October 1996 arXiv papers — page 7

Clifford V. Johnson, Robert C. Myers

D-brane technology and strong/weak coupling duality supplement traditional orbifold techniques by making certain background geometries more accessible. In this spirit, we consider some of the geometric properties of the type IIB theory on R^6 \times M where M is an `Asymptotically Locally Euclidean (ALE)' gravitational instanton. Given the self-duality o

B. Rusakov

Exact loop-variables formulation of pure gauge lattice QCD_3 is derived from the Wilson version of the model. The observation is made that the resulting model is two-dimensional. This significant feature is shown to be a unique property of the gauge field. The model is defined on the infinite genus surface which covers regularly the original three-dimensiona

M. M. Musakhanov, F. C. Khanna

The QCD + QED axial anomaly low-energy theorems are applied to estimate the accuracy of an instanton vacuum - based chiral quark model. The low-energy theorems give an exact relation between the matrix elements of the gluon and photon parts of the QCD + QED axial anomaly operator equation. The matrix elements between vacuum and two photon states and between

Manoelito M. de Souza

We do a critical review of the Faraday-Maxwell concept of classical field and of its quantization process. With the hindsight knowledge of the essentially quantum character of the interactions, we use a naive classical model of field, based on exchange of classical massless particles, for a comparative and qualitative analysis of the physical content of the

S. Dell'Aringa, E. Ercolessi, G. Morandi, P. Pieri

We derive a path-integral expression for the effective action in the continuum limit of an AFM Heisenberg spin ladder with an arbitrary number of legs. The map is onto an $O(3)$ nonlinear $σ$-model (NL$σ$M) with the addition of a topological term that is effective only for odd-legged ladders and half-odd integer spins. We derive the parameters of the effecti

K. Sailer, W. Greiner

The phase structure of the scalar field theory with arbitrary powers of the gradient operator and a local non-analytic potential is investigated by the help of the RG in Euclidean space. The RG equation for the generating function of the derivative part of the action is derived. Infinitely many non-trivial fixed points of the RG transformations are found. Th

Gert Aarts, Jan Smit

We investigate the renormalizability of the classical $ϕ^4$ theory at finite temperature. We calculate the time-dependent two point function to two loop order and show that it can be rendered finite by the counterterms of the classical static theory. As an application the classical plasmon damping rate is found to be $γ= λ^2 T^2/1536 πm$. When we use the hig

C. Fuchs, L. Sehn, E. Lehmann, J. Zipprich

We investigate the influence of medium corrections to the pion dispersion relation on the pion dynamics in intermediate energy heavy ion collisions. To do so a pion potential is extracted from the in-medium dispersion relation and used in QMD calculations and thus we take care of both, real and imaginary part of the pion optical potential. The potentials are

H. W. Diehl

An introduction into the theory of boundary critical phenomena and the application of the field-theoretical renormalization group method to these is given. The emphasis is on a discussion of surface critical behavior at bulk critical points of magnets, binary alloys, and fluids. Yet a multitude of related phenomena are mentioned. The most important distinct

M. Anselmino, E. Leader, F. Murgia

We consider possible mechanisms for single spin asymmetries in inclusive Deep Inelastic Scattering (DIS) processes with unpolarized leptons and transversely polarized nucleons. Tests for the effects of non-zero $\bfk_\perp$, for the properties of spin dependent quark fragmentations and for quark helicity conservation are suggested.

Indranil Dasgupta

We show that in Euclidean field theories that have bounce solutions, the bounce with the least action is the global minimum of the action in an open space of field configurations. A rigorous upper bound on the minimal bounce action can therefore be obtained by finite numerical methods. This sets a lower bound on the tunneling rate which, fortunately, is ofte

Wen-Xiu Ma, Fu-Kui Guo

It is showed that Kronecker product can be applied to construct not only new Lax representations but also new zero curvature representations of integrable models. Meantime a different characteristic between continuous and discrete zero curvature equations is pointed out.

Ph. Blanchard, A. Jadczyk

We extend the ideas of L.P. Horwitz and C. Piron and we propose a relativistic version of Event Enhanced Quantum Theory, with an event generating algorithm for spin one-half particle detectors. The algorithm is based on proper time formulation of the relativistic quantum theory. Although we use indefinite metric, all the probabilities controlling the random

Marko Robnik, Luca Salasnich

We perform a systematic WKB expansion to all orders for a one-dimensional system with potential $V(x)=U_0/\cos^2{(αx)}$. We are able to sum the series to the exact energy spectrum. Then we show that at any finite order the error of the WKB approximation measured in the natural units of the mean energy level spacing does not go to zero when the quantum number

Giovanni Felder, Alexander Varchenko

We study the algebra of difference operators that commute with the two-body Ruijsenaars operator, a $q$-deformation of the Lamé differential operator, for generic values of the deformation parameter. The algebra is commutative. It is the algebra of polynomial functions on an affine hyperelliptic curve $Y^2=P(X^2)$. We also compute the difference Galois group

Jintai Ding, Boris Feigin

For the current realization of the affine quantum groups, a simple comultiplication for the quantum current operators was given by Drinfeld. With this comultiplication, we prove that, for the integrable modules of $U_q(\hat {\frak sl}(2))$ of level $k+1$, $x^\pm(z)x^\pm(zq^{\pm 2}) \cdot\cdot\cdot x^\pm(zq^{\pm 2k})$ are vertex operators satisfying certain q

M. Bawin, S. A. Coon

We reconsider the Dirac-Foldy contribution $μ^2/m$ to the neutron electric polarizability. Using a Dirac equation approach to neutron-nucleus scattering, we review the definitions of Compton continuum ($\barα$), classical static ($α^n_E$), and Schrödinger ($α_{Sch}$) polarizabilities and discuss in some detail their relationship. The latter $α_{Sch}$ is the

H. Sorge

Elliptical energy flow patterns in non-central Au(11.7AGeV) on Au reactions have been studied employing the RQMD model. The strength of these azimuthal asymmetries is calculated comparing the results in two different modes of RQMD (mean field and cascade). It is found that the elliptical flow which is readily observable with current experimental detectors ma

W-Y. P. Hwang, Ze-sen Yang, Y. S. Zhong, Z. N. Zhou

We use the method of QCD sum rules in the presence of an external pion field to investigate isospin symmetry breakings in pion-nucleon couplings. Possible manifestations of such isospin symmetry breaking are examined in the context of low-energy nucleon-nucleon ($NN$) scattering. We discuss numerical results in relation to both the existing data and other th

A. J. Buchmann, Amand Faessler, M. I. Krivoruchenko

We investigate dense nuclear matter with a dibaryon Bose-Einstein condensate as a possible intermediate state before the quark-gluon phase transition. An exact analysis of this state of matter is presented in a one-dimensional model. The analysis is based on a reduction of the quantization rules for the N-body problem to N coupled algebraic transcendental eq

R. Machleidt

The main progress in the field of nucleon-nucleon (NN) potentials, which we have seen in recent years, is the construction of some very quantitative (high-quality/high-precision) NN potentials. These potentials will serve as excellent input for microscopic nuclear structure calculations and will allow for a systematic investigation of off-shell effects. Afte

J. Barrette

Experimental results and a detailed analysis are presented of the transverse energy and charged particle azimuthal distributions measured by the E877 collaboration for different centralities of Au+Au collisions at a beam momentum of 10.8 A GeV/c. The anisotropy of these distributions is studied with respect to the reaction plane reconstructed on an event-by-

K. K. Nwabueze, F. Van Oystaeyen

Using the Burnside ring theoretic methods a new setting and a complete description of the Artin exponent $A(G)$ of finite $p$-groups was obtained in a previous article of the first-named author. In this paper, we compute $A(G)$ for any finite group $G$ -- hence providing the global version of that result.

Alan Chodos, Hisakazu Minakata

We compute the $1/N$ correction to the location of the previously found first-order phase transition in the Gross-Neveu model at a chemical potential $μ= μ_c = {1 \over \sqrt{2}} m$, where $m$ is the fermion mass. We employ an expression for the free energy $f(μ)$ given by the thermodynamic Bethe ansatz under the approximation that the fundamental fermions d

Prem P. Srivastava

The light-front (LF) quantization of the bosonized Schwinger model is discussed in the "continuum formulation". The proposal, successfully used earlier for describing the spontaneous symmetry breaking (SSB) on the LF, of separating first the scalar field into the dynamical condensate and the fluctuation fields before employing the "standard"

Kurt Haller, Edwin Lim-Lombridas

We discuss topologically massive QED --- the Abelian gauge theory in which (2+1)-dimensional QED with a Chern-Simons term is minimally coupled to a spinor field. We quantize the theory in covariant gauges, and construct a class of unitary transformations that enable us to embed the theory in a Fock space of states that implement Gauss's law. We show that

M. Billo', M. Caselle, A. D'Adda, S. Panzeri

Our aim is to give a self-contained review of recent advances in the analytic description of the deconfinement transition and determination of the deconfinement temperature in lattice QCD at large N. We also include some new results, as for instance in the comparison of the analytic results with Montecarlo simulations. We first review the general set-up of f

Christophe Fraser, Timothy J. Hollowood

The weak coupling spectrum of BPS saturated states of pure $N=2$ supersymmetric SU$(n)$ gauge theory is investigated. The method uses known results on the dyon spectrum of the analogous theory with $N=4$ supersymmetry, along with the action on these states of the semi-classical monodromy transformations. For dyons whose magnetic charge is not a simple root o

Harry Braden, Paul Sutcliffe

We calculate explicitly in terms of complete elliptic integrals the metric on the moduli space of tetrahedrally-symmetric, charge four, SU(2) monopoles. Using this we verify that in the asymptotic regime the metric of Gibbons and Manton is exact up to exponentially suppressed corrections.

J. F. Gunion, P. C. Martin

We examine the prospects for measuring the photon-photon branching ratio of a Standard-Model-like Higgs boson ($h$) at the Next Linear $e^+e^-$ Collider when the Higgs boson is produced via $W^+W^-$--fusion: $e^+e^-\toν_e \barν_e h$. In particular, we study the accuracy of such a measurement and the statistical significance of the associated signal as a func

F. Caravaglios

We will study some possible non universal corrections that could affect single measurements of the Weinberg angle sin^2(theta) (leaving the full average essentially unchanged). We will concentrate on the class of the models that introduces a new light gauge boson and an extended Higgs sector, but we restrict the Higgs charges choice in order to automatically

V. V. Anisovich, Yu. D. Prokoshkin, A. V. Sarantsev

A classification of the $IJ^{PC}=00^{++}$ mesons is performed on the basis of the K-matrix analysis of meson spectra in the reactions: (i) GAMS data on $πp\to π^0π^0 n$, $ηηn$, $ηη' n$; (ii) Crystal Barrel data on $p\bar p~(at~rest)\to π^0π^0π^0$, $π^0π^0η$, $π^0ηη$; (iii) CERN-Münich data on $πp\to π^+π^- n$; (iiii) BNL data on $πN\to K\bar K N$. The an

Stefano Catani

I briefly review some recent results on soft-gluon resummation and present applications to heavy-quark and jet production in hadron collisions.

Shi-lin Zhu, W-Y. P. Hwang, Ze-sen Yang

The method of QCD sum rules in the presence of the external electromagnetic $F_{μν}$ field is used to analyze radiative decays of charmed or bottomed mesons such as $D^{\ast}\to Dγ$ and $B^{\ast}\to Bγ$, with the susceptibilities obtained previously from the study of baryon magnetic moments. Our predictions on $D^{\ast}$ decays agree very well with the exper

J. Ellis, T. Falk, K. A. Olive, M. Schmitt

The constraints on neutralino dark matter χobtained from accelerator searches at LEP, the Fermilab Tevatron and elsewhere are reviewed, with particular emphasis on results from LEP 1.5. These imply within the context of the minimal supersymmetric extension of the Standard Model that m_χ\ge 21.4 GeV if universality is assumed, and yield for large tanβa signif

N. N. Achasov, G. N. Shestakov

The main dynamical mechanisms of the reaction $π^-p \rightarrow a^0_0 (980)n \rightarrow π^0ηn$ at high energies, currently investigated at Serpukhov and Brookhaven, are considered in detail. It is shown that the observed forward peak in its differential cross section can be explained within the framework of the Regge pole model only by the conspiring $ρ_2$

J. Blümlein, E. Boos, A. Kryukov

The scalar and vector leptoquark pair production cross sections in hadronic collisions are calculated. In a model independent analysis we consider the most general C and P conserving couplings of gluons to both scalar and vector leptoquarks described by an effective low--energy Lagangian which obeys SU(3)_c invariance. Analytrical expressions are derived for

Gerhard A. Schuler

The validity of the equivalent-photon approximation for two-photon processes in electron--positron collisions is critically examined. Commonly used forms to describe hadronic two-photon production are shown to lead to sizeable errors. An improved two-photon luminosity function is presented, which includes beyond-leading-logarithmic effects and scalar-photon

Alexandre Dolgov, Katherine Freese, Raghavan Rangarajan, Mark Srednicki

We calculate the baryon asymmetry created by the decay of a pseudo Nambu-Goldstone boson whose interactions violate baryon number conservation. Our results are in disagreement with previous results in the original spontaneous baryogenesis models for the asymmetry produced by the decay of an oscillating scalar field with B number violating derivative coupling

David J. Muller, Satya Nandi

We consider the extended electroweak gauge group SU(2)_1 \times SU(2)_2 \times U(1)_Y where the first and second families of fermions couple to SU(2)_1 while the third family couples to SU(2)_2. Bounds based an precision electroweak observables and heavy gauge boson searches are placed on the new parameters of the theory. The extra gauge bosons can be as lig

M. J. Musolf, H. -W. Hammer, D. Drechsel

The strange-quark vector current form factors of the nucleon are analyzed within the framework of dispersion relations. Particular attention is paid to contributions made by $K\bar{K}$ intermediate states to the form factor spectral functions. It is shown that, when the $K\bar{K}\to N\bar{N}$ amplitude is evaluated in the Born approximation, the $K\bar{K}$ c

Randy Lewis, R. M. Woloshyn

The rho, K* and phi decay constants and the vector current renormalization factor are studied by using an O(a^2) classically-improved, tadpole-improved action. Tree-level calculations are used to show how the classical improvement of the action, involving next-nearest-neighbour timesteps, is transferred to the matrix elements. Simulations are performed on co

Helia Hollmann

After dimensional reduction the stationary spherically symmetric sector of Einstein's gravity is identified with an SL(2,R)/SO(2) Sigma model coupled to a one dimensional gravitational remnant. The space of classical solutions consists of a one parameter family interpolating between the Schwarzschild and the Taub-NUT solution. A Dirac Quantization of thi

Jiri Bicak, Jerry B. Griffiths

We consider space-times with two isometries which represent gravitational waves with distinct wavefronts which propagate into exact Friedmann-Robertson-Walker (FRW) universes. The geometry of possible wavefronts is analysed in detail in all three types of FRW models. In the spatially flat and open universes, the wavefronts can be planar or cylindrical; in th

Jiang-Hua Lu

We relate Kostant's theorem on the cohomology of a flag manifold $G/B$ with the geometry of the Bruhat-Poisson structure. We express Kostant's harmonic forms in terms of the moment maps (for the torus action) and the Liouville volume forms for the symplectic structures on the Schubert cells induced by the Bruhat-Poisson structure. We do this by writi

I. I. Mazin, V. I. Anisimov

We report calculations of the electronic structure of FeO in the LDA and LDA+U approximation with and without rhombohedral distortion. In both cases LDA renders an antiferromagnetic metal, and LDA+U opens a Hubbard gap. However, the character of the gap is qualitatively different in the two structure, and the difference can be traced down to underlying LDA b

Daniel S. Fisher

A description of a dislocation-free elastic glass phase in terms of domain walls is developed and used as the basis of a renormalization group analysis of the energetics of dislocation loops added to the system. It is found that even after optimizing over possible paths of large dislocation loops, their energy is still very likely to be positive when the dis

P. Daguier, B. Nghiem, E. Bouchaud, F. Creuzet

The fatigue fracture surfaces of a metallic alloy, and the stress corrosion fracture surfaces of glass are investigated as a function of crack velocity. It is shown that in both cases, there are two fracture regimes, which have a well defined self-affine signature. At high enough length scales, the universal roughness index 0.78 is recovered. At smaller leng

P. W. Brouwer, M. Buttiker

We consider the admittance of a chaotic quantum dot, capacitively coupled to a gate and connected to two electron reservoirs by multichannel ballistic point contacts. For a dot in the regime of weak-localization and universal conductance fluctuations, we calculate the average and variance of the admittance using random-matrix theory. We find that the admitta

Henrik Bruus, Jean-Christian Anglès d'Auriac

The energy level statistics of the Hubbard model for $L \times L$ square lattices (L=3,4,5,6) at low filling (four electrons) is studied numerically for a wide range of the coupling strength. All known symmetries of the model (space, spin and pseudospin symmetry) have been taken into account explicitly from the beginning of the calculation by projecting into

Enrico Carlon, Giorgio Mazzeo, Henk van Beijeren

The phase diagram of the staggered six vertex, or body centered solid on solid model, is investigated by transfer matrix and finite size scaling techniques. The phase diagram contains a critical region, bounded by a Kosterlitz-Thouless line, and a second order line describing a deconstruction transition. In part of the phase diagram the deconstruction line a

Michael S. Briggs

I discuss low-energy lines in gamma-ray bursts. The process of deconvolving gamma-ray spectral data and the steps needed to demonstrate the existence of a line are explained. Previous observations and the current status of the analysis of the BATSE data are described.

Michael S. Briggs, David L. Band, Robert D. Preece, Geoffrey N. Pendleton

A computer-based technique has been developed to search bright BATSE gamma-ray bursts for spectral lines in a comprehensive manner. The first results of the search are discussed and an example line candidate shown.

Michael S. Briggs, William S. Paciesas, Geoffrey N. Pendleton, Charles A. Meegan

If gamma-ray bursts originate in the Galaxy, at some level there should be a galactic pattern in their distribution on the sky. We test published galactic models by comparing their dipole and quadrupole moments with the moments of the BATSE 3B catalog. While many models have moments that are too large, several models are in acceptable or good agreement with

N. Benitez, E. Martinez-Gonzalez, J. L. Sanz, A. Aguirre

We have performed RIJHK_S imaging of the field around the z=2.67 quasar Q0836+113, which presents several metal line and a damped Lyαabsorption systems in its spectrum. The images reveal the existence of a red K_S=18.9 object \approx 11 arcsec from the quasar. On the basis of the empirical relationships between absorption radius and luminosity we conclude th

Jason W. Ferguson, Gary J. Ferland

Many large scale numerical simulations of astrophysical plasmas must also reproduce the hydrogen ionization and the resulting emission spectrum, in some cases quite accurately. We describe a compact model hydrogen atom that can be readily incorporated into such simulations. It reproduces the recombination efficiency and line spectrum predicted by much larger

Tomislav Prokopec, Thomas G. Roos

We study numerically the decay of the inflaton by solving the full non-linear equations of motion on the lattice. We confirm that parametric resonance is effective in transferring energy from the inflaton to a scalar field as long as the self-interactions of the second field are very small. However, in the very broad resonance case (q>>1) the decay rate is l

Eric Braaten, Yu-Qi Chen

Dimensional regularization is incompatible with the standard covariant projection methods that are used to calculate the short-distance coefficients in inclusive heavy quarkonium production and annihilation rates. A new method is developed that allows dimensional regularization to be used consistently to regularize the infrared and ultraviolet divergences th

M. V. Simkin, J. M. Kosterlitz

The effects of finite size and of finite current on the current-voltage characteristics of Josephson junction arrays is studied both theoretically and by numerical simulations. The cross-over from non-linear to linear behavior at low temperature is shown to be a finite size effect and the non-linear behavior at higher temperature, $T>T_{KT}$, is shown to be

U. Baur, T. Han, R. Sobey, D. Zeppenfeld

The process $p \bar p \rightarrow μ^- \bar νγγ$ is calculated including finite lepton mass effects. Implications for precision measurements of the $W$ mass at the Tevatron are discussed.

Joseph Christensen, Terrence Draper, Craig McNeile

We calculate the $B_{B}$ parameter, relevant for $\overline{B}^0$ -- $B^0$ mixing, from a lattice gauge theory simulation at $β= 6.0$. The bottom quarks are simulated in the static theory, the light quarks with Wilson fermions. Improved smearing functions produced by a variational technique, MOST, are used to reduce statistical errors and minimize excited-st

V. Alan Kostelecky, Stuart Samuel

The annihilation of electron-positron pairs around one second after the big bang distorts the Fermi-Dirac spectrum of neutrino energies. We determine the distortions assuming neutrino mixing with an inverted neutrino-mass hierarchy. Nonequilibrium thermodynamics, the Boltzmann equation, and numerical integration are used to achieve the results. The various t

Miguel S. Costa

We generalise all the known supersymmetric composite M-branes to the corresponding black configurations. Thermodynamical formulae is written by using the simple rules to construct these black branes.

Nathan Berkovits

Superstring field theory was recently used to derive a covariant action for a self-dual five-form field strength. This action is shown to be a ten-dimensional version of the McClain-Wu-Yu action. By coupling to D-branes, it can be generalized in the presence of sources. In four dimensions, this gives a local Maxwell action with electric and magnetic sources.

B. Dion, L. Marleau, G. Simon

We perform a Monte-Carlo simulation of scalar leptoquark pair production at the Tevatron (energy =1.8 TeV and luminosity =100 pb^{-1}) with ISAJET. We also investigate the dominant sources of Standard Model background: Z*jj, ZZ production and heavy quark top-antitop. We find that the top-antitop background is the most important except near the Z pole where t

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

We study the non-linear dynamics of an inflationary phase transition in a quartically self coupled inflaton model within the framework of a de Sitter background. Large N and Hartree non-perturbative approximations combined with non-equilibrium field theory methods are used to study the self-consistent time evolution including backreaction effects. We find th

Giampiero Esposito

Recent work on the quantization of Maxwell theory has used a non-covariant class of gauge-averaging functionals which include explicitly the effects of the extrinsic-curvature tensor of the boundary, or covariant gauges which, unlike the Lorentz case, are invariant under conformal rescalings of the background four-metric. This paper studies in detail the adm

R. Sappey, E. Vincent, M. Ocio, J. Hammann

A new experimental procedure is discussed, which aims at separating thermal from quantum behavior independently of the energy barrier distribution in small particle systems. Magnetization relaxation data measured between 60 mK and 5 K on a sample of nanoparticles is presented. The comparison between experimental data and numerical calculations shows a clear

B. M. Zupnik

Analytical harmonic superfields are the basic variables of a standard harmonic formalism of SYM^2_4-theory. We consider superfield actions for alternative formulations of this theory using the unconstrained harmonic prepotentials. The corresponding equations of motion are equivalent to the component field equations of SYM^2_4-theory. The analyticity conditio

C. Boros, Liang Zuo-tang, Meng Ta-chung

The reaction mechanisms of the following proton diffractive scattering processes are studied and compared with one another: $γ^* p\to Vp,γ^* p\to Xp, pp\to (ΛK^+)p$ and $pA\to ΛK^+A$ (Here, $γ^*$ stands for the space-like photon in inelastic electron-proton scattering, $V$ for the vector mesons $ρ,ω,ϕ,J/ψ$, and $A$ for a target nucleus.) It is shown that, by

V. Gimenez, G. Martinelli

We present a high statistics, quenched lattice calculation of the B-parameters $B_{B_d}$ and $B_{B_s}$, computed at lowest order in the HQET. The results were obtained using a sample of 600 quenched gauge field configurations, generated by Monte Carlo simulation at $β=6.0$ on a $24^{3}\times 40$ lattice. For the light quarks the SW-Clover action was used; th

Krzysztof A. Meissner

In this paper we explicitly prove the invariance of the time-dependent string gravity Lagrangian with up to four derivatives under the global $O(d,d)$ symmetry.

Dirk Kreimer

We investigate Feynman diagrams which are calculable in terms of generalized one-loop functions, and explore how the presence or absence of transcendentals in their counterterms reflects the entanglement of link diagram constructed from them and explains unexpected relations between them.

F. Nesti

We study the large N limit in the presence of magnetic monopoles in the Yang-Mills/Higgs model in three dimensions. The physics in the limit depends strongly on the distribution of eigenvalues of the Higgs field in the vacuum, and we propose a particular, nondegenerate configuration. It minimizes the free energy at the moment of symmetry breaking. Given this

Anatol N. Kirillov, Toshiaki Maeno

We study the algebraic aspects of equivariant quantum cohomology algebra of the flag manifold. We introduce and study the quantum double Schubert polynomials, which are the Lascoux-Schutzenberger type representatives of the equivariant quantum cohomology classes. Our approach is based on the quantum Cauchy identity. We define also quantum Schubert polynomial

K. Dannbom, L. Ya. Glozman, C. Helminen, D. O. Riska

The large relativistic corrections to the constituent quark current operators improve the predictions for the axial couplings of the baryons, but worsen those for their magnetic moments. The exchange current corrections that are associated with flavor and spin dependent hyperfine interactions between the quarks with a form suggested by pseudoscalar meson exc

Y. Iwasaki, K. Kanaya, T. Kaneko, T. Yoshié

We study the scaling properties of the static quark potential and the ratio of the critical temperature $T_c$ to the square root of the string tension $σ$ in the SU(3) pure gauge theory using a renormalization group improved action. We first determine the critical coupling $β_c$ on lattices with temporal extension $N_t=3$, 4, and 6, and then calculate the st

Paul Benioff

This paper extends work done to date on quantum computation by associating potentials with different types of computation steps. Quantum Turing machine Hamiltonians, generalized to include potentials, correspond to sums over tight binding Hamiltonians each with a different potential distribution. Which distribution applies is determined by the initial state.

L. P. Horwitz, E. Eisenberg, Y. Strauss

The scattering theory of Lax and Phillips, designed primarily for hyperbolic systems, such as electromagnetic or acoustic waves, is described. This theory provides a realization of the theorem of Foias and Nagy; there is a subspace of the Hilbert space in which the unitary evolution of the system, restricted to this subspace, is realized as a semigroup. The

Hong-Chen Fu, Ryu Sasaki

We introduce the negative binomial states with negative binomial distribution as their photon number distribution. They reduce to the ordinary coherent states and Susskind-Glogower phase states in different limits. The ladder and displacement operator formalisms are found and they are essentially the Perelomov's su(1,1) coherent states via its Holstein-P

Peter Kostaedt, Mario Liu

The choice of the 4-velocity in the relativistic hydrodynamics proposed by Landau and Lifshitz is demonstrated to be the only one satisfying all general principles. Especially the far more widely adopted Eckart choice has to be abandoned.

M. Effenberger, A. Hombach, S. Teis, U. Mosel

We calculate the cross sections for inclusive one-pion, two-pion and eta photoproduction in nuclei in the photon energy range from 300 MeV to 900 MeV within the framework of a semi-classical BUU transport model. Our results are compared with existing experimental data and discussed with respect to a calculation of the total photoabsorption cross section.

Dale E. Alspach

It is shown that if $α,ζ$ are ordinals such that $1\leq ζ<α<ζω,$ then there is an operator from $C(ω^{ω^α})$ onto itself such that if $Y$ is a subspace of $C(ω^{ω^α})$ which is isomorphic to $C(ω^{ω^α})$ $,$ then the operator is not an isomorphism on $Y.$ This contrasts with a result of J. Bourgain that implies that there are uncountably many ordinals $α$ fo

Csaba Csaki, Martin Schmaltz, Witold Skiba

We give necessary criteria for N=1 supersymmetric theories to be in a smoothly confining phase without chiral symmetry breaking and with a dynamically generated superpotential. Using our general arguments we find all such confining SU and Sp theories with a single gauge group and no tree level superpotential.

M. Adler, A. Morozov, T. Shiota, P. van Moerbeke

In this paper we solve the following problems: (i) find two differential operators P and Q satisfying [P,Q]=P, where P flows according to the KP hierarchy \partial P/\partial t_n = [(P^{n/p})_+,P], with p := \ord P\ge 2; (ii) find a matrix integral representation for the associated $\t au$-function. First we construct an infinite dimensional space {\cal W}=\

Shoichi Ichinose, Noriaki Ikeda

We consider a gauge symmetry in a quantum Hilbert space. The symmetry leads to that of the heat-kernel and of the anomaly formulae which were previously obtained by the authors. This greatly simplifies and clarifies the structure of the formulae. We explicitly obtain the anomaly formulae in two and four dimensions, which ``unify&#39;&#39; all kinds of anomal

Lawrence M. Krauss, Hong Liu, Junseong Heo

An approach based on considerations of the non-classical energy momentum tensor outside the event horizon of a black hole provides additional physical insight into the nature of discrete quantum hair on black holes and its effect on black hole temperature. Our analysis both extends previous work based on the Euclidean action techniques, and corrects an omiss

T. DeGrand

These lectures provide an introduction to lattice methods for nonperturbative studies of quantum field theories, with an emphasis on Quantum Chromodynamics. Lecture 1 (Ch. 2): gauge field basics Lecture 2 (Ch. 3): Abelian duality with a lattice regulator (Ch. 4): simple lattice intuition Lecture 3 (Ch. 5): standard methods (and results) for hadron spectrosco

I. L. Shapiro

The theory described by the sum of the Einstein-Hilbert action and the action of conformal scalar field possesses the duality symmetry which includes some special conformal transformation of the metric, and also inversion of scalar field and of the gravitational constant. In the present paper the conformal duality is generalized for arbitrary space-time dime

Alexander Migdal

The local SUSY symmetry of the loop dynamics of QCD is found. The remarkable thing is, there is no einbein-gravitino on this theory, which makes it a 1D topological supergravity, or locally SUSY quantum mechanics. Using this symmetry, we derive the large $N_c$ loop equation in momentum superloop space. Introducing as before the position operator $\Xμ$ we arg

M. Klein

A summary is presented of deep inelastic physics results obtained by the H1 collaboration during its first three years of experimentation at the electron-proton collider HERA.

S. V. Bashinsky, R. L. Jaffe

We reduce the problem of many-channel hadron scattering at nonrelativistic energies to calculations on the scale of a few fermis. Having thus disentangled kinematics from interior quark dynamics, we study their interplay when a quark state occurs near a hadronic threshold. Characteristic parameters, such as the observed peak width, the decay width, and the s

L. Wolfenstein, P. I. Krastev

On the basis of present solar neutrino observations and relaxing the constraints from solar models it is possible that most (or nearly all) of the flux of electron neutrinos detected comes from electron capture in $^7{Be}$. These solutions arise from neutrino oscillations in which $ν_e$ $-$ $ν_τ$ mixing suppresses high energy $ν_e$ and $ν_e - ν_μ$ mixing sup

Wolfgang Ochs

Recent results on the energy spectra in QCD jets are reported. Within the Modified Leading Logarithmic Approximation (MLLA) and the Local Parton Hadron Duality (LPHD) model one finds a very good description of the $e^+e^-$ data from the lowest up to the LEP 1.5 energies. A model with fixed $α_s$ can be excluded, already in certain finite energy intervals. Th

T. DeGrand

These lectures provide an introduction to lattice methods for nonperturbative studies of Quantum Chromodynamics. Lecture 1 (Ch. 2): Basic techniques for QCD and results for hadron spectroscopy using the simplest discretizations; lecture 2 (Ch. 3): ``improved actions&#39;&#39;--what they are and how well they work lecture 3 (Ch. 4): SLAC physics from the latt

I. Gogoladze, A. Kobakhidze

The proton decay in supersymmetric (SUSY) Grand Unified Theories (GUTs), where the special mechanism provides the natural suppression of the dimension 5 ($d=5$) operators, was studied. Due to this mechanism, $d=5$ operator induced proton decay takes place only through the mixing of light generation fermions with those from third generation and crucially depe

M. Anselmino, M. Boglione, J. Hansson, F. Murgia

The production of hadrons in polarized lepton-nucleon deep inelastic scattering is discussed. The helicity density matrix of the hadron is computed within the QCD hard scattering formalism and its elements are shown to yield information on the spin structure of the nucleon and the spin dependence of the quark fragmentation process. The case of $ρ$ vector mes

M. Anselmino, M. Boglione, F. Murgia

We consider a general formalism, previously developed to describe single spin asymmetries (SSA) in inclusive particle production at moderately large $p_T$ in hadron-hadron high-energy processes. In this approach SSA can originate from non perturbative, universal, quark distribution analyzing powers, provided the quark intrinsic motion is taken into account.

Ch. Royon

The $F_{2}$, $F_{G}$, $R=F_{L}/F_{T}$ proton structure functions are derived in the QCD dipole picture of BFKL dynamics. We get a three parameter fit describing the 1994 H1 proton structure function $F_{2}$ data in the low $x$, moderate $Q^{2}$ range. Without any additional parameter, the gluon density and the longitudinal structure functions are predicted.T

Matthias Neubert

We give an introduction to the heavy-quark effective theory and the $1/m_Q$ expansion, which provide the modern framework for a systematic, model-independent description of the properties and decays of hadrons containing a heavy quark. We discuss the applications of these concepts to spectroscopy and to the weak decays of $B$ mesons.