December 1994 arXiv papers — page 9

C. Liu, K. Jansen, J. Kuti

Simulation results are presented on Higgs mass calculations in the spontaneously broken phase of the Higgs sector in the minimal Standard Model with a higher derivative regulator. A heavy Higgs particle is found in the TeV mass range in the presence of a complex conjugate ghost pair at higher energies. The ghost pair evades easy experimental detection. As a

Karl Svozil

As quantum parallelism allows the effective co-representation of classical mutually exclusive states, the diagonalization method of classical recursion theory has to be modified. Quantum diagonalization involves unitary operators whose eigenvalues are different from one.

O. Debarre

This is the published version. Previous version had minor errors. In French.

J. David Brown

It is shown that in the instanton approximation the rate of creation of black holes is always enhanced by a factor of the exponential of the black hole entropy relative to the rate of creation of compact matter distributions (stars). This result holds for any generally covariant theory of gravitational and matter fields that can be expressed in Hamiltonian f

O. Debarre

This is the published (Crelles Journal 467 (1995), 187--197) version of an e-print entitled "ON SUBVARIETIES OF ABELIAN VARIETIES".

K. A. Matveev

We study the equilibrium properties of a quantum dot connected to a bulk lead by a single-mode quantum point contact. The ground state energy and other thermodynamic characteristics of the grain show periodic dependence on the gate voltage (Coulomb blockade). We consider the case of almost perfect transmission, and show that the oscillations exist as long as

R. Enomoto

We have carried out an inclusive measurement of $K^0(\bar{K^0})$ production in two-photon processes at TRISTAN. The mean $\sqrt{s}$ was 58 GeV and the integrated luminosity was 199 pb$^{-1}$. High-statistics $K_s$ samples were obtained under such conditions as no-, anti-electron, and remnant-jet tags. The remnant-jet tag, in particular, allowed us, for the f

Mark B. Mineev-Weinstein, Ronnie Mainieri

We repeat the numerical experiments for diffusion limited aggregation (DLA) and show that there is a potentially infinite set of conserved quantities for the long time asymptotics. We connect these observations with the exact integrability of the continuum limit of the DLA (quasi-static Stefan problem). The conserved quantities of the Stefan problem (harmoni

M. Gonin, Ole Hansen, B. Moskowitz, F. Videbaek

Predictions from the RQMD model are systematically compared to recently published charged hadron distributions of AGS Experiment 802 for central Si+Au collisions at 14.6$A$ GeV/$c$, taking into account both the experimental trigger condition and acceptance. The main features of the data, including K$^+$ production, can be understood quantitatively to better

S. Nishizaki, J. Wambach

The double-dipole strength distribution in $^{40}$Ca is calculated microscopically within a model space of 1p1h - and 2p2h excitations. Anharmonic effects in the centroid energies of the $0^+$- and $2^+$ components are found to be small, in agreement with experimental observation. Firm conclusions about the spreading width cannot be drawn, as yet, due to com

V. Mull, G. Janssen, J. Speth, K. Holinde

Meson-meson correlation effects are investigated in the $\NNb\toρπ$ annihilation process using a realistic meson-exchange model for the $ρπ$ interaction determined previously, together with a conventional baryon-exchange transition model and a consistent $\NNb$ interaction. For $\NNb$ $S$-states, they have a drastic effect and bring the relative (${^1S_0}/{^

Klaus Werner

We review basic theoretical concepts to describe nuclear collisions at ultrarelativistic energies. We discuss relativistic strings, Gribov--Regge theory (GRT) of hadronic interactions and string models based on GRT, and finally generalizations to nucleus--nucleus scattering. - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Invited Le

N. Tajima, N. Onishi, S. Takahara

We perform Hartree-Fock+BCS calculations for even-even nuclei with 2 <= Z <= 82 and N ranging from outside the proton drip line to the experimental frontier on the neutron-rich side. The ground state solutions are obtained for 737 nuclei, together with shape-coexistence solutions for 480 nuclei. Our method features the Cartesian-mesh representation of single

Moti Gitik

This is a continuation of &#34;Some results on nonstationry ideal&#34;. The upper bound on precipitousness of NS_lambda^+ for a regular lambda given in this paper is proved to be exact.It is shown that saturatedness of NS_kappa^aleph_0 over inaccessible kappa requires at least o(kappa)=kappa^++.The upper bounds on the strength of NS_kappa precipitous for ina

Joseph Bernstein, Tanya Khovanova

We start with the observation that the quantum group SL_q(2), described in terms of its algebra of functions has a quantum subgroup, which is just a usual Cartan group. Based on this observation we develop a general method of constructing quantum groups with similar property. We also describe this method in the language of quantized universal enveloping alge

Eric D&#39;Hoker, Pierre Sikivie, Youli Kanev

We develop a general formalism to calculate the force between beads attached to a flat $d$-dimensional membrane due to the quantum fluctuations of the membrane. The interaction potential is derived as a function of $d$ and the membrane energy density, tension, stiffness and temperature. We find that the induced interactions turn off when $d$ exceeds a certai

D. Boyanovsky, H. J. de Vega, R. Holman

In this brief review we introduce the methods of quantum field theory out of equilibrium and study the non-equilibrium aspects of phase transitions. Specifically we critically study the picture of the ``slow-roll&#39;&#39; phase transition in the new inflationary models, we show that the instabilities that are the hallmark of the phase transition, that is th

C. J. Fewster

We present an inverse scattering construction of generalised point interactions (GPI) -- point-like objects with non-trivial scattering behaviour. The construction is developed for single centre $S$-wave GPI models with rational $S$-matrices, and starts from an integral transform suggested by the scattering data. The theory of unitary dilations is then appli

K. Svozil

The Hilbert space formalism of quantum mechanics is reviewed with emphasis on applications to quantum computing. Standard interferomeric techniques are used to construct a physical device capable of universal quantum computation. Some consequences for recursion theory and complexity theory are discussed.

K. Svozil

Quantum coherence allows the computation of an arbitrary number of distinct computational paths in parallel. Based on quantum parallelism it has been conjectured that exponential or even larger speedups of computations are possible. Here it is shown that, although in principle correct, any speedup is accompanied by an associated attenuation of detection rate

Itzhak Bars

Recent progress on the complete set of solutions of two dimensional classical string theory in any curved spacetime is reviewed. When the curvature is smooth the string solutions are deformed folded string solutions as compared to flat spacetime folded strings that were known for 19 years. However, surprizing new stringy behavior becomes evident at singulari

Dae-Yup Song

By applying the Lehmann-Symanzik-Zimmermann (LSZ) reduction formalism, we study the S matrix of collective field theory in which fermi energy is larger than the height of potential. We consider the spatially symmetric and antisymmetric boundary conditions. The difference is that S matrices are proportional to momenta of external particles in antisymmetric bo

Han-Ying Guo, Yu Cai, Hong-Bo Teng

There exist certain intrinsic relations between the ultraviolet divergent graphs and the convergent ones at the same loop order in renormalizable quantum field theories. Whereupon we may establish a new method, the intrinsic regularization method, to regulate those divergent graphs. In this note, we present a proposal, the inserter proposal, to the method. T

Gregory MAHLON, Stephen PARKE

Motivated by evidence that the top quark mass lies near the $bWZ$ threshold, we compute the decay rate for $t\rightarrow bWZ$ in the Standard Model, including the effects of the finite widths of the $W$ and $Z$ bosons. In the limit where the width effects are negligible, our results disagree with previously published calculations. We also examine the decay $

K. Kołodziej, A. Leike, R. Rückl

Using photon-photon collisions as a particularly transparent study case we investigate the production mechanisms for $B_c$ mesons. In nonrelativistic approximation and to $O(α^2α_s^2)$ it is shown that recombination of $\bar{b}$- and $c$-quarks dominates by far over $\bar{b}$ and $c$ fragmentation. This dominance persists up to the highest accessible transve

M. Benmerrouche, N. C. Mukhopadhyay, J. F. Zhang

We investigate eta photoproduction in the $N^{*}(1535)$ resonance region within the effective Lagrangian approach (ELA), wherein leading contributions to the amplitude at the tree level are taken into account. These include the nucleon Born terms and the leading $t$-channel vector meson exchanges as the non-resonant pieces. In addition, we consider five reso

P. N. Pandita

We calculate an upper bound on the lightest Higgs boson mass in the supersymmetric singlet majoran model containing SU(2) X U(1) singlet right handed neutrino fields and a chiral singlet having two units of lepton number. We show that although the singlet vacuum expectation values and supersymmetry breaking masses do not decouple from the upper bound, even a

Suzhou HUANG, Marcello LISSIA

Within the framework of the operator product expansion (OPE) and the renormalization group equation (RGE), we show that the temperature and chemical potential dependence of the zeroth moment of a spectral function (SF) is completely determined by the one-loop structure in an asymptotically free theory, and in particular in QCD. Logarithmic corrections are fo

Debajyoti Choudhury, Frank Cuypers

We study the production and decay of heavy selectrons in the electron-photon mode of a linear collider of the next generation. The standard model backgrounds can be substantially reduced by appropriate kinematical cuts. As a consequence, selectrons far heavier than the kinematical threshold for pair production are shown to be easily discoverable for large po

Wei-Min Zhang

In this article we review the basic formulation of light-front field theory and light-front phenomena in strong interaction. We also explore various approaches to the understanding of these phenomena and the associated problems of hadronic bound states based on QCD (quantum chromodynamics) on the light-front.

Stephen R. Sharpe

This is the written version of four lectures given at the 1994 TASI. My aim is to explain the essentials of lattice calculations, give an update on (though not a review of) the present status of calculations of phenomenologically interesting quantities, and to provide an understanding of the various sources of uncertainty in the results. I illustrate the imp

M. Alford, W. Dimm, G. Hockney, P. Lepage

We show that the perturbatively-improved gluon action for QCD, once it is tadpole-improved, gives accurate results even with lattice spacings as large as 0.4~fm. {\em No\/} tuning of the couplings is required. Using this action and lattice spacing, we obtain a static potential that is rotationally invariant to within a few percent, the spin-averaged charmoni

Ursula Bassler, Gregorio Bernardi

We review and compare the reconstruction methods of the inclusive deep inelastic scattering variables used at HERA. We introduce a new prescription, the $Σ$ method, which allows to measure the structure function of the proton $F_2(x,Q^2)$ in a large kinematic domain, and in particular in the low x-low$Q^2$ region, with small systematic errors and small radia

Pietro Menotti

A review is given of some classical and quantum aspects of 2+1 dimensional gravity.

Donald Marolf

A formalism for quantizing time reparametrization invariant dynamics is considered and applied to systems which contain an `almost ideal clock.&#39; Previously, this formalism was successfully applied to the Bianchi models and, while it contains no fundamental notion of `time&#39; or `evolution,&#39; the approach does contain a notion of correlations. Using

Gabriela Gonzalez, Ranjeet S Tate

We solve the complex Einstein equations for Bianchi I and II models formulated in the Ashtekar variables. We then solve the reality conditions to obtain a parametrization of the space of Lorentzian solutions in terms of real canonically conjugate variables. In the Ashtekar variables, the dynamics of the universe point particle is governed by only a curved su

Arunava Chakrabarti, S. N. Karmakar, R. K. Moitra

A new type of correlated disorder is shown to be responsible for the appearance of extended electronic states in one-dimensional aperiodic systems like the Thue-Morse lattice. Our analysis leads to an understanding of the underlying reason for the extended states in this system, for which only numerical evidence is available in the literature so far. The pre

Giorgio Parisi

In this lecture I will present some models of neural networks that have been developed in the recent years. The aim is to construct neural networks which work as associative memories. Different attractors of the network will be identified as different internal representations of different objects. At the end of the lecture I will present a comparison among t

Michael R. Geller, Giovanni Vignale

The equilibrium current distribution in a quantum Hall fluid that is subjected to a slowly varying confining potential is shown to generally consist of strips or channels of current, which alternate in direction, and which have universal integrated strengths. A measurement of these currents would yield direct independent measurements of the proper quasiparti

Jian-Sheng Wang

Extensive Monte Carlo simulation results of the standard two-dimensional driven diffusive systems are obtained using a multispin coding technique. The nonequilibrium phase transition is analyzed with anisotropic finite-size scaling, both at the critical point and off the critical point. The field-theoretical values of critical exponents fit the data well. (T

Joerg P. Ueberla

Statistical language models frequently suffer from a lack of training data. This problem can be alleviated by clustering, because it reduces the number of free parameters that need to be trained. However, clustered models have the following drawback: if there is ``enough&#39;&#39; data to train an unclustered model, then the clustered variant may perform wor

Steven A. Henck, Martin A. Mason, Wen - Bin Yan, Kevin K. Lehmann

Using microwave detected, microwave-optical double resonance, we have measured the homogeneous linewidths of individual rovibrational transitions in the à state of NH3, NH2D, NHD2, and ND3. We have used this excited state spectroscopic data to characterize the height of the dissociation barrier and the mechanisms by which the molecule uses its excess vibrati

Ovidiu Costin, Joel L. Lebowitz

Let $N(L)$ be the number of eigenvalues, in an interval of length $L$, of a matrix chosen at random from the Gaussian Orthogonal, Unitary or Symplectic ensembles of ${\cal N}$ by ${\cal N}$ matrices, in the limit ${\cal N}\rightarrow\infty$. We prove that $[N(L) - \langle N(L)\rangle]/\sqrt{\log L}$ has a Gaussian distribution when $L\rightarrow\infty$. This

R. Jeffrey Wilkes

Astrophysics is gaining increased attention from the particle and nuclear physics communities, as budget cuts, delays, and cancellations limit opportunities for breakthrough research at accelerator laboratories. Observations of cosmic rays (protons and nuclei), gamma rays and neutrinos present a variety of puzzles whose eventual solution will shed light on m

Adam G. Riess, William H. Press, Robert P. Kirshner

We have measured our Galaxy's motion relative to distant galaxies in which type Ia supernovae (SN Ia) have been observed. The effective recession velocity of this sample is 7000 km s$^{-1}$, which approaches the depth of the survey of brightest cluster galaxies by Lauer and Postman (1994). We use the Light Curve Shape (LCS) method for deriving distances to S

J. Patricia Vader, Brian Chaboyer

We present UBR and H$α$ imaging of NGC 1620, a highly inclined spiral galaxy that contains a large scale, arc-like feature of radius 3 kpc in its outer disk at a distance of $\sim$ 11 kpc from the center. What is unusual about this arc-like feature is its stellar nature and the presence of a luminous star cluster at its center. The arc is fragmented into HII

Brian Chaboyer

The main sequence turnoff luminosity is the best stellar `clock&#39; which can be used to determine the absolute ages of globular clusters. This is due to the fact that it is generally assumed that the luminosity and lifetimes of main sequence globular cluster stars are independent of the properties of stellar convection and atmospheres, two areas of stellar

Viacheslav V. Nikulin

We name an indecomposable symmetrizable generalized Cartan matrix $A$ and the corresponding Kac--Moody Lie algebra ${\goth g} ^\prime (A)$ {\it of the arithmetic type} if for any $β\in Q$ with $(β| β)<0$ there exist $n(β)\in {\Bbb N}$ and an imaginary root $α\in Δ^{im}$ such that $n(β)β\equiv α\mod Ker\ (.|.)$ on $Q$. Here $Q$ is the root lattice. This gener

V. M. Belyaev

We consider a nonlocal lattice action for fermions fermion doubling in lattice theories. It is shown, that it is possible to avoid the fermionic doubling in the case of free fermions, but this approach does not reproduce results for the effective action for gauge fields in the continuum theory, because the high frequency fermion modes have a strong dependenc

Tae-Suk Kim, D. L. Cox

We introduce a model for Ce$^{3+}$ impurities in cubic metals which exhibits competition between the Fermi-liquid fixed point of the single channel Kondo model and the non-Fermi-liquid fixed point of the two- and three-channel Kondo models. Using the non-crossing approximation and scaling theory, we find: (i) A possible three-channel Kondo effect between the

Anupam Singh

Increasing improvements in the independent determinations of the Hubble constant and the age of the universe now seem to indicate that we need a small non-vanishing cosmological constant to make the two independent observations consistent with each other. The cosmological constant can be physically interpreted as due to the vacuum energy of quantized fields.

A. G. Grozin

Although the methods of calculation of power corrections in QCD sum rules are well known, algebraic complexity rapidly grows with the increase of vacuum condensates&#39; dimensions. Currently, state-of-the-art calculations include dimension 7 and 8 condensates. I summarize and extend algorithms of such calculations. First, I present all the formulae necessar

Piotr A. Raczka, Andrzej Szymacha

The perturbative QCD corrections to the semileptonic decay width of the tau lepton are evaluated in the next-next-to-leading order from the contour integral representation in various renormalization schemes, using numerical solution of the renormalization group equation for complex energies. A quantitative estimate of the ambiguities resulting from the freed

D. S. Salopek

Cosmological inflation provides the simplest and most promising mechanism for generating fluctuations for structure formation. Using powerful Hamilton-Jacobi methods, I will describe (1) how to compute density fluctuations and cosmic microwave anisotropies arising from inflation, and (2) improvements of the Zel'dovich approximation describing gravitational c

F. Y. Wu, H. Y. Huang

We consider a vertex model in d dimensions characterized by lines which run in a preferred direction. We show that this vertex model is soluble if the weights of vertices with intersecting lines are given by a free-fermion condition, and that a fugacity -1 is associated to each loop of lines. The solution is obtained by mapping the model into a dimer problem

Uwe C. Täuber, Hongjie Dai, David R. Nelson, Charles M. Lieber

The positions of columnar pins and magnetic flux lines determined from a decoration experiment on BSCCO were used to calculate the single--particle density of states at low temperatures in the Bose glass phase. A wide Coulomb gap is found, with gap exponent $s \approx 1.2$, as a result of the long--range interaction between the vortices. As a consequence, th

L. Ya. Glozman, D. O. Riska

The spectra of the nucleons and the strange hyperons are well described by a harmonic confinement potential for the constituent quarks and an SU(3) flavor-symmetric interaction mediated by the pseudoscalar octet that is associated with the hidden approximate chiral symmetry of QCD. The spectrum is formed of multiplets of $SU(6)_{FS}\times U(6)_{conf}$, which

B. Bonnier, Y. Leroyer, E. Pommiers

We study analytically and numerically a model of random sequential adsorption (RSA) of segments on a line, subject to some constraints suggested by two kinds of physical situations: - deposition of dimers on a lattice where the sites have a spatial extension; - deposition of extended particles which must overlap one (or several) adsorbing sites on the substr

R. Chitra, Swapan K. Pati, H. R. Krishnamurthy, D. Sen

Using the density matrix renormalization group technique, we study the ground state phase diagram and other low-energy properties of an isotropic antiferromagnetic spin-half chain with both dimerization and frustration, i.e., an alternation $δ$ of the nearest neighbor exchanges and a next-nearest-neighbor exchange $J_2~$. For $δ= 0$, the system is gapless fo

J. -F. Lagae, K. -F. Liu

We discuss the finite $ma$ corrections associated with the computation of sea quark matrix elements. We find them to differ from the standard normalization used for valence quarks and to depend strongly on the Lorentz structure of the current under consideration. Phenomenological implications of these results are briefly discussed in two examples. We also me

Alexander Berkovich, Barry M. McCoy

We present fermionic sum representations of the characters $χ^{(p,p&#39;)}_{r,s}$ of the minimal $M(p,p&#39;)$ models for all relatively prime integers $p&#39;>p$ for some allowed values of $r$ and $s$. Our starting point is binomial (q-binomial) identities derived from a truncation of the state counting equations of the XXZ spin ${1\over 2}$ chain of anisot

Michael J. Booth

Quenched chiral perturbation is used to study the decay constants for heavy-light mesons beyond the leading order in 1/M. The results are used to estimate the error in quenched lattice calculations of the decay constants. For the double ratio $R_1 = ( f_{D_s}/f_D) / (f_{B_s}/f_B)$ we find that the error is small, conservatively 6%, but likely smaller. We als

R. A. Sharipov, R. I. Yamilov

Bäcklund transformation for the Bullough-Dodd-Jiber-Shabat equation $u_{xx}-u_{tt}=e^u-e^{-2u}$ is found. The construction of integrable boundary condition for this equation together with the algebro-geometric solutions satisfying it are suggested.

T-Y Saito, I. R. Afnan

By calculating the contribution of the $π-π$ three-body force to the three-nucleon binding energy in terms of the $πN$ amplitude using perturbation theory, we are able to determine the importance of the energy dependence and the contribution of the different partial waves of the $πN$ amplitude to the three-nucleon force. A separable representation of the non

Eiji Tsuchida, Masaru Tsukada

We have applied the Finite Element Method to the self-consistent electronic structure calculations of molecules and solids for the first time. In this approach all the calculations are performed in &#34;real space&#34; and the use of non-uniform mesh is made possible, thus enabling us to deal with localized systems with ease. To illustrate the utility of thi

David W. Farmer

The GUE Hypothesis, which concerns the distribution of zeros of the Riemann zeta-function, is used to evaluate some integrals involving the logarithmic derivative of the zeta-function. Some connections are shown between the GUE Hypothesis and other conjectures.

C. Bryan Dawson

Given an operator $T:U_X(Σ)\to Y$ or ${T:U(Σ)\to Y$, one may consider the net of conditional expectation operators $(T_π)$ directed by refinement of the partitions $π$. It has been shown previously that $(T_π)$ does not always converge to $T$. This paper gives several conditions under which this convergence does occur, including complete characterizations wh

Janos Polonyi

The running coupling constants are introduced in Quantum Mechanics and their evolution is described by the help of the renormalization group equation.

D. J. Lamb, A. Z. Capri, M. Kobayashi

In this paper we calculate the particle creation as seen by a stationary observer in 3+1 de Sitter space. This particle creation is calculated using an observer dependent geometrically based definition of time which is used to quantize a field on two different spacelike surfaces. The Bogolubov transformation relating these two quantizations is then calculate

Reinhard Oehme

For gauge theories with confinement, the analytic structure of amplitudes is explored. It is shown that the analytic properties of physical amplitudes are the same as those obtained on the basis of an effective theory involving only the composite, physical fields. The corresponding proofs of dispersion relations remain valid. Anomalous thresholds are conside

M. P. Grabowski, P. Mathieu

We examine a simple heuristic test of integrability for quantum chains. This test is applied to a variety of systems, including a generic isotropic spin-1 model with nearest-neighbor interactions and a multiparameter family of spin-1/2 models generalizing the XYZ chain, with next-to-nearest neighbor interactions and bond alternation. Within the latter family

Chongying Dong, Zongzhu Lin

For a vertex operator algebra $V$ and a vertex operator subalgebra $V&#39;$ which is invarinant under an automorphism $g$ of $V$ of finite order, we introduce a $g$-twisted induction functor from the category of $g$-twisted $V&#39;$-modules to the category of $g$-twisted $V$-modules. This functor satisfies the Frobenius reciprocity and transitivity. The resu

Chongying Dong, Geoffrey Mason

For a simple vertex operator algebra $V$ and a finite automorphism group $G$ of $V$ then $V$ is a direct sum of $V^χ$ where $χ$ are irreducible character of $G$ and $V^χ$ is the subspace of $V$ which $G$ acts according to the character $χ.$ We prove the following: 1. Each $V^χ$ is nonzero. 2. $V^χ$ is a tensor product $M_χ\otimes V_χ$ where $M_χ$ is an irred

Michael P. Tuite

We consider the application of Abelian orbifold constructions in Meromorphic Conformal Field Theory (MCFT) towards an understanding of various aspects of Monstrous Moonshine and Generalised Moonshine. We review some of the basic concepts in MCFT and Abelian orbifold constructions of MCFTs and summarise some of the relevant physics lore surrounding such const

Julian Lee, Branko Urosevic

This paper is devoted to the study of closed string field theory in two dimensions. We compare two different approaches: BRST closed string field theory and the string effective Lagrangian. We show that the quadratic action and the pole structures of tree-level scattering amplitudes agree. We study merits and drawbacks of various gauge fixing procedures. In

M. Kreuzer, H. Skarke

We complete the classification of (2,2) vacua that can be constructed from Landau--Ginzburg models by abelian twists with arbitrary discrete torsions. Compared to the case without torsion the number of new spectra is surprisingly small. In contrast to a popular expectation mirror symmetry does not seem to be related to discrete torsion (at least not in the p

Chi-Keung Chow

A systematic study of multiquark exotics with one or $N_c-1$ heavy quarks in the large $N_c$ limit is presented. By binding a chiral soliton to a heavy meson, either a normal $N_c$-quark baryon or an exotic $(N_c+2)$-quark baryon is obtained. By replacing the heavy quark with $N_c-1$ heavy antiquarks, exotic $(2N_c-2)$-quark and $2N_c$-quark mesons are obtai

Claudio Rebbi, Robert Singleton,

We describe an application of computational techniques to the study of instanton induced baryon decay in high energy electroweak interactions.

Valery A. Khoze

In this talk I attempt to survey some selected physics issues on radiative interference phenomena in the production of heavy unstable particles. A special emphasis is placed on the reactions $e^+e^- \rightarrow W^+W^- \rightarrow 4$ jets and $e^+e^- \rightarrow t\bar{t} \rightarrow bW^+\bar{b}W^-$. A transparent recipe is given for quantifying the level of s

X. Wang, J. Lopez, D. Nanopoulos

We compute the scattering rates for the lightest neutralino $χ^0_1$ in the forthcoming germanium $(^{73}{\rm Ge}+^{76}{\rm Ge})$ detector and a proposed lead detector $(^{207}{\rm Pb})$, within the framework of $SU(5)\times U(1)$ supergravity. We find that in only a small portion ($\lsim10\%$) of the parameter spaces of this class of models, are the rates in

Hanxin He, Xiangdong Ji

We seek to understand the physical significance of the nucleon&#39;s tensor charge and make estimates of its size in phenomenological models and the QCD sum rule.

Michael Martin Nieto, T. Goldman, John D. Anderson, Eunice L. Lau

We know that the generally accepted theories of gravity and quantum mechanics are fundamentally incompatible. Thus, when we try to combine these theories, we must beware of physical pitfalls. Modern theories of quantum gravity are trying to overcome these problems. Any ideas must confront the present agreement with general relativity, but yet be free to wond

C. W. Kim

The apparent cosmological conflict between the age of the Universe, predicted in the standard Friedman cosmology by using the recent measurement of the larger Hubble constant from a direct calibration of the distance to the Virgo galaxy cluster, and the ages of the oldest stars and globular clusters is resolved by invoking the scale dependence of cosmologica

Ruth Gregory

We examine a Nambu-Goto string trajectory in the neighbourhood of a cusp and determine the extrinsic curvature invariants. These are demonstrated to be finite, in contradiction with naive expectation. Thus the Nambu action is a valid approximation for the motion of a cosmic string vortex even at cusps. This suggests that cusp annihilation is not a feasible m

E. L. Bratkovskaya, E. A. Kuraev, Z. K. Silagadze, O. V. Teryaev

We discuss special type of polarization asymmetry (``handedness&#34;) in the process $e^+e^-\to 4π$, when one of initial particles is longitudinally polarized. The asymmetry is proportional to the degree of polarization and to the width to mass ratio of rho-meson. It can reach 4-5\% in some kinematical region. Both channels $2 π^+ 2 π^-$ and $2 π^0 π^+ π^-$

R. Aleksan, A. Le Yaouanc, L. Oliver, O. Pène

We point out that current estimates of form factors fail to explain the non-leptonic decays $B \to ψK(K^{\ast})$ and that the combination of data on the semi-leptonic decays $D \to K(K^{\ast})\ell ν$ and on the non-leptonic decays $B \to ψK(K^{\ast})$ (in particular recent po\-la\-ri\-za\-tion data) severely constrain the form (normalization and $q^2$ depend

I. I. Bigi

the KM expectations of large CP asymmetries in $B$ decays are reviewed. I describe some observable signatures for the intervention of New Physics and list benchmarks defining the `ultimate&#39; measurements in beauty physics. I also stress the need for dedicated searches for CP asymmetries in $D$ decays; attaining a sensitivity level of $10^{-3}$ could well

Chris Michael

Recent results in light hadron spectroscopy are reviewed. Attention is given to the requirements of precision determinations in lattice gauge theory. Different methods for extracting the running coupling constant $α_S$ are compared. Some recent results in determining the nature of the interaction between static quarks are also discussed.

Arjan Hulsebos

We study numerically 4+1 dimensional pure gauge theory.

Arjan Hulsebos, Peer Ueberholz

We study a topological updating scheme in three dimensional U(1) gauge theory. Some expectations for four dimensional SU(N) gauge theories are discussed.

A. M. Green, J. Lukkarinen, P. Pennanen, C. Michael

This contribution -- a continuation of earlier work -- reports on recent developments in the calculation and understanding of 4-quark energies generated using lattice Monte Carlo techniques.

M. Gockeler, H. A. Kastrup, J. Viola, J. Westphalen

Encouraged by the successful applications of Lüscher&#39;s method to boson--boson scattering we discuss the possibility of extracting scattering phase shifts from finite--volume energies for fermion--fermion scattering in the Gross--Neveu model.

G. S. Bali, V. Bornyakov, M. Müller-Preussker, F. Pahl

An overrelaxed variant of simulated annealing is applied to the problem of maximally abelian gauge fixing. The superiority of this algorithm over the commonly used relaxation procedure is demonstrated. Biases on non gauge invariant quantities due to gauge fixing ambiguities are discussed.

Shinji Ejiri, Shun-ichi Kitahara, Yoshimi Matsubara, Tsuneo Suzuki

Monopole and photon contributions to abelian Wilson loops are calculated using Monte-Carlo simulations of finite-temperature $SU(2)$ QCD in the maximally abelian gauge. The string tension is reproduced by monopole contribution alone also in finite temperature SU(2) QCD. The spatial string tension scales as $\sqrtσ \propto g^{2}(T)T$ and is reproduced almost

M. Fukugita, Y. Kuramashi, M. Okawa, A. Ukawa

$π$-$N$ $σ$ term and proton axial vector matrix elements are calculated including disconnected contributions with a variant wall source method using the Wilson quark action at $β=5.7$ in quenched QCD. For the $σ$ term, we find $σ_{disc}/σ_{conn}=2.35(46)$ and $σ=44(6)$MeV--60(9)MeV. The fraction of proton spin carried by quarks is $ΔΣ=Δ{u}+Δ{d}+Δ{s}=+0.638(5

J. B. Kogut, J. -F. Lagae

We discuss the advantages of using the momentum space lattice method for studying the phase diagram of quenched QED_4. Preliminary results of a numerical simulation are presented. They indicate that the method avoids the contamination by 4-fermi interactions which plagues the conventional position space non-compact formulation.

G. E. Forden

D0 has used W -> e nu events produced in association with a high $p_T$ jet to examine the effects of strong radiative corrections. We have compared the primary jet pseudorapidity distribution, as a function of reconstructed W rapidity to leading order (LO) and next to leading order (NLO) QCD Monte Carlos, as well as a model based on extended color dipoles. O

Abhay Ashtekar, Jerzy Lewandowski, Donald Marolf, José Mourão

The Segal-Bargmann transform plays an important role in quantum theories of linear fields. Recently, Hall obtained a non-linear analog of this transform for quantum mechanics on Lie groups. Given a compact, connected Lie group $G$ with its normalized Haar measure $μ_H$, the Hall transform is an isometric isomorphism from $L^2(G, μ_H)$ to ${\cal H}(G^{\Co})\c

Dirk Graudenz

We describe the time evolution of quantum systems in a classical background space-time by means of a covariant derivative in an infinite dimensional vector bundle. The corresponding parallel transport operator along a timelike curve $\cC$ is interpreted as the time evolution operator of an observer moving along $\cC$. The holonomy group of the connection, wh

Igor Herbut

We consider the problem of randomly distributed positive delta-function scatterers in a strong magnetic field and study the behavior of density of states close to the spectral boundary at $E=\hbarω_{c}/2$ in both two and three dimensions. Starting from dimensionally reduced expression of Brezin et al. and using the semiclassical approximation we show that th