October 1996 arXiv papers — page 13

T. Banks, W. Fischler, S. H. Shenker, L. Susskind

We suggest and motivate a precise equivalence between uncompactified eleven dimensional M-theory and the N = infinity limit of the supersymmetric matrix quantum mechanics describing D0-branes. The evidence for the conjecture consists of several correspondences between the two theories. As a consequence of supersymmetry the simple matrix model is rich enough

G. Müller, Ulf-G. Meißner

The complete renormalization of the generating functional for Green functions of quark currents between one--baryon states in three flavor heavy baryon chiral perturbation theory is performed to order q^3. As an example, we study the kaon loop induced divergences in neutral pion photoproduction off protons.

J. Bijnens, P. Talavera

Within Chiral Perturbation Theory (CHPT) we compute the form factors A, V and $γ= A/V$ in the $π\to νl γ$ decay to $O(p^6)$. A and $γ$ obtain corrections of order 25%.

Francois David

The c<1 and c>1 matrix models are analyzed within large N renormalization group, taking into account touching (or branching) interactions. The c<1 modified matrix model with string exponent gamma>0 is naturally associated with an unstable fixed point, separating the Liouville phase (gamma<0) from the branched polymer phase (gamma=1/2). It is argued that at c

B. A. Kniehl, G. Kramer, M. Spira

The cross section for the inclusive photoproduction of large-p_T D^*+- mesons is calculated at next-to-leading order, adopting different approaches to describe the fragmentation of charm quarks into D^*+- mesons. We treat the charm quark according to the massless factorization scheme, where it is assumed to be one of the active flavours inside the proton and

Mogens H. Jensen, Poul Olesen

We introduce a shell (``GOY&#39;&#39;) model for turbulent binary fluids. The variation in the concentration between the two fluids acts as an active scalar leading to a redefined conservation law for the energy, which is incorporated into the model together with a conservation law for the scalar. The model is studied numerically at very high values of the P

D. R. Karakhanyan

A new method for integrating anomalous Ward identities and finding the effective action is proposed. Two-dimensional supergravity and $W_3$-gravity are used as examples to demonstrate its potential. An operator is introduced that associates each physical quantity with a Ward identity, i.e., a quantity that is transformed without anomalous terms and can be nu

J. Hwang

A coherently oscillating scalar field, an axion as an example, is known to behave as a cold dark matter. The arguments were usually made in the Newtonian context. Ratra proved the case in relativistic context using the synchronous gauge. In this paper we present another proof based on a more suitable gauge choice, the uniform-curvature gauge, which fits the

W-S. Chung

In this paper we used the finite Fourier transformation to obtain the polar decomposition of the q-deformed boson algebra with $q$ a root of unity.

David Montgomery, Jason W. Bates, Shuojun Li

Resistive steady states in toroidal magnetohydrodynamics (MHD), where Ohm&#39;s law must be taken into account, differ considerably from ideal ones. Only for special (and probably unphysical) resistivity profiles can the Lorentz force, in the static force-balance equation, be expressed as the gradient of a scalar and thus cancel the gradient of a scalar pres

David Montgomery, Jason W. Bates, H. Ralph Lewis

It was recently demonstrated that static, resistive, magnetohydrodynamic equilibria, in the presence of spatially-uniform electrical conductivity, do not exist in a torus under a standard set of assumed symmetries and boundary conditions. The difficulty, which goes away in the ``periodic straight cylinder approximation,&#39;&#39; is associated with the neces

A. M. Bernstein, E. Shuster, R. Beck, M. Fuchs

A rigorous multipole analysis of the recent γp -> π^{0}p cross section measurement is presented. The data were taken using the photon spectrometer TAPS at the tagged photon beam of the Mainz microtron. The s and p wave multipoles were extracted using minimal model assumptions. The predicted unitary cusp for the s wave multipole E_{0+} due to the two step γp

Denny H. Leung

Let $\Ps(\N)$ be the set of all finite subsets of $\N$, endowed with the product topology. A description of the compact subsets of $\Ps(\N)$ is given. Two applications of this result to Banach space theory are shown : (1) a characterization of the symmetric sequence spaces which embed into $C(\om^\om)$, and (2) a characterization, in terms of the Orlicz func

Nigel J. Kalton, A. Pelczynski

If $Q$ is a surjection from $L^1(μ)$, $μ$ $σ$-finite, onto a Banach space containing $c_0$ then (*) $\ker Q$ is uncomplemented in its second dual. If $Q$ is a surjection from an ${\cal L}_1$-space onto a Banach space containing uniformly $\ell_n^\infty$ ($n=1,2,\dots$) then (**) there exists a bounded linear operator from $\ker Q$ into a Hilbert space which

Peter G. Casazza, Nigel J. Kalton

We prove a general result on complemented unconditional basic sequences in Banach lattices and apply it to give some new examples of spaces with unique unconditional basis. We show that Tsirelson space and certain Nakano spaces have the unique unconditional bases. We also construct an example of a space with a unique unconditional basis with a complemented s

Greg Hjorth

Becker and Kechris showed that if a Polish group G acts continuously on a Polish space X, then for any invariant Borel set B we can change the topology on X so that B becomes open, the Borel structure is preserved, and the action continues to be continuous. In this brief paper a short proof is presented for their theorem. The method also gives optimal bounds

Prem P. Srivastava

Some basic topics in Light-Front (LF) quantized field theory are reviewed. Poincarè algebra and the LF Spin operator are discussed. The local scalar field theory of the conventional framework is shown to correspond to a non-local Hamiltonian theory on the LF in view of the constraint equations on the phase space, which relate the bosonic condensates to the n

Chien-Hao Liu

Two topological issues on membranes in M-theory are studied: (1) Soliton is an important subject in M-theory. Under the framework of obstruction theory with the help from framed links in $S^3$, we give a complete enumeration of topological membrane solitons in a string-admissible target-space of the form a product of Minkowskian space-times, tori, and K3-sur

Michael R. Douglas

We give a broad overview of superstring duality, Dirichlet branes, and some implications of both for questions about the structure of space-time at short distances.

Jose Gaite

We consider relative entropy in Field Theory as a well defined (non-divergent) quantity of interest. We establish a monotonicity property with respect to the couplings in the theory. As a consequence, the relative entropy in a field theory with a hierarchy of renormalization group fixed points ranks the fixed points in decreasing order of criticality. We arg

A. Zabrodin

The recent progress in revealing classical integrable structures in quantum models solved by Bethe ansatz is reviewed. Fusion relations for eigenvalues of quantum transfer matrices can be written in the form of classical Hirota&#39;s bilinear difference equation. This equation is also known as the completely discretized version of the 2D Toda lattice. We exp

Dmitrij Sorokin, Francesco Toppan

We show that a Hamiltonian reduction of affine Lie superalgebras having bosonic simple roots (such as $OSp(1|4)$) ``does&#39;&#39; produce supersymmetric Toda models, with superconformal symmetry being nonlinearly realised for those fields of the Toda system which are related to the bosonic simple roots of the superalgebra. A fermionic $b-c$ system of confor

M. V. Libanov

Threshold amplitudes are considered for $n$-particle production in arbitrary scalar theory. It is found that, like in $ϕ^4$, leading-$n$ corrections to the tree level amplitudes, being summed over all loops, exponentiate. This result provides more evidence in favor of the conjecture on the exponential behavior of the multiparticle amplitudes.

F. Lizzi, G. Mangano, G. Miele, G. Sparano

In this paper we study the structure of the Hilbert space for the recent noncommutative geometry models of gauge theories. We point out the presence of unphysical degrees of freedom similar to the ones appearing in lattice gauge theories (fermion doubling). We investigate the possibility of projecting out these states at the various levels in the constructio

S. P. Brumby, G. C. Joshi

We present some striking global consequences of a model quaternionic quantum field theory which is locally complex. We show how making the quaternionic structure a dynamical quantity naturally leads to the prediction of cosmic strings and non-baryonic hot dark matter candidates.

Enrique Alvarez, Yuri Kubyshin

It is well known that under T-duality the sigma model dilaton (which is normally thought to be related to the string coupling constant through the simple formula $κ= exp <ϕ>$), undergoes an additive shift. On the other hand, Kugo and Zwiebach, using a simplified form of string field theory, claim that the string coupling constant does not change under the T-

H. W. Lee, Y. S. Myung, Jin Young Kim, D. K. Park

We investigate the five and six-dimensional black strings within Einstein-Maxwell theory. The extremal black strings are endowed with the null Killing symmetry. We study the propagation of Einstein-Maxwell modes in the extremal black string background by using this symmetry. It turns out that one graviton is a propagating mode, while both the Maxwell $F$ and

A. Schenk

In this article we provide a manifestly gauge-invariant approach to charged particles. It involves (1) Green functions of gauge-invariant operators and (2) Feynman rules which do not depend on any kind of gauge-fixing condition. First, we provide a thorough analysis of QED. We propose a specific set of gauge-invariant Green functions and describe a manifestl

Richard J. Gonsalves, C. F. Wai

In the Standard Model the process $q\bar{q}\rightarrow q\bar{q}V$ (where $V=W^\pm,Z^0$ or $γ$) can occur via gluon exchange and also via $W^\pm$ or $Z^0$ exchange. The corresponding chromodynamic and electroweak amplitudes can interfere with one another. These interference cross sections are largest when the exchanged $W^\pm$ or $Z^0$ is on-shell when they a

Nathan Isgur

Some emerging difficulties in the theoretical description of exclusive semileptonic $\bar B$ decays are discussed in the context of the quark model. While there are no unambiguous problems at this time, I discuss physics beyond the valence quark model which should eventually be probed by precision measurements of $\bar B$ semileptonic decays.

L. N. Lipatov

We review the parton model and the Regge approach to the QCD description of the deep-inelastic $ep$ scattering at the small Bjorken variable $x$ and demonstrate their relation with the DGLAP and BFKL evolution equations. It is shown, that in the leading logarithmic approximation the gluon is reggeized and the pomeron is a compound state of two reggeized gluo

L. Frankfurt, A. V. Radyushkin, M. Strikman

We calculate in QCD the cross section for the scattering of an energetic small-size wave packet off a hadron target. We use our results to study the small-$σ$ behaviour of $P_π(σ)$, the distribution over cross section for the pion, in the leading $α_{s}$-order.

Kurt Riesselmann

This lecture reviews various Higgs-sector amplitudes which have been calculated to two loops in the Higgs quartic coupling. After explaining the framework of these calculatins, the perturbative behaviour of the amplitudes is discussed, and perturbative upper bounds on the Higgs boson mass are given.

Thomas Hambye, Kurt Riesselmann

Matching conditions relate couplings to particle masses. We discuss the importance of one-loop matching conditions in Higgs and top-quark sector as well as the choice of the matching scale. We argue for matching scales $μ_{0,t} \simeq m_t$ and $μ_{0,H} \simeq max[ m_t, M_H ]$. Using these results, the two-loop Higgs mass upper bounds are reanalyzed. Previous

A. Dedes, A. B. Lahanas, J. Rizos, K. Tamvakis

We make a complete analysis of radiative symmetry breaking in the MSSM and its $SU(5)$ extensions including low- and high-energy threshold effects in the framework of the two-loop renormalization group. In particular, we consider minimal $SU(5)$, the ``missing-doublet&#39;&#39; $SU(5)$, a Peccei-Quinn invariant version of $SU(5)$ as well as a version with li

Paul Hoyer

I propose that the properties of QCD perturbation theory should be investigated when the boundary state (`perturbative vacuum&#39;) at $t= \pm\infty$ includes gluons. Any boundary state that has an overlap with the true QCD ground state generates a perturbative series that (when summed to all orders) is formally exact. Through an analogy with the boundary co

Stefano Forte, Richard D. Ball

We review recent HERA data on the structure function F_2 at small x and large Q^2. We show that the salient features of the data are revealed by comparing them to the double asymptotic scaling behaviour which F_2 is predicted to satisfy in perturbative QCD.

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.

J. Bolz, P. Kroll, G. A. Schuler

We investigate the theoretical uncertainties of $P$-wave charmonium decays into two pions, $χ_{\c J}\rightarrow π^+π^-$, $π^0π^0$. Constraining the pion distribution-amplitude from the recent precise data on $F_{πγ}(Q^2)$, we find an order-of-magnitude discrepancy between data and prediction. The disagreement persists even after inclusion of transverse degre

Jihn E. Kim

We report that the hypothesis that the upper bound on the axion decay constant can be moved up beyond $10^{12}$ GeV in models with a stronger QCD in the early universe is not realized. This proof is possible by studying the superpotential in the dual model and obtaining the form of the axion potential respecting the original global symmetries.

Igor F. Herbut

A recently proposed form of dual theory for the three dimensional superconductor is rederived starting from the lattice electrodynamics and studied by renormalization group. The superfluid density below and close to the transition vanishes as inverse of the correlation length of the disorder field. The corresponding universal amplitude is given by the fixed

Cristian Rojas, Jorge V. José

We present results from an extensive analytic and numerical study of a two-dimensional model of a square array of ultrasmall Josephson junctions. We include the ultrasmall self and mutual capacitances of the junctions, for the same parameter ranges as those produced in the experiments. The model Hamiltonian studied includes the Josephson, $E_J$, as well as t

Haranath Ghosh, S. N. Behera, S. K. Ghatak, D. K. Ray

The interplay between the band Jahn-Teller distortion and the superconductivity is studied for the system whose Fermi level lies in two-fold degenerate band. Assuming that the lattice distortion is coupled to the orbital electron density and the superconductivity arises due to BCS pairing mechanism between the electrons, the phase diagram is obtained for dif

Peter D. Olmsted, F. C. MacKintosh

We study the mechanism of the `pearling&#39; instability seen recently in experiments on lipid tubules under a local applied laser intensity. We argue that the correct boundary conditions are fixed chemical potentials, or surface tensions Σ, at the laser spot and the reservoir in contact with the tubule. We support this with a microscopic picture which inclu

V. Fiorentini, M. Methfessel

The formation energy of a solid surface can be extracted from slab calculations if the bulk energy per atom is known. It has been pointed out previously that the resulting surface energy will diverge with slab thickness if the bulk energy is in error, in the context of calculations which used different methods to study the bulk and slab systems. We show here

V. Fiorentini, F. Bernardini, A. Bosin, D. Vanderbilt

Impurity levels and formation energies of acceptors in wurtzite GaN are predicted ab initio. Be_Ga is found to be the shallow (thermal ionization energy $\sim$ 0.06 eV); $Mg_{Ga}$ and $Zn_{Ga}$ are mid-deep acceptors (0.23 eV and 0.33 eV respectively); $Ca_{Ga}$ and $Cd_{Ga}$ are deep acceptors ($\sim$0.65 eV); $Si_N$ is a midgap trap with high formation ene

Fabio Bernardini, Vincenzo Fiorentini, R. M. Nieminen

Zn in GaN forms an efficient radiative center and acts as a deep acceptor which can make the crystal insulating. Four different Zn-related centers have been by now identified, leading to light emission in the range between 1.8 eV and 2.9 eV. We present a first-principles investigation total energy and electronic structure calculations for Ga-substitutional a

Lothar Spies, Walter Apel, Bernhard Kramer

We derive an exact result for the averaged Feynman propagator and the corresponding density of states of an electron in two dimensions in a perpendicular homogeneous magnetic field and a Gaussian random potential with long-range spatial correlations described by a quadratic correlation function.

Alex Levine, Sriram Ramaswamy, Robijn Bruinsma

A nonlinear two-fluid stochastic hydrodynamical description of velocity and concentration fluctuations in sedimenting suspensions is constructed, and analyzed using self-consistent (SC) and renormalization group (RG) methods. The advection of particles by velocity fluctuations is shown to be ``relevant&#39;&#39; in all dimensions $d < 6$ . Both RG and SC ana

W. Apel, Yu. A. Bychkov

We study interacting electrons in two dimensions moving in the lowest Landau level under the condition that the Zeeman energy is much smaller than the Coulomb energy and the filling factor is one. In this case, Skyrmion quasiparticles play an important role. Here, we present a simple and transparent derivation of the corresponding effective Lagrangian. In it

Hemant Bokil, Onuttom Narayan

We study the problem of flux penetration into type--I superconductors with high demagnetization factor (slab geometry).Assuming that the interface between the normal and superconducting regions is sharp, that flux diffuses rapidly in the normal regions, and that thermal effects are negligible, we analyze the process by which flux invades the sample as the ap

Kazuhiko Kuroki, Takashi Kimura, Hideo Aoki

An extensive Quantum Monte Carlo calculation is performed for the two-leg Hubbard ladder model to clarify whether the singlet pairing correlation decays slowly, which is predicted from the weak-coupling theory but controversial from numerical studies. Our result suggests that the discreteness of energy levels in finite systems affects the correlation enormou

Hans Henrik Rugh

We consider real-analytic maps of the interval $I=[0,1]$ which are expanding everywhere except for a neutral fixed point at 0. We show that on a certain function space the spectrum of the associated Perron-Frobenius operator ${\cal M}$ has a decomposition $Sp ({\cal M}) = σ_c \cup σ_p$ where $σ_c=[0,1]$ is the continuous spectrum of ${\cal M}$ and $σ_p$ is t

A. J. Connolly, A. S. Szalay, D. C. Koo, A. K. Romer

We present strong evidence for the existence of a supercluster at a redshift of z=0.54 in the direction of Selected Area 68. From the distribution of galaxies with spectroscopic redshifts we find that there is a large over-density of galaxies (a factor of four over the number expected in an unclustered universe) within the redshift range 0.530 < z < 0.555. B

Claudio Firmani, Vladimir Avila-Reese, Xavier Hernández

The formation and evolution of disk galaxies in the cosmological context is studied. We consider the observable properties of disk galaxies and treat the disk formation and galactic evolutionary processes in a self-consistent fashion. We find the matter accretion regime to be the dominant ingredient in establishing the Hubble sequence. The accretion regime i

Vladimir Avila-Reese, Claudio Firmani

The spherical gravitational collapse and virialization of arbitrary density fluctuations in an expanding universe is studied. In the context of the standard cosmological model and the peak $ansatz$, disk galaxies are supposed to be the product of &#34;extended&#34; gravitational collapses of regions surrounding local-maxima of the density fluctuation field.

Steven Weinberg

This is a talk given at the conference ``Critical Dialogues in Cosmology&#39;&#39; at Princeton University, June 24-- 27, 1996. It gives a brief summary of our present theoretical understanding regarding the value of the cosmological constant, and describes how to calculate the probability distribution of the observed cosmological constant in cosmological th

Gerard A. Kriss

Observations of the C IV and Mg II absorption lines in the Seyfert 1 galaxy NGC 4151 obtained with the GHRS in October 1994 are presented. The data from the STScI archive show multiple broad and narrow components in both species. In addition to Galactic absorption, four narrow and four broad systems associated with NGC 4151 are identified. Two broad systems

G. Bonelli, M. Matone, M. Tonin

The recently rigorously proved nonperturbative relation between u and the prepotential, underlying N=2 SYM with gauge group SU(2), implies both the reflection symmetry $\overline{u(τ)}=u(-\barτ)$ and $u(τ+1)=-u(τ)$ which hold exactly. The relation also implies that $τ$ is the inverse of the uniformizing coordinate u of the moduli space of quantum vacua. In t

Simon C. Benjamin, Neil F. Johnson

We present a simple one-dimensional Cellular Automaton (CA) which has the property that an initial state composed of two binary numbers evolves quickly into a final state which is their sum. We call this CA the Adding Cellular Automaton (ACA). The ACA requires only 2N two-state cells in order to add any two N-1 bit binary numbers. The ACA could be directly r

B. Brent Gordon, Jacob P. Murre

The main result of this paper is the proof for elliptic modular threefolds of conjectures on the existence and structure of a filtration on the Chow groups of smooth projective varieties. In the form we prove them these conjectures were formulated by the second-named author, but as Jannsen has shown, these conjectures are equivalent to a conjecture of Beilin

Erik Sjoeqvist, Henrik Carlsen, Harvey R. Brown

It is shown that geometric phase in non-relativistic quantum mechanics is not Galilean invariant.

MUH collaboration, M. C. Fujiwara, G. A. Beer, J. L. Beveridge

A method is reported for measuring the thickness and uniformity of thin films of solidified gas targets. The energy of alpha particles traversing the film is measured and the energy loss is converted to thickness using the stopping power. The uniformity is determined by measuring the thickness at different positions with an array of sources. Monte Carlo simu

Paul Sutcliffe

We study charge k SU(2) BPS monopoles which are symmetric under the cyclic group of order k. Approximate twistor data (spectral curves and Nahm data) is constructed using a new technique based upon a Painleve analysis of Nahm&#39;s equation around a pole. With this data both analytical and numerical approximate ADHMN constructions are performed to study the

I. Ya. Aref&#39;eva

A modified interaction representation for the master field describing connected $SU(N)$-invariant Wightman&#39;s functions in the large $N$ limit of matrix fields is constructed. This construction is based on the representation of the master field in terms of Boltzmannian field theory found before. In the modified interaction representation we deal with two

E. K. G. Sarkisyan, L. K. Gelovani, G. L. Gogiberidze

Fractal structure of charged particle distributions in the pseudorapidity and transverse momentum in central C-Cu collisions at 4.5A GeV/c is studied by means of intermittency approach and multifractal analysis. The modifications to take into account statistical bias are applied. Intermittency study in the pseudorapidity phase space indicates a non-thermal p

G. Amelino-Camelia

The investigation of symmetry nonrestoration scenarios has led to a controversy, with certain nonperturbative approximation schemes giving indications in sharp disagreement with those found within conventional perturbation theory. A Rayleigh-Ritz variational approach to the problem, which might be useful in bridging the gap between perturbative and nonpertur

D. Fasching

A fast numerical algorithm for the evolution of parton distributions in x space is described. The method is close in spirit to `brute&#39; force techniques. The necessary integrals are performed by summing the approximate contributions from small steps of the integration region. Because it is a numerical evaluation it shares the advantage with brute force nu

Bruce Kleiner, Bernhard Leeb

We determine the structure of finitely generated groups which are quasi-isometric to symmetric spaces of noncompact type, allowing Euclidean de Rham factors If $X$ is a symmetric space of noncompact type with no Euclidean de Rham factor, and $\Ga$ is a finitely generated group quasi-isometric to the product $\E^k\times X$, then there is an exact sequence $1\

Matthew P. A. Fisher, Leonid I. Glazman

In this paper we review recent theoretical results for transport in a one-dimensional (1d) Luttinger liquid. For simplicity, we ignore electron spin, and focus exclusively on the case of a single-mode. Moreover, we consider only the effects of a single (or perhaps several) spatially localized impurities. Even with these restrictions, the predicted behavior i

Olga Perkovic, James P. Sethna

The traditional magnetic storage mechanisms (both analog and digital) apply an external field signal H(t) to a hysteretic magnetic material, and read the remanent magnetization M(t), which is (roughly) proportional to H(t). We propose a new analog method of recovering the signal from the magnetic material, making use of the shape of the hysteresis loop M(H).

I. L. Aleiner, A. I. Larkin

We study logarithmical in $\hbar$ effects in the statistical description of quantum chaos. We found analytical expressions for the deviations from the universality in the weak localization corrections and the level statistics and showed that the characteristic scale for these deviations is the Ehrenfest time, $t_E= λ^{-1}|\ln\hbar|$, where $λ$ is the Lyapuno

Andrei G. Doroshkevich, Stefan Gottloeber, Soeren Madsen

The large-scale matter distribution represents a complex network of structure elements such as voids, clusters, filaments, and sheets. This network is spanned by a point distribution. The global properties of the point process can be measured by different statistical methods, which, however, do not describe directly the structure elements. The morphology of

Stanley J. Brodsky, Francesco Hautmann, Davison E. Soper

The total cross section for scattering virtual photons at high energy is sensitive to pomeron physics. If the photons are sufficiently virtual, QCD perturbation theory applies, so that the reaction probes the short distance pomeron. We study this reaction for present and future e+/- e- colliders.

Patrick Huet, D. T. Son

We derive a set of equations describing the real time dynamics of modes with spatial momentum of order g^2 T in a high temperature gauge theory, where g is the coupling constant and T is the temperature. This dynamics is stochastic in nature. Important implications for baryon number violation at high temperature and for the physics at the electroweak phase t

H. Srikanth, Balam A. Willemsen, T. Jacobs, S. Sridhar

New features are reported in precision measurements of the complex microwave conductivity of high quality $YBa_{2}Cu_{3}O_{6.95}$ crystals grown in $BaZrO_{3}$ crucibles. A third peak in the normal conductivity, $σ_{1}(T)$, at around $80K$, and enhanced pair conductivity $σ_{2}(T)$ below $\sim 65K$ are observed. The data are inconsistent with a single order

M. Savci

We investigate the pseudoscalar neutral Higgs-boson A^0 production in the polarized (gamma e) collisions with two different center of mass energies sqrt{s} = 500 GeV and sqrt{s} = 1 TeV. The cross-section of the process (gamma e -> e A^0) and the polarization asymmetry due the spin of the initial beams are calculated.

T. M. Aliev, A. Ozpineci, M. Savci

The formfactors of B_1 -> pi and D_1 -> pi transitions, where B_1(D_1) is the 1^+ P-wave -> Q gamma_νγ_5q meson state, are calculated in the framework of the light cone QCD. Furthermore these formfactors are compared with the pole dominance model prediction using the values of the strong coupling constants g_{B_1 B^* pi} and g_{D_1 D^* pi}, and a good agreem

Dima Mozyrsky, Vladimir Privman, Steven P. Hotaling

Considerations of feasibility of quantum computing lead to the study of multispin quantum gates in which the input and output two-state systems (spins) are not identical. We provide a general discussion of this approach and then propose an explicit two-spin interaction Hamiltonian which accomplishes the quantum XOR gate function for a system of three spins:

Andrew G. Cohen, David B. Kaplan, Francois Lepeintre, Ann E. Nelson

We discuss how to extract non-Standard Model effects from B-factory phenomenology. We then analyze the prospects for uncovering evidence for Effective Supersymmetry, a class of supersymmetric models which naturally suppress flavor changing neutral currents and electric dipole moments without squark universality or small CP violating phases, in experiments at

Manoelito M. de Souza

A review of old inconsistencies of Classical Electrodynamics (CED) and of some new ideas that solve them is presented. Problems with causality violating solutions of the wave equation and of the electron equation of motion, and problems with the non-integrable singularity of its self-field energy tensor are well known. The correct interpretation of the two (

Stéphane Lavignac

Abelian family symmetries provide a predictive framework for neutrino mass models. In seesaw models based on an abelian family symmetry, the structures of the Dirac and the Majorana matrices are derived from the symmetry, and the neutrino masses and mixing angles are determined by the lepton charges under the family symmetry. Such models can lead to mass deg

T. M. Aliev, A. Ozpineci, M. Savci

Using the light cone QCD Sum Rules Method, we study the rare B -> nu barnu gamma decay and and find that the branching ratios are, B(B_s -> nu barnu gamma) = 7.5 10^{-8}, B(B_d -> nu -> nu gamma) = 4.2 10^{-9}. A comparision of our results, on branching ratio, with constituent quark and pole dominance model predictions are presented.

T. Matsuki, K. Yazaki

The consistency of effective models with QCD is investigated through the use of the QCD sum rule. Taking the potential model for the heavy quark system, we apply the method to two phenomenologically successful parameter sets, and obtain the dependences of the model parameters on the QCD scale $Λ$. Comparison with the expected scaling laws allows us to reject

N. V. Mikheev, L. A. Vassilevskaya, M. L. Zilberman

The massive neutrino radiative decay $ν_i \rightarrow ν_j γ$ ($i \ne j$) is investigated within the Minimal Quark-Lepton Symmetry of the Pati-Salam type based on the $SU(4)_V \times SU(2)_L \times G_R$ group in an external constant crossed field ($\vec {\cal E} \perp \vec H$, ${\cal E}=H$). The matrix element $ΔM^{(X)}$ and the decay probability $W^{(X)}$ du

Daniel M. Kaplan

Using a sample of >10^5 J/psi to mu+mu- decays, Fermilab experiment 789 has studied production of J/psi and psi-prime in 800-GeV proton-nucleon collisions. Differential cross sections and nuclear dependences have been measured for charmonium as well as for charm and beauty production. While charm and beauty production are consistent with perturbative QCD cal

P. M. C. de Oliveira, T. J. P. Penna, H. J. Herrmann

Ferrenberg and Swendsen histogram method is based on Boltzmann probability distribution which presents exponentially decaying tails. Thus, it gives accurate measures only within a narrow window around the simulated temperature. The larger the system, the narrower this window, and the worst the performance of this method. We present a quite different approach

J. A. Sauls, D. Rainer

The Fermi-liquid theory of superconductivity is applicable to a broad range of systems that are candidates for unconventional pairing. Fundamental differences between unconventional and conventional anisotropic superconductors are illustrated by the unique effects that impurities have on the low-temperature transport properties of unconventional superconduct

M. P. Ulmer, G. M. Bernstein, D. R. Martin, R. C. Nichol

We present the results of a search for low surface brightness galaxies (hereafter LSBs) in the Coma cluster. Bernstein et al. report on deep CCD observations in R of a 7.5 by 7.5 arcminute region in the core of the Coma cluster, and we extend this work by finding and measuring 36 LSBs within this field. We report both R and Bj results. The average magnitude

Philip R. Page, Xue-Qian Li

The eta(1760) may be significantly produced in J/Psi radiative decay. We deduce from experimental data that its branching ratio to two gluons is bounded, 0.4 +- 0.3 < BR(eta(1760) -> gg) < 0.9 +- 0.3, consistent with gluonic admixture. Moreover, the expectation that there should be an isoscalar analogue of the gluonic (hybrid) meson candidate pi(1800) is arg

Klaus Krebs, Sven Sandow

We show that all zero energy eigenstates of an arbitrary $m$--state quantum spin chain Hamiltonian with nearest neighbor interaction in the bulk and single site boundary terms, which can also describe the dynamics of stochastic models, can be written as matrix product states. This means that the weights in these states can be expressed as expectation values

Gabriele Travaglini

We discuss the regularization of chiral gauge theories on the lattice introducing only physical degrees of freedom. This is obtained by writing the Wilson term in a Majorana form, at the expense of the U(1) symmetry related to fermion number conservation. The idea of restoring chiral invariance in the continuum by introducing a properly chosen set of counter

Giancarlo D&#39;Ambrosio, Jorge Portoles

We have studied in the framework of Chiral Perturbation Theory (ChPT) the O(p^6) Vector Meson contributions to K -> pi gamma gamma and K(L) -> gamma gamma^*. We construct the most general ChPT lagrangian for the weak Vector-Pseudoscalar-Photon (VPgamma) vertex for K -> pi gamma gamma and K(L) -> gamma gamma^* and consequently we get the full structure of the

Sergey M. Troshin

On the basis of the U-matrix form of s-channel unitarization, we consider constraints unitarity provides for the spin structure function $g_1(x,Q^2)$ at $x\to 0$. Corresponding constraint for the spin structure function $h_1(x, Q^2)$ is given along.

M. C. Britton, C. R. Gwinn, M. J. Ojeda

We conducted a very long baseline interferometric observation of 5 nearby pulsars and did not resolve the scattering disks of any of these sources. Using our upper limits on the angular diameters of these scattering disks and published values of the broadening times and proper motion velocities, we constrain the possible distributions of scattering material.

Pijush K. Ghosh

We construct two different Calogero-Sutherland type models with only two-body interactions in arbitrary dimensions. We obtain some exact wave functions, including the ground states, of these two models for arbitrary number of spinless nonrelativistic particles.

Gaetano Fiore

Any deformation of a Weyl or Clifford algebra A can be realized through a `deforming map&#39;, i.e. a formal change of generators in A. This is true in particular if A is covariant under a Lie algebra g and its deformation is induced by some triangular deformation $U_h g$ of the Hopf algebra $Ug$. We propose a systematic method to construct all the correspon

A. V. Tsiganov

Two outer automorphisms of infinite-dimensional representations of $sl(2)$ algebra are considered. The similar constructions for the loop algebras and yangians are presented. The corresponding linear and quadratic $R$-brackets include the dynamical $r$-matrices.

Ken Umeno

An impossibility theorem on approximately simulating quantum non-integrable Hamiltonian systems is presented here. This result shows that there is a trade-off between the unitary property and the energy expectation conservation law in time-descretization of quantum non-integrable systems, whose classical counterpart is Ge-Marsden&#39;s impossibility result a

Angel Ballesteros, Francisco J. Herranz, Preeti Parashar

All Lie bialgebra structures on the Heisenberg--Weyl algebra $[A_+,A_-]=M$ are classified and explicitly quantized. The complete list of quantum Heisenberg--Weyl algebras so obtained includes new multiparameter deformations, most of them being of the non-coboundary type.