November 1997 arXiv papers — page 16

J. L. F. Barbon, A. Pasquinucci

We consider a family of non-supersymmetric MQCD five-brane configurations introduced by Witten, and discuss the dependence of the curves on the microscopic theta angle and its relation with CP. We find evidence for a non-trivial spectral flow of the curves (vacua) and for the level-crossing of adjacent curves at a particular value of the theta angle, with sp

A. Bialas, H. Navelet, R. Peschanski

Using the QCD dipole picture of the BFKL pomeron, the cross-section of single diffractive dissociation of virtual photons at high energy and large diffractively excited masses is calculated. The calculation takes into account the full impact-parameter phase-space and thus allows to obtain an exact value of the triple BFKL Pomeron vertex. It appears large eno

Nemanja Kaloper, Ian I. Kogan, Keith A. Olive

We consider solutions to the cosmological equations of motion in 11 dimensions with and without 4-form charges. We show explicitly the correspondence between some of these solutions and known solutions in 10 dimensional string gravity. New solutions involving combinations of 4-form charges are explored. We also speculate on the possibility of removing curvat

P. H. Damgaard, S. M. Nishigaki

We derive the large-N spectral correlators of complex matrix ensembles with weights that in the context of Dirac spectra correspond to N_f massive fermions, and prove that the results are universal in the appropriate scaling limits. The resulting microscopic spectral densities satisfy exact spectral sum rules of massive Dirac operators in QCD.

M. Masip

We study the form factor f_+^H (H=D,B) involved in H-πtransitions. We use data on D^0 \to π^- l^+ νto find f_+^D at low recoil. Then we use perturbative QCD methods to calculate at larger recoil the contributions to f_+^H that break heavy quark symmetry (HQS). Using HQS relations we obtain an estimate of f_+^B which includes first order corrections in 1/(2m_

T. Bieker, S. Dietrich

As a first step towards a microscopic understanding of the effective interaction between colloidal particles suspended in a solvent we study the wetting behavior of one-component fluids at spheres and fibers. We describe these phenomena within density functional theory which keeps track of the microscopic interaction potentials governing these systems. In pa

A. B. Bylev, V. A. Franke, E. V. Prokhvatilov

Light-front Hamiltonian for Yukawa type models is determined without the framework of canonical light-front formalism. Special attention is given to the contribution of zero modes.

Jiin-Chang Shaw, Ming-Hsien Tu

The gauge equivalence between the Manin-Radul and Laberge-Mathieu super KdV hierarchies is revisited. Apart from the Inami-Kanno transformation, we show that there is another gauge transformation which also possess the canonical property. We explore the relationship of these two gauge transformations from the Kupershmidt-Wilson theorem viewpoint and, as a by

A. Petrov

The Lie product and the order relation are viewed as defining structures for Hamiltonian dynamical systems. Their admissible combinations are singled out by the requirement that the group of the Lie automorphisms be contained in the group of the order automorphisms (Lie algebras with invariant cones). Taking advantage of the reciprocal independence of the re

Asher Peres

This is an "Essay-Review" of a book with the same title, by Jeffrey Bub (Cambridge University Press, 1997).

Daniel I. Fivel

We consider experimental evidence for the hypothesis that the Planck energy, $E_p \approx 10^{19}GeV$, sets the scale $ε$ at which wave function collapse causes deviations from linear Schrödinger evolution. With a few plausible assumptions about the collapse process, we first show that the observed CP violation in $K_L$ decay implies a lower bound on $ε$ rem

T. H. Baker, P. J. Forrester

We examine two isomorphisms between affine Hecke algebras of type $A$ associated with parameters $q^{-1}$, $t^{-1}$ and $q$, $t$. One of them maps the non-symmetric Macdonald polynomials $E_η(x;q^{-1},t^{-1})$ onto $E_η(x;q,t)$, while the other maps them onto non-symmetric analogues of the multivariable Al-Salam & Carlitz polynomials. Using the properties of

K. Hagino, S. Kuyucak, N. Takigawa

We discuss the effects of multi-phonon excitations on heavy-ion fusion reactions at energies near and below the Coulomb barrier, focusing especially on the role of anharmonicities. We carry out a systematic study of those effects on the excitation function of the fusion cross section and on the fusion barrier distribution, by using the vibrational limit of t

D. Anselmi, J. Erlich, D. Z. Freedman, A. Johansen

The relation between the trace and R-current anomalies in supersymmetric theories implies that the U$(1)_RF^2$, U$(1)_R$ and U$(1)_R^3$ anomalies which are matched in studies of N=1 Seiberg duality satisfy positivity constraints. Some constraints are rigorous and others conjectured as four-dimensional generalizations of the Zamolodchikov $c$-theorem. These c

H. Awata, D. Minic

A possible avenue towards the covariant formulation of the bosonic Matrix Theory is explored. The approach is guided by the known covariant description of the bosonic membrane. We point out various problems with this particular covariantization scheme, stemming from the central question of how to enlarge the original U(N) symmetry of Matrix Theory while pres

Jens Hoppe

For a supersymmetric Hamiltonian appearing in the matrix model related to 11 dimensional supermembranes, zero energy states are constructed. A useful symmetry, and an energy-equipartition property is pointed out.

J. Burzlaff, W. J. Zakrzewski

The $CP^2$ model, with and without a generalized Hopf term, is studied using the collective coordinate approximation. In the spirit of this approximation, an ansatz is given which in previous numerical studies was seen to give a good parameterization of the numerical solution. The equations of motion for the collective coordinates are then solved analyticall

A N Theron, F G Scholtz, H B Geyer

We discuss various bosonization schemes from a path integral perspective. Our analysis shows that the existence of different bosonization schemes, such as abelian bosonization of non-abelian models and non-abelian bosonization of fermions with colour and flavour indices, can be understood as different ways of factoring out a dynamically trivial coset which c

Faheem Hussain, Roberto Iengo, Carmen Nunez, Claudio A. Scrucca

We discuss various D-brane configurations in 4-dimensional orbifold compactifications of type II superstring theory which are point-like 0-branes from the 4-dimensional space-time point of view. We analyze their interactions and compute the amplitude for the emission of a massless NSNS boson from them, in the case where the branes have a non vanishing relati

Faheem Hussain, Roberto Iengo, Carmen Nunez, Claudio A. Scrucca

We discuss D-brane dynamics in orbifold compactifications of type II superstring theory. We compute the interaction potential between two D-branes moving with constant velocities and give a field theory interpretation of it in the large distance limit.

Vladimir A. Kazakov

We present a hermitian matrix chain representation of the general solution of the Hirota bilinear difference equation of three variables. In the large N limit this matrix model provides some explicit particular solutions of continuous differential Hirota equation of three variables. A relation of this representation to the eigenvalues of transfer matrices of

Kazuyuki Fujii

A volume form $H$ on the $n$--dimensional sphere $S^n$ is closed $(dH=0)$, so that it is locally written as $H=dB$, where B is a $(n-1)$--form. In the first half we give an explicit form to B and, moreover, a speculation concerning higher order U(1) bundles. In the second half we apply our B in the case $n=3$ to a string soliton solution discussed by Perry a

M. Göckeler, R. Horsley, H. Perlt, P. Rakow

We report on new results of the spin dependent structure functions $g_1$ and $h_1$ of the nucleon. An attempt is made to convert the moments, which is what one computes on the lattice, to quark distribution functions.

A. Djouadi, J. -L. Kneur, G. Moultaka

We investigate the production of Higgs particles in association with the supersymmetric scalar partners of the top quark at proton colliders. In the minimal supersymmetric extension of the Standard Model, the cross sections for the production of the lightest neutral Higgs boson in association with top squark pairs can be rather large, substantially exceeding

Rainer Sommer

In these lectures, we discuss different types of renormalization problems in QCD and their non-perturbative solution in the framework of the lattice formulation. In particular the recursive finite size methods to compute the scale-dependence of renormalized quantities is explained. An important ingredient in the practical applications is the Schrödinger func

Edward Boos, Thorsten Ohl

We present a general classification of all four fermion final states in $γγ$~collisions and a calculation of cross sections below the $W^+W^-$-threshold.

Philip R. Page

We calculate the strong decays of hybrid mesons to conventional mesons for all the lowest lying J^PC hybrids of flavour uu, dd, ss, cc and bb. A decay operator developed from the heavy quark expansion of quantum chromodynamics is employed. We show that the selection rule that hybrid mesons do not decay to identical S-wave mesons, found in other models, is pr

F. Benatti, R. Floreanini

We study the behaviour of correlated neutral kaons produced in phi-meson decays under the hypothesis that the quantum mechanical time-evolution is completely positive. We show that planned experiments at phi-factories could give precise bounds on the phenomenological parameters of the model.

G. Amoros, M. Neubert

The renormalization of local dimension-4 operators containing a heavy and a light quark field at scales below the heavy-quark mass is discussed, using the formalism of the heavy-quark effective theory. The anomalous dimensions of these operators and their mixing are calculated to two-loop order. Some phenomenological applications are briefly discussed.

Xiao-Fei Zhang, Cong-Feng Qiao, Xiao-Xia Yao, Wei-Qin Chao

$J/ψ$ and $ψ'$ production cross sections in fixed-target experiment is calculated, considering the contributions from both color-singlet and color-octet mechanisms.The results are applied to the investigations of the $J/ψ$ suppression and the $ψ'/ψ$ ratio problems in p-A collisions. The results agree with the experimental data as the $(c \bar c)-$nuc

I. Joichi, Sh. Matsumoto, M. Yoshimura

Time evolution of the decay process of unstable particles is investigated in field theory models. We first formulate how to renormalize the non-decay amplitude beyond perturbation theory and then discuss short-time behavior of very long-lived particles. Two different formalisms, one that does and one that does not, assume existence of the asymptotic field of

C. Macesanu

Using the analytic properties of two-point functions in QCD, as well as unitarity, bounds on the B meson form factor F(q^2) can be derived. Heavy quark spin symmetry, correctly taken into account, is shown to improve these bounds significantly.

Dirk Graudenz

DISASTER++ is a C++ class library for the calculation of (1+1) and (2+1)-jet-like quantities in deeply inelastic lepton-nucleon scattering for one-photon exchange in next-to-leading-order QCD perturbation theory. The calculation is based on the subtraction formalism. The user has access to an event record such that an arbitrary set of infrared-safe observabl

S. Oda, N. Tsuda, T. Yukawa

The string susceptibility exponents of dynamically triangulated two dimensional surfaces with sphere and torus topology were calculated using the grand-canonical Monte Carlo method. We also simulated the model coupled to d-Ising spins (d=1,2,3,5).

S. Capitani, M. Göckeler, R. Horsley, H. Perlt

Some basic concepts are discussed to derive renormalisation factors of local lattice operators relevant to deep inelastic structure functions and to other measurable quantities. These $Z$ factors can be used to relate matrix elements measured by lattice techniques to their continuum counterparts. We discuss the $O(a)$ improvement of point and one-link lattic

Lakshmi Venkataraman, Gregory Kilcup

We have computed the eta-prime pseudoscalar octet mass splitting using staggered fermions on both dynamical and quenched gauge configurations. We have used Wuppertal smeared operators to reduce excited state contributions. We compare our results with the theoretical forms predicted by partially quenched chiral perturbation theory in the lowest order. Using l

S. Aoki, Y. Taniguchi

One loop corrections to the domain-wall quark propagator are calculated in massless QCD. It is shown that no additative counter term to the current quark mass is generated in this theory, and the wave function renormalization factor of the massless quark is explicitly evaluated. We also show that an analysis with a simple mean-field approximation can explain

The CHOOZ collaboration

Initial results are presented from CHOOZ, a long-baseline reactor-neutrino vacuum-oscillation experiment. Electron antineutrinos were detected by a liquid scintillation calorimeter located at a distance of about 1 km. The detector was constructed in a tunnel protected from cosmic rays by a 300 MWE rock overburden. This massive shielding strongly reduced pote

S. R. Brandt, B. Bruegmann

We construct initial data for several black holes with arbitrary momenta and spins by a new method that is based on a compactification of Brill-Lindquist wormholes. When treated numerically, the method leads to a significant simplification over the conventional approach which is based on throats and an isometry condition.

H. P. de Oliveira, I. Damiao Soares, T. J. Stuchi

We show that anisotropic Bianchi type-IX models, with matter and cosmological constant have chaotic dynamics, connected to the presence of a saddle-center in phase space. The topology of cylinders emanating from unstable periodic orbits about the saddle-center provides an invariant characterization of chaos in the models. The model can be thought to describe

Rafael A. Vera

According to this principle (EEP), in order that the local physical laws cannot change, after changes of velocity and potentials of a measuring system, the relativistic changes of any particle and any stationary radiation (like those used to measure it) must occur in identical proportion. Thus particles and stationary radiations must have the same general ph

Lior M. Burko

Recent numerical simulations have found that the Cauchy horizon inside spherical charged black holes, when perturbed nonlinearly by a self-gravitating, minimally-coupled, massless, spherically-symmetric scalar field, turns into a null weak singularity which focuses monotonically to $r=0$ at late times, where the singularity becomes spacelike. Our main object

W. B. Bonnor, N. O. Santos, M. A. H. MacCallum

We match the vacuum, stationary, cylindrically symmetric solution of Einstein's field equations with $Λ$, in a form recently given by Santos, as an exterior to an infinite cylinder of dust cut out of a Gödel universe. There are three cases, depending on the radius of the cylinder. Closed timelike curves are present in the exteriors of some of the solutio

Takeshi Shirafuji, Gamal G. L. Nashed

We study the energy and momentum of an isolated system in the tetrad theory of gravitation, starting from the most general Lagrangian quadratic in torsion, which involves four unknown parameters. When applied to the static spherically symmetric case, the parallel vector fields take a diagonal form, and the field equation has an exact solution. We analyze the

Hideki Asada, Toshifumi Futamase

We consider the propagation of gravitational waves generated by slow motion sources in Coulomb type potential due to the mass of the source. Then, the formula for gravitational waveform including tail is obtained in a straightforward manner by using the spherical Coulomb function. We discuss its relation with the formula in the previous work.

Andrey V. Chubukov, Joerg Schmalian

We consider thermal evolution of the spectral function A(Omega, T) in underdoped cuprates at T >Tc. We find that in the strong coupling limit, the fermionic Green's function near (0,π) behaves as G^{-1} (Omega) ~ \sqrt{Omega} in the whole frequency range relevant to photoemission experiments. The analysis of the pairing problem with this form of G yields

Stephen W. Pierson

Fundamental properties of the Kosterlitz-Thouless-Berezinskii (KTB) transition which occurs in systems in the universality class of the two-dimensional X-Y model are reviewed here with an emphasis on the real-space renormalization group analysis used to derive the recursion relations. A derivation of the unique temperature dependence of the correlation lengt

Jonathan Doye, David Wales

Using a Monte Carlo minimization approach we report the global minima for metal clusters modelled by the Sutton-Chen family of potentials with N<81, where N is the number of atoms. The resulting structures are discussed in the light of both experimental and theoretical data for clusters of the appropriate elements.

Michael Lassig

The Kardar-Parisi-Zhang universality class of stochastic surface growth is studied by exact field-theoretic methods. From previous numerical results, a few qualitative assumptions are inferred. In particular, height correlations should satisfy an operator product expansion and, unlike the correlations in a turbulent fluid, exhibit no multiscaling. These prop

N. Papanicolaou

A direct link between the topological complexity of magnetic media and their dynamics is established through the construction of unambiguous conservation laws for the linear and angular momenta as moments of a topological vorticity. As a consequence, the dynamics of topological magnetic solitons is shown to exhibit the characteristic features of the Hall eff

Omri Gat, Reuven Zeitak

The Kraichnan rapid advection model is recast as the stochastic dynamics of tracer trajectories. This framework replaces the random fields with a small set of stochastic ordinary differential equations. Multiscaling of correlation functions arises naturally as a consequence of the geometry described by the evolution of N trajectories. Scaling exponents and s

F. Luczak, F. Brosens, J. T. Devreese, L. F. Lemmens

A numerical implementation scheme is presented for the recently developed many-body diffusion approach for identical particles, in the case of harmonic potentials. The procedure is free of the sign problem, by the introduction of the appropriate absorption or reflection conditions for the walkers at the boundary of a state space. These conditions are imposed

T. Nakajima, H. Aoki

A &#34;squeezed-vacuum&#34; state considered in quantum optics is shown to be realized in the ground-state wavefunction for the bilayer quantum Hall system at the total Landau level filling of $ν=1/m$ (m: odd integer). This is derived in the boson approximation, where a particle-hole pair creation across the symmetric-antisymmetric gap, $Δ_{SAS}$, is regarde

H. van Beijeren, A. Latz, J. R. Dorfman

We compute the Lyapunov spectrum and the Kolmogorov-Sinai entropy for a moving particle placed in a dilute, random array of hard disk or hard sphere scatterers - i.e. the dilute Lorentz gas model. This is carried out in two ways: First we use simple kinetic theory arguments to compute the Lyapunov spectrum for both two and three dimensional systems. In order

David Langlois, David M. Sedrakian, Brandon Carter

It is shown how to set up a mathematically elegant and fully relativistic superfluid model that can provide a realistic approximation (neglecting small anisotropies due to crust solidity, magnetic fields, et cetera, but allowing for the regions with vortex pinning) of the global structure of a rotating neutron star, in terms of just two independently moving

V. Korchagin, Y. D. Mayya, E. I. Vorobyov, A. K. Kembhavi

We compute surface brightness profiles of galactic disks for outwardly propagating waves of star formation with a view to investigate the stellar populations in ring galaxies. We consider two mechanisms which can create outwardly propagating star forming rings in a purely gaseous disk --- a self-induced wave and a density wave. We show that the surface brigh

J. M. Colberg, S. D. M. White, A. Jenkins, F. R. Pearce

We use two high resolution CDM simulations to show that (i) when clusters of galaxies form the infall pattern of matter is not random but shows clear features which are correlated in time; (ii) in addition, the infall patterns are correlated with the cluster&#39;s surrounding Large Scale Structure; (iii) Large Scale Structure shows a mix of both filaments an

Edward A. Baltz, Andrew J. Westphal, Daniel P. Snowden-Ifft

Mica can store (for >1 Gy) etchable tracks caused by atoms recoiling from WIMPs. Ancient mica is a directional detector despite the complex motions it makes with respect to the WIMP &#34;wind&#34;. We can exploit the properties of directionality and long integration time to probe for structure in the dark matter halo of our galaxy. We compute a sample of pos

Myles Corcoran, Thomas P. Ray

Intermediate dispersion spectroscopic observations of 37 Herbig Ae/Be stars reveal that the equivalent widths of their [OI] 6300A and Halpha emission lines, are related to their near-infrared colours in the same fashion as the T-Tauri stars. Such a correlation strongly supports the idea that the winds from Herbig Ae/Be stars arise in the same manner as those

H. Wu, Z. L. Zou, X. Y. Xia, Z. G. Deng

This paper presents the results of spectral observations for the largest complete sample of very luminous IRAS galaxies obtained to date. The sample consists of those 73 objects for which log (L_IR/L_sun) => 11.5 (H0=50 km/s/Mpc, q0=0.5) and mag =< 15.5, and was extracted from the 2 Jy IRAS redshift catalog. All the spectra were obtained using 2.16m telescop

C. Balland, J. Silk, R. Schaeffer

We present a semi-analytical model in which galaxy collisions and strong tidal interactions, both in the field and during the collapse phase of groups and clusters help determine galaxy morphology. From a semi-analytical analysis based on simulation results of tidal collisions (Aguilar & White 1985), we propose simple rules for energy exchanges during collis

N. Brosch, E. Almoznino, L. Hoffman

We describe results of a multi-spectral study of a blue compact dwarf galaxy in Virgo. The object was observed with broad-band and H$α$ imaging, UV observations, and radio synthesis. Our data were combined with published optical observations, with HI single-beam observation and with FIR data, and were compared to results of evolutionary synthesis programs. T

Alexei Skorobogatov

We construct a (smooth, projective) surface over the field of rational numbers, which is a counterexample to the Hasse principle not accounted for by the Manin obstruction. The construction relies on the classical 4-descent on elliptic curves. By combining the Manin obstruction with descent we define a refinement of the Manin obstruction which for surfaces o

M. C. Beltrametti, S. Di Rocco, A. J. Sommese

The map given by the anticanonical bundle of a Fano manifold is investigated with respect to a number of natural notions of higher order embeddings of projective manifolds. This is of importance in the understanding of higher order embeddings of the special varieties of adjunction theory, which are usually fibered by special Fano manifolds. An analysis is ca

Kazusumi Ino

We consider the multiple edge states of the Laughlin state and the Pfaffian state. These edge states are globally constrained through the operator algebra of conformal field theory in the bulk. We analyze these constraints by introducing an expression of quantum hall state by the chiral vertex operators and obtain the multiple edge partition functions by usi

George M. Fuller, Xiangdong Shi

We propose that the gravitational collapse of supermassive objects ($ M\ga 10^4 M_\odot$), either as relativistic star clusters or as single supermassive stars (which may result from stellar mergers in dense star clusters), could be a cosmological source of $γ$-ray bursts. These events could provide the seeds of the supermassive black holes observed at the c

A. L. Fauchere, G. B. Lesovik, G. Blatter

We express the low-frequency shot noise in a disordered normal-metal - superconductor (NS) junction at finite (subgap) voltage in terms of the normal scattering amplitudes and the Andreev reflection amplitude. In the multichannel limit, the conductance exhibits resonances which are accompanied by an enhancement of the (differential) shot noise. In the study

Manuela Campanelli, Carlos O. Lousto

Gravitational perturbations about a Kerr black hole in the Newman-Penrose formalism are concisely described by the Teukolsky equation. New numerical methods for studying the evolution of such perturbations require not only the construction of appropriate initial data to describe the collision of two orbiting black holes, but also to know how such new data mu

A. Bramon, R. Escribano, M. D. Scadron

The value of the $η- η&#39;$ mixing angle $θ_P$ is phenomenologically deduced from a rather exhaustive and up-to-date analysis of data including strong decays of tensor and higher-spin mesons, electromagnetic decays of vector and pseudoscalar mesons, $J/ψ$ decays into a vector and a pseudoscalar meson, and other transitions. A value of $θ_P$ between $-17^\ci

V. L. Eletsky, A. C. Kalloniatis, F. Lenz, M. Thies

SU(2) Yang-Mills theory at finite extension or, equivalently, at finite temperature is probed by a homogeneous chromomagnetic field. We use a recent modified axial gauge formulation which has the novel feature of respecting the center symmetry in perturbation theory. The characteristic properties of the Z_2-symmetric phase, an extension-dependent mass term a

Tohsuke Urabe

The category of real-analytic sets and real-analytic maps is the most important category in application. However, in spite of efforts by F. Bruhat, H. Cartan, H. Whitney et al., the basic theory of real-analytic category does not yet seem to be well-developed. In this article I would like to point out several basic problems.

A. D. Challinor, A. N. Lasenby

We discuss three recent developments in the calculation of CMB anisotropies. First, we consider relativistic corrections to the Sunyaev-Zel&#39;dovich effect. By extending the Kompaneets equation to the relativistic domain we are able to derive simple analytic forms for the SZ spectral distortion. Second, we discuss covariant kinetic theory methods for the g

Th. Weidmann, E. L. Bratkovskaya, W. Cassing, U. Mosel

We present a dynamical study of $e^+e^-$ production in $π^-$A reactions at 1.3 and 1.7 GeV on the basis of the Coupled-Channel-BUU approach. The contributions from vector mesons ($ρ,ω$) are calculated taking into account the collisional broadening effect and are compared to background sources in the dilepton spectrum from the Dalitz decays of $ω$ and $η$ mes

L. Mankiewicz, G. Piller, T. Weigl

We present an analysis of twist-2, leading order QCD amplitudes for hard exclusive leptoproduction of mesons in terms of double/nonforward parton distribution functions. After reviewing some general features of nonforward nucleon matrix elements of twist-2 QCD string operators, we propose a phenomenological model for quark and gluon nonforward distribution f

Hiroshi Shimahara

Nonuniform superconducting state due to strong spin magnetism is studied in two-dimensional type-II superconductors near the second order phase transition line between the normal and the superconducting states. The optimum spatial structure of the orderparameter is examined in systems with cylindrical symmetric Fermi surfaces. It is found that states with tw

Snigdha Das, Pushpa Khare

We have performed proximity effect analysis of low and high resolution data, considering detailed frequency and redshift dependence of the AGN spectra processed through galactic and intergalactic material. We show that such a background flux, calculated using the observed distribution of AGNs, falls short of the value required by the proximity effect analysi

Jeongwon Ho, Won Tae Kim, Young-Jai Park

We consider T-duality of the quasilocal black hole thermodynamics for the three-dimensional low energy effective string theory. Quasilocal thermodynamic variables in the first law are explicitly calculated on a general axisymmetric three-dimensional black hole solution and corresponding dual one. Physical meaning of the dual invariance of the black hole entr

Yasunori Nomura, K. Tobe, T. Yanagida

We construct a gauge mediation model of dynamical supersymmetry breaking (DSB) based on a vector-like gauge theory, in which there is a unique color-preserving true vacuum. The DSB scale $Λ/4π$ turns out to be as high as $Λ/4π\simeq 10^{8-9} GeV$, since the transmission of the DSB effects to the standard model sector is completed through much higher loops. T

J. Brodie, S. Ramgoolam

We compare the $(0,2)$ theory of the single M5 brane decoupled from gravity in the lightcone with transverse $R^4$, and a matrix model description in terms of quantum mechanics on instanton moduli space. We give some tests of the Matrix model in the case of multi fivebranes on $R^4$. We extract constraints on the operator content of the field theory of the m

Guo-xing Ju, Chi Xiong

The Lax pair for the one-dimensional open XYZ spin chain is constructed, this shows that the system is completely integrable .

Jeong-Young Ji, Kwang-Sup Soh

We introduce a time-dependent perturbation method to calculate the number of created particles in a 1D cavity with an oscillating wall of the frequency $Ω. $ This method makes it easy to find the dominant part of the solution which results from the parametric resonance. The maximal number of particles are created at the mode frequency $Ω/2 . $ Using the Floq

T. Detmer, P. Schmelcher, L. S. Cederbaum

The electronic structure of the hydrogen molecule in a magnetic field is investigated for parallel internuclear and magnetic field axes. The lowest states of the $Π$ manifold are studied for spin singlet and triplet$(M_s = -1) $ as well as gerade and ungerade parity for a broad range of field strengths $0 \leq B \leq 100 a.u.$ For both states with gerade par

Song Gao, Charles Gale

The production of dielectrons in reactions involving a_1 mesons and pions is studied. We compare results obtained with different phenomenological Lagrangians that have been used in connection with hadronic matter and finite nuclei. We insist on the necessity for those interactions to satisfy known empirical properties of the strong interaction. Large off-she

V. Pascalutsa, J. A. Tjon

We argue that most of the relativistic 3-D (quasipotential) equations used in hadron physics are inconsistent with the discrete symmetries like charge conjugation and CPT, yielding an incorrect Lorentz structure for the calculated Green&#39;s functions. An exception to this is the equal time approximation to the Bethe-Salpeter equation. We present a covarian

Barak Kol

A recent proposal for 6d &#34;gauge&#34; theories with rational theta angle is discussed. These theories were constructed from n_C coinciding (p,q) 5-branes of IIB in the limit of vanishing string constant. They have (1,1) supersymmetry and the low energy theory is 6d Yang-Mills with gauge group SU(n_C) and a rational theta angle theta_6/(2 pi)=f/q, where fp

V. P. Gusynin, D. K. Hong, I. A. Shovkovy

We investigate the effect of a constant external non-Abelian field on chiral symmetry breaking in a (2+1)-dimensional Nambu-Jona-Lasinio model and in 3D QCD by solving the gap equation and the Bethe-Salpeter equation, and also by RG analysis. In the (2+1)-dimensional NJL model chiral symmetry breaking occurs for any weak coupling constant but in 3D QCD catal

G. K. Savvidy, K. G. Savvidy

We discuss the basic properties of the gonihedric string and the problem of its formulation in continuum. We propose a generalization of the Dirac equation and of the corresponding gamma matrices in order to describe the gonihedric string. The wave function and the Dirac matrices are infinite-dimensional. The spectrum of the theory consists of particles and

M. Hosch, R. J. Oakes, K. Whisnant, Jin Min Yang

We investigate the possibility of observing the exotic decay mode of the top quark into the lightest stop ($\tilde t_1$) and neutralino ($\tildeχ^0_1$) in the minimal supersymmetric standard model with R-parity at the upgraded Tevatron. First we determine the allowed range for the branching fraction $B(t\to \tilde t_1 \tildeχ^0_1)$ in the region of parameter

Y. Sumino

We review the physics involved in the production and decay of top quarks in e^+e^- -> ttbar near threshold, with special emphasis on the recent theoretical study on the decay process of top quarks in the threshold region. The energy-angular distribution of l^+ in semileptonic top decays is calculated including the full O(alpha_s) corrections. Various effects

R. Barbieri

The present status of Unified Theories is summarized with special emphasis on their possible experimental tests. Outline: i) Unification of couplings; ii) Where can a positive signal come from? iii) HERA anomaly and Unification; iv) Recent progress in model building; v) Flavour and Unification.

Thorsten Feldmann, Peter Kroll

We reanalyze the eta-gamma and eta&#39;-gamma transition form factors within the modified hard scattering approach on the basis of new experimental data from CLEO and L3. Our approach perfectly describes the experimental data over a wide range of the virtuality of the probing photon, 1 GeV^2 < Q^2 < 15 GeV^2. The analysis provides hints that the conventional

D. Bardin, J. Blümlein, P. Christova, L. Kalinovskaya

Two computer codes relevant for the description of deep inelastic scattering off polarized targets are discussed. The code $μ$ela deals with radiative corrections to elastic $μe$ scattering, one method applied for muon beam polarimetry. The code HECTOR allows to calculate both the radiative corrections for unpolarized and polarized deep inelastic scattering,

N. I. Kochelev

The contribution of the quark-quark and quark-gluon interaction induced by instantons to the valence quark and proton spin-dependent structure functions $g_1(x,Q^2)$ is estimated within the instanton liquid model for QCD vacuum. It is shown, that this interaction leads to a rather large violation of the Ellis-Jaffe sum rule.

G. Calucci, D. Treleani

CDF has recently measured a large number of double parton scatterings. The observed value of $σ_{eff}$, the non perturbative parameter which characterizes the process, is considerably smaller as compared with the naive expectation. The small value of $σ_{eff}$ is likely to be an indication of the importance of the two-body parton correlations in the many-bod

E. Mirkes

The large center of mass energy and increasing statistical precision for a wide range of hadronic final state observables at the HERA lepton-proton collider has provided a detailed testing ground for QCD dynamics. Fully flexible next-to-leading order calculations are mandatory on the theoretical side for such tests and will be discussed in detail. Next-to-le

R. S. Thorne, R. G. Roberts

The transition from the low $Q^2$ region in deep inelastic scattering where charm production is described by photon-gluon fusion to a region where the charm structure function $F_2^c$ is largely generated by a charm quark density should be a smooth passage. The all orders prescription for matching between the two schemes does not uniquely determine all the r

U. van Kolck

The application of the chiral effective theory to processes with two or more nucleons is discussed. We gain a qualitative understanding of the gross features of nuclear physics and quantitative, testable postdictions and predictions involving photons and pions.

A. Niégawa

A complete derivation, from first principles, of the reaction-rate formula for a generic process taking place in a heat bath of finite volume is given. It is shown that the formula involves no finite-volume correction. Through perturbative diagrammatic analysis of the resultant formula, the detailed-balance formula is derived. The zero-temperature limit of t

Taekoon Lee

A systematic method of summing the corrections to the renormalon residue arising from higher order renormalons is discussed.

Paul H. Frampton, Pham Quang Hung

Several lines of reasoning suggest that there might exist a non-sequential fourth generation of heavy quarks having very small mixing with light quarks and hence exceptionally long lifetime.