November 1992 arXiv papers — page 2

Takashi Sano

The N=1,2 supergravities with non-zero cosmological constants are investigated in the Ashtekar formalism. We solve the constraints of the N=1,2 supergravities semi-classically. The resulting WKB wave functions are expressed by exponentials of supersymmetric-extended SL(2,C) Chern-Simons functional.

Paulo F. Bedaque, Ashok Das

We compare results from $δ$--expansion, in simple theories, with self--consistent calculations as well as calculations involving the principle of minimal sensitivity. We show that the latter methods give relatively more accurate results order by order.

Matthias Neubert

We complete the QCD sum rule analysis of the Isgur Wise form factor $ξ(v\cdot v')$ at next-to-leading order in renormalization-group improved perturbation theory. To this end, the exact result for the two-loop corrections to the perturbative contribution is derived using the heavy quark effective theory. Several techniques for the evaluation of two-loop

S. D. H. Hsu, Pierre Sikivie

The exchange of two massless neutrinos gives rise to a long range force which couples to weakly charged matter. As has been noted previously in the literature, the potential for this force is $\VN \propto G_{F}^2 / r^5$ with monopole-monople, spin-spin and more complicated interactions. Unfortunately, this is far too small to be observed in present day exper

Ulf-G. Meißner

In this lecture, I review progress made in the calculations of the parity-violating meson-nucleon interaction regions. The underlying framework is the topological chiral soliton model of the nucleon. Emphasis is put on the computation of theoretically and experimentally accessible nuclear parity violating observables. I stress the importance of the interplay

Vineer Bhansali, Stephen D. H. Hsu

We formulate ``Witten'' matching conditions for confining gauge theories. The conditions are analogous to 't Hooft's, but involve Witten's global SU(2) anomaly. Using a group theoretic result of Geng, Marshak, Zhao and Okubo, we show that if the fourth homotopy group of the flavor group $H$ is trivial ($Π_4(H) = 0$) then realizations of m

Steven Weinberg

Talk presented at the XXVI International Conference on High Energy Physics, Dallas, Texas, August, 12, 1992.

Derek B. Leinweber, Thomas D. Cohen

Logarithmic divergences in pion and proton charge radii associated with chiral loops are investigated to assess systematic uncertainties in current lattice determinations of charge radii. The chiral corrections offer a possible solution to the long standing problem of why present lattice calculations yield proton and pion radii which are similar in size.

R. Gupta, D. Daniel, J. Grandy

Results for semi-leptonic form-factors for processes like $D \to K l ν$ and the Bethe-Salpeter amplitudes (BSA) for pion and rho mesons are presented. The form-factor data is consistent with previous calculations. We find that the long distance fall-off of BSA for both $π$ and $ρ$ is very well fit by an exponential, but surprisingly the effective mass govern

Ruy Exel

We prove that every AF-algebra is isomorphic to a crossed product of a commutative AF-algebra by a partial automorphism. The case of UHF-algebras is treated in detail.

M. Wallin, S. M. Girvin

The vortex glass transition in the presence of columnar defects is studied by Monte Carlo simulations of a vortex loop model, suggested by the analogy to the $T=0$ superconductor-insulator transition for dirty bosons in (2+1)D. From finite-size scaling analysis of the $I$-$V$ characteristic we find two dynamical exponents describing the non-equilibrium behav

Kun Yang, K. L. Warman, S. M. Girvin

The frustrated spin-one-half Heisenberg model on triangualr and Kagome Lattices is mapped onto a single specis of fermion carrying statistical flux. The corresponding Chern-Simons gauge theory is analyzed at the Gaussian level and found to be massive. This provides a new motivation for the spin-liquid Kalmeyer-Laughlin wave function. Good overlap of this wav

Doron Gepner

We study the connection between Rational Conformal Field Theory (RCFT), $N=2$ massive supersymmetric field theory, and solvable Interaction Round the Face (IRF) lattice models. Specifically, one identifies the fusion rings with the chiral rings. The theories so obtained are conjectured, and largely shown, to be integrable. A variety of examples and the struc

S. Cecotti, C. Vafa

We find a relation between the spectrum of solitons of massive $N=2$ quantum field theories in $d=2$ and the scaling dimensions of chiral fields at the conformal point. The condition that the scaling dimensions be real imposes restrictions on the soliton numbers and leads to a classification program for symmetric $N=2$ conformal theories and their massive de

William Arveson

We extend the results of our previous paper "C*-algebras and numerical linear algebra" to cover the case of "unilateral" sections. This situation bears a close resemblance to the case of Toeplitz operators on Hardy spaces, in spite of the fact that the operators here are far from Toeplitz operators. In particular, there is a short exact seque

N. K. Glendenning, D. Von-Eiff, M. Haft, H. Lenske

Single--particle spectra of $Λ$ and $Σ$ hypernuclei are calculated within a relativistic mean--field theory. The hyperon couplings used are compatible with the $Λ$ binding in saturated nuclear matter, neutron-star masses and experimental data on $Λ$ levels in hypernuclei. Special attention is devoted to the spin-orbit potential for the hyperons and the influ

T. S. Biro, B. Mueller

We develop a semiclassical method to calculate the density of magnetic monopoles in non-abelian gauge theories at finite temperature in the dilute gas approximation. This quantity is related to the inverse magnetic screening length for which we obtain $μ_M = 0.255 g^2T$ in SU(2).

C. S. Xiong

We propose one possible generalization of the KP hierarchy, which possesses multi bi--hamiltonian structures, and can be viewed as several KP hierarchies coupled together.

Patrick J. O'Donnell

I review some aspects of $K$ and $B$ physics both in the context of the standard model and in some cases in a scenario which is rather different from the standard model. I discuss, in particular, where we are likely to see deviations from the standard model in the near future before new colliders are built.

P. Ball, H. G. Dosch, M. A. Shifman

Hadronic systems built from a heavy quark and a cloud of light quarks and massless gluons posess the Isgur-Wise symmetry resulting in certain relations between various form factors. These relations can not be valid in the entire complex plane. We identify contributions which unavoidably violate strongly the symmetry in the time-like domain near thresholds. A

A. Wirzba

As an alternative approach to the infinite-array description of dense matter in the Skyrme model, we report about the properties of a single skyrmion on a compact 3-sphere of finite radius. The density of this matter can be increased by decreasing the hypersphere radius. As in the array calculations one encounters a transition to a distinct high density phas

Gernot Muenster, Markus Plagge

Lattice theories that contain chiral multiplets of fermions can have complex fermion determinants. This is for example the case for the $\rm U(1)_L \otimes U(1)_R$ symmetric Yukawa model with mirror fermions, if the number of generations of fermions and mirror fermions is odd. Whether a numerical simulation of such a model is possible depends on the magnitud

S. Gupta, A. Irbaeck

We study the finite-size scaling of moments of the magnetization in the low-temperature phase of the two-dimensional Ising model.

E. Calzetta, C. El Hasi

We show that the dynamics of a spatially closed Friedmann - Robertson - Walker Universe conformally coupled to a real, free, massive scalar field, is chaotic, for large enough field amplitudes. We do so by proving that this system is integrable under the adiabatic approximation, but that the corresponding KAM tori break up when non adiabatic terms are consid

Jysoo Lee, Hans J. Herrmann

We present an implementation of realistic static friction in molecular dynamics (MD) simulations of granular particles. In our model, to break contacts between two particles, one has to apply a finite amount of force, determined by the Coulomb criterion. Using a two dimensional model, we show that piles generated by avalanches have a {\it finite} angle of re

William Arveson

We consider problems associated with the computation of spectra of self-adjoint operators in terms of the eigenvalue distributions of their n x n sections. Under rather general circumstances, we show how these eigenvalues accumulate near points of the essential spectrum of the given operator, and we prove that their averages converge to a measure concentrate

F. D. Mazzitelli, J. G. Russo

We consider a renormalizable two-dimensional model of dilaton gravity coupled to a set of conformal fields as a toy model for quantum cosmology. We discuss the cosmological solutions of the model and study the effect of including the backreaction due to quantum corrections. As a result, when the matter density is below some threshold new singularities form i

L. Feher

We review the construction of Drinfeld-Sokolov type hierarchies and classical W-algebras in a Hamiltonian symmetry reduction framework. We describe the list of graded regular elements in the Heisenberg subalgebras of the nontwisted loop algebra based on $gl_n$ and deal with the associated hierarchies. We exhibit an $sl_2$ embedding for each reduction of a Ka

A. Mishra, H. Mishra, S. P. Misra

We consider chiral symmetry breaking through nontrivial vacuum structure with an explicit construct for the vacuum with quark antiquark condensates in QCD with Coulomb gauge for different phenomenological potentials. The dimensional parameter for the condensate function gets related to $<{\bar ψ}ψ>$ of Shifman, Vainshtein and Zakharov. We then relate the con

Philippe de Forcrand, Keh-Fei Liu

We measure Coulomb-gauge wavefunctions of the scalar and tensor glueballs in SU(2) Yang-Mills. The problem of contamination by flux states is discussed, and a new analysis method described. The large size of the tensor glueball is confirmed. Preliminary results in the deconfined phase show no significant changes.

Ruy Exel

We introduce a method to study C*-algebras possessing an action of the circle group, from the point of view of its internal structure and its K-theory. Under relatively mild conditions our structure Theorem shows that any C*-algebra, where an action of the circle is given, arises as the result of a construction that generalizes crossed products by the group

H. Roeder, A. R. Bishop, J. Tinka Gammel

We discuss the consequences of including both electron-phonon and electron-electron couplings in multi-band models, focusing on numerical studies of a one-dimensional two-band model in the intermediate regime for both coupling strengths. Spin-Peierls as well as long-period, frustrated ground states are identified, reminisent of those found in antiferromagnet

E. M. Chirka

The following theorem is proved: Let M be a locally Lipschitz hypersurface in C^n with one-sided extension property at each point (e.g., without analytic discs). Let S be a closed subset of M and f : M \ S ---> C^m \ E is a CR-mapping of class L^{\infty} such that the cluster set of f on S along of Lebesque points of f is contained in a closed complete pluri

I. A. Batalin, I. V. Tyutin

A generalized version is proposed for the field-antifield formalism. The antibracket operation is defined in arbitrary field-antifield coordinates. The antisymplectic definitions are given for first- and second-class constraints. In the case of second-class constraints the Dirac&#39;s antibracket operation is defined. The quantum master equation as well as t

Zhu Yang

Fixed angle scattering at high energy in a string theory with boundaries satisfying Dirichlet conditions (Dirichlet strings) in $D=4$ is shown to have logarithmic dependence on energy, in addition to the power-like behavior known before. High temperature free energy also depends logarithmically on temperature. Such a result could provide a matching mechanism

Peter Ossadnik

We study numerically the growth of a crack in an elastic medium under the influence of a travelling shockwave. We describe the implementation of a fast algorithm which is perfectly suited for a data parallel computer. Using large scale simulations on the Connection Machine we generate cracks with more than 10000 sites on a $\scriptstyle 1024 \times 1024$ lat

P. I. Krastev

Resonant spin--flavour conversion of neutrinos (RSFCN) in twisting magnetic fields might be at the origin of the apparent anticorrelation between the $^{37}$Ar production--rate in the Homestake solar neutrino detector and the solar activity. Moreover, it can account for the results of all solar neutrino experiments reported so far including the recent result

Douglas O. Carlson, C. -P. Yuan

We show that studying the single top quark production via the $W$--gluon fusion process can provide unique information on: (i) the measurement of the decay width $\width$; (ii) probing the symmetry breaking mechanism by measuring the form factor of~\tbW; (iii) testing the Effective--$W$ Approximation prior to supercolliders; (iv) testing CP violation by obse

Tanmay Vachaspati, Richard Watkins

We show that the electroweak $Z-$string can be stabilized by the presence of bound states of a complex scalar field. We argue that fermions coupled to the scalar field of the string can also make the string stable and discuss the physical case where the string is coupled to quarks and leptons. This stabilization mechanism is expected to work for other embedd

Berndt Mueller

Central nuclear collisions at energies far above 1 GeV/nucleon may provide for conditions, where the transition from highly excited hadronic matter into quark matter or quark-gluon plasma can be probed. Here I review our current understanding of the physical properties of a quark-gluon plasma and review ideas about the nature of, and signals for, the deconfi

N. J. MacKay

It is pointed out that the apparent presence of the fusing rule for purely elastic scattering theories in theories with dynamical Yangian invariance implies beautiful and hitherto unseen structure in the finite-dimensional representation theory of Yangians.

A. Lossev

It is argued that gravitational descendants in Landau-Ginsburg theory coupled to topological gravity can be constructed from the matter fields only. For example, $σ_1 (Φ) = V&#39;\int Φ$. This descendants turn out to be connected with K.Saito higher residue pairing. Naive computaitions are corrected with the help of the contact term, the form of this term is

J. Schechter

We first outline the calculations of the neutron-proton mass difference and of the axial singlet matrix element (relevant to the &#34;proton spin&#34; puzzle) in a generalized Skyrme model of pseudoscalars and vectors. These two calculations are, perhaps surprisingly, linked to each other and furthermore are sensitive to some fine details of symmetry breakin

Stephen P. Martin

We propose a scenario in which the electroweak symmetry is spontaneously broken by an $SU(4)$ technicolor gauge interaction which also manages to break itself completely. The technicolor gauge bosons and technifermions are not confined by the technicolor force, but get large masses. Starting with a single technidoublet, one emerges with a complete standard m

John N. Bahcall

If the published event rates of the chlorine and Kamiokande solar neutrino experiments are correct, then the energy spectrum of neutrinos produced by the decay of $^8$B in the sun must be different from the energy spectrum determined from laboratory nuclear physics measurements. This change in the energy spectrum requires physics beyond the standard electrow

Frank Wilczek

QCD is now a mature theory, and it is possible to begin to view its place in the conceptual universe of physics with appropriate perspective. There is a certain irony in the achievements of QCD. For the problems which initially drove its development only limited insight has been achieved. However I shall argue that QCD is actually {\it more\/} special and im

Christopher D. Carone, Rowan T. Hamilton

We consider the phenomenology of a composite technicolor model proposed recently by Georgi. Composite technicolor interactions produce four-quark operators in the low energy theory that contribute to flavor changing neutral current processes. While we expect operators of this type to be induced at the compositeness scale by the flavor-symmetry breaking effec

R. Foot, H. Lew, R. R. Volkas

Quark-lepton symmetric models are a class of gauge theories motivated by the similarities between the quarks and leptons. In these models the gauge group of the standard model is extended to include a ``color&#39;&#39; group for the leptons. Consequently, the quarks and leptons can then be related by a $Z_2$ discrete quark-lepton symmetry which is spontaneou

J. Lopez, D. Nanopoulos, X. Wang, A. Zichichi

We compute the number of trilepton events to be expected at Fermilab as a result of the reaction $p\bar p\toχ^\pm_1χ^0_2X$, where $χ^\pm_1$ is the lightest chargino and $χ^0_2$ is the next-to-lightest neutralino. This signal is expected to have very little background and is the best prospect for supersymmetry detection at Fermilab if the gluino and squarks a

Minoru Tanaka

Using the heavy quark effective theory, chiral structure of the $b\rightarrow c$ charged current can be determined by the semileptonic $Λ_b$ decay with satisfactory theoretical accuracy. We define an asymmetry which is sensitive to the chirality of the $b\rightarrow c$ charged current. We show that this asymmetry has no theoretical uncertainty in the heavy q

R. Alkofer

The baryon number one soliton of the NJL model is investigated. The Euclidian effective action is regularized using Schwinger&#39;s proper time method. Numerical results for the static soliton energy are presented for the cases without and with vector and axialvector fields. It is found that the baryon number is carried by the polarized Dirac sea of the quar

K. L. Kowalski, C. C. Taylor

Theoretical speculations and experimental data suggesting the possibility of observing disoriented chiral condensates at a Full Acceptance Detector are reviewed.

W. T. A. ter Veldhuis

An upperbound on the mass of the lightest neutral scalar Higgs boson is calculated in an extended version of the minimal supersymmetric standard model that contains an additional Higgs singlet. We integrate the renormalization group equations of the model, and impose low energy boundary conditions consistent with present experimental results, and ultra-viole

P. R. Brady, D. Nunez, S. Sinha

A perturbed Reissner-Nordström-de Sitter solution is used to emphasize the nature of the singularity along the Cauchy horizon of a charged spherically symmetric black hole. For these solutions, conditions may prevail under which the mass function is bounded and yet the curvature scalar $R_{αβγδ} R^{αβγδ}$ diverges.

Thorsten Poeschel

Two-dimensional Molecular Dynamics simulations are used to model the free surface flow of spheres falling down an inclined chute. The interaction between the particles in our model is assumed to be subjected to the Hertzian contact force and normal as well as shear friction. The stream of particles shows a characteristic height profile, consisting of layers

P. -M. Binder, V. Privman

We review recent numerical studies and the phenomenology of spatially synchronized collective states in many-body dynamical systems. These states exhibit thermodynamic noise superimposed on the collective, quasiperiodic order parameter evolution with typically one basic irrational frequency. We concentrate on the description of the global temporal properties

Joel R. Primack

The IV Rencontres de Blois, on Particle Astrophysics, held at the Château de Blois, June 15-20, 1992, was a meeting well-timed for a reconsideration of the issues in particle astrophysics in the light of the COBE discovery of the cosmic microwave background (CMB) fluctuations. This is a summary of what I thought were the most interesting things discussed at

C. Holm, W. Janke

We report measurements of the critical exponents of the classical three-dimensional Heisenberg model on simple cubic lattices of size $L^3$ with $L$ = 12, 16, 20, 24, 32, 40, and 48. The data was obtained from a few long single-cluster Monte Carlo simulations near the phase transition. We compute high precision estimates of the critical coupling $K_c$, Binde

M. Praszalowicz

We discuss the phenomenology of SU(3) Skyrme and Nambu--Jona-Lasinio models. We show that while the Skyrme model, in its simplest version, is unable do reproduce the hyperon spectrum, the NJL model describes both hyperon and isospin splittings with satisfactory accuracy. The difference between the two models lies in new {\em anomalous} moments of inertia, wh

N. J. Cornish, J. W. Moffat, D. C. Tatarski

We prove that the flux of gravitational radiation from an isolated source in the Nonsymmetric Gravitational Theory is identical to that found in Einstein&#39;s General Theory of Relativity.

A. P. Isaev, P. N. Pyatov

We consider GLq(N)-covariant quantum algebras with generators satisfying quadratic polynomial relations. We show that, up to some inessential arbitrariness, there are only two kinds of such quantum algebras, namely, the algebras with q-deformed commutation and q-deformed anticommutation relations. The connection with the bicovariant differential calculus on

Rolf Schimmrigk

A new method for constructing flows between distinct Landau-Ginzburg theories at fixed central charge is presented. The essential ingredient of the construction is an enlarged moduli space obtained by adding theories with zero central charge. The flows involve only marginal directions hence they can be applied to transitions between string vacua, in particul

Jean-Loup Gervais, Lochlainn O&#39;Raifeartaigh, Alexander V. Razumov, Mikhail V. Saveliev

There is a constrained-WZNW--Toda theory for any simple Lie algebra equipped with an integral gradation. It is explained how the different approaches to these dynamical systems are related by gauge transformations. Combining Gauss decompositions in relevent gauges, we unify formulae already derived, and explictly determine the holomorphic expansion of the co

Hidetoshi Awata

We consider the q-deformed Knizhnik-Zamolodchikov equation for the two point function of q-deformed vertex operators of $U_q(sl_2^)$. We give explicitly the fundamental solutions, the connection matrices and the exchange relations for the q-vertex operators of spin 1/2 and $j \in {1\over 2}{\bf Z}_{\geq 0}$. Consequently, we confirm that the connection matri

S. Randjbar-Daemi, J. Strathdee

The renormalization group equations for a class of non--relativistic quantum $σ$--models targeted on flag manifolds are given. These models emerge in a continuum limit of generalized Heisenberg antiferromagnets. The case of the ${SU(3)\over U(1)\times U(1)}$ manifold is studied in greater detail. We show that at zero temperature there is a fixed point of the

Sumit R. Das

We discuss the basic features of the double scaling limit of the one dimensional matrix model and its interpretation as a two dimensional string theory. Using the collective field theory formulation of the model we show how the fluctuations of the collective field can be interpreted as the massless &#34;tachyon&#34; of the two dimensional string in a linear

John N. Bahcall

Recent results on standard solar models are reviewed. I shall summarize briefly three of the themes that I stressed at the Neutrino &#39;92 Conference: 1) Different solar model codes give the same answers when the same input data are used; 2) Improved calculations of standard solar models include helium diffusion, the Livermore radiative opacity, the meteori

Eric D. Carlson, Meng Yuan Wang

Models with spontaneously broken parity symmetry can solve the strong $CP$ problem in a natural way. We construct such a model in the context of $\SU3^3$ unification. Parity has the conventional meaning in this model, and the gauge group is unified.

Meng Y. Wang, Eric D. Carlson

We find that massless Higgs doublets at the GUT scale can be the natural result of a discrete symmetry. Such a mechanism does not require elaborate fine tuning or complicated particle content. The same discrete symmetry will also protect against proton decay and flavor changing neutral currents. However, this mechanism always predicts non-minimal standard mo

Xiao-Gang He, J. P. Ma, B. McKellar

We study CP violation in $J/\psi \rightarrow \Lambda \bar{\Lambda}$ decay. This decay provides a good place to look for CP violation. Some observables are very sensitive to the $\Lambda$ electric dipole moment $d_\Lambda$ and therefore can be used to improve the experimental upper bound on $d_\Lambda$. CP violations in the lepton pair decays of $J/\psi$ and

C. -P. Yuan

We discuss how to experimentally study the symmetry breaking sector by observing $W_L W_L \rightarrow W_L W_L$ interactions in the TeV region. We discuss some general features of the event structure in the signal and background events. Various tricks to enhance the signal--to--background ratio are also presented. We show how to detect longitudinal $W$--boson

C. Vohwinkel

I present a modification of the shadow-lattice technique, which allows one to derive low temperature series for discrete spin models to high orders. Results are given for the 3-d Ising model up to 64 excited bonds, for the 4-d Ising model up to 96 excited bonds and the 3-d Potts model up to 56 excited bonds.

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

We obtain estimates of several hadron mass ratios, for Wilson quarks in the valence (quenched) approximation, extrapolated to physical quark mass, infinite volume and zero lattice spacing.

Lawrence E. Kidder, Clifford M. Will, Alan G. Wiseman

We derive the contributions of spin-orbit and spin-spin coupling to the gravitational radiation from coalescing binary systems of spinning compact objects. We calculate spin effects in the symmetric, trace-free radiative multipoles that determine the gravitational waveform, and the rate of energy loss. Assuming a balance between energy radiated and orbital e

R. Mansouri, M. Mohazzab

Tunneling rate is investigated in homogenous and anisotropic cosmologies. The calculations is done by two methods: Euclidean and Hamiltonian approaches. It is found that the probability decreases exponentialy as anisotropy is increased.

G. A. Ladinsky, C. -P. Yuan

We describe how to probe new physics through examination of the form factors describing the Ztt couplings via the scattering process e^-e^+->t+tbar. We focus on experimental methods on how the top quark momentum can be determined and show how this can be applied to select polarized samples of $t\bar{t}$ pairs through the angular correlations in the final sta

F. Borzumati

The contribution to the decay $b\to s γ$ in the Minimal Supersymmetric Standard Model with radiative electroweak breaking is presented. The impact of a detection of this inclusive decay at the SM level is discussed. Results for other inclusive $b-s$ transitions are also mentioned.

I. Bakas, E. Kiritsis

Various typos corrected

Alessandro Pelizzola

The half filled Hubbard model is studied in the pair approximation of the Cluster Variation Method. The use of the $SO(4)$ symmetry of the model makes possible to give a complete analytical characterization of the ground state, by means of explicit expressions for the double occupancy and the nearest neighbor correlation functions. The finite temperature ana

Jerzy Szulga

We prove a number of decoupling inequalities for nonhomogeneous random polynomials with coefficients in Banach space. Degrees of homogeneous components enter into comparison as exponents of multipliers of terms of certain Poincaré-type polynomials. It turns out that the fulfillment of most of types of decoupling inequalities may depend on the geometry of Ban

Gianfranco Pradisi, Augusto Sagnotti

The study of string models including both unoriented closed strings and open strings presents a number of new features when compared to the standard case of models of oriented closed strings only. We review some basic features of the construction of these models, describing in particular how gauge symmetry breaking can be achieved in this case. We also revie

A. Mikovic

Reduced phase space formulation of CGHS model of 2d dilaton gravity is studied in en extrinsic time gauge. The corresponding Hamiltonian can be promoted into a Hermitian operator acting in the physical Hilbert space, implying a unitary evolution for the system. Consequences for the black hole physics are discussed. In particular, this manifestly unitary theo

E. Kiritsis

The duality symmetries of WZW and coset models are discussed. The exact underlying symmetry responsible for semiclassical duality is identified with the symmetry under affine Weyl transformations. This identification unifies the treatement of duality symmetries and shows that in the compact and unitary case they are exact symmetries of string theory to all o

Hiroshi Ishikawa, Mitsuhiro Kato

We study the relation between the $SL(2,R)/U(1)$ black hole and the $c=1$ Liouville theory. A deformation, which interpolates the BRST operators of both models, is explicitly constructed. This interpolation is isomorphic, and the physical spectrum of the black hole is equivalent to that of the $c=1$ model tensored by a topological $U(1)/U(1)$ model. Some imp

Tamiaki Yoneya

(Lecture at the workshop &#34;Basic Problems in String Theory&#34;, Yukawa Institute for Theoretical Physics, Kyoto, October 19-21) In this talk, we first review the possibility of matrix models toward a nonperturbative (critical) string theory. We then discuss whether the $c=1$ matrix model can describe the black hole solution of 2D critical string theory.

F. Borzumati

The problem of dealing with the resolved photon contribution to $P^2$-integrated $ep$ cross sections is discussed. Suitable approximations have to be found, since no parametrization of the photon structure function in the full range of virtuality of the exchanged photon exists.

Vidyut Jain

We present an alternative calculation for the leading Higgs mass dependent one--loop corrections to the standard model Lagrangian, using a background field technique. Cross--sections computed from our one--loop Lagrangian provide a check of and reproduce results already obtained in the existing literature using diagrammatic methods, as well as allowing an an

S. M. Bilenky, C. Giunti

We consider $ ν_μ \to ν_τ $ oscillations under the assumption that there is a see-saw type mixing of the light neutrinos with heavy Majorana particles. It is shown that the existing data, including the recent LEP data, do not exclude the possibility that the additional terms in the transition probability due to this mixing could be of the same order of magni

Lisa Randall, Eric Sather

We argue that consistency of the combined heavy quark and chiral effective lagrangian requires the QCD scale which multiplies $1/M$ in the heavy quark expansion to be the chiral symmetry breaking scale, $Λ_{CSB}$, rather than the QCD scale, $Λ_{QCD}$. This means that either there is large uncertainty in the accuracy with which the heavy quark effective theor

Lisa Randall, Eric Sather

We show that there is a large discrepancy between the expected light flavor dependence of the heavy pseudoscalar--vector mass splittings and the measured values. We demonstrate that the one--loop calculation is unreliable. Moreover, agreement with experiment requires the leading dependence on SU(3) symmetry breaking to be nearly cancelled, so that the heavy

H. Gausterer, Sean Lee

We discuss conditions under which expectation values computed from a complex Langevin process $Z$ will converge to integral averages over a given complex valued weight function. The difficulties in proving a general result are pointed out. For complex valued polynomial actions, it is shown that for a process converging to a strongly stationary process one ge

K. Rummukainen

In this talk I present a multicanonical hybrid-like two-step algorithm, which consists of a microcanonical spin system update with demons, and a multicanonical demon refresh. The demons act as a buffer between the multicanonical heat bath and the spin system, allowing for a large variety of update schemes. In this work the cluster algorithm is demonstrated w

Claude Bernard, James Labrenz, Amarjit Soni

We have computed the decay constants for the $B$ and $D$ mesons, using quenched lattices at $β=6.3$, by interpolating between the static approximation of Eichten and the conventional (``heavy&#39;&#39; Wilson fermion) method. A more careful treatment of the static result using better sources with longer time-displacements and a modification to the Wilson qua

H. G. Evertz, M. Marcu

We present the loop algorithm, a new type of cluster algorithm that we recently introduced for the F model. Using the framework of Kandel and Domany, we show how to GENERALIZE the algorithm to the arrow flip symmetric 6 vertex model. We propose the principle of least possible freezing as the guide to choosing the values of free parameters in the algorithm. F

Hideo Kodama

The basic features of the complex canonical formulation of general relativity and the recent developments in the quantum gravity program based on it are reviewed. The exposition is intended to be complementary to the review articles available already and some original arguments are included. In particular the conventional treatment of the Hamiltonian constra

H. J. Herrmann

A thermodynamic formulation for moving granular material is proposed. The fluctuations due to the constant flux and dissipation of energy are controlled in a `granular&#39; ensemble by a pressure $\wp$ (`compression&#39;) which is conjugate to a contact volume (`contactopy&#39;). The corresponding response function (`dissipativity&#39;) describes how dissipa

Enrico Celeghini

Lie groups and quantum algebras are connected through their common universal enveloping algebra. The adjoint action of Lie group on its algebra is naturally extended to related q-algebra and q-coalgebra. In such a way, quantum structure can be dealt more or less as the Lie one and we do not need to introduce the not easy to handle topological groups. Compose

D. G. C. McKeon, A. Rebhan

In this paper it is shown how the generating functional for Green&#39;s functions in relativistic quantum field theory and in thermal field theory can be evaluated in terms of a standard quantum mechanical path integral. With this calculational approach one avoids the loop-momentum integrals usually encountered in Feynman perturbation theory, although with t

UKQCD Collaboration, presented by David Richards

We present preliminary results for the spectrum and decay matrix elements for heavy-light and heavy-heavy mesons, obtained on the 64-node Meiko Computing Surface at the University of Edinburgh. Quark propagators are computed with an O(a)-improved fermion action on 24^3x48 lattices at beta = 6.2, using three values of the quark mass up to around the strange q

J. L. Hewett

We show that the present limit from CLEO on the inclusive decay $b\to sγ$ provides strong constraints on the parameters of the charged Higgs sector in two-Higgs-Doublet-Models. Only a slight improvement in the experimental bound will exclude the region in the Supersymmetric Higgs parameter space which is inaccessible to collider searches.