arXiv papers from December 1994

G. Domokos, S. Kovesi-Domokos

In this paper we begin the development of a formalism for the description of high energy neutrino interactions. It is based upon field theory quantized on a null plane. We set up the general formalism as well as some techniques needed to perform phenomenological calculations. We show that the formalism developed by Wolfenstein is recovered at the cost of mak

L. Accardi, Y. G. Lu, I. Volovich

In this report we discuss some results of non--commutative (quantum) probability theory relating the various notions of statistical independence and the associated quantum central limit theorems to different aspects of mathematics and physics including: $q$--deformed and free central limit theorems; the description of the master (i.e. central limit) field in

P. Sawicki, J. Wosiek

First applications of the new algorithm simulating dynamical fermions are reported. The method reproduces previous results obtained with different techniques.

Ka Lok Ng, Kin-Wang Ng, 19 pages, latex

We discuss the effect of matter reionization on the large-angular-scale anisotropy and polarization of the cosmic microwave background radiation (CMBR) in the standard CDM model. We separate three cases in which the anisotropy is induced by pure scalar, pure tensor, and mixed metric perturbations respectively. It is found that, if reionization occurs early e

J. Wosiek

The analogy between the intermittency and scaling in statistical physics is extended to the case of more variables. It is shown that the inclusive densities predicted by the perturbative QCD obey generalized homogeneity principle which leads to many consequences in statistical physics. In particular the hyperscaling may be a prototype for the hyperintermitte

Tsvi Piran

Neutron star binaries, such as the one observed in the famous binary pulsar PSR 1916+13, end their life in a catastrophic merge event (denoted here NS$^2$M). The merger releases $\approx 5 \cdot 10^{53}$ergs, mostly as neutrinos and gravitational radiation. A small fraction of this energy suffices to power $\gamma$-ray bursts (GRBs) at cosmological distances

J. R"ohler, R. Cr"usemann

We have analyzed the Cu K-EXAFS of Bi_2Sr_1.5Ca_1.5Cu_2O_8+d using a full multiple scattering analysis in a cluster with diameter d = 7.6 AA. The numerous quasi one-dimensional structural elements give rise to significant multiple scattering contributions in the EXAFS. We confirm the Sr/Ca ratio of the sample is 1:1, and one Ca atom is located close to a nom

Wei-Min Zhang, Guey-Lin Lin, Chi-Yee Cheung

The light-front heavy quark effective theory is derived to all orders in $1/m_Q$. In the limit $m_Q\rightarrow \infty$, the theory exhibits the familiar heavy quark spin-flavor symmetry. This new formalism permits a straightforward canonical quantization to all orders in $1/m_Q$; moreover, higher order terms have rather simple operator structures. The light-

Arvind, B. Dutta, N. Mukunda, R. Simon

A general analysis of squeezing transformations for two mode systems is given based on the four dimensional real symplectic group $Sp(4,\Re)\/$. Within the framework of the unitary metaplectic representation of this group, a distinction between compact photon number conserving and noncompact photon number nonconserving squeezing transformations is made. We e

Kevin Cahill, Gary Herling

We have applied a new gauge-invariant, noncompact, Monte Carlo method to simulate the $U(1)$, $SU(2)$, and $SU(3)$ gauge theories on $8^4$ and $12^4$ lattices. The Creutz ratios of the Wilson loops agree with the exact results for $U(1)$ for $\beta \ge 0.5$ apart from a renormalization of the charge. The $SU(2)$ and $SU(3)$ Creutz ratios robustly display qua

Vu B Ho

General relativity is applied to the strong interaction; the nexus between the two being arrived at by constructing a line element having the Yukawa form, which is used to describe geometrically the classical dynamics of a particle moving under the influence of the short-range strong interaction. It is shown that, with reasonable assumptions, the theory of g

J. Dorfmeister, G. Haak

This work is based on the approach developed by J.~Dorfmeister, F.~Pedit and H.~Wu [GANG and KITCS preprint, Report KITCS94-4-1] to construct maps $\Phi:D\rightarrow R^3$, $D$ being the unit disk in $C$, whose images are surfaces of constant mean curvature. They start from certain meromorphic one forms, so called meromorphic potentials, which take values in

Olaf Lechtenfeld

I review the covariant quantization of the critical $N{=}2$ fermionic string with and without a global ${\bf Z}_2$ twist. The BRST analysis yields massless bosonic and fermionic vertex operators in various ghost and picture number sectors, as well as picture-changers and their inverses, depending on the field basis chosen for bosonization. Two distinct GSO p

Wei-Shu Hou, Gwo-Guang Wong

Recent data indicate that $V_{ub}\cong \lambda^4 \cong (0.22)^4$, while $m_t$ seems to be $174$ GeV. The relations $m_d/m_s\sim m_s/m_b \sim \delta \sim \lambda^2 \simeq \vert V_{cb}\vert$ and $m_u/m_c\sim m_c/m_t \sim \delta^2 \sim \lambda^4 \sim \vert V_{ub}\vert$ suggest that %a plausible clean separation of the %origin of the quark mixing matrix: the dow

B. Diekmann, P. Borrmann, E. R. Hilf

Geometries and energies for H3+(H2)n clusters (n = 0, ..., 11) have been calculated using standard "ab initio" methods. Up to clusters with n = 6, four different Pople basis sets (DZ, TZ, TZP) have been used in the calculations. For larger cluster sizes, the calculations have been carried out with one basis set (DZ) using the HF/CISD method. We discu

Thomas J. Phillips

The gravitational force on antimatter has never been directly measured. A method is suggested for measuring the acceleration of antimatter $(\bar g)$ by measuring the deflection of a beam of neutral antihydrogen atoms in the Earth's gravitational field. While a simple position measurement of the beam could be used, a more efficient measurement can be made us

Adam Doliwa, Paolo Maria Santini

We show that the following geometric properties of the motion of discrete and continuous curves select integrable dynamics: i) the motion of the curve takes place in the N dimensional sphere of radius R, ii) the curve does not stretch during the motion, iii) the equations of the dynamics do not depend explicitly on the radius of the sphere. Well known exampl

Prem P. Srivastava

The light-front Hamiltonian formulation for the scalar field theory contains a new ingredient in the form of a constraint equation. Renormalization of the two dimensional $\phi^{4}$ theory, described in the continuum, is discussed. The mass renormalization condition and the renormalized constraint equation contain all the information to describe the phase tr

Danilo Villarroel, Rodrigo Rivera

An exact solution of Lorentz-Dirac equations where the energy conservation law is violated, is described herein for the case of two charges.

Prem P. Srivastava

Chern-Simons theory coupled to complex scalars is quantized on the light- front in the local light-cone gauge by constructing the self-consistent hamiltonian theory. It is shown that no inconsistency arises on using two local gauge-fixing conditions in the Dirac procedure. The light-front Hamiltonian turns out to be simple and the framework may be useful to

M. C. W. van Rossum, Johannes F. de Boer, Th. M. Nieuwenhuizen

The probability distribution of the total transmission is studied for waves multiple scattered from a random, static configuration of scatterers. A theoretical study of the second and third cumulant of this distribution is presented. Within a diagrammatic approach a theory is developed which relates the third cumulant normalized to the average, $\langle \lan

N. G. Deshpande, Xiao-Gang He

We prove that CP violating rate difference $\Delta (\bar B^0 \rightarrow \pi^+\pi^-) = \Gamma (\bar B^0 \rightarrow \pi^+\pi^-) - \Gamma ( B^0 \rightarrow \pi^-\pi^+)$ is related to $\Delta (\bar B^0 \rightarrow \pi^+ K^-) = \Gamma (\bar B^0 \rightarrow \pi^+K^-) - \Gamma (B^0 \rightarrow \pi^-K^+)$ in the three generation Standard Model. Neglecting small an

J. Gasser

We discuss $\pi\pi$ scattering in the framework of chiral perturbation theory. In particular, we recall the predictions made some time ago for the threshold parameters and for the phase shift difference $\delta_0^0-\delta_1^1$.

P. S. Letelier, V. T. Zanchin

Supersymmetric Wess-Zumino type models are considered as classical material media that can be interpreted as fluids of ordered strings with heat flow along the strings or a mixture of fluids of ordered strings with either a cloud of particles or a flux of directed radiation.

Debashis Gangopadhyay, Soumitra Sengupta

A possible generalisation is given to the meaning of maximal symmetry in the presence of torsion

Wolfgang Scherer

An exact analogue of the method of averaging in classical mechanics is constructed for self--adjoint operators. It is shown to be completely equivalent to the usual Rayleigh--Schr\"odinger perturbation theory but gives the sums over intermediate states in closed form expressions. The anharmonic oscillator and the Henon--Heiles system are treated as examples

Wolfgang Scherer

An analogue of Kolmogorov's superconvergent perturbation theory in classical mechanics is constructed for self adjoint operators. It is different from the usual Rayleigh--Schr\"odinger perturbation theory and yields expansions for eigenvalues and eigenvectors in terms of functions of the perturbation parameter.

J. C. R. Magueijo

We propose to minimise the cosmic confusion between Gaussian and non Gaussian theories by investigating the structure in the m's for each multipole of the cosmic radiation temperature anisotropies. We prove that Gaussian theories are (nearly) the only theories which treat all the m's equally. Hence we introduce a set of invariant measures of ``m-preference''

C. Schwiebert

A generalization of the quantum inverse scattering method is proposed replacing the quantum group $RLL$ commutation relations of Lax operators by reflection equation type $RLRL$ commutation relations. Under some natural assumptions the most general algebra of this type allowing to construct the neccessary integrals of motion is found. It serves to describe L

Ivan Cherednik

In the previous author's paper the Macdonald norm conjecture (including the famous constant term conjecture) was proved. This paper contains the proof of the remaining two (the duality and evaluation conjectures). The evaluation theorem is in fact a $q,t$-generalization of the classic Weyl dimension formula. As to the duality theorem, it states that the gene

Danilo Villarroel, Rodrigo Rivera

We present an exact formula for the computation of the interference rate of radiation in the case of two charges revolving with constant angular velocity at opposite ends of a diameter in a fixed circle. The formula is valid for arbitrary velocities of the charges, and can be easily studied by numerical methods, even for velocities very close to the velocity

David R. Morrison, M. Ronen Plesser

We use the gauged linear sigma model introduced by Witten to calculate instanton expansions for correlation functions in topological sigma models with target space a toric variety $V$ or a Calabi--Yau hypersurface $M \subset V$. In the linear model the instanton moduli spaces are relatively simple objects and the correlators are explicitly computable; moreov

the HEMCGC, MILC Collaborations

We present results from studies of high temperature QCD with two flavors of Kogut-Susskind quarks on $16^3\times 8$ lattices at a quark mass of $am_q=0.00625$ and on $24^3\times 12$ lattices at quark masses $am_q=0.008$ and 0.016. The value of the crossover temperature is consistent with that obtained on coarser lattices and/or at larger quark masses. Result

Peter Borrmann, Bernd Diekmann, Eberhard R. Hilf, David Tomanek

We investigate the magnetic properties of small transition metal clusters using a simple statistical model, which requires some input data from ab initio spin-density functional calculations. In our study we consider a thermodynamically equilibrated ensemble of clusters with different structures, spin multiplicities, and ground state energies. We calculate t

J. R. Shepard, V. Dmitrašinović, J. A. McNeil

We study constraint effective potentials for various strongly interacting $\phi^4$ theories. Renormalization group (RG) equations for these quantities are discussed and a heuristic development of a commonly used RG approximation is presented which stresses the relationships among the loop expansion, the Schwinger-Dyson method and the renormalization group ap

B. Crowell, M. P. Carpenter, R. V. F. Janssens, D. J. Blumenthal

An experiment using the Eurogam Phase II gamma-ray spectrometer confirms the existence of an excited superdeformed (SD) band in 190Hg and its very unusual decay into the lowest SD band over 3-4 transitions. The energies and dipole character of the transitions linking the two SD bands have been firmly established. Comparisons with RPA calculations indicate th

J. Sucher

In quantum field theory the concept of a Lagrangian interaction density, expressed in terms of fields, is primary. Forces between two particles are regarded as arising primarily from the exchange of quanta of the bosonic fields. Thus, in contrast to nonrelativistic quantum mechanics, the concept of a two-body poten tial is secondary. Potentials are not given

P. Ramond

We review the Standard Model in a form conducive to formulating its possible short distance extensions. This depends on the value of the Higgs mass, the only unknown parameter of the model. We suggest methods to reproduce many of the small numbers in the model in terms of scale ratios, applying see-saw like ideas to the breaking of chiral symmetries. We then

I. G. Halliday, P. Suranyi

The dual of an arbitrary $D$-dimensional nonabelian lattice gauge theory, obtained after character expansion and integration over the gauge group, is shown to be a {\em local} lattice theory in the eigenspace of the Casimir operators. For $D\leq4$ we also provide the explicit form of the action as a product of character expansion coefficients and Racah coeff

Jnanadeva Maharana

A string action is considered in four spacetime dimensions which is obtained by dimensionally reducing the ten dimensional effective action. The equations of motion admit string like solutions. The symmetry properties of the four dimensional action is discussed. It is shown that new background configurations can be generated by implementing suitable $O(d,d)$

P. Ramond

As the title indicates

J. Lopez

We advocate the study of supergravity models as well motivated few-parameter low-energy supersymmetric models. In this context we survey a broad range of phenomenological constraints and future tests, including present and near-future Tevatron ($\tilde q,\tilde g,\chi^\pm_1,\tilde t_1$) and LEP ($h,\chi^\pm_1$) mass limits, collider indirect tests ($\Gamma_Z

Howard L. Richards, Scott W. Sides, M. A. Novotny, Per Arne Rikvold

The magnetic relaxation of ferromagnetic powders has been studied for many years, largely due to its importance to recording technologies. However, only recently have experiments been performed that resolve the magnetic state of individual sub-micron particles. Motivated by these experimental developments, we use droplet theory and Monte Carlo simulations to

Pierre Binetruy, Pierre Ramond

We augment the Minimal Supersymmetric Standard Model with a gauged family-dependent $U(1)$ to reproduce Yukawa textures compatible with experiment. In the simplest model with one extra chiral electroweak singlet field, acceptable textures require this $U(1)$ to be anomalous. The cancellation of its anomalies by a generic Green-Schwarz mechanism requires $\si

Ian I. Kogan

We discuss the possibility that quantum black holes have discrete mass spectrum. Different arguments leading to this conclusion are considered, particularly the decoupling between left and right sectors in string theory - the so-called heterotic principle. The case of a $2+1$ dimensional black holes is considered as an argument in favour of this argument. Th

Peter Borrmann, Dorian Gloski, Eberhard R. Hilf

The thermodynamic properties such as the specific heat are uniquely determined by the second moments of the energy distribution for a given ensemble averaging. However for small particle numbers the results depend on the ensemble chosen. We calculated the higher moments of the distributions of some observables for both the canonical and the microcanonical en

Wolfgang Ochs, Jacek Wosiek

We derive the angular correlation functions between an arbitary number of partons inside a quark or gluon jet emerging from a high energy hard collision. As an application results for the correlation in the relative angle between two partons as well as the multiplicity moments of any order for partons in a sidewise angular region are calculated. At asymptoti

Younghoon Park, Yongsung Yoon

The Pauli Hamiltonian for a spin $\frac{1}{2}$ charged particle interacting with a point magnetic vortex and $1/r^{2}$ potential exhibits a dynamical supersymmetry $Osp(1,1)$ on the plane except at the origin. Using this symmetry, the spectrum and the wave functions have been obtained. And, the dynamical supersymmetry could be imported to the case when an ex

Wolfram Boenkost

In this work we describe the mathematical foundations used in the construction of primary fields of minimal models of conformal field theory. The work contains two parts: In the first part we give a description of Verma and Fock modules for the Virasoro algebra and develop their imbedding patterns. This part is a simplification of the work of Feigin and Fuks

E. Brezin, S. Hikami, A. Zee

We consider the (smoothed) average correlation between the density of energy levels of a disordered system, in which the Hamiltonian is equal to the sum of a deterministic H0 and of a random potential $\varphi$. Remarkably, this correlation function may be explicitly determined in the limit of large matrices, for any unperturbed H0 and for a class of probabi

A. A. Slavnov

A manifestly gauge invariant formulation of chiral theories with fermions on the lattice is developed. It combines SLAC lattice derivative \cite{DWY}, \cite{ACS}, \cite{S} and generalized Pauli-Villars regularization \cite{FS}. The theory is free of fermion doubling, requires only local gauge invariant counterterms and produces correct results when applied t

Huazhong Zhang

The possibilities of global (non-perturbative) gauge anomalies for a class of gauge groups are investigated. Intimately connected to branching rules and topological aspect of gauge groups, the results are applied to the study of unification gauge groups such as SO(10), SU(5), $E_6$, $E_8$ etc. Especially, we discuss extensively about the selection rule for g

David R. Nelson, Randall D. Kamien

Crystalline order in dense packings of long polymers with a definite handedness is difficult to reconcile with the tendency of these chiral objects to twist and braid about each other. If the chirality is weak, the state of lowest energy is a triangular lattice of rigid rods. When the chirality is strong, however, screw dislocations proliferate, leading to e

V. Bazhanov, S. Lukyanov, A. Zamolodchikov

We construct the quantum versions of the monodromy matrices of KdV theory. The traces of these quantum monodromy matrices, which will be called as ``${\bf T}$-operators'', act in highest weight Virasoro modules. The ${\bf T}$-operators depend on the spectral parameter $\lambda$ and their expansion around $\lambda = \infty$ generates an infinite set of commut

Joaquim Gomis, Jordi Paris, Stuart Samuel

The antibracket formalism for gauge theories, at both the classical and quantum level, is reviewed. Gauge transformations and the associated gauge structure are analyzed in detail. The basic concepts involved in the antibracket formalism are elucidated. Gauge-fixing, quantum effects, and anomalies within the field-antifield formalism are developed. The conce

A. Arhrib, M. Capdequi-Peyranere, A. Djouadi

We calculate the QCD radiative corrections to the production of supersymmetric scalar partners of quarks in e+e- annihilation. We include both the standard gluonic corrections and the genuine supersymmetric QCD corrections due to quark--gluino loops, and allow for mixing between left-- and right--handed scalar quarks which leads to the possibility that the t

J. W. Moffat

In the weak field approximation, the nonsymmetric gravitational theory has, in addition to the Newtonian gravitational potential, a Yukawa potential produced by the exchange of a spin $1^+$ boson between fermions. If the range $r_0$ is of order $30$ kpc, then the potential due to the interaction of known neutrinos in the halos of galaxies can explain the fla

Jon Pumplin

I extend the two gluon exchange picture of elastic scattering, known as the Low-Nussinov or Subtractive Quark Model, to predict cross sections for double pomeron exchange processes. In particular, I calculate p p-bar to p p-bar q q-bar where the q q-bar partons appear as jets separated from the final p and p-bar by large gaps in rapidity. The predicted cross

M. Fabrizio, Alexander O. Gogolin, Ph. Nozières

We analyze the structure of the perturbation expansion of the general multichannel Kondo model with channel anisotropic exchange couplings and in the presence of an external magnetic field, generalizing to this case the Anderson-Yuval technique. For two channels, we are able to map the Kondo model onto a generalized resonant level model. Limiting cases in wh

G. Degrassi, S. Fanchiotti, F. Feruglio, P. Gambino

The assumption that two-loop top corrections are well approximated by the $O(G_mu^2 mt^4)$ contribution is investigated. It is shown that in the case of the ratio neutral-to-charged current amplitudes at zero momentum transfer the $O(G_mu^2 mt^2 M_Z^2)$ terms are numerically comparable to the $m_t^4$ contribution for realistic values of the top mass. An esti

F. M. Borzumati, M. Olechowski, S. Pokorski

It is shown that the minimal supersymmetric SO(10) model with electroweak radiative breaking and universal soft mass terms at the GUT scale is strongly disfavoured by the combination of constraints from the $b\to s \gamma$ decay and the condition $\Omega h^2 < 1$ for the lightest (stable) neutralino. The constraints are, however, easily satisfied for certain

A. Llorente, J. Perez-Mercader

We study the effect from a general ultralocal supermetric on primordial nucleosynthesis for Friedmann-Robertson-Walker Cosmology. The parameter $\lambda$ of the supermetric changes the effective number of degrees of freedom, $g_*$, which modifies the Friedmann equation. This modification produces variations in the production of primordial $^4He$. The observa

J. Jaklic, P. Prelovsek

The finite-temperature optical conductivity $\sigma(\omega)$ in the planar $t-J$ model is analysed using recently introduced numerical method based on the Lanczos diagonalization of small systems (up to 20 sites), as well as by analytical approaches, including the method of frequency moments and the retraceable-path approximation. Results for a dynamical mob

A. E. Dorokhov, N. I. Kochelev, Yu. A. Zubov

The spectrum of $q^2\bar q^2, J^p=0^+,2^+$ mesons is discussed. We have shown that due to instanton - induced forces the physical states are strong mixtures of the $SU_f(3)$ group basis states. The cross-sections for annihilation of the $N\bar N$ system into $(q^2\bar q^2)(q\bar q)$ mesons are obtained. The $a_0(980)$ meson is considered as $q^2\bar q^2$ mes

Hiroshi Shirokura

We study one (or two) matrix models modified by terms of the form $g(\rho(P))^2 + g'(\rho'({\cal{O}}))^2$, where the matrix representation of the puncture operator $P$ and the one of a scaling operator ${\cal{O}}$ are denoted by $\rho(P)$ and $\rho'({\cal{O}})$ respectively. We rewrite the modified models as effective theories of baby universes. We find an u

L. Biferale, A. Crisanti, M. Vergassola, A. Vulpiani

Standard and anomalous transport in incompressible flow is investigated using multiscale techniques. Eddy-diffusivities emerge from the multiscale analysis through the solution of an auxiliary equation. From the latter it is derived an upper bound to eddy-diffusivities, valid for both static and time-dependent flow. The auxiliary problem is solved by a pertu

Masao Jinzenji, Yi Sun

Using the associativity relations of the topological Sigma Models with target spaces, $CP^3, CP^4$ and $Gr(2,4)$ , we derive recursion relations of their correlation and evaluate them up to certain order in the expansion over the instantons. The expansion coeffieients are regarded as the number of rational curves in $CP^3, CP^4$ and $Gr(2,4)$ which intersect

Koichiro Harada, Mong Lung Lang

We investigate the relation between the generating functions of the highest weight vectors of the Monster module and the McKay-Thompson series.

Koichiro Harada, Mong Lung Lang

Let $ \Bbb V = \coprod_{h = 0}^{\infty} \Bbb V_h$ be the graded monster module of the monster simple group $\Bbb M$ and let $\chi_k$ be an irreducible representation of $\Bbb M$. The generating function of $c_{hk}$ (the multiplicity of $\chi_k$ in $\Bbb V_h$) is determined. Furthermore, the invariance group of the modular function associated with the generat

Yoshimi Matsubara, Sawut Ilyar, Tsuyoshi Okude, Kenji Yotsuji

Monte-Carlo simulations of abelian projection in $T \neq 0$ pure lattice QCD show that 1)\ Polyakov loops written in terms of abelian link fields alone play a role of an order parameter of deconfinement transition 2)\ the abelian Polyakov loops are decomposed into contributions from Dirac strings of monopoles and from photons 3)\ vanishing of the abelian Pol

Shun-ichi Kitahara, Yoshimi Matsubara, Tsuneo Suzuki

We investigate the role of monopoles in the deconfinement transition of finite temperature $SU(2)$ QCD in the maximally abelian gauge. In the confinement phase a long monopole loop exists in each configuration, whereas no long loop exists in the deep deconfinement region. Balancing of the energy and the entropy of loops of the maximally extended monopoles ca

M. Khorrami

A general formlulation for discrete-time quantum mechanics, based on Feynman's method in ordinary quantum mechanics, is presented. It is shown that the ambiguities present in ordinary quantum mechanics (due to noncommutativity of the operators), are no longer present here. Then the criteria for the unitarity of the evolution operator is examined. It is shown

A. Ukawa

The CP-PACS Project, which started in April 1992, is a five-year plan to develop a massively parallel computer for carrying out research in computational physics with primary emphasis on lattice QCD. This article describes the architectural design of the CP-PACS computer, the entire computing system including the front end and mass storage, and results of be

D. S. Hwang, C. S. Kim, W. Namgung

The Fermi motion parameter $p_{_F}$ is the most important parameter of ACCMM model, and the value $p_{_F} \sim 0.3$ GeV has been used without clear theoretical or experimental evidence. So, we attempted to calculate the value for $p_{_F}$ theoretically in the relativistic quark model using quantum mechanical variational method. We obtained $p_{_F} \sim 0.5$

C. S. Kim, A. D. Martin

We show that the observation of energetic charged leptons from semileptonic $B$-meson decays 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,

Yoichi Kazama

A pedagogical discussion is given of some aspects of \lq\lq quantum black holes", primarily using recently developed two-dimensional models. After a short preliminary concerning classical black holes, we give several motivations for studying such models, especially the so called dilaton gravity models in $1+1$ dimensions. Particularly attractive is the one p

Youichi Shibukawa

As for an elliptic $R$-operator which satisfies the Yang--Baxter equation, the incoming and outgoing intertwining vectors are constructed, and the vertex--IRF correspondence for the elliptic $R$-operator is obtained. The vertex--IRF correspondence implies that the Boltzmann weights of the IRF model satisfy the star--triangle relation. By means of these inter

Amnon Rosenmann

Given the Cayley graph of a finitely generated group $G$, with respect to a presentation $G^{\alpha}$ with $n$ generators, the quotient of the rank of the fundamental group of subgraphs of the Cayley graph by the cardinality of the set of vertices of the subgraphs gives rise to the definition of the normalized cyclomatic quotient $\Xi (G^{\alpha})$. The asym

Amnon Rosenmann

Schreier formula for the rank of a subgroup of finite index of a finitely generated free group $F$ is generalized to an arbitrary (even infinitely generated) subgroup $H$ through the Schreier transversals of $H$ in $F$. The rank formula may also be expressed in terms of the cogrowth of $H$. We introduce the rank-growth function $rk_H(i)$ of a subgroup $H$ of

Peter Borrmann

A new method ( PI-DFT ) which combines path integrals and density functional theory is proposed as a pathway to many fields of physics. Within path integral theory it is possible to construct particle densities without explicitly calculating individual wave functions. These densities can directly be used as an input to energy density functionals. Thus our me

The CDF Collaboration

The lifetime of the $B_s$ meson is measured using the semileptonic decay $B_s \to D_s^- \ell^+ \nu X$. The data sample consists of 19.3 pb$^{-1}$ of $p \bar{p}$ collisions at $\sqrt{s} = 1.8$ TeV collected by the CDF detector at the Fermilab Tevatron collider during 1992-1993. There are $76 \pm 8$ $\ell^{+} D_s^{-}$ signal events where the $D_s$ is identifie

Jaime Besprosvany, S. A. Gurvitz

Hard-core final state interaction effects in the response function are investigated in the asymptotic limit of momentum transfer q->Infinity. A new treatment of the response is presented, which displays the relevant scattering contribution. A modification of the otherwise expected free response is obtained for Fermi and Bose systems and smearing of the conde

S. James Gates,

We extend Witten's discussion of actions related to the Landau-Ginzburg description of Calabi-Yau hypersurfaces in weighted projective spaces to cover the mirror class of models that include twisted chiral matter multiplets and a newly discovered 2D, N = 2 twisted vector multiplet. Certain integrability obstructions are observed that constrain the most gener

Amnon Neeman

Grothendieck proved that if $f:X\longrightarrow Y$ is a proper morphism of nice schemes, then $Rf_*$ has a right adjoint, which is given as tensor product with the relative canonical bundle. The original proof was by patching local data. Deligne proved the existence of the adjoint by a global argument, and Verdier showed that this global adjoint may be compu

Stefan Herrlich, Ulrich Nierste

The anomalous dimension matrix of dimensionally regularized four-quark operators is known to be affected by evanescent operators, which vanish in $D=4$ dimensions. Their definition, however, is not unique, as one can always redefine them by adding a term proportional to $(D-4)$ times a physical operator. In the present paper we compare different definitions

Claude LeBrun

Let (M,J) be a minimal compact complex surface of Kaehler type. It is shown that the smooth 4-manifold M admits a Riemannian metric of positive scalar curvature iff (M,J) admits a KAEHLER metric of positive scalar curvature. This extends previous results of Witten and Kronheimer.

C. Steidel, D. Bowen, J. C. Blades, M. Dickinson

We present {\it Hubble Space Telescope} and ground--based data on the $z_{abs}=0.8596$ metal line absorption system along the line of sight to PKS 0454+0356. The system is a moderate redshift damped Lyman alpha system, with ${\rm N(HI)}=(5.7\pm0.3)\times10^{20}$~cm$^{-2}$ as measured from the {\it Faint Object Spectrograph} spectrum. We also present ground--

Victor Matveev, Robert Shrock

We study the complex-temperature properties of a rare example of a statistical mechanical model which is exactly solvable in an external symmetry-breaking field, namely, the Ising model on the square lattice with $\beta H = \pm i \pi/2$. This model was solved by Lee and Yang \cite{ly}. We first determine the complex-temperature phases and their boundaries. F

Paul Z. Quintas

The cross sections for W and Z production in p-pbar collisions at sqrt(s)=1.8 TeV are measured using the D0 detector at the Fermilab Tevatron collider. The detected final states are W->e nu, Z->ee, W->mu nu, and Z->mu mu. In the ratio of these measurements, many common sources of systematic error cancel and we measure the ratio of the W and Z cross-sections.

Rajamani Narayanan, Herbert Neuberger

It is shown that the lattice overlap correctly reproduces the chiral determinant on a two dimensional torus in the presence of nontrivial background Polyakov loop variables.

Y. Iwasaki

Phase diagram of QCD with Wilson fermions for various numbers of flavors $N_F$ is discussed. Our simulations mainly performed on a lattice with the temporal size $N_t =4$ indicate the following: The chiral phase transition is of first order when $3 \le N_F \le 6$, while it is continuous when $N_F=2$. For the realistic case of massless u and d quarks and the

T. H. Hansson, J. M. Leinaas, S. Viefers

We construct a field theory for anyons in the lowest Landau level starting from the $N$-particle description, and discuss the connection to the full field theory of anyons defined using a statistical gauge potential. The theory is transformed to free form, with the fields defined on the circle and satisfying modified commutation relations. The Fock space of

Tsevi Mazeh, Itzhak Goldman

We call attention to the surprising similarity between the newly discovered planetary system around PSR B1257+12 and the inner solar system. The similarity is in the ratios of the orbital radii and the masses of the three planets.

Mihoko M. Nojiri

The $\tau$ lepton arising from the scalar tau ($\st$) decay is naturally polarized. $\ptau$ depends on the left--right mixing of the $\st$ and the gaugino--higgsino mixing of the neutralino. The polarization $\ptau$ could be measured from the energy distribution of the decay products of $\tau$ at future $\epem$ colliders. A measurement of $\ptau$and of the $

R. Itoh

Inclusive momentum spectra are measured for all charged particles and for each of $\pi^{\pm}$, $K^{\pm}$, $K^0/\bar{K^0}$, and $p/\bar{p}$ in hadronic events produced via $e^+e^-$ annihilation at $\sqrt{s}$=58GeV . The measured spectra are compared with QCD predictions based on the modified leading log approximation(MLLA). The MLLA model reproduces the measu

Nguyen Ai Viet, Kameshwar C. Wali

We consider a four-dimensional space-time supplemented by two discrete points assigned to a $Z_2$ algebraic structure and develop the formalism of noncommutative geometry. By setting up a generalised vielbein, we study the metric structure. Metric compatible torsion free connection defines a unique finite field content in the model and leads to a discretized

T. Kifune, CANGAROO Collaboration

We have obtained evidence of gamma-ray emission above 1 TeV from PSR1706-44, using a ground-based telescope of the atmospheric \v{C}erenkov imaging type located near Woomera, South Australia. This object, a $\gamma$-ray source discovered by the COS B satellite (2CG342-02), was identified with the radio pulsar through the discovery of a 102 ms pulsed signal w

Dan Ashlock, Mark D. Smucker, E. Ann Stanley, Leigh Tesfatsion

Partner selection is an important process in many social interactions, permitting individuals to decrease the risks associated with cooperation. In large populations, defectors may escape punishment by roving from partner to partner, but defectors in smaller populations risk social isolation. We investigate these possibilities for an evolutionary prisoner's

Peter Borrmann, Eberhard R. Hilf

We show that the computational effort for the numerical solution of fermionic quantum systems, occurring e.g., in quantum chemistry, solid state physics, field theory in principle grows with less than the square of the particle number for problems stated in one space dimension and with less than the cube of the particle number for problems stated in three sp

Nicholas Dorey, Michael Mattis

We explicitly relate effective meson-baryon Lagrangian models, chiral bags, and Skyrmions in the following way. First, effective Lagrangians are constructed in a manner consistent with an underlying large-N_c QCD. An infinite set of graphs dress the bare Yukawa couplings at *leading* order in 1/N_c, and are summed using semiclassical techniques. What emerges