July 1999 arXiv papers

Z. Maassarani

In the framework of quantum groups and additive R-matrices, the fusion procedure allows to construct higher-dimensional solutions of the Yang-Baxter equation. These solutions lead to integrable one-dimensional spin-chain Hamiltonians. Here fusion is shown to generalize naturally to non-additive R-matrices, which therefore do not have a quantum group symmetry

V. B. Kuznetsov, M. Salerno, E. K. Sklyanin

For the integrable case of the discrete self-trapping (DST) model we construct a Backlund transformation. The dual Lax matrix and the corresponding dual Backlund transformation are also found and studied. The quantum analog of the Backlund transformation (Q-operator) is constructed as the trace of a monodromy matrix with an infinite-dimensional auxiliary spa

T. M. Aliev, M. Savci

We calculate the transition form factor for the 'B_c -> B_u^* gamma' decay taking into account only the short distance contribution, in framework of QCD sum rules method. We observe that the transition form factor predicted by the QCD sum rules method is approximately two times larger compared to the result predicted by the Isgur, Scora, Grinstein an

Chuan-Wei Zhang, Chuan-Feng Li, Guang-Can Guo

We derive a lower bound for the optimal fidelity for deterministic cloning a set of n pure states. In connection with states estimation, we obtain a lower bound about average maximum correct states estimation probability.

M. Bordag, V. Skalozub

We investigate the effective potential for a scalar $Φ^{4}$ theory with spontaneous symmetry breaking at finite temperature. All 'daisy' and 'super daisy' diagrams are summed up and the properties of the corresponding gap eqation are investigated. It is shown exactly that the phase transition is first order.

P D Jarvis, S P Corney, I Tsohantjis

A covariant spinor representation of $iosp(d,2/2)$ is constructed for the quantization of the spinning relativistic particle. It is found that, with appropriately defined wavefunctions, this representation can be identified with the state space arising from the canonical extended BFV-BRST quantization of the spinning particle with admissible gauge fixing con

Bo Sundborg

N=4 Super Yang-Mills theory supplies us with a non-Abelian 4D gauge theory with a meaningful perturbation expansion, both in the UV and in the IR. We calculate the free energy on a 3-sphere and observe a deconfinement transition for large N at zero coupling. The same thermodynamic behaviour is found for a wide class of toy models, possibly also including the

A. Cillis, S. J. Sciutto

The influence of the geomagnetic field on the development of air showers is studied. The well known International Geomagnetic Reference Field was included in the AIRES air shower simulation program as an auxiliary tool to allow calculating very accurate estimations of the geomagnetic field given the geographic coordinates, altitude above sea level and date o

Chuan-Wei Zhang, Chuan-Feng Li, Guang-Can Guo

We realize the probabilistic cloning and identifying linear independent quantum states of multi-particles system, given prior probability, with universal quantum logic gates using the method of unitary representation. Our result is universal for separate state and entanglement. We also provide the realization in the condition given $M$ initial copies for eac

Chuan-Wei Zhang, Chuan-Feng Li, Guang-Can Guo

We derive general discrimination of quantum states chosen from a certain set, given initial $M$ copies of each state, and obtain the matrix inequality, which describe the bound between the maximum probability of correctly determining and that of error. The former works are special cases of our results.

Athanasios N. Petridis

The procedure of maximization of information entropy can be used to improve our knowledge of parton distributions. This method has been applied in order to achieve improved description of the nuclear effect in Y production due to gluon distribution modification in nuclei.

David S. Metzler

For an $S^{1}$-manifold with boundary, we prove a localization formula applying to any equivariant cohomology theory satisfying a certain algebraic condition. We show how the localization result of Kalkman and a case of the quantization commutes with reduction theorem follow easily from the localization formula.

Yuli Rudyak, Aleksy Tralle

We consider closed symplectically aspherical manifolds, i.e. closed symplectic manifolds $(M,ω)$ satisfying the condition $[ω]|_{π_2M}=0$. Rudyak and Oprea [RO] remarked that such manifolds have nice and controllable homotopy properties. Now it is clear that these properties are mostly determined by the fact that the strict category weight of $[ω]$ equals 2.

Steven S. Gubser

We explore the interplay between black holes in supergravity and quantum field theories on the world-volumes of D-branes. A brief summary of black hole entropy calculations for D-brane black holes is followed by a detailed study of particle absorption by black holes whose string theory description involves D-branes intersecting along a string. A conformal fi

H. Arthur Weldon

In the high temperature, chirally invariant phase of QCD, the quark propagator is shown to have two sets of poles with different dispersion relations. A reflection property in momentum space relates all derivatives at zero-momentum of the particle and hole energies, the particle and hole damping rates, and the particle and hole residues. No use is made of pe

Y. Kouchi, Y. Takeuchi, S. Y. Tsai

To study violation of CP, T and/or CPT symmetries in the $K^0-\bar{K^0}$ systems, one has to parametrize the relevant mixing parameters and decay amplitudes in such a way that each parameter represents violation of these symmetries in a well-defined way. Parametrization is of course not unique and is always subject to phase ambiguities. We discuss these prob

The OPAL collaboration, G. Abbiendo

A search for neutral Higgs bosons has been performed with the OPAL detector at LEP, using approximately 170 pb-1 of e+e- collision data collected at sqrt(s)~189GeV. Searches have been performed for the Standard Model (SM) process e+e- to H0Z0 and the MSSM processes e+e- to H0Z0, A0h0. The searches are sensitive to the b b-bar and tau antitau decay modes of t

The OPAL collaboration, G. Abbiendi

The rate of secondary charm-quark-pair production has been measured in 4.4 million hadronic Z0 decays collected by OPAL. By selecting events with three jets and tagging charmed hadrons in the gluon jet candidate using leptons and charged D* mesons, the average number of secondary charm-quark pairs per hadronic event is found to be (3.20+-0.21+-0.38)x10-2.

V. A. De Lorenci, R. D. M. De Paola, N. F. Svaiter

We analyse the properties of a fluid generating a spinning cosmic string spacetime with flat limiting cases corresponding to a constant angular momentum in the infinite past and static configuration in the infinite future. The spontaneous loss of angular momentum of a spinning cosmic string due to particle emission is discussed. The rate of particle producti

Neven Bilic

Sound wave propagation in a relativistic perfect fluid with a non-homogeneous isentropic flow is studied in terms of acoustic geometry. The sound wave equation turns out to be equivalent to the equation of motion for a massless scalar field propagating in a curved space-time geometry. The geometry is described by the acoustic metric tensor that depends local

Clovis J. de Matos, Robert E. Becker

It is extraordinarely difficult to detect the extremely weak gravitomagnetic (GM) field of even as large a body as the earth. To detect the GM field, the gravitational analog of an ordinary magnetic field, in a modest terrestrial laboratory should be that much more difficult. Here we show, however, that for certain superconductor configuration and topologies

Subir Sachdev, Matthias Vojta

We present a general introduction to the non-zero temperature dynamic and transport properties of low-dimensional systems near a quantum phase transition. Basic results are reviewed in the context of experiments on the spin-ladder compounds, insulating two-dimensional antiferromagnets, and double-layer quantum Hall systems. Recent large N computations on an

M. E. Cates, V. M. Kendon, P. Bladon, J-C. Desplat

Symmetric binary fluids, quenched into a regime of immiscibility, undergo phase separation by spinodal decomposition. In the late stages, the fluids are separated by sharply defined, but curved, interfaces: the resulting Laplace pressure drives fluid flow. Scaling ideas (of Siggia and of Furukawa) predict that, ultimately, this flow should become turbulent a

S. Rouhani, J. Davoudi

Derrida's model can be used for construction and transmission of error correcting codes, in an optimal way. we use the extreme statistics method to derive the optimal signal to noise ratio.

Ganesh Sundaram, Qian Niu

We present a unified theory for wave-packet dynamics of electrons in crystals subject to perturbations varying slowly in space and time. We derive the wave-packet energy up to the first order gradient correction and obtain all kinds of Berry-phase terms for the semiclassical dynamics and the quantization rule. For electromagnetic perturbations, we recover th

Y. Morita, K. Ishibashi, Y. Hatsugai

Transitions between the quantum Hall state and the Anderson insulator are studied in a two dimensional tight binding model with a uniform magnetic field and a random potential. By the string (anyon) gauge, the weak magnetic field regime is explored numerically. The regime is closely related to the continuum model. The change of the Hall conductance and the t

Meesoon Ha, Hyunggyu Park, Marcel den Nijs

We consider a fully asymmetric one-dimensional model with mass-conserving coalescence. Particles of unit mass enter at one edge of the chain and coalescence while performing a biased random walk towards the other edge where they exit. The conserved particle mass acts as a passive scalar in the reaction process $A+A\to A$, and allows an exact mapping to a res

Stephan Roche

Contributions of quantum interference effects occuring in quasicrystals are emphasized. First conversely to metallic systems, quasiperiodic ones are shown to enclose original alterations of their conductive properties while downgrading long range order. Besides, origins of localization mechanisms are outlined within the context of the original metal-insulato

Hagai El-Ad, Tsvi Piran

We present a comparison between the voids in two nearly all sky redshift surveys: the ORS and the IRAS 1.2 Jy. While the galaxies in these surveys are selected differently and their populations are known to be biased relative to each other, the two void distributions are similar. We compare the spatial distribution of the two void populations and demonstrate

Dieter Breitschwerdt, Stefanie Komossa

The development of galactic fountain theories is reviewed with special emphasis on the different approaches and concepts that have been used in the past. In particular the outstanding contribution of Franz Kahn to our physical understanding is appreciated. It is argued that galactic outflows represent an essential phase during galaxy evolution. The dynamics

Arnon Dar, A. De Rújula, Nikos Antoniou

Cosmic ray nuclei, cosmic ray electrons with energy above a few GeV, and the diffuse gamma-ray background radiation (GBR) above a few MeV, presumed to be extragalactic, could all have their origin or residence in our galaxy and its halo. The mechanism accelerating hadrons and electrons is the same, the electron spectrum is modulated by inverse Compton scatte

F. X. Lee, T. Mart, C. Bennhold, H. Haberzettl

Investigations of the quasifree reaction A$(γ, K Y)$B are presented in the distorted wave impulse approximation (DWIA). For this purpose, we present a revised tree-level model of elementary kaon photoproduction that incorporates hadronic form factors consistent with gauge invariance, uses SU(3) values for the Born couplings and uses resonances consistent wit

R. Sasik, Luis M. A. Bettencourt, Salman Habib

We carry out an analytical and numerical study of the motion of an isolated vortex in thermal equilibrium, the vortex being defined as the point singularity of a complex scalar field $ψ(\r,t)$ obeying a nonlinear stochastic Schrödinger equation. Because hydrodynamic fluctuations are included in this description, the dynamical picture of the vortex emerges as

S. Baek, J. -H. Jang, P. Ko, J. H. Park

We show that, on the contrary to the usual claims, fully supersymmetric CP violations in the kaon system are possible through the gluino mediated flavor changing interactions. Both $ε_K$ and ${\rm Re} (ε' / ε_K)$ can be accommodated for relatively large $\tanβ$ without any fine tunings or contradictions to the FCNC and EDM constraints.

Dallas C. Kennedy

A model-independent reconstruction of mechanical profiles (density, pressure) of the solar interior is outlined using the adiabatic sound speed and bouyancy frequency profiles. These can be inferred from helioseismology if both p- and g-mode frequencies are measured. A simulated reconstruction is presented using a solar model bouyancy frequency and available

A. Crisanti, F. Ritort

connected spin-glass models with a discontinuous transition. In the thermodynamic limit the equilibrium properties in the high temperature phase are described by the schematic Mode Coupling Theory of super-cooled liquids. We show that {\it finite-size} fully connected spin-glass models do exhibit properties typical of Lennard-Jones systems when both are near

Yael Shadmi, Yuri Shirman

Supersymmetry is one of the most plausible and theoretically motivated frameworks for extending the Standard Model. However, any supersymmetry in Nature must be a broken symmetry. Dynamical supersymmetry breaking (DSB) is an attractive idea for incorporating supersymmetry into a successful description of Nature. The study of DSB has recently enjoyed dramatic

D. S. Golubev, A. D. Zaikin

We establish an explicit correspondence between perturbative and nonperturbative results in the problem of quantum decoherence in disordered conductors. We demonstrate that the dephasing time $τ_ϕ$ cannot be unambiguously extracted from a perturbative calculation. We show that the effect of the electron-electron interaction on the magnetoconductance is descr

R. J. Fries, B. Müller, A. Schäfer, E. Stein

We calculate the nuclear enhancement in the angular distribution of Drell-Yan pairs produced in proton-nucleus reactions. Nuclear effects are encoded in universal twist-4 parton correlation functions. We find that the Lam-Tung relation for the angular coefficients of the lepton-pair distribution holds for the double-hard, but not for the soft-hard contributi

V. Pasquier

We develop a microscopic formalism to study the fractional quantum Hall plateaus at filling factors $ν$ away from $1/2β$ $β$ an integer. The theory is in terms of quasiparticles which carry a charge $e^{\ast}$ equal to $1-2βν$ times the charge of the electron. The wave functions obtained following our approach are shown to coincide precisely with the form pr

Astrid Lambrecht, Serge Reynaud

We study the influence of finite conductivity of metals on the Casimir effect. We put the emphasis on explicit theoretical evaluations which can help comparing experimental results with theory. The reduction of the Casimir force is evaluated for plane metallic plates. The reduction of the Casimir energy in the same configuration is also calculated. It can be

E. E. Donets, A. Pashnev, J. Juan Rosales, M. M. Tsulaia

The multidimensional N=4 supersymmetric quantum mechanics (SUSY QM) is constructed using the superfield approach. As a result, the component form of the classical and quantum Lagrangian and Hamiltonian is obtained. In the considered SUSY QM both classical and quantum N=4 algebras include central charges, and this opens various possibilities for partial super

Jiannis Pachos, Paolo Zanardi, Mario Rasetti

In the holonomic approach to quantum computation information is encoded in a degenerate eigenspace of a parametric family of Hamiltonians and manipulated by the associated holonomic gates. These are realized in terms of the non-abelian Berry connection and are obtained by driving the control parameters along adiabatic loops. We show how it is possible, for a

Jonatan Kutchinsky, Rafael Taboryski, Claus B. Sorensen, Jorn Bindslev Hansen

We report for the first time enhancement of the supercurrent by means of injection in a mesoscopic three terminal planar SNSNS device made of Al on GaAs. When a current is injected from one of the superconducting Al electrodes at an injection bias $V=Δ(T)/e$, the DC Josephson current between the other two superconducting electrodes has a maximum, giving evid

A. N. Dranishnikov

We establish some basic theorems in dimension theory and absolute extensor theory in the coarse category of metric spaces. Some of the statements in this category can be translated in general topology language by applying the Higson corona functor. The relation of problems and results of this `Asymptotic Topology' to Novikov and similar conjectures is di

Karin Dick, Manfred Lindner, Michael Ratz, David Wright

We describe a "neutrinogenesis" mechanism whereby, in the presence of right-handed neutrinos with sufficiently small pure Dirac masses, (B+L)-violating sphaleron processes create the baryon asymmetry of the Universe, even when B=L=0 initially. It is shown that the resulting neutrino mass constraints are easily fulfilled by the neutrino masses suggest

Richard J. Mathar

The set of Gaussian Type Orbitals g(n1,n2,n3) of order (n+1)(n+2)/2, of common n=n1+n2+n3<=7, common center and exponential, is customized to define a set of 2n+1 linear combinations t(n,m) (-n<=m<=n) such that each t(n,m) depends on the azimuthal and polar angle of the spherical coordinate system like the real or imaginary part of the associated Spherical H

T. Christodoulakis, G. Kofinas, Vasilios Zarikas

A diffuse matter filled Type V Universe is studied. The anisotropic behaviour, the distortion caused to the CMBR and the parameter region allowed by present cosmological bounds are examined. It is shown how the overall sky pattern of temperature anisotropies changes under a non-infinitesimal spatial coordinate transformation that preserves the Type V manifes

Ichi Tanaka, Toru Yamada, Alfonso Aragón-Salamanca, Tadayuki Kodama

We previously reported a significant clustering of red galaxies (R-K=3.5--6) around the radio-loud quasar B2 1335+28 at z=1.086. In this paper, we establish the existence of a rich cluster at the quasar redshift, and study the properties of the cluster galaxies through further detailed analysis of the photometric data. The color distribution of the galaxies

Fu-Guang Cao, A. I. Signal

The sea quark content of the $Σ^+$ baryon is investigated using light-cone baryon-meson fluctuation model suggested by Brodsky and Ma. It is found that the $Σ^+$ sea is flavour asymmetric ($\dbar > \ubar > \sbar$) and quark-antiquark asymmetric ($q \not= \qbar$). Our prediction for the flavour asymmetry, $\dbar > \ubar > \sbar$, is significantly different fr

J. Ambjorn, K. N. Anagnostopoulos, J. Jurkiewicz

We study the coupling of Abelian gauge theories to four-dimensional simplicial quantum gravity. The gauge fields live on dual links. This is the correct formulation if we want to compare the effect of gauge fields on geometry with similar effects studied so far for scalar fields. It shows that gauge fields couple equally weakly to geometry as scalar fields,

Hiromitsu Magira, Y. P. Jing, Yasushi Suto

We examine the cosmological redshift-space distortion effect on the power spectrum of the objects at high-redshifts, which is an unavoidable observational contamination in general relativistic cosmology. In particular, we consider the nonlinear effects of density and velocity evolution using high-resolution N-body simulations in cold dark matter models. We f

C. L. Carilli, K. M. Menten, M. S. Yun, F. Bertoldi

We discuss various aspects of centimeter and millimeter wavelength continuum and line observations of high redshift star forming galaxies. Perhaps the most important lesson is that sensitive observations at submm through cm wavelengths reveal a population of active star forming galaxies at high redshift which are unseen in deep optical surveys due to dust ob

Chuan-Wei Zhang, Zi-Yang Wang, Chuan-Feng Li, Guang-Can Guo

Probabilistic quantum cloning and identifying machines can be constructed via unitary-reduction processes [Duan and Guo, Phys. Rev. Lett. 80, 4999 (1998)]. Given the cloning (identifying) probabilities, we derive an explicit representation of the unitary evolution and corresponding Hamiltonian to realize probabilistic cloning (identification). The logic netw

A. J. Roberts

We solve Poisson's equation using new multigrid algorithms that converge rapidly. The novel feature of the 2D and 3D algorithms are the use of extra diagonal grids in the multigrid hierarchy for a much richer and effective communication between the levels of the multigrid. Numerical experiments solving Poisson's equation in the unit square and unit cube show

Oliver Cohen

An exploratory approach to the possibility of analyzing nonorthogonality as a quantifiable property is presented. Three different measures for the nonorthogonality of pure states are introduced, and one of these measures is extended to single-particle density matrices using methods that are similar to recently introduced techniques for quantifying entangleme

Oliver Cohen

It is shown that the outcomes of measurements on systems in separable mixed states can be partitioned, via subsequent measurements on a disentangled extraneous system, into subensembles that display the statistics of entangled states. This motivates the introduction of the concept of &#34;counterfactual&#34; entanglement, which can be associated with all sep

G. Alber

The main aim of this article is to discuss characteristic physical phenomena which govern the destruction of quantum coherence of material wave packets.

O. Zobay, G. Alber

The interaction of a weakly bound Rydberg electron with an electromagnetic half-cycle pulse (HCP) is described with the help of a multidimensional semiclassical treatment. This approach relates the quantum evolution of the electron to its underlying classical dynamics. The method is nonperturbative and is valid for arbitrary spatial and temporal shapes of th

G. Alber, O. Zobay

A multi-dimensional semiclassical description of excitation of a Rydberg electron by half-cycle pulses is developed and applied to the study of energy- and angle-resolved ionization spectra. Characteristic novel phenomena observable in these spectra such as interference oscillations and semiclassical glory and rainbow scattering are discussed and related to

G. Alber

Optimal universal entanglement processes are discussed which entangle two quantum systems in an optimal way for all possible initial states. It is demonstrated that the linear character of quantum theory which enforces the peaceful coexistence of quantum mechanics and relativity imposes severe restrictions on the structure of the resulting optimally entangle

Stefan Weigert

The expectation values of a hermitean operator A in (2s+1)(2s+1) specific coherent states of a spin are known to determine the operator unambiguously. As shown here, (almost) any other (2s+1)(2s+1) coherent states also provide a basis for self-adjoint operators. This is proven by considering the determinant of the Gram matrix associated with the coherent sta

Walter T. Strunz, Lajos Diosi, Nicolas Gisin, Ting Yu

We present the stochastic Schroedinger equation for the dynamics of a quantum particle coupled to a high temperature environment and apply it the dynamics of a driven, damped, nonlinear quantum oscillator. Apart from an initial slip on the environmental memory time scale, in the mean, our result recovers the solution of the known non-Lindblad quantum Brownia

A. V. Burlakov, M. V. Chekhova, O. A. Karabutova, D. N. Klyshko

Polarization state of biphoton light generated via collinear frequency-degenerate spontaneous parametric down-conversion is considered. A biphoton is described by a three-component polarization vector, its arbitrary transformations relating to the SU(3) group. A subset of such transformations, available with retardation plates, is realized experimentally. In

Rolf Tarrach, Guifre Vidal

We present optimal and minimal measurements on identical copies of an unknown state of a qubit when the quality of measuring strategies is quantified with the gain of information (Kullback of probability distributions). We also show that the maximal gain of information occurs, among isotropic priors, when the state is known to be pure. Universality of optima

Alexander Yu. Vlasov

Clifford algebras are used for definition of spinors. Because of using spin-1/2 systems as an adequate model of quantum bit, a relation of the algebras with quantum information science has physical reasons. But there are simple mathematical properties of the algebras those also justifies such applications. First, any complex Clifford algebra with 2n generato

Joachim Brand, Lorenz S. Cederbaum, Hans-Dieter Meyer

We derive a rigorous optical potential for electron-molecule scattering including the effects of nuclear dynamics by extending the common many-body Green&#39;s function approach to optical potentials beyond the fixed-nuclei limit for molecular targets. Our formalism treats the projectile electron and the nuclear motion of the target molecule on the same foot

R. Gallego, M. San Miguel, R. Toral

We study domain growth in a nonlinear optical system useful to explore different scenarios that might occur in systems which do not relax to thermodynamic equilibrium. Domains correspond to equivalent states of different circular polarization of light. We describe three dynamical regimes: a coarsening regime in which dynamical scaling holds with a growth law

A. O. Macchiavelli, P. Fallon, R. M. Clark, M. Cromaz

The binding energies of even-even and odd-odd N=Z nuclei are compared. After correcting for the symmetry energy we find that the lowest T=1 state in odd-odd N=Z nuclei is as bound as the ground state in the neighboring even-even nucleus, thus providing evidence for isovector np pairing. However, T=0 states in odd-odd N=Z nuclei are several MeV less bound tha

J. C. R. Bloch, C. D. Roberts, S. M. Schmidt, A. Bender

Nucleon form factors are calculated on q^2 in [0,3] GeV^2 using an Ansatz for the nucleon&#39;s Fadde&#39;ev amplitude motivated by quark-diquark solutions of the relativistic Fadde&#39;ev equation. Only the scalar diquark is retained, and it and the quark are confined. A good description of the data requires a nonpointlike diquark correlation with an electr

C. Ernst, S. A. Bass, S. Soff, H. Stöcker

Dilepton spectra are calculated within the microscopic transport model UrQMD and compared to data from the CERES experiment. The invariant mass spectra in the region 300 MeV < M < 600 MeV depend strongly on the mass dependence of the $ρ$ meson decay width which is not sufficiently determined by the Vector Meson Dominance model. A consistent explanation of bo

A. S. Rinat

We discuss applications of previously computed nuclear structure functions (SF) to inclusive cross sections, compare predictions with recent CEBAF data and perform two scaling tests. We mention that the large $Q^2$ plateau of scaling functions may only in part be due to the asymptotic limit of SF, which prevents the extraction of the nucleon momentum distrib

V. A. Plujko

A closed-form thermodynamic pole approach,TPA, is developed for average description of the E1 radiative strength functions using the microcanonical ensemble for initial states. A semiclassical description of the collective excitation damping in this method is based on modern physical notion on the relaxation processes in Fermi systems.The TPA model gives rat

T. Lefort, D. Dore, D. Cussol, Y. G. Ma

Intermediate velocity products in Ar+Ni collisions from 52 to 95 A.MeV are studied in an experiment performed at the GANIL facility with the 4$π$ multidetector INDRA. It is shown that these emissions cannot be explained by statistical decays of the quasi-projectile and the quasi-target in complete equilibrium. Three methods are used to isolate and characteri

F. Rambo, P. Achenbach, J. Ahrens, H. -J. Arends

Differential cross sections and beam asymmetries for coherent π^\circ photoproduction from ^4He in the Δenergy-range have been measured with high statistical and systematic precisions using both decay photons for identifying the process.The experiment was performed at the MAinz MIcrotron using the TAPS photon spectrometer and the Glasgow/Mainz tagged photon

A. J. Macfarlane, H. Pfeiffer

Two approaches are developed to exploit, for simple complex or compact real Lie algebras g, the information that stems from the characteristic equations of representation matrices and Casimir operators. These approaches are selected so as to be viable not only for `small&#39; Lie algebras and suitable for treatment by computer algebra. A very large body of n

Daniel Allcock

We define the braid groups of a two-dimensional orbifold and introduce conventions for drawing braid pictures. We use these to realize the Artin groups associated to the spherical Coxeter diagrams A_n, B_n=C_n and D_n and the affine diagrams tilde{A}_n, tilde{B}_n, tilde{C}_n and tilde{D}_n as subgroups of the braid groups of various simple orbifolds. The ca

Daniel Allcock

We consider the automorphism groups of various Lorentzian lattices over the Eisenstein, Gaussian, and Hurwitz integers, and in some of them we find reflection groups of finite index. These provide new finite-covolume reflection groups acting on complex and quaternionic hyperbolic spaces. Specifically, we provide groups acting on CH^n for all n<6 and n=7, and

X. Gual-Arnau, J. J. Nuno-Ballesteros

We give a stereological version of the Gauss-Bonnet formula in order to compute the Euler characteristic of a domain with boundary in a smooth orientable surface in R^3, by looking at contacts with a &#34;sweeping&#34; plane.

James Conant

In this article it is proven that if a knot, K, bounds an imbedded grope of class n, then the knot is n/2-trivial in the sense of Gusarov and Stanford. That is, all type n/2 invariants vanish on K. We also give a simple way to construct all knots bounding a grope of a given class. It is further shown that this result is optimal in the sense that for any n th

Daniel Allcock

We study branched covering spaces in several contexts, proving that under suitable circumstances the cover satisfies the same upper curvature bounds as the base space. The first context is of a branched cover of an arbitrary metric space that satisfies Alexandrov&#39;s curvature condition CAT(k), over an arbitrary complete convex subset. The second context i

Goro Hatayama, Atsuo Kuniba, Masato Okado, Taichiro Takagi

Fermionic formulae originate in the Bethe ansatz in solvable lattice models. They are specific expressions of some q-polynomials as sums of products of q-binomial coefficients. We consider the fermionic formulae associated with general non-twisted quantum affine algebra U_q(X^{(1)}_n) and discuss several aspects related to representation theories and combina

Yurii A. Sitenko

We show that the vacuum of the quantized massless spinor field in 2+1-dimensional space-time is polarized in the presence of a singular magnetic vortex. Depending on the choice of the boundary condition at the location of the vortex, either chiral symmetry or parity is broken; the formation of the appropriate vacuum condensates is comprehensively studied. In

G. Roepstorff

The mathematical framework of superbundles suggests that one considers the Higgs field as a natural constituent of a superconnection. I propose to take as superbundle the exterior algebra obtained from a Hermitian vector bundle of rank 5 for the Standard Model.

Y. S. Kim

The two-by-two representation of the SL(2,c) group is for spin-1/2 particles. Starting from this two-by-two representation, it is possible to construct the four-by-four matrices for spin-1 particles. For massless particles, it is possible to construct four-potentials from two-component SL(2,c) spinors. Four potentials are subject to gauge transformations and

Vipul Periwal

Marchesini showed that the Fokker-Planck Hamiltonian for Yang-Mills theories is the loop operator. Jevicki and Rodrigues showed that the Fokker-Planck Hamiltonian of some matrix models co\&#34;ıncides with temporal gauge non-critical string field theory Hamiltonians constructed by Ishibashi and Kawai (and their collaborators). Thus the loop operator for Yang

E. Gabrielli, V. A. Ilyin, B. Mele

We study the bounds on the anomalous contributions to the gamma-gamma-H and Z-gamma-H vertices that can be obtained via the process e-gamma-->e H. We consider the representative case of an intermediate Higgs mass production of MH=120 GeV and for a center of mass energy of Sqrt{S}=500 GeV and Sqrt{S}=1500 GeV. We use a model independent analysis based on SU(2

Gary R. Goldstein

A hybrid model is presented for hadron polarization that is based on perturbative QCD subprocesses and the recombination of polarized quarks to form polarized hadrons. The model, originally applied to polarized $Λ$&#39;s that were inclusively produced by proton beams, is extended to include pion beams and polarized $Λ_c$&#39;s. The resulting polarizations ar

Stephen Godfrey, Pat Kalyniak, Basim Kamal, Arnd Leike

We examine the sensitivity of the process e+e- -> nu nubar + gamma to additional W-like bosons which arise in various models. The process is found to be sensitive to W&#39; masses up to several TeV.

S. Kabana, P. Minkowski

We elaborate on the hypothesis that in high energy hadron hadron and nucleus nucleus collisions the lowest mass glueballs are copiously produced from the gluon rich environment especially at high energy density. We discuss the particular glueball decay modes: $0^{++}, 2^{++} \to K \bar{K}$ and $0^{++} \to π^{+} π^{-} \ell^{+} \ell^{-}$.

B. Badelek, J. Kiryluk, J. Kwiecinski

Theoretical description of the spin dependent structure function g_1(x,Q^2) in the region of low values of x and Q^2 is presented. It contains the Vector Meson Dominance contribution and the QCD improved parton model suitably extended to the low Q^2 domain. Theoretical predictions are compared with the recent experimental data in the low x, low Q^2 region.

M. Diehl

I review recent theory developments for hard exclusive and semi-exclusive production of mesons, emphasising the variety of physics issues that can be studied in these processes.

M. Martinis, V. Mikuta-Martinis, J. Črnugelj

The leading-particle effect and the factorization property of the scattering amplitude in the impact parameter space are used to study semiclassical production of pions in the central region. The mechanism is related to the isospin-uniform solution of the nonlinear $ σ$-model coupled to quark degrees of freedom. The multipion exchange potential between two q

Don Colladay

One possible ramification of unified theories of nature such as string theory that may underlie the conventional standard model is the possible spontaneous breakdown of Lorentz and CPT symmetry. In this talk, the formalism for inclusion of such effects into a low-energy effective field theory is presented. An extension of the standard model that includes Lor

R. A. Alanakyan, L. A. Manukyan

In this paper we consider bound states and resonances of the particles with identical charge in the presence of the strong magnetic field.

R. Alkofer, S. Ahlig, C. Fischer, M. Oettel

We treat baryons as bound states of scalar or axialvector diquarks and a constituent quark which interact through quark exchange. We obtain fully four-dimensional wave functions for both octet and decuplet baryons as solutions of the corresponding Bethe-Salpeter equation. Applications currently under investigation are: electromagnetic and strong form factors

P. N. Pandita, P. Francis Paulraj

We study the renormalization group evolution and the infra-red stable fixed points of the Yukawa couplings of the non-minimal supersymmetric standard model (NMSSM) with R-parity violation. Retaining only the R-parity violating couplings of higher generations, we analytically study the solutions of the renormalization group equations of all the couplings of t

T. Asaka, K. Hamaguchi, M. Kawasaki, T. Yanagida

We investigate the leptogenesis via decays of heavy Majorana neutrinos which are produced non-thermally in inflaton decays. We make a comprehensive study on the leptogenesis assuming various supersymmetric (SUSY) models for hybrid, new and topological inflations. For an estimation of the lepton asymmetry we adopt the Froggatt-Nielsen mechanism for mass matri

A. Benslama, N. Mebarki

We reformulate the left-right gauge model of Pati-Mohapatra in the framework of nonassociative geometry. At the tree level we obtain the same mixing angles as the ones predicted by SO(10) GUT. However the model does not show the parity breakdown.

A. Di Giacomo

The guiding lines of lattice investigations on colour confinement are reviewed, together with recent results.