in a grand canonical picture with explicit conservation of electric charge, isospin, total angular momentum, and the parity quantum numbers $P$, $C$, and $G$ via the projection operator formalism. Bose statistics

V. Barger, M. S. Berger, P. Ohmann

Some recent results in supersymmetric grand unified theories are reviewed.

K. Honscheid, K. Schubert, R. Waldi

Consequences of the interference between external and internal spectator amplitudes for the lifetimes and semileptonic decay fractions of $B^0$ and $B^+$ mesons are discussed. Extrapolating from the constructive interference observed in 11 exclusive hadronic $B$ decays we find an inclusive semileptonic decay fraction of $(11.2 \pm 0.5 \pm 1.7)$\%, significan

Rajesh Parwani, Claudio Coriano`

The computation of order $e^4$ and $e^5$ contributions to the pressure of massless quantum electrodynamics at a temperature $T$ is overviewed.

V. G. Kiselev, H. So

We argue for the existence of an upper bound $m_*$ on the Higgs mass at which the lowest excited state of the Higgs field ceases to be the conventional plane wave. An explicit construction of an alternative nonperturbative state is discussed. This excitation is spatially localized. The field fluctuations inside the localization region are large. The energy o

F. R. Klinkhamer

Potential implications of a new constrained instanton solution in the electroweak standard model are discussed. Notably, there may be a non-perturbative unitarity violating contribution to the total cross-section at high collision energies.

T. Yanagida

We construct a supersymmetric grand unified model in which a dynamical symmetry breaking of SU(5)$_{GUT}$ generates large masses for color-triplet Higgs multiplets while keeping SU(2)$_L$-doublet Higgs multiplets naturally light. The vanishing masses for the Higgs doublets are guaranteed by the Peccei-Quinn symmetry. We also show that the Peccei-Quinn symmet

Raul Toral, A. L. Ferreira

We propose a modification of the Hybrid Monte-Carlo method to sample equilibrium distributions of continuous field models. The method allows an efficient implementation of Fourier acceleration and is shown to reduce completely critical slowing down for the Gaussian model, i. e., $z=0$.

Maarten Golterman, Yigal Shamir

In this paper we return to a model with domain wall fermions in a waveguide. This model contains a Yukawa coupling $y$ which is needed for gauge invariance. A previous paper left the analysis for large values of this coupling incomplete. We fill the gap by developing a systematic expansion suitable for large $y$, and using this, we gain an analytic understan

M. I. Adamovich

The polarization of Lambda0, AntiLambda0, Sigma+ and Xi- inclusively produced in Sigma- induced interactions at 330 GeV has been measured in the experiment WA89 at CERN. This is the first measurement of polarization of baryons produced by a hyperon beam. No polarization of AntiLambda is observed, as was also the case in proton beam data. At transverse moment

Donald Marolf

This submission to the Proceedings of the Seventh Marcel-Grossman Conference is an advertisement for the use of the ``spectral analysis inner product&#34; for minisuperspace models in quantum gravity.

Patrick R Brady

Homothetic scalar field collapse is considered in this article. By making a suitable choice of variables the equations are reduced to an autonomous system. Then using a combination of numerical and analytic techniques it is shown that there are two classes of solutions. The first consists of solutions with a non-singular origin in which the scalar field coll

J. S. F. Chan, R. B. Mann

We show that mass inflation occurs inside spinning black cosmic string, which is a solution of a low-energy effective string theory in $(3+1)$-dimensions. This confirms Poisson and Israel&#39;s conjecture that the inner mass parameter diverges even if spacetime is not spherically symmetric.

Jan de Boer, A. D. Jackson, Tilo Wettig

We consider two, apparently similar, models of biological evolution which have been claimed to exhibit self-organized critical behaviour. A careful reanalysis of these models, including several new analytic results for one of them, suggests that they are qualitatively different. We demonstrate the limitations of the mean field description of these systems. W

F. Dominguez-Adame, E. Macia, B. Mendez

We study the electronic structure of a new type of Fibonacci superlattice based on Si $δ$-doped GaAs. Assuming that $δ$-doped layers are equally spaced, quasiperiodicity is introduced by selecting two different donor concentrations and arranging them according to the Fibonacci series along the growth direction. The one-electron potential due to $δ$-doping is

Paulo C. Marques, Antonio H. Castro Neto

We study the quantum dissipative dynamics of a particle coupled linearly to a set of two-level systems (the heat bath) via the master equation method which we extract from the path integral formalism independently from the form of the bath spectral density. We compare our results with the standard models based on bosonic heat baths showing their main differe

Peter Grassberger, Rainer Hegger, Lothar Schaefer

We present simulation results for long ($N\leq 4000$) self-avoiding walks in four dimensions. We find definite indications of logarithmic corrections, but the data are poorly described by the asymptotically leading terms. Detailed comparisons are presented with renormalization group flow equations derived in direct renormalization and with results of a field

Peter Grassberger, Rainer Hegger

We present simulation results for single a-thermal chain polymers in finite volumes. For this we use a recently proposed recursive implementation of the enrichment method. In 3 dimensions it allows the simulation of extremely long chains (up to $N=300,000$). It is much less efficient for $d=2$, but we can also there extend considerably the previously accessi

Rainer Hegger, Peter Grassberger

We present results of simulations which show unambiguously that DLA clusters are not self-affine, in contrast to frequent claims. The measured observable is the asymmetry of the last step of a walker before he sticks to the growing cluster. Using deposition onto an originally straight line off lattice, we show that this asymmetry tends to zero algebraically

Peter Grassberger

We present numerical evidence for the fact that the damage spreading transition in the Domany-Kinzel automaton found by Martins {\it et al.} is in the same universality class as directed percolation. We conjecture that also other damage spreading transitions should be in this universality class, unless they coincide with other transitions (as in the Ising mo

Hans-Martin Broeker, Peter Grassberger

We point out a new mechanism which can lead to mean field type behaviour in nonequilibrium critical phenomena. We demonstrate this mechanism on a two-dimensional model which can be understood as a stochastic and non-conservative version of the abelian sandpile model of Bak {\it et al.} ~\cite{bak}. This model has a second order phase transition whose critica

Andrea Crisanti, Peter Grassberger

We present two classes of nonequilibrium models with critical behavior. Each model is characterized by an integer $q>1$, and is defined on configurations of $q$-valued spins on regular lattices. The definitions of the models are very similar to the updating rules in Wolff&#39;s algorithm for the Potts model, but both classes break detailed balance, except fo

E. Bogomolny, P. Leboeuf

We investigate the statistical distribution of the zeros of Dirichlet $L$--functions both analytically and numerically. Using the Hardy--Littlewood conjecture about the distribution of prime numbers we show that the two--point correlation function of these zeros coincides with that for eigenvalues of the Gaussian unitary ensemble of random matrices, and that

S. J. Sturner, C. D. Dermer

We propose that some of the unidentified Galactic plane (-10 degrees < b < 10 degrees) sources listed in the first EGRET catalog (Fichtel et al. 1994) are associated with nearby supernova remnants. The probability that the association of strong EGRET sources with supernova remnants is due to chance alignment is found to be < 1/2200. Three of the most convinc

Joachim Wambsganss, Renyue Cen, Jeremiah P. Ostriker, Edwin L. Turner

Gravitational lensing provides a strict test of cosmogonic models. Detailed numerical propagation of light rays through a universe having a distribution of inhomogeneities derived from the standard CDM (cold dark matter) scenario with the aid of massive, fully nonlinear computer simulations is used to test the model. It predicts that we should have seen far

J. Greiner, C. Motch

Spectroscopic observations provide evidence that the optical transient object observed in 1966 on archival plates of Sonneberg Observatory is a B=18.5 dMe star. For an assumed flare duration of 40 min. (or longer) the flare amplitude was $\bigtriangleup$m$_{B}$ $\approx$ 5.2 mag. If the recorded event was belonging to the class of &#39;fast&#39; flares its a

H. C. Pan, C. Jordan

The flare/spotted spectroscopic binary star CC Eri was observed with the Position Sensitive Proportional Counter (PSPC) on the X-ray satellite ROSAT on 1990 July 9-11 and 1992 January 26-27. During the observations, the source was variable on time scales from a few minutes to several hours, with the X-ray (0.2-2 keV) luminosity in the range $\sim 2.5-6.8\tim

Shiho Kobayashi, Shin Sasaki, Yasushi Suto

We compute the angular two-point correlation functions of the gamma-ray bursts at cosmological distances. Since the gamma-ray burst emission mechanism is not yet established, we simply assume that the gamma-ray burst sources are associated with high-redshift galaxies in some way. Then on the basis of several simple models for the evolution of galaxy spatial

L. Susskind

According to &#39;t Hooft the combination of quantum mechanics and gravity requires the three dimensional world to be an image of data that can be stored on a two dimensional projection much like a holographic image. The two dimensional description only requires one discrete degree of freedom per Planck area and yet it is rich enough to describe all three di

Leon Takhtajan

Lectures given at International School of Physics ``Enrico Fermi&#39;&#39;, Varenna, Villa Monastero, June 28-July 7 1994

T. Binoth, J. J. van der Bij

The influence of massless scalar singlets on Higgs signals is discussed. It is shown, that in the case of strong interactions between the Higgs boson and the singlet fields, signals could be suppressed in such a way, that detection of the Higgs boson becomes impossible.

Hoi-Kwong Lo

We reexamine the self-helicity and the intercommutation of electroweak strings. A plausible argument for baryon number conservation when electroweak strings intercommute is presented. The connection between a segment of electroweak strings and a sphaleron is also discussed.

Sean Gavin

Can we study hot QCD using nuclear collisions? Can we learn about metallic hydrogen from the impact of comet Shoemaker-Levy 9 on Jupiter? The answer to both questions may surprise you! I summarize progress in relativistic heavy ion theory reported at DPF `94 in the parallel sessions.

Paavo Helde, Katri Huitu, Jukka Maalampi, Martti Raidal

The $W$-boson pair production in $e^-e^-$ collisions with polarized beams is investigated. The helicity amplitudes are derived for general couplings and the conditions for a good high-energy behaviour of the cross-section are given. The results are applied to the heavy vector boson production in the context of the left-right symmetric model. The Ward identit

G. T. Gussie

The published properties of M1-78 are discussed with the purpose to resolve the object's classification as either a planetary nebula or an ultracompact HII region. A classification as a planetary nebula is rejected primarily because of the high luminosity of the object, but because of the chemical composition and expansion velocity of the nebula, a novel cla

A. Bianconi, S. Jeschonnek, N. N. Nikolaev, B. G. Zakharov

We present a systematic study of the final-state interaction (FSI) effects in $D(e,e&#39;p)$ scattering in the CEBAF energy range with particular emphasis on the phenomenon of the angular anisotropy of the missing momentum distribution. We find that FSI effects dominate at missing momentum $p_m \gsim 1.5 $fm$^{-1}$. FSI effects in the excitation of the $S$-w

H. T. Cho, R. Kantowski

We use the metric on the space of gravity fields given by DeWitt to construct a unique kinematic measure on the space of FRW simple fluids and show that when the mass parameter $Ω$ is used as a coordinate this measure is singular at $Ω= 1$. This singularity, combined with the time evolution of $Ω$, distorts distributions of $Ω$ values to be concentrated in t

Chang-Pu Sun

The systematical studies on the dynamical approach of wavefunction collapse in quantum measurement are reported in this paper based on the Hepp-Coleman&#39;s model and its generalizations. Under certain physically reasonable conditions, which are easily satisfied by the practical problems, it is shown that the off-diagonal elements of the reduced density mat

Chang-Pu Sun

A generalized approach of the Born-Oppenheimer approximation is developed to analytically deal with the influence exercised by the spatial motion of atom&#39;s mass-center on a two-level atom in an optical ring cavity with a quantized single-mode electromagnetic field. The explicit expressions of tunneling rate are obtained for various cases, such as that wi

C. M. Naón, M. C. von Reichenbach, M. L. Trobo

We extend the path-integral approach to bosonization to the case in which the fermionic interaction is non-local. In particular we obtain a completely bosonized version of a Thirring-like model with currents coupled by general (symmetric) bilocal potentials. The model contains the Tomonaga-Luttinger model as a special case; exploiting this fact we study the

Thomas Heinzl

We discuss the light-front formulation of SU(2) Yang-Mills theory on a torus. The gauge choice we use allows for an exact and unambiguous solution of Gauss&#39;s law.

Matthias Jamin, Manfred M&#34;unz

The strange quark mass is calculated from QCD sum rules for the divergence of the vector as well as axial-vector current in the next-next-to-leading logarithmic approximation. The determination for the divergence of the axial-vector current is found to be unreliable due to large uncertainties in the hadronic parametrisation of the two-point function. From th

M. J. Duncan, M. H. Reno

We evaluate the feasibility of measuring the $Z$ polarization from a heavy Higgs signal in the decay channel $H\rightarrow ZZ \rightarrow \ell^+ \ell^-ν\barν$. Including gluon fusion production of the Higgs, continuum production of $Z$ pairs and the QCD background of single $Z$ production with a missing jet, we find that the average value of a new variable t

Matthias Burkardt

In the limit of an infinite number of colors, we derive an analytic expression for the quark condensate in $QCD_{1+1}$ as a function of the quark mass and the gauge coupling constant. For zero quark mass, a nonvanishing quark condensate is obtained. Nevertheless, we prove that there is no phase transition as a function of the quark mass. It is furthermore sh

Paul H. Frampton

It now appears phenomenologically that the third family of fundamental fermions may be essentially different fron the first two. Particularly the high value (174GeV?) of the top quark mass suggests a special role. In the standard model all three families are treated similarly [becoming exactly the same at asymptotically high energies] so we need to extend th

Paul H. Frampton, Thomas W. Kephart

The use of nonabelian discrete groups G as family symmetries is discussed in detail. Out of all such groups up to order g = 31, the most appealing candidates are two subgroups of SU(2): the dicyclic [double dihedral] group G = $Q_6 ={ }^{(d)}D_3$ ( g = 12 ) and the double tetrahedral group $^{(d)}T = Q_4\tilde{\times}Z_3$ ( g = 24 ). Both can allow a hierarc

T. Csorgo

Bose-Einstein correlations and momentum distributions are calculated for longitudinally expanding systems, like jets or high energy heavy ion collisions with light projectiles. The expansion generates a thermal length-scale in the longitudinal direction, and the geometrical length-scale is also finite. The Bose-Einstein correlation functions are dominated by

F. Berends, R, Kleiss, R. Pittau

A Monte Carlo program is presented that computes all four fermion processes in $e^+ e^-$ annihilation. QED initial state corrections and QCD contributions are included. Fermions are taken to be massless, allowing a very fast evaluation of the matrix element. A systematic, modular and self-optimizing strategy has been adopted for the Monte Carlo integration,

Barry R. Holstein

Symmetry tests provide an important probe for the structure of elementary particle interactions and for the validity of the standard model. However, it is pointed out that in the interpretation of such experiments one must keep in mind that in many cases apparent &#34;violations&#34; of such tests are actually the result of ordinary effects within the standa

Paul H. Frampton, Thomas W. Kephart

Absract It is proposed that there exist, within a new $SU(2)^{'}$, a gauged discrete group $Q_6$ (the order 12 double dihedral group) acting as a family symmetry. This nonabelian finite group can explain hierarchical features of families, using an assignment for quarks and leptons dictated by the requirements of anomaly cancellation and of no additional quar

Thomas R. Hemmert, Barry R. Holstein, Nimai C. Mukhopadhyay

We examine mass-corrected SU(6) symmetry predictions in the quark model relating vector, axial-vector and strong NN and NΔcouplings, and demonstrate that the experimental NΔvalue is significantly higher than predicted in each case. Nevertheless the Goldberger-Treiman relation is satisfied in both sectors. Possible origins of the discrepancy of the quark mode

E. A. Golosov, I. B. Khriplovich, A. I. Milstein, A. S. Yelkhovsky

The order $α^4 (m/M) R_{\infty}$ shift of hydrogen P levels is found. The corrections are predominantly of relativistic origin. Our approach is a straightforward extension of that developed and applied by us previously to positronium P levels. The corrections to the Lamb shift in hydrogen constitute numerically δE(2 P_{1/2})=0.55 kHz, δE(2 P_{3/2}) =0.44 kHz

A. V. Kuznetsov, N. V. Mikheev

A possible Standard Model extension of the Pati-Salam type with a lepton number as the fourth color is reexamined. A new type of mixing in the interaction of the $SU(4)_V$--leptoquark with quarks and leptons is shown to be required. An additional arbitrariness of the mixing parameters could allow to decrease noticeably the lower bound on the leptoquark mass

Zhi-zhong Xing

A reliable prediction for $CP$ violation in $B^{0}_{d}$ vs $\bar{B}^{0}_{d}\rightarrow π^{+}π^{-}$ suffers from the penguin-diagram induced uncertainty. With the help of SU(3) relations, we show that both the magnitude and strong phase shift of the penguin amplitude can be approximately determined only from the branching ratios of $B^{0}_{d}\rightarrow π^{+}

C. S. Kim, A. D. Martin

We show that the observation of energetic charged leptons from semileptonic $b$ becays at the LEP and SLC $Z$--boson factories offers a unique opportunity to measure the quark mixing matrix element $V_{ub}$. We present various distributions of the $b$ decay products to show that the $b \to u$ decays can be cleanly separated from the $b \to c$ decays, with a

E. Braaten, K. Cheung, S. Fleming, T. C. Yuan

The perturbative QCD fragmentation functions for a heavy quark to fragment into heavy-light mesons are studied in the heavy-quark limit. The fragmentation functions for S-wave pseudoscalar and vector mesons are calculated to next-to-leading order in the heavy-quark mass expansion using the methods of heavy-quark effective theory. The results agree with the $

Hsiang-nan Li, Hoi-Lai Yu

We develop the perturbative QCD formalism including Sudakov effects for semi-leptonic $B$ meson decays. We evaluate the differential decay rate of $B\to πl ν$, and find that the perturbative calculation is reliable for the energy fraction of the pion above 0.3. Combining predictions from the soft pion theorems, we extract the value of the matrix element $|V_

Maria Luigia Paciello, Silvano Petrarca, Bruno Taglienti, Anastassios Vladikas

We study the influence of Gribov copies, in the Landau gauge, on the lattice renormalisation constant of the axial current, obtained from a Ward identity on quark state correlation functions, with the Clover action, in quenched SU(3) gauge theory. A comparison between the gauge invariant determination of the renorma= lization constant and the gauge dependent

Paul H. Frampton, Thomas W. Kephart

We argue that it is inconsistent to ignore the gravitational backreaction for on-shell superstring states at the Planck mass and beyond, and that these quantum states become Kerr black holes in the classical limit. Consequences are discussed.

R. M. Noack, S. R. White, D. J. Scalapino

The properties of the two-chain Hubbard Model doped away from half-filling are investigated. The charge gap is found to vanish, but a finite spin gap exists over a range of interchain hopping strength $t_\perp$. In this range, there are modified $d_{x^2-y^2}$--like pairing correlations whose strength is correlated with the size of the spin gap. It is found t

H. W. Diehl, M. Shpot

The critical behavior of semi-infinite systems in fixed dimensions $d<4$ is investigated theoretically. The appropriate extension of Parisi&#39;s massive field theory approach is presented.Two-loop calculations and subsequent Padé-Borel analyses of surface critical exponents of the special and ordinary phase transitions yield estimates in reasonable agreemen

F. V. Kusmartsev

We study the effect of strong electron-electron interactions on the persistent current in a multichannel ring with the aid of Bosonization and the Bethe ansatz equation discussed by Sutherland and Tsvelik. The interaction acts differently on a single and multichannel ring. If, in the first case, the current is suppressed, then in the second case the current

Renyue Cen, Neta A. Bahcall, Mirt Gramann

We determine the velocity correlation function, pairwise peculiar velocity difference, and root-mean-square pairwise peculiar velocity dispersion of rich clusters of galaxies, as a function of pair separation, for three cosmological models: Omega=1 and Omega=0.3 CDM, and Omega=0.3 PBI models (all flat and COBE-normalized). We find that close cluster pairs, w

Clifford M. Will, Paul J. Steinhardt

We examine the possibility that an epoch of inflationary expansion induces high-frequency oscillations of Newton&#39;s constant, $G$. The effect occurs because inflation can shift the expectation value of a non-minimally coupled, Brans-Dicke-like field away from the minimum of its effective potential. At some time after inflation ends, the field begins to os

Max Tegmark, Benjamin Bromley

We present a new method for reconstructing the cosmological density, peculiar velocity and peculiar gravitational potential on large scales from redshift data. We remove the distorting effects of line-of-sight peculiar motions by using the linear theory of gravitational instability, in which the potential is the solution to a linear partial differential equa

S. C. Beluardi, Rafael Ferraro

An extrinsic time is identified in most isotropic and homogeneous cosmological models by matching them with the ideal clock - a parametrized system whose only &#34;degree of freedom&#34; is time -. Once this matching is established, the cosmological models are quantized in the same way as the ideal clock. The space of solutions of the Wheeler-DeWitt equation

A. D. Martin

We review recent developments in the application of perturbative QCD to phenomena at small x.

B. Enriquez, B. L. Feigin

We compute the local integrals of motions of the classical limit of the lattice sine-Gordon system, using a geometrical interpretation of the local sine-Gordon variables. Using an analogous description of the screened local variables, we show that these integrals are in involution. We present some remarks on relations with the situation at roots of 1 and res

Jens-U. H. Petersen

Here is a list of chapters: 1 Introduction 2 Notation and preliminaries Part I: Finite quantum groups 3 2x2 Matrix quantum groups and the quantum plane 4 Quantum enveloping algebras at a root of unity Part II: q-Oscillators 5 Representations of q-oscillators at a root of unity 6 qr-Oscillator at a root of unity Part III: Infinite quantum groups 7 Quantum aff

Enrico Nardi, Esteban Roulet, Daniele Tommasini

We derive limits on a class of new physics effects that are naturally present in grand unified theories based on extended gauge groups, and in particular in $E_6$ and $SO(10)$ models. We concentrate on $i$) the effects of the mixing of new neutral gauge bosons with the standard $Z_0$; $ii$) the effects of a mixing of the known fermions with new heavy states.

U. Ritschel, H. W. Diehl

The time evolution of systems relaxing towards thermal equilibrium is examined near the critical temperature $T_c$, with special attention paid to the role of the initial value $m_i$ of the order parameter $ϕ$. To this end, the $n$-component model A for a cube of length $L$ is investigated. The common belief that all memory of $m_i$ is necessarily lost after

Matthias Neubert

I discuss the theoretical uncertainties in the extraction of $|\,V_{cb}|$ from a measurement of the $\bar B\to D^*\ell\,\barν$ decay rate close to zero recoil. In particular, I combine previous estimates of the $1/m_Q^2$ corrections to the normalization of the hadronic form factor at zero recoil with sum rules derived by Shifman {\it et al}.\ to obtain a new

Denis Juriev

An approach to description of interactive psychoinformation systems, based on the concept of &#34;virtualization&#34; and essentially using the technique of the &#34;secondary image synthesis&#34; (adap-org/9409002), is sketched. The article has a rather discussional character and maybe considered as a comment to some statements of the introduction to the au

Lajos Diosi

It is shown that $N^2$ is the upper limit for the number of histories in a decohering family of $N$-state quantum system. Simple criterion is found for a family of $N^2$ fine grained decohering histories of Gell-Mann and Hartle to be identical with a family of Griffiths&#39; consistent quantum trajectories.

Murray A. Moinester

For the gamma-pion interaction, the perturbative expansion of the effective chiral Lagrangian (chi-PT) can be limited to terms quartic in momenta and masses (O(p4)), or to higher order. The abnormal intrinsic parity (chiral anomaly) component of the lagrangian leads to interesting predictions for the processes pi0 -----> 2 gamma and gamma ----->3 pi. These a

Gerald A. Miller, Willem T. H. van Oers

Charge independence and charge symmetry are approximate symmetries of nature, violated by the perturbing effects of the mass difference between up and down quarks and by electromagnetic interactions. The observations of the symmetry breaking effects in nuclear and particle physics and the implications of those effects are reviewed.

Y. J. Feng, C. S. Lam

String theories should reduce to ordinary four-dimensional field theories at low energies. Yet the formulation of the two are so different that such a connection, if it exists, is not immediately obvious. With the Schwinger proper-time representation, and the spinor helicity technique, it has been shown that field theories can indeed be written in a string-l

C. S. Lam

Feynman diagram expressions in ordinary field theories can be written in a string-like manner. The methods and the advantages for doing so are briefly discussed.

O. Moritsch, M. Schweda, T. Sommer, L. Tataru

The BRST transformations for the Yang-Mills gauge fields in the presence of gravity described by Ashtekar variables are obtained by using the so-called Maurer-Cartan horizontality conditions. The BRST cohomology group expressed by the Wess-Zumino consistency condition is solved with the help of an operator $δ$ introduced by S.P. Sorella which in our case has

P. Maraner

A complete perturbative expansion for the Hamiltonian describing the motion of a quantomechanical system constrained to move on an arbitrary submanifold of its configuration space $R^n$ is obtained.

A. A. Deriglazov, A. V. Galajinsky

The classical (1,0) superparticle in a curved superspace is considered. The minimal set of constraints to be imposed on the background for correct inclusion of interaction is found. The most general form of Siegel-type local fermionic symmetry is presented. Local algebra of the theory is shown to be closed off-shell and nontrivially deformed as compared to t

Harald Skarke

The paper commented upon gives the impression that whether the gauged version of a sigma model gives rise to the original or the dual model depends on the choice of gauge fixing. It is demonstrated here that this is not so.

G. Delfino, G. Mussardo, P. Simonetti

The scattering theory of the integrable statistical models can be generalized to the case of systems with extended lines of defect. This is done by adding the reflection and transmission amplitudes for the interactions with the line of inhomegeneity to the scattering amplitudes in the bulk. The factorization condition for the new amplitudes gives rise to a s