March 1994 arXiv papers — page 2

Valeri V. Dvoeglazov, Antonio del Sol Mesa

The equations for various spin particles with oscillator-like interactions are discussed in this talk. Contents: 1. Comment on "The Klein-Gordon Oscillator"; 2. The Dirac oscillator in quaternion form; 3. The Dirac-Dowker oscillator; 4. The Weinberg oscillator; 5. Note on the two-body Dirac oscillator.

F. Krmpotić

After briefly reviewing $ββ$ decay as a test of the neutrino mass, I examine the nuclear structure involved in this process. Simple formulas (à la Padé) are designed for the transition amplitudes and the general behavior of $ββ$ decay amplitudes in the quasiparticle random phase approximation are discussed. Results of a calculation for $^{48}Ca$, $^{76}Ge $,

A. Mariano, F. Krmpotić, A. F. R. de Toledo Piza

We study normalization problems associated with use of perturbatively correlated ground-states in extended RPA schemes in the context of a specific but typical example. The sensitivity of the results to the amount of $2p2h$ admixtures to the correlated ground state is also investigated in terms of a modification of the standard perturbative approach.

Peter G. Casazza, Hans Jarchow

The question which led to the title of this note is the following: {\it If $X$ is a Banach space and $K$ is a compact subset of $X$, is it possible to find a compact, or even approximable, operator $v:X\to X$ such that $K\subset\ol{v(B_X)}$?} This question was first posed by P.G.Dixon [6] in connection with investigating the problem of the existence of appro

Mikhail I. Ostrovskii

A quojection (projective limit of Banach spaces with surjective linking mappings) without infinite dimensional Banach subspaces is constructed. This results answers a question posed by G.Metafune and V.B.Moscatelli.

Bernard Maurey, Vitali D. Milman, Nicole Tomczak-Jaegermann

In this paper structure of infinite dimensional Banach spaces is studied by using an asymptotic approach based on stabilization at infinity of finite dimensional subspaces which appear everywhere far away. This leads to notions of asymptotic structures and asymptotic versions of a given Banach space. As an example of application of this approach, a class of

G. Mack, V. Schomerus

Quantum field planes furnish a noncommutative differential algebra $Ω$ which substitutes for the commutative algebra of functions and forms on a contractible manifold. The data required in their construction come from a quantum field theory. The basic idea is to replace the ground field ${\bf C}$ of quantum planes by the noncommutative algebra ${\cal A}$ of

M. Baker, James S. Ball, F. Zachariasen

We present Dirac's method for using dual potentials to solve classical electrodynamics for an oppositely charged pair of particles, with a view to extending these techniques to non-Abelian gauge theories.

A. de Souza Dutra, Marcelo Hott

We quantize a generalized electromagnetism in 2 + 1 dimensions which contains a higher-order derivative term by using Dirac's method. By introducing auxiliary fields we transform the original theory in a lower-order derivative one which can be treated in a usual way.

Georg Junker

A certain class of one-dimensional classical lattice models is considered. Using the method of abstract harmonic analysis explicit thermostatic properties of such models are derived. In particular, we discuss the low-temperature behavior of some of these models.

E. Shuryak, M. Velkovsky

For {\it low} T new strict results for the instanton density n(T) are reported. Using the PCAC methods, we express n(T) in terms of {\it vacuum} average values of certain operators, times their {\it calculated} T-dependence. At high T, we discuss the {\it applicability} limits of the perturbative results. We further speculate about possible behaviour of n(T)

Chuan-Tsung Chan, E. M. Henley, Th. Meissner

The $q^2$ dependence of the $π$-$η$ mixing amplitude is examined with the use of QCD sum rules. The linear slope of the mixing function $θ(q^2)$ is found to be much smaller than that for $ρ$-$ω$ mixing. Thus the mixing amplitude is approximately the same in the space-like region as in the time-like one, and one may neglect the $q^2$ dependence of the mixing.

The CLEO Collaboration

A measurement of the cross section for the combined two-photon production of charged pion and kaon pairs is performed using 1.2~$\rm fb^{-1}$ of data collected by the CLEO~II detector at the Cornell Electron Storage Ring. The cross section is measured at invariant masses of the two-photon system between 1.5 and 5.0 GeV/$c^2$, and at scattering angles more th

Joannis Papavassiliou, Alberto Sirlin

We use the S-matrix pinch technique to derive to one loop order an effective renormalizable self-energy for the W gauge boson, when the theory is quantized in the unitary gauge. We then show that this amplitude is identical to the $ξ$-independent W self-energy previously constructed by applying the pinch technique in the context of the renormalizable $R_ξ$ g

S. V. Goloskokov, O. V. Selyugin

Theoretical predictions for the behavior of $A_{LL}$ asymmetry determined by the pomeron-hadron vertex are done. Strong dependence of the asymmetry on the mass creating quarks and transfer momenta is shown.

Yuval Grossman, Zoltan Ligeti

We calculate in the framework of two Higgs doublet models the differential decay rate for inclusive $\bar B\toτ\,\barν\,X$ transitions to order $1/m_b^2$ in the heavy quark expansion, for both polarized and unpolarized tau leptons. In contrast to the situation in the standard model, we find sizeable $1/m_b^2$ corrections. A systematic heavy quark expansion s

M. E. Carrington, G. Kunstatter

2+1 dimensional massless scalar QED with $(ϕ^*ϕ)^3$ scalar self-coupling is modified by the addition of a non- minimal Chern-Simons term that couples the dual of the electromagnetic field strength to the covariant current of the complex scalar field. The theory is shown to be fully one- loop renormalizable. The one loop effective potential for the scalar fie

Gautam Bhattacharyya

We investigate the mixing of an extra ${Z^0}^\prime$ with the standard $Z^0$ and mixings of exotic fermions with their standard counterparts through some precisely measured electroweak observables. These observables are geared to search for physics beyond the Standard Model. We observe that although most of such mixings are severely constrained by the recent

R. Delbourgo, Dongsheng Liu

We analyse the Lorentz structures of weak decay matrix elements bewteen meson states of arbitrary spin. Simplifications arise in the transition amplitudes for a heavy meson decaying into a light one via a Bethe-Salpeter approach which incorporates heavy quark symmetry. Phenomenological consequences on several semileptonic, nonleptonic and FCNC induced decays

S. P. de Alwis, D. A. MacIntire

We discuss the derivation of the so-called semi-classical equations for both mini-superspace and dilaton gravity. We find that there is no systematic derivation of a semi-classical theory in which quantum mechanics is formulated in a space-time that is a solution of Einstein's equation, with the expectation value of the matter stress tensor on the right-

Thibault Damour, Gilles Esposito-Farese

We reexamine non-Einsteinian effects observable in the orbital motion of low-orbit artificial Earth satellites. The motivations for doing so are twofold: (i) recent theoretical studies suggest that the correct theory of gravity might contain a scalar contribution which has been reduced to a small value by the effect of the cosmological expansion; (ii) presen

U. Brauer, A. Rendall, O. Reula

The validity of the cosmic no-hair theorem is investigated in the context of Newtonian cosmology with a perfect fluid matter model and a positive cosmological constant. It is shown that if the initial data for an expanding cosmological model of this type is subjected to a small perturbation then the corresponding solution exists globally in the future and th

Arvind Borde

The existence of initial singularities in expanding universes is proved without assuming the timelike convergence condition. The assumptions made in the proof are ones likely to hold both in open universes and in many closed ones. (It is further argued that at least some of the expanding closed universes that do not obey a key assumption of the theorem will

Per Kraus

We study the behaviour of scalar fields on background geometries which undergo quantum tunneling. The two examples considered are a moving mirror in flat space which tunnels through a potential barrier, and a false vacuum bubble which tunnels to form a black hole. WKB approximations to the Schrodinger and Wheeler-DeWitt equations are made, leading one to sol

G. George Batrouni, Terence Hwa

We report the results of large scale numerical studies of the dynamic and static properties of the random phase model of the randomly pinned flux lines confined in a plane. From the onset of nonlinear IV characteristics, we identify a vortex glass transition at the theoretically anticipated temperature. However, the vortex glass phase itself is much {\it les

Moshe Moshe, Herbert Neuberger, Boris Shapiro

A random matrix ensemble incorporating both GUE and Poisson level statistics while respecting $U(N)$ invariance is proposed and shown to be equivalent to a system of noninteracting, confined, one dimensional fermions at finite temperature.

Giovannni Gallavotti

The implications of the original misunderstanding of the etymology of the word "ergodic" are discussed, and the contents of a not too well known paper by Boltzmann are critically examined. The connection with the modern theory of Ruelle is attempted

Ph. Jetzer

Recently the Polish-American collaboration OGLE has reported the observation of four possible microlensing events by monitoring, over several months, the brightness of millions of stars in the region of the galactic bulge. If these events are due to microlensing, the most accurate way to get information on the mass of the dark compact objects, that acted as

S. P. Ellingsen, R. P. Norris, J. B. Whiteoak, R. A. Vaile

A sensitive search for 6.7--GHz methanol maser emission has been made towards 10 galaxies that have yielded detectable microwave molecular--line transitions. These include several which show OH megamaser or superluminous \water\/ maser emission. Within the Galaxy, \methanol\/ and OH masers often occur in the same star formation regions and, in most cases, th

Christoph Sorger

Nous calculons le groupe de Picard de l'espace des modules $Θ_{\planp}(d)$ des thêta-caractéristiques des courbes planes (non forcément lisses) de degré $d$. Nous montrons que pour $d\ge 6$, le groupe de Picard de la composante paire est engendré par le fibré déterminant ${\cal{D}}$ et l'image réciproque ${\cal{L}}$, sous le morphisme support schémat

B. L. Ioffe, A. Khodjamirian

The twist-two chirality violating proton structure function $h_1(x)$ measurable in the polarized Drell-Yan process is calculated by means of QCD sum rules at intermediate $x$, $0.3 < x < 0.7$ and $Q^2 \approx 5-10 GeV^2$.

Richard M. Hain

In this paper we give an exposition of Dennis Johnson's work on the first homology of the Torelli groups and show how it can be applied, alone and in concert with Saito's theory of Hodge modules, to study the geometry of moduli spaces of curves. For example, we show that the picard groups of moduli spaces of curves with a fixed level structure are finitely g

T. Papenbrock, C. Wetterich

A nonperturbative method is proposed for the approximative solution of the exact evolution equation which describes the scale dependence of the effective average action. It consists of a combination of exact evolution equations for independent couplings with renormalization group improved one loop expressions of secondary couplings. Our method is illustrated

A. E. Dorokhov

From the analysis of the recent CCFR data for the \st\ $xF_3(x,Q^2)$ ($0.015<x<0.65$ and $1.2\ GeV^2 < |Q^2| < 501\ GeV^2$) of the deep inelastic neutrino - nucleon scattering we conclude that probably part of the nucleon baryon number is due to the vacuum polarization effects.

S. Narison

Using the {\it hybrid} moments-Laplace sum rule (HSR), which is well-defined for $M_b \rar \infty$, in contrast with the $popular$ double Borel (Laplace) sum rule (DLSR), which blows up in this limit when applied to the heavy-to-light processes, we show that the form factor of the $B \rar K^* \ γ$ radiative transition is dominated by the light-quark condensa

G. M. T. Watts

We develop the notions of fusion for representations of the W_3 algebra along the lines of Feigin and Fuchs. We present some explicit calculations for a W_3 minimal model.

K. Ezawa

The previous discussion \cite{ezawa} on reducing the phase space of the first order Einstein gravity in 2+1 dimensions is reconsidered. We construct a \lq\lq correct&#34; physical phase space in the case of positive cosmological constant, taking into account the geometrical feature of SO(3,1) connections. A parametrization which unifies the two sectors of th

Gustav W. Delius, Yao-Zhong Zhang

We give a general construction for finite dimensional representations of $U_q(\hat{\G})$ where $\hat{\G}$ is a non-twisted affine Kac-Moody algebra with no derivation and zero central charge. At $q=1$ this is trivial because $U(\hat{\G})=U({\G})\otimes \C(x,x^{-1})$ with $\G$ a finite dimensional Lie algebra. But this fact no longer holds after quantum defor

Minos Axenides, Arne L. Larsen

We investigate the nucleation of circular cosmic strings in models of generalized inflationary universes with an accelerating scale factor. We consider toy cosmological models of a smooth inflationary exit and transition into a flat Minkowski spacetime. Our results establish that an inflationary expanding phase is necessary but not sufficient for quantum nuc

L. Diosi, N. Gisin, J. J. Halliwell, I. G. Percival

We demonstrate a close connection between the decoherent histories (DH) approach to quantum mechanics and the quantum state diffusion (QSD) picture, for open quantum systems described by a master equation of Lindblad form. The (physically unique) set of variables that localize in the QSD picture also define an approximately decoherent set of histories in the

Ryoichi Kawai, Joseph F. Tombrello, John H. Weare

A pseudorotating state of Li$_5$ observed in a recent EPR experiment is investigated using the local density functional method. The calculated isotropic spin population indicates that a planar $C_{2v}$ structure is more consistent with the experimental result than a suggested trigonal bipyramid. A new pseudorotating state based on the planar structure is pro

Avery Meiksin

Results are presented for one-dimensional numerical hydrodynamics computations of the structure and evolution of Lya forest clouds gravitationally confined by dark matter minihalos. The clouds are developed from linear perturbations at high redshift and exposed to either a QSO- or galaxy-dominated metagalactic radiation field at moderate redshifts. While the

M. Kawasaki, T. Moroi

Gravitino production and decay in the inflationary universe are reexamined. Assuming that the gravitino mainly decays into a photon and a photino, we calculate the upperbound on the reheating temperature. Compared to previous works, we have essentially improved the following two points: (i) the helicity $\pm\frac{3}{2}$ gravitino production cross sections ar

R. Ragazzon, D. Treleani

Representing the semi-hard partonic interactions by the exchange of Lipatov&#39;s perturbative Pomeron, we express the semi-hard nuclear cross section as a self shadowing cross section. With the help of a generating functional technique, we obtain average numbers of multiple semi-hard partonic collisions without any need of using explicit expressions for the

Enrique Álvarez, Luis Álvarez-Gaumé, Yolanda Lozano

A general study of non-abelian duality is presented. We first identify a possible obstruction to the conformal invariance of the dual theory for non-semisimple groups. We construct the exact non-abelian dual for any Wess-Zumino-Witten (WZW) model for any anomaly free subgroup, and the corresponding extension for coset conformal field theories. We characteriz

J. Dai, J. F. Gunion, R. Vega

We demonstrate that simultaneous detection of two of the neutral Higgs bosons of the Minimal Supersymmetric Model will be possible at the LHC in the $b\anti b b\anti b$ final state, provided $\tanb$ is large and $b$-tagging can be performed with good efficiency and purity. This mode enhances the already established guarantee that there is no region of supers

Alakabha Datta, Sandip Pakvasa, Utpal Sarkar

We consider the gravity induced dimension six terms in addition to the dimension five terms in the SUSY GUT Lagrangian and find that the prediction for $\alpha_s$ may be washed out completely in supersymmetric grand unified theories unless the triplet higgs mass is smaller than $ 7\times 10^{16} $ GeV.

A. Brandenburg, S. J. Brodsky, V. V. Khoze, D. Müller

We calculate the angular distribution of the lepton produced in the Drell-Yan reaction taking into account pion bound state effects. We work in the kinematic region where one of the pion constituents goes far off-shell, which allows us to treat the bound state problem perturbatively. We show that the angular distribution is very sensitive to the shape of the

Joel Langer, Ron Perline

The planar filament equation and its relation to the modified Korteweg-deVries equation are studied in the context of Poisson geometry. The structure of the planar filament equation is shown to be similar to that of the 3-D localized induction equation, previously studied by the authors.

Doron Gepner

We study here the spectrum of soliton scattering theories based on interaction round the face lattice models. We take for the admissibility condition the fusion rules of each of the simple Lie algebras. It is found that the mass spectrum is given by that of the corresponding Toda theory, or, that the mass ratios of the different kinks in the model are descri

M. G. Schmidt, C. Schubert

We propose a multiloop generalization of the Bern-Kosower formalism, based on Strassler&#39;s approach of evaluating worldline path integrals by worldline Green functions. Those Green functions are explicitly constructed for the basic two-loop graph, and for a loop with an arbitrary number of propagator insertions. For scalar and abelian gauge theories, the

P. Bowcock

We investigate the W-algebra resulting from Drinfel&#39;d-Sokolov reduction of a $B_2$ WZW model with respect to the grading induced by a short root. The quantum algebra, which is generated by three fields of spin-2 and a field of spin-1, is explicitly constructed. A `free field&#39; realisation of the algebra in terms of the zero-grade currents is given, an

C. L. Ho, Y. Hosotani

We show that the argument in Phys Rev Lett 70 (1993) 1360 is correct and consistent, and that Hagen & Sudarshan&#39;s solution has inconsistency leading to non-vanishing commutators of $[P^1, P^2]$ and $[P^j, H]$ even in physical states. This proves that many of HS&#39;s statements in their Comment are based merely on incorrect guess, but not on careful alge

A. P. Isaev

We show that the differential complex $Ω_{B}$ over the braided matrix algebra $BM_{q}(N)$ represents a covariant comodule with respect to the coaction of the Hopf algebra $Ω_{A}$ which is a differential extension of $GL_{q}(N)$. On the other hand, the algebra $Ω_{A}$ is a covariant braided comodule with respect to the coaction of the braided Hopf algebra $Ω_

Bo-Yu Hou, Bo-Yuan Hou, Zhong-Qi Ma

In this paper, from the $q$-gauge covariant condition we define the $q$-deformed Killing form and the second $q$-deformed Chern class for the quantum group $SU_{q}(2)$. Developing Zumino&#39;s method we introduce a $q$-deformed homotopy operator to compute the $q$-deformed Chern-Simons and the $q$-deformed cocycle hierarchy. Some recursive relations related

M. Drees, R. M. Godbole, M. Nowakowski, S. D. Rindani

In this note we investigate the production of charged heavy particles via \gaga\ fusion at high energy pp colliders. We revise previous claims that the \gaga\ cross section is comparable to or larger than that for the corresponding Drell-Yan process at high energies. Indeed we find that the \gaga\ contribution to the total production cross section at pp is f

K. Sailer

Retaining only the `timelike&#39; component $A_0$ of the vector potential a skelet model with explicit global center symmetry is constructed for $SU(2)$ Yang-Mills theory. It is shown that the $A_0$ gluon vacuum is equivalent with the 4-dimensional Coulomb-gas. In 1--loop approximation, the effective theory of the skelet model exhibits non-local self-interac

M. Jeżabek, J. H. Kühn

Angular-energy distributions are studied for charged leptons and neutrinos from the decays of polarised top quarks. A small admixture of V+A interactions is incorporated. The polarisation dependent part of the neutrino distribution which can be measured experimentally through the missing momentum is particularly sensitive towards deviations from the V-A stru

J. R Forshaw, R. G. Roberts

We study the cross section for dijet production via direct photons, as seen at the HERA collider. Rather than assuming the standard factorisation formula for the cross section (where the incoming partons are assumed to be on-shell), we use the $k_T$-factorisation formula. This formalism ought to be more appropriate for jet production in regions where the cro

The CLEO Collaboration

We have investigated $D^{+}π^{-}$ and $D^{*+}π^{-}$ final states and observed the two established $L=1$ charmed mesons, the $D_1(2420)^0$ with mass $2421^{+1+2}_{-2-2}$ MeV/c$^{2}$ and width $20^{+6+3}_{-5-3}$ MeV/c$^{2}$ and the $D_2^*(2460)^0$ with mass $2465 \pm 3 \pm 3$ MeV/c$^{2}$ and width $28^{+8+6}_{-7-6}$ MeV/c$^{2}$. Properties of these final state

Oscar Sotolongo, Enrique Lopez

The advantages of introducing a fractal viewpoint in the field of combustion is emphasized. It is shown that the condition for perfect combustion of a collection of drops is the self-similarity of the distribution.

D. Juriev

A geometric interpretation of quantum self-interacting string field theory is given. Relations between various approaches to the second quantization of an interacting string are described in terms of the geometric quantization. An algorithm to construct a quantum nonperturbative interacting string field theory in the quantum group formalism is proposed. prob

Yoshio Koide, Hideo Fusaoka

A unified mass matrix model of quarks and leptons with a seesaw-type form $M_f=m M_F^{-1} m$ is proposed on the basis of a non-standard Higgs scenario. The matrix $m$ is provided by U(3)-family nonet bosons $ϕ$, and the matrix $M_F$ is a mass matrix of heavy fermions $F_i$ corresponding to the ordinary fermions $f_i=ν_i,e_i,u_i,d_i$ ($i=1,2,3$). It is shown

R. R. Volkas

The minimal model of spontaneously broken leptonic colour and discrete quark-lepton symmetry predicts that charged leptons have the same masses as their partner charge $+2/3$ quarks up to small radiative corrections. By invoking a different pattern of symmetry breaking, a similar model can be constructed with the structural feature that charged leptons have

G. Haak

We construct a Grassmannian-like formulation for the potential KP-hierarchy including additional ``negative&#39;&#39; flows. Our approach will generalize the notion of a tau-function to include negative flows. We compare the resulting hierarchy with results by Hirota, Satsuma and Bogoyavlenskii.

Cumrun Vafa

Some aspects of Mirror symmetry are reviewed, with an emphasis on more recent results extending mirror transform to higher genus Riemann surfaces and its relation to the Kodaira-Spencer theory of gravity (talk given in the Geometry and Topology Conference, April 93, Harvard, in honor of Raoul Bott)

Fiorenzo Bastianelli, Nobuyoshi Ohta, Jens Lyng Petersen

We construct a hierarchy of supersymmetric string theories by showing that the general N-extended superstrings may be viewed as a special class of the (N+1)-extended superstrings. As a side result, we find a twisted (N+2) superconformal algebra realized in the N-extended string.

Marek P. Grabowski, Pierre Mathieu

An explicit expression for all the quantum integrals of motion for the isotropic Heisenberg $s=1/2$ spin chain is presented. The conserved quantities are expressed in terms of a sum over simple polynomials in spin variables. This construction is direct and independent of the transfer matrix formalism. Continuum limits of these integrals in both ferrromagneti

Martin Lavelle, David McMullan

BRST invariance supplies a sufficient condition for the observability of fields. We show that there is a global obstruction to the observability of quarks and gluons and argue that they will not become observables at finite temperature. We give expressions for quarks and gluons that are, however, {\it perturbatively\/} BRST invariant, and hence locally obser

K. Cheung, S. Dawson, T. Han, G. Valencia

We consider the possibility of observing deviations from the Standard Model gauge-boson self-couplings at future $e\gamma$ colliders. We concentrate on the process $e^-\gamma \rightarrow \nu W^- Z$, which is particularly sensitive to the parity violating coupling $g_5^Z$ at high energies. We find that a 2~TeV $e^+ e^-$ collider operating in the $e^- \gamma$

Marc Kamionkowski

I review several proposed techniques for indirect detection of weakly interacting massive particles (WIMPs) in the halo. I focus on distinctive signatures from cosmic-ray positrons, antiprotons, and gamma rays produced by annihilation of WIMPs in the galactic halo. (To appear in Particle Astrophysics, Atomic Physics, and Gravitation}, proceedings of the the

Rogerio Rosenfeld

We perform a preliminary study of the deviations from the Standard Model prediction for the cross section for the process $e γ\rightarrow ν_e W γ$. We work in the context of a higgsless chiral lagrangian model that includes an extra vector resonance $V$ and an anomalous $γW V$ coupling. We find that this cross section can provide interesting constraints on t

R. Horvat, D. Kekez, D. Palle, D. Klabučar

The bound--state problem for the pion as a quarkonium with the funnel (Coulomb--plus--linear) interaction is solved in a framework that combines the bilocal approach to mesons with the covariant generalization of the instantaneous--potential model. The potential interaction leads to dynamical breaking of chiral symmetry. However, the Coulomb potential leads

Thomas M. Gould, Stephen D. H. Hsu, Erich R. Poppitz

We show that scattering amplitudes between initial wave packet states and certain coherent final states can be computed in a systematic weak coupling expansion about classical solutions satisfying initial value conditions. The initial value conditions are such as to make the solution of the classical field equations amenable to numerical methods. We propose

V. Bernard, N. Kaiser, Ulf-G. Meißner

Using chiral Ward identities of QCD, we derive a relation for the induced pseudoscalar coupling constant which is accurate within a few percent, $g_P = 8.44 \pm 0.16$.

A. S. Joshipura, M. Nowakowski

We point out the possibility of spontaneous and hard CP-violation in the scalar potential of R-parity broken supersymmetric Standard Model. The existence of spontaneous CP-violation depends crucially on the R-parity breaking terms in the superpotential and, in addition, on the choice of the soft supersymmetry breaking terms. Unlike in theories with R-parity

F. Guinea, J. Gonzalez, M. A. H. Vozmediano

The multiplet structure induced by the Coulomb interactions in C$_{60}^{n-}$ ($n = 1 - 12$) is analyzed. The partially ocuppied LUMO gives rise to a set of levels which fill a relatively wide band ( $\approx 2-3$ eV ). A large ($\sim 1$ eV) intramolecular effective repulsion is found. The anions are also shown to be highly polarizable. The optical absorption

Prasenjit Saha, Scott Tremaine

We describe an algorithm for long-term planetary orbit integrations, including the dominant post-Newtonian effects, that employs individual timesteps for each planet. The algorithm is symplectic and exhibits short-term errors that are $O(εΩ^2τ^2)$ where $τ$ is the timestep, $Ω$ is a typical orbital frequency, and $ε\ll1$ is a typical planetary mass in solar

Stella Seitz, Peter Schneider, Juergen Ehlers

We reformulate the transport equation which determines the size, shape and orientation of infinitesimal light beams in arbitrary spacetimes. The behaviour of such light beams near vertices and conjugate points is investigated, with special attention to the singular behaviour of the optical scalars. We then specialize the general transport equation to the cas

Matthias Bartelmann, Peter Schneider, Guenther Hasinger

We announce the detection of correlations on angular scales of $\ga10&#39;$ between optically bright, high-redshift, radio-loud QSOs with diffuse X-ray emission seen by ROSAT in the {\it All-Sky Survey}. These correlations reach significance levels of up to $99.8\%$. A comparison of the results with a sample of control fields, bootstrapping analyses, and Kol

W. Siegel

We find a simpler formulation of the Green-Schwarz action, for which the Wess-Zumino term is the square of supersymmetric currents, like the rest of the action. On a random lattice it gives Feynman diagrams of a particle superfield theory.

S. M. Bilenky, C. Giunti

We discuss here what model independent information about properties of neutrinos and of the sun can be obtained from future solar neutrino experiments (SNO, Super-Kamiokande). It is shown that in the general case of transitions of solar $ν_e$&#39;s into $ν_μ$ and/or $ν_τ$ the initial $^8\mathrm{B}$ neutrino flux can be measured by the observation of NC event

Frank De Jonghe

Only the first 15 percent of the file survived the censor that is hidden in the network resources in a previous attempt to submit this thesis to the bulletin board. Hopefully this makes an uncorrupted file available.

R. Coquereaux

The Brattelli diagram associated with a given bicolored Dynkin-Coxeter graph of type $A_n$ determines planar fractal sets obtained by infinite dissections of a given triangle. All triangles appearing in the dissection process have angles that are multiples of $π/ (n+1).$ There are usually several possible infinite dissections compatible with a given $n$ but

H. Dorn, H. -J. Otto

Based on our generalization of the Goulian-Li continuation in the power of the 2D cosmological term we construct the two and three-point correlation functions for Liouville exponentials with generic real coefficients. As a strong argument in favour of the procedure we prove the Liouville equation of motion on the level of three-point functions. The analytica

K. Geiger, J. I. Kapusta

This comment is hereby withdrawn, because the paper by D. Seibert, KSUCNR-005-94 and nucl-th/9403005 was withdrawn and it was acknowleged that the parton cascade model does approach chemical equilibrium correctly. Therefore our reply to Seibert&#39;s paper is now obsolete.

U. Borgeest, K. -J. Schramm

HQM is an optical broad-band photometric monitoring program carried out since Sept.~1988. Our main intention is to search for indications of microlensing in a sample of $\sim$\,100 selected quasars; however, we also want to study the intrinsic variability. We use a CCD camera equipped to the MPIA 1.2$\,$m telescope. Fully automatic photometric reduction rela

T. Yoshikawa, H. Takata, T. Morozumi

Effective Lagrangian including technimesons is constructed for a realistic one-family Technicolor model without exact custodial symmetry. Tree level contribution to oblique correction parameters $S$ and $U$ due to spin 1 technimesons are computed with the effective Lagrangian. An isospin breaking term which is associated with technilepton vector mesons gives

M. Hotta, M. Shino, M. Yoshimura

The moving mirror model is designed to extract essential features of the black hole formation and the subsequent Hawking radiation by neglecting complication due to a finite curvature. We extend this approach to dynamically treat back reaction against the mirror motion due to Hawking radiation. It is found that a unique model in two spacetime dimensions exis

M. T. Batchelor, C. M. Yung

Quantum spin chains with exact valence-bond ground states are of great interest in condensed-matter physics. A class of such models was proposed by Affleck et al., each of which is su(2)-invariant and constructed as a sum of projectors onto definite total spin states at neighbouring sites. We propose to use the machinery of the q-deformation of su(2) to obta

K. Varga, R. J. Liotta

Pauli-projected random gaussians are used as a representation to solve the shell model equations. The elements of the representation are chosen by a variational procedure. This scheme is particularly suited to describe cluster formation and cluster decay in nuclei. It overcomes the basis-size problem of the ordinary shell model and the technical difficulties

Andrew R. Kustin

Let $\u_{1\times n}$, $\X_{n\times n}$, and $\v_{n\times 1}$ be matrices of indeterminates, $\Adj \X$ be the classical adjoint of $\X$, and $H(n)$ be the ideal $I_1(\u\X)+I_1(\X\v)+I_1(\v\u-\Adj \X)$. Vasconcelos has conjectured that $H(n)$ is a perfect Gorenstein ideal of grade $2n$. In this paper, we obtain the minimal free resolution of $H(n)$; and thereb

V. P. Nair

The effective action for hard thermal loops in QCD is related to a gauged WZNW theory. Some of the technical issues of this approach are clarified and the Hamiltonian formulation is presented. The two-point correlation function for the induced current in QCD is obtained; some simplifications of the dynamics of the longitudinal modes are also pointed out.

V. P. Nair

The generating functional for hard thermal loops in QCD is important in setting up a resummed perturbation theory. I review how this functional is related to the eikonal for a Chern-Simons theory, and using an auxiliary field, to the gauged WZNW-action. The induced current due to hard thermal loops, properly incorporating damping effects, is also briefly dis

N. Aizawa

It is shown that there exists an isomorphism between q-oscillator systems covariant under $ SU_q(n) $ and $ SU_{q^{-1}}(n) $. By the isomorphism, the defining relations of $ SU_{q^{-1}}(n) $ covariant q-oscillator system are transmuted into those of $ SU_q(n) $. It is also shown that the similar isomorphism exists for the system of q-oscillators covariant un

Silvio J. Rabello, Arvind N. Vaidya

The transition amplitudes for the free spinless and spinning relativistic particles are obtained by applying an operator method developed long ago by Dirac and Schwinger to the BFV form of the BRST theory for constrained systems.

L. Beldjoudi, T. N Truong

The S and P wave $ππ$ phase shifts are recalculated in terms of two phenomenological parameters using the one loop CPTh and the elastic unitarity condition. Using these phase shifts, the vector and scalar form factors are calculated and shown to be in a good agreement with experimental data. It is found that the simpler and more phenomenological approach, wh

W. T. Giele, E. W. N. Glover, D. A. Kosower

We study the two-jet inclusive cross section via the triply differential distribution $d^3σ/dE_{T}dη_1 dη_2$ to next-to-leading order in QCD. The predicted distributions can be compared directly with forthcoming data from the D0 and CDF experiments at Fermilab. We discuss differences with the leading-order predictions, and examine uncertainties due to the ch

B. Ananthanarayan, Saurabh D. Rindani

We show that certain CP-odd momentum correlations in the production and subsequent decay of tau pairs in $e^+e^-$ collisions get enhanced when the electron beam is longitudinally polarized. Analytic expressions for these correlations are obtained when $τ^+τ^-$ have a ``weak&#34; dipole form factor (WDFF) coupling to $Z$ in the case of two-body decay modes of

C. C. Lassig, R. R. Volkas

In the simplest examples of models with a discrete quark-lepton symmetry, an electroweak symmetry breaking sector with more than one Higgs doublet is necessary to obtain the correct mass relations between quarks and leptons. A two Higgs doublet model has flavour-nonconserving Yukawa couplings, which are proportional to the masses of the quark-lepton symmetri