August 1994 arXiv papers — page 5

I. M. Dremin

It is shown that, as functions of their rank, cumulants of QCD multiplicity distributions in small phase space bins possess the quasi- oscillating behavior similar to that found for them in the total rapidity range. First minimum moves to lower ranks for smaller bins. For the total rapidity range, it moves to higher ranks with energy increase. The running pr

Masayuki Asakawa, Zheng Huang, Xin-Nian Wang

We demonstrate that semiclassical fluctuations, their relaxation, and the chiral phase transition are automatically incorporated in the numerical simulations of the classical equations of motion in the linear $σ$-model when longitudinal and transverse expansions are included. We find that domains of disoriented chiral condensate with 4--5 fm in size can form

S. Scherer, H. W. Fearing

The construction of effective Lagrangians commonly involves the application of the `classical equation of motion' to eliminate redundant structures and thus generate the minimal number of independent terms. We investigate this procedure in the framework of chiral perturbation theory. The use of the 'classical equation of motion' is interpreted in

John G. Learned, Sandip Pakvasa

It is suggested that a large deep underocean (or ice) neutrino detector, given the presence of significant numbers of neutrinos in the PeV energy range as predicted by various models of Active Galactic Nuclei, can make unique measurements of the properties of neutrinos. It will be possible to observe the existence of the tau neutrino, measure its mixing with

N. S. Ananikian, R. R. Shcherbakov

The Z(3) gauge model with double plaquette representation of the action on the flat triangular and square lattices is constructed. It is reduced to the spin-1 Blume-Emery-Griffiths (BEG) model. An Ising-type critical line of a second-order phase transition is found.

N. S. Ananikian, R. R. Shcherbakov

The Z(3) gauge model with double plaquette representation of the action on a generalized Bethe lattice of plaquettes is constructed. It is reduced to the spin-1 Blume-Emery-Griffiths (BEG) model. An Ising-type critical line of a second-order phase transition ending in the tricritical point is found.

Juergen Audretsch, Rainer Mueller

We consider an atom in interaction with a massless scalar quantum field. We discuss the structure of the rate of variation of the atomic energy for an arbitrary stationary motion of the atom through the quantum vacuum. Our main intention is to identify and to analyze quantitatively the distinct contributions of vacuum fluctuations and radiation reaction to t

Maxim Braverman

Consider a flat vector bundle F over compact Riemannian manifold M and let f be a self-indexing Morse function on M. Let g be a smooth Euclidean metric on F. Set g_t=exp(-2tf)g and let ρ(t) be the Ray-Singer analytic torsion of F associated to the metric g_t. Assuming that the vector field $grad f$ satisfies the Morse-Smale transversality conditions, we prov

Pasi Tapanainen, Atro Voutilainen

We discuss combining knowledge-based (or rule-based) and statistical part-of-speech taggers. We use two mature taggers, ENGCG and Xerox Tagger, to independently tag the same text and combine the results to produce a fully disambiguated text. In a 27000 word test sample taken from a previously unseen corpus we achieve 98.5% accuracy. This paper presents the d

J. J. Dalcanton

At large redshifts, a cluster or group may be too distant for the galaxies within the cluster to be detected individually. However, the light from these ``undetected'' galaxies still modulates the surface brightness of the background sky. Clusters can appear as 10"-1.5' sized fluctuations in the surface brightness of the EBL. The fluctuations

Andrew Ulmer

Bursts from soft gamma repeaters have been shown to be super-Eddington by a factor of 1000 and have been persuasively associated with compact objects. Here, a model of super-Eddington radiation transfer on the surface of a strongly magnetic ($\geq 10^{13}$ gauss) neutron star is studied and related to the observational constraints on soft gamma repeaters. In

Carolin Seitz, Peter Schneider

The weak distortions of high-redshift galaxies caused by gravitational light deflection near clusters of galaxies can be used to reconstruct the projected (two-dimensional) surface mass density of intermediate redshift clusters. This technique, pioneered by Tyson, Valdes & Wenk, and Kaiser & Squires, is reconsidered in the present paper, where we generalize

P. J. Forrester

Some integration formulas which either occur or are implicit in Ha&#39;s recent exact calculation of some correlations in the Calogero-Sutherland model are discussed. These integration formulas include the calculation of the inner product $<0|ρ(0)|κ>$ between the density operator acting on an excited state and the ground state, and a generalization of the Se

Reyer Sjamaar

Consider a Hamiltonian action of a compact Lie group on a compact symplectic manifold. A theorem of Kirwan&#39;s says that the image of the momentum mapping intersects the positive Weyl chamber in a convex polytope. I present a new proof of Kirwan&#39;s theorem, which gives explicit information on how the vertices of the polytope come about and on how the sh

A. Jaffe, N. Kaiser

We apply a likelihood analysis to the data of \markcite{Lauer \& Postman 1994} With $P(k)$ parametrized by $(σ_8, Γ)$, the likelihood function peaks at $σ_8\simeq0.3$, $Γ\lesssim0.025$, indicating at face value very strong large-scale power, though at a level incompatible with COBE\@. There is, however, a ridge of likelihood such that more conventional power

Ashoke Sen

Following an old result of Marcus and Schwarz we argue that in the heterotic string theory compactified on a seven dimensional torus, the target space duality group O(7,23;Z) and the strong-weak coupling duality transformations combine into the group O(8,24;Z). We discuss symmetry of the combined spectrum of elementary particles and solitons in the theory, a

M. Neubert

In view of new precise measurements of the $\bar B\to D^*\ell \barν$ decay rate near zero recoil, we reconsider the theoretical uncertainties in the extraction of $| V_{cb}|$ using heavy quark symmetry. In particular, we combine our previous estimate of $1/m_Q^2$ corrections to the normalization of the hadronic form factor at zero recoil with sum rules deriv

Jun-ichirou Koga, Kei-ichi Maeda

We consider a superradiance effect around rotating dilatonic black holes. We analyze two cases: one is an exact solution with the coupling constant $α=\sqrt{3}$, which effective action is reduced from the 5-dimensional Kaluza-Klein theory, and the other is a slowly rotating dilatonic black holes with arbitrary coupling constant. We find that there exists a c

David Kaiser

Primordial spectral indices are calculated to second order in slow-roll parameters for three closely-related models of inflation, all of which contain a scalar field non-minimally coupled to the Ricci curvature scalar. In most cases, $n_s$ may be written as a function of the non-minimal curvature coupling strength $ξ$ alone, with $n_s (ξ) \leq 1$, although t

R. B. Wiringa, V. G. J. Stoks, R. Schiavilla

We present a new high-quality nucleon-nucleon potential with explicit charge dependence and charge asymmetry, which we designate Argonne $v_{18}$. The model has a charge-independent part with fourteen operator components that is an updated version of the Argonne $v_{14}$ potential. Three additional charge-dependent and one charge-asymmetric operators are add

M. Radici, S. Boffi, Steven C. Pieper, V. R. Pandharipande

Effects of nucleon-nucleon correlations on exclusive $(e,e&#39;p)$ reactions on closed-shell nuclei leading to single-hole states are studied using $^{16}O(e,e&#39;p)^{15}N$ ($6.32$ MeV, $3/2^-$) as an example. The quasi-hole wave function, calculated from the overlap of translationally invariant many-body variational wave functions containing realistic spat

Joseph N. Ginocchio, Calvin W. Johnson

We briefly review various mappings of fermion pairs to bosons, including those based on mapping operators, such as Belyaev-Zelevinskii, and those on mapping states, such as Marumori; in particular we consider the work of Otsuka-Arima-Iachello, aimed at deriving the Interacting Boson Model. We then give a rigorous and unified description of state-mapping proc

Andrzej Rosłanowski, Saharon Shelah

We prove that the Sacks forcing collapses the continuum onto the dominating number d, answering the question of Carlson and Laver. Next we prove that if a proper forcing of the size at most continuum collapses omega_2 then it forces diamond_{omega_1} .

Uri Abraham, Saharon Shelah

Assuming an inaccessible cardinal kappa, there is a generic extension in which MA + 2^{aleph_0} = kappa holds and the reals have a Delta^2_1 well-ordering.

Alan H. Mekler, Saharon Shelah

The essentially non-free spectrum is the class of uncountable cardinals kappa in which there is an essentially non-free algebra of cardinality kappa which is almost free. In L, the essentially non-free spectrum of a variety is entirely determined by whether or not the construction principle holds. In ZFC may be more complicated. For some varieties, such as g

Akihiko Yukie

Let (G,V) be an irreducible prehomogeneous vector space defined over a number field k, P in k[V] a relative invariant polynomial, and X a rational character of G such that P(gx)=X(g)P(x). Let V_k^{ss}={x \in V_k such that P(x) is not equal to 0}. For x in V_k^{ss}, let G_x be the stabilizer of x, and G_x^0 the connected component of 1 of G_x. We define L_0 t

Ralph Blumenhagen, Andreas Wisskirchen

We explicitly construct the extension of the N=2 super Virasoro algebra by two super primary fields of dimension two and three with vanishing u(1)-charge. Using a super covariant formalism we obtain two different solutions both consistent for generic values of the central charge c. The first one can be identified with the super W_4-algebra - the symmetry alg

Ian I. Kogan, Alex Kovner

We perform a variational calculation in the SU(N) Yang Mills theory in 3+1 dimensions. Our trial variational states are explicitly gauge invariant, and reduce to simple Gaussian states in the zero coupling limit. Our main result is that the energy is minimized for the value of the variational parameter away form the perturbative value. The best variational s

U. Baur

A comparative study of amplitude zeros in $Wγ$ and $WZ$ production in hadronic collisions is presented. The Standard Model amplitude for $q_1 \bar q_2 \rightarrow W^\pm Z $ at the Born-level is shown to exhibit an approximate zero located at $\cosθ= (g^{q_1}_{-} + g^{q_2}_{-}) / (g^{q_1}_{-} - g^{q_2}_{-})$ at high energies, where the $g^{q_i}_{-}$ ($i=1,2$)

Martin J. Savage

The radiative decay $Σ_Q^* \rightarrow Λ_Qγ$ can have both magnetic dipole (M1) and electric quadrupole (E2) components. In the heavy quark limit $M_Q\rightarrow\infty$ the transition arises from the spin of the light degrees of freedom changing from $s_l=1$ to $s_l=0$ and hence the E2 contribution vanishes. We compute the leading contribution to the E2 stre

T. Woehrmann, H. Fraas

We examine for representative gaugino-higgsino mixing scenarios sneutrino-neutralino and sneutrino-chargino production in deep inelastic ep-scattering at the cm-energy of 1.8 TeV. The cross sections for sneutrino-chargino production are more than one order of magnitude bigger than those for sneutrino-squark production. Also for zino-like neutralinos we find

S. D. Bass

The trace anomaly is relevant to the renormalisation of the unpolarised parton distributions. The role of the trace anomaly in F_2 is compared with the axial anomaly in g_1.

B. L. Ioffe

C o n t e n t s 1. Introduction. 2. General Relations. 3. Small $x$ Domain -- Regge Behaviour. 4. The Parton Model. 5. Sum Rules in the Parton Model. 6. QCD Corrections to Sum Rules. 7. Nucleon Axial Coupling Constants. 8. The Experimental Data on $g_1(x)$ and Their Interpretation. 9. Suggestions for Future Experiments. 10. The Structure Function $g_2(x)$. 1

Dieter Stoll

For the sake of eliminating gauge variant degrees of freedom we discuss the way to introduce angular variables in the hamiltonian formulation of QCD. On the basis of an analysis of Gauss&#39; law constraints a particular choice is made for the variable transformation from gauge fields to angular field variables. The resulting formulation is analogous to the

Dieter Stoll

The unitary gauge fixing technique is applied to the QCD hamiltonian formulated in terms of angular variables. It is demonstrated that in this formulation projections on the physical Hilbert space are unnecessary to separate physical and unphysical degrees of freedom. Therefore the application of the unitary gauge fixing technique can be extended to the oper

A. V. Berezhnoy, A. K. Likhoded, M. V. Shevlyagin

The cross section of the $γγ\rightarrow B_c(B_c^*) \bar b c $ process is calculated. It is shown that near threshold the pseudoscalar state production is much suppressed with respect to the vector one. At large energies their ratio becaims $σ(B_c^*)/sigma(B_c)\sim 4$. The process of heavy quark recombination dominates in the production of $B_c(B_c^*)$ states

Yuval Kluger

We study the dynamics of the chiral phase transition expected during the expansion of the quark-gluon plasma produced in a high energy hadron or heavy ion collision, using the $O(4)$ linear sigma model in the mean field approximation. Starting from an approximate equilibrium configuration at an initial proper time $τ$ in the disordered phase, we study the tr

Ulrich Alfes, Henning Müller zum Hagen

In this paper we show the existence of a large class of spherically symmetric data $d$ (on a spacelike hypersurface $S$), from which a perfect fluid spacetime (surrounded by vacuum) develops. This spacetime contains an event horizon (with trapped surfaces behind it). The data $d$ are regular and {\it innociuous}, i.e. the data--surface $S$ does not contain a

Dhurjati Prasad Datta

Decoherence in quantum cosmology is shown to occur naturally in the presence of induced geometric gauge interactions associated with particle production.A new &#39;gauge &#39;-variant form of the semiclassical Einstein equations is also presented which makes the non-gravitating character of the vacuum polarisation energy explicit.

Neil C. Rowe

We discuss implementation issues of MARIE-1, a mostly symbolic parser fully implemented, and MARIE-2, a more statistical parser partially implemented. They address a corpus of 100,000 picture captions. We argue that the mixed approach of MARIE-2 should be better for this corpus because its algorithms (not data) are simpler.

R. J. Nemiroff, J. P. Norris, J. T. Bonnell, W. A. D. T. Wickramasinghe

We find that dim gamma-ray bursts (GRBs) are softer than bright GRBs, as indicated on average by data from the Burst and Transient Source Experiment (BATSE) on board the Compton Gamma Ray Observatory. We show that this correlation is statistically significant with respect to variations due to random differences between GRBs. This effect is discernable using

C. R. Robinson, F. A. Cordova

An analysis of ROSAT observations for the eclipsing magnetic cataclysmic binary DP Leo provides constraints on the origin, size, temperature, variability and structure of the soft X-ray emission region on the surface of the white dwarf. These data, when combined with prior observations, show a progression of approximately 2 degrees per year in the impact pos

Kailash C. Sahu

The recently reported microlensing events of the LMC have caused much excitement, and have been interpreted as due to `dark objects&#39; (MACHOs) in the halo of our Galaxy. It is shown here that the stars within the LMC play a dominant role as gravitational lenses and can indeed account for the observed events. The MACHO event and one of the EROS events lie

A. Newsam, J. F. L. Simmons, M. A. Hendry

Much current interest in cosmology has revolved around the peculiar velocity field of galaxies. Many methods have been proposed to derive this, probably the most prominent being POTENT (Dekel et al. 1990). However, this is prone to many forms of systematic error or bias. Here, we examine some of the methods currently used to minimise these biases, particular

R. G. Carlberg

Velocity bias offers a single parameter ($b_v$) description of the likely segregation of mass and light in a galaxy cluster. The relation between the projected mass profile and the light profile, normalized by the virial $M/L$, is presented as a function of $b_v\equivσ_\ell/σ_ρ$, the ratio of the RMS velocity dispersions of the galaxies and the underlying da

M. J. Montes, R. V. Wagoner

We extend the approximate radiative transfer analysis of Hershkowitz, Linder, and Wagoner (1986) to a more general class of supernova model atmospheres, using a simple fit to the effective continuum opacity produced by lines (Wagoner, Perez, and Vasu 1991). At the low densities considered, the populations of the excited states of hydrogen are governed mainly

C. Daboul, J. Daboul, P. Slodowy

We show that the dynamical symmetry of the hydrogen atom leads in a natural way to an infinite-dimensional algebra, which we identify as the positive subalgebras of twisted Kac-Moody algebras of $ so(4)$. We also generalize our results to the $N$-dimensional hydrogen atom. For odd $N$, we identify the dynamical algebra with the positive part of the twisted a

Berndt Mueller

I review recent progress in our understanding of the basis of statistical models for hadronic reactions and of the mechanisms of thermalization in nonabelian gauge theories. (Invited talk given at the NATO Advanced Research Workshop on Hot Hadronic Matter: Theory and Experiment, Divonne-le-Bains, June 1994) **Note: The PostScript file of one figure is too la

Dan Maoz, Alexei V. Filippenko, Luis C. Ho, Hans-Walter Rix

Low-ionization nuclear emission-line regions (LINERs), which exist in a large fraction of galaxies, may be the least luminous manifestation of quasar activity. The nature of LINERs has, however, remained controversial because an AGN-like nonstellar continuum source has not been directly observed in them. We report the detection of bright, unresolved (FWHM $\

Ellen G. Zweibel, James E. Rhoads

We develop an analytical theory of reconnection between colliding, twisted magnetic flux tubes. Our analysis is restricted to direct collisions between parallel tubes and is based on the collision dynamics worked out by Bogdan (1984). We show that there is a range of collision velocities for which neutral point reconnection of the Parker-Sweet type can occur

Pavel Etingof, Mikhail Khovanov

In this note we illustrate by a few examples the general principle: interesting algebras and representations defined over Z_+ come from category theory, and are best understood when their categorical origination has been discovered. We show that indecomposable Z_+-representations of the character ring of SU(2) satisfying certain conditions correspond to affi

Chong-Shou Gao, Cai-Dian Lu, Zhao-Ming Qiu

QCD corrections to the penguin induced charmless inclusive $B$ decays are performed to an improved leading-log approximation. For process $b \to s q\overline{q} $ (q=uds) and $ b \overline{q} \to s \overline{q} $, four previous missed 4-quark operators are included to make a complete leading log QCD corrected result. Furthermore, part of the next-leading log

Valeri V. Dvoeglazov

In the framework of the classical field theory a mapping between antisymmetric tensor matter fields and Weinberg&#39;s $2(2j+1)$ component &#34;bispinor&#34; fields is considered. It is shown that such a mapping exists and equations which describe the $j=1$ antisymmetric tensor field coincide with the Hammer-Tucker equations completely and with the Weinberg

H. -C. Kao, K. Lee, C. Lee, T. Lee

We study one-loop corrections to the Chern-Simons coefficient $κ$ in abelian self-dual Chern-Simons Higgs systems and their $N=2$ and $N=3$ supersymmetric generalizations in both symmetric and asymmetric phases. One-loop corrections to the Chern-Simons coefficient of these systems turn out to be integer multiples of $1/4π$ in both phases. Especially in the m

A. V. Berezhnoy, A. K. Likhoded, M. V. Shevlyagin

On the basis of the exact formulas of QCD perturbation theory and parton model the hadronic production cross-sections for $B_c({B_c}^*)$-mesons ($1^1S_0,1^3S_1,2^1S_0,2^3S_1$-states) are calculated. The method used is the direct calculation of appropriate amplitudes with the help of a FORTRAN program and subsequent Monte-Carlo integration over the phase spac

Hisashi Kikuchi, Ernest Ma

The tau neutrino with a mass of about 10 MeV can be the ``late decaying particle'' in the cold dark matter scenario for the formation of structure in the Universe. We show how this may be realized specifically in the recently proposed doublet Majoron model.

Eric V. Siegel, Kathleen R. McKeown

We apply decision tree induction to the problem of discourse clue word sense disambiguation with a genetic algorithm. The automatic partitioning of the training set which is intrinsic to decision tree induction gives rise to linguistically viable rules.

R. Siebenmorgen, A. A. Zijlstra, E. Kruegel

We present a radiative-transfer calculation which reproduces the infrared spectrum of the planetary nebula BD~+30$^{\circ}$3639. We calculate the transfer process through absorption and scattering in a spherical-symmetric multi-grain dust shell. The emission of transiently heated particles is taken into account, as well as polycyclic aromatic hydrocarbons. W

Randall D. Kamien, John Toner

We show that polymer cholesterics have much longer pitches than comparable short molecule cholesterics, due to their anomalous elasticity. The pitch $P$ of a chiral mixture with concentration $c$ near the racemic (non-chiral) concentration $c^*$ diverges like $\vert c-c^*\vert^{-ν}$ with $ν=1.43 \pm 0.04$ (for short molecule cholesterics $ν=1$). The short mo

D. F. Coker, L. Xiao

We show how the dynamically nonlocal formulation of classical nuclear motion in the presence of quantal electronic transitions presented many years ago by Pechukas can be localized in time using time dependent perturbation theory to give an impulsive force which acts when trajectories hop between electronic surfaces. The action of this impulsive force is com

Cumrun Vafa, Edward Witten

By studying the partition function of $N=4$ topologically twisted supersymmetric Yang-Mills on four-manifolds, we make an exact strong coupling test of the Montonen-Olive strong-weak duality conjecture. Unexpected and exciting links are found with two-dimensional rational conformal field theory.

A. Cucchieri, S. Deser, M. Porrati

We analyse the high-energy behavior of tree-level graviton Compton amplitudes for particles of mass m and arbitrary spin, concentrating on a combination of forward amplitudes that will be unaffected by eventual cross- couplings to other, higher spins. We first show that for any spin larger than 2, tree-level unitarity is already violated at energies well bel

K. V. L. Sarma

This is a survey of the current experimental information on some of the interesting issues in neutrino physics: neutrino species, neutrino masses, neutrino magnetic moments, solar neutrinos, and the atmospheric neutrino anomaly.

M. Schaefer, H. C. Doenges, U. Mosel

We explore the possibility to verify vector meson dominance for the nucleon by measuring the half-off-shell form factor in the vector-meson mass region. Cross sections for the process $γp \rightarrow p + e^+e^-$ be presented.

Jean-Loup Gervais, Jean-François Roussel

The strong coupling physics of two dimensional gravity at C=7, 13, 19 is deciphered, by building up on previous works along the same line (for a recent review, of the background material, see hep-th/9408069). It is shown that chirality becomes deconfined. The string suceptibility is derived, and found to be real contrary to the continuation of the KPZ formul

Ricardo Amorim, Ashok Das

We show that for a system containing a set of general second class constraints which are linear in the phase space variables, the Abelian conversion can be obtained in a closed form and that the first class constraints generate a generalized shift symmetry. We study in detail the example of a general first order Lagrangian and show how the shift symmetry not

Leszek Hadasz, Pawel Wegrzyn

We investigate classical strings defined by the Nambu-Goto action with the boundary term added. We demonstrate that the latter term has a significant bearing on the string dynamics. It is confirmed that new action terms that depend on higher order derivatives of string coordinates cannot be considered as continuous perturbations from the starting string func

V. V. Nesterenko, A. Feoli, G. Scarpetta

Models of relativistic particle with Lagrangian ${\cal L}(k_1)$, depending on the curvature of the worldline $k_1$, are considered. By making use of the Frenet basis, the equations of motion are reformulated in terms of the principal curvatures of the worldline. It is shown that for arbitrary Lagrangian function ${\cal L}(k_1)$ these equations are completely

O. M. Khudaverdian

We introduce some new classes of algebras and estabilish in these algebras Campbell--Hausdorff like formula. We describe the application of these constructions to the problem of the connectivity of the Feynman graphs corresponding to the Green functions in Quantum Fields Theory.

Jean-Loup Gervais

The quantum group structure of the Liouville theory is reviewd and shown to be an important tool for solving the theory.

S. N. Solodukhin

The quantum corrections to the entropy of charged black holes are calculated. The Reissner-Nordstrem and dilaton black holes are considered. The appearance of logarithmically divergent terms not proportional to the horizon area is demonstrated. It is shown that the complete entropy which is sum of classical Bekenstein-Hawking entropy and the quantum correcti

R. N. Mohapatra, S. Nussinov

We examine the implications of the hypothesis that the decays of the b-quark occur via pure right-handed couplings. We show that the existing lower limits on neutrinoless double beta decay imply that any gauge model realizing this idea must have either an $L_e-L_μ$ or $L_e-L_τ$ symmetry. We then show that constraints of cosmology together with observations f

Keith A. Olive, Serge Rudaz

We consider the viability of the minimal supersymmetric standard model with a light ($m_{\tilde t_1} < $ 45 GeV) stop. In order for its relic abundance to be cosmologically significant, the photino as dark matter must be quite close in mass to the stop, $(m_{\tilde t_1} - m_{\tilde γ}) \simeq 3 - 7 $ GeV. However, as we show, the photino despite its low mass

J. Lopez

I review the theoretical expectactions for the top-quark mass in a variety of models: the Standard Model, unified models (GUTs), low-energy supersymmetric models (SUSY), unified supersymmetric models (SUSY GUTs), supergravity models, and superstring models. In all instances I consider the constraints on the top-quark mass which arise by demanding that these

E. L. Gubankova, A. Yu. Dubin

The generalization of the effective action [1] of the quark--antiquark system in the confining vacuum is performed for the case of arbitrary quark masses. The interaction of quarks is described by the averaged Wilson loop for which we use the minimal area law asymptotics. The system is quantized by the path integral method and the quantum Hamiltonian is obta

Peter Arnold, Chengxing Zhai

We compute the free energy density for pure non-Abelian gauge theory at high temperature and zero chemical potential. The three-loop result to $O(g^4)$ is [a lovely formula. Get the paper and print it out.] We examine the sensitivity of this result to the choice of renormalization scale. We also give a result for the free energy of scalar $\phi^4$ theory, co

E. Hofstetter, M. Schreiber

The critical behaviour of 3-dimensional disordered systems with magnetic field is investigated by analyzing the spectral fluctuations of the energy spectrum. We show that in the thermodynamic limit we have two different regimes, one for the metallic side and one for the insulating side with different level statistics. The third statistics which occurs only e

A. Kogut, G. Hinshaw, C. L. Bennett

High-contrast peaks in the cosmic microwave background (CMB) anisotropy can appear as unresolved sources to observers. We fit simulated CMB maps generated with a cold dark matter model to a set of unresolved features at instrumental resolution 0.5 degrees to 1.5 degrees and present the integral density per steradian n(>|T|) of unresolved features brighter th

G. Hinshaw, C. L. Bennett, A. Kogut

We have simulated full-sky maps of the Cosmic Microwave Background (CMB) anisotropy expected from Cold Dark Matter (CDM) models at 0.5 and 1.0 degree angular resolution. Statistical properties of the maps are presented as a function of sky coverage, angular resolution, and instrument noise, and the implications of these results for observability of the Doppl

C. L. Bennett

The properties of the cosmic microwave background radiation provide unique constraints on cosmological models, i.e. on the content, history, and evolution of the Universe. I discuss the latest measurements of the spectral and spatial properties of the cosmic microwave background radiation. Recent measurements from NASA&#39;s Cosmic Background Explorer (COBE)

R. A. Battye, E. P. S. Shellard

We review the current status of axion cosmology in the light of recent work. We conclude that in the standard scenario, in which a global string network forms at the Peccei-Quinn phase transition, the largest contribution to the axion density is from loops, even when uncertainties in the nature of the QCD phase transition are taken into account. We also brie

D. Choudhury, F. Eberlein, A. König, J. Louis

The smallness of flavor changing neutral currents constrains the soft parameter space of supersymmetric extensions of the Standard Model. These low energy constraints are translated to the soft parameter space generated at some high energy scale $\Mgut$. For gaugino masses larger than the scalar masses and non-universal $A$-terms the constraints are signific

Ch. Sauermann, B. L. Friman, W. Nörenberg

A model for $π$N scattering and $η$-meson production in the S$_{11}$ channel is presented. The model includes $π$N-scattering Born terms as well as the N$^*${} resonances S$_{11}$(1535) and S$_{11}$(1610). The $T$-matrix is computed in the $K$-matrix approximation. The parameters of the model are determined by fitting the elastic $π$N-scattering $T$-matrix t

Vitor Lemes, Ricardo Renan, S. P. Sorella

The algebraic renormalization of a recently proposed abelian axial gauge model with antisymmetric tensor matter fields is presented.

Dmitri Fursaev

Ultraviolet regime in quantum theory with horizons, contrary to ordinary theory, depends on the temperature of the system due to additional surface divergences in the effective action. We evaluate their general one-loop structure paying attention to effects of the curvature of the space-time near the horizon. In particular, apart from the area term, the entr

I. Tsutsui, L. Feher

It is well-known that the Toda Theories can be obtained by reduction from the Wess-Zumino-Novikov-Witten (WZNW) model, but it is less known that this WZNW $\rightarrow$ Toda reduction is \lq incomplete&#39;. The reason for this incompleteness being that the Gauss decomposition used to define the Toda fields from the WZNW field is valid locally but not global

J. M. Cornwall, D. A. Morris

The elegant instanton calculus of Lipatov and others used to find factorially-divergent behavior (g^N * N!) for N*g >> 1 in g*phi^4 perturbation theory is strictly only applicable when all external momenta vanish; a description of high-energy 2 --> N scattering with N massive particles is beyond the scope of such techniques. On the other hand, a standard mul

Eric Braaten, Agustin Nieto

The Debye screening mass for a quark-gluon plasma at high temperature is calculated to next-to-leading order in the QCD coupling constant from the correlator of two Polyakov loops. The result agrees with the screening mass defined by the location of the pole in the gluon propagator as calculated by Rebhan. It is logarithmically sensitive to nonperturbative e

Mitchell Golden

Some years ago Appelquist and Chanowitz considered the scattering of fermion--anti-fermion into a pair of longitudinal gauge bosons. Their calculation established that unitarity implies that the physics giving mass to a quark of mass $m_f$ must be below a mass scale of $16 πv^2 / m_f$ ($v=246$ GeV). This bound is a bit difficult to interpret, because the uni

Avijit Ganguly, Jitendra C. Parikh, Utpal Sarkar

We propose a new mechanism for baryogenesis. We study the effective potential of left-right extension of the standard model and show that there can be a first order phase transition at the left-right symmetry breaking and hence $(B-L)$ symmetry breaking scale, which is around TeV in our scenario. As a result, although $(B-L)$ violating interactions are in eq

Sandip Pakvasa

In this talk I would like to discuss two aspects of charm physics. One is to show that many standard model predictions for rare decay modes (along with $D^0 -\bar{D}^0$ mixing and CP violation) are extremely small thus opening a window for new physics effects\cite{1}; and the other is to review the expectations from several plausible and interesting new phys

Michael E. Peskin

I review the physics capabilities of the machines proposed for the next generation of high-energy experimentation: in hadron physics, the LHC, and in electron physics, a $500$--$1500$ GeV $e^+e^-$ linear collider. Using for illustration two specific models of electroweak symmetry breaking, I show how the $pp$ and $e^+e^-$ techniques are expected to complemen

M. N. Chernodub, M. I. Polikarpov, A. I. Veselov

We show that the monopole confinement mechanism in lattice gluodynamics is a particular feature of the maximal abelian projection. We give an explicit example of the $SU(2) \rightarrow U(1)$ projection (the minimal abelian projection), in which the confinement is due to topological objects other than monopoles. We perform analytical and numerical study of th

J. -G. Demers

Using the influence functional formalism, the problem of an accelerating detector in the presence of a scalar field in its ground state is considered in Minkowski space. As is known since the work of Unruh, to a quantum mechanical detector following a definite, classical acceleration, the field appears to be thermally excited. We relax the requirement of per

J. Gegenberg, G. Kunstatter, D. Louis-Martinez

We consider the most general dilaton gravity theory in 1+1 dimensions. By suitably parametrizing the metric and scalar field we find a simple expression that relates the energy of a generic solution to the magnitude of the corresponding Killing vector. In theories that admit black hole solutions, this relationship leads directly to an expression for the entr

Raphael Blumenfeld

A statistical theory of two-dimensional Laplacian growths is formulated from first-principles. First the area enclosed by the growing surface is mapped conformally to the interior of the unit circle, generating a set of dynamically evolving quasi-particles. Then it is shown that the evolution of a surface-tension-free growing surface is Hamiltonian. The Hami

F. B. Anders

In the framework of direct perturbation theory a fully self-consistent approximation beyond the well known NCA will be presented for the Anderson Model. The resummation of a class of skeleton diagrams up to infinite order in $V$ includes all contribution up to the order $O(1/N^2)$ ( $N$ = degeneracy of the magnetic state). Qualitative improvements in maintai

Alejandro Gangui, Leandros Perivolaropoulos

By using a simple analytical model based on counting random multiple impulses inflicted on photons by a network of cosmic strings we show how to construct the general q-point temperature correlation function of the Cosmic Microwave Background radiation. Our analysis is sensible specially for large angular scales where the Kaiser-Stebbins effect is dominant.

M. M. Briley, J. E. Hesser, R. A. Bell, M. Bolte

Observations of CN and CH band strengths among a random sample of main-sequence turn-off stars (+3.9 < MV < +4.6) in the globular cluster 47 Tuc (NGC 104, C0021-723) were made with the CTIO Argus fiber spectrograph for the purpose of determining the ratio of CN-strong to CN-weak stars and investigating the behavior of CH relative to CN. Of the 20 turn-off st

Michael Penkava, Albert Schwarz

We introduce the notion of cyclic cohomology of an A-infinity algebra and show that the deformations of an A-infinity algebra which preserve an invariant inner product are classified by this cohomology. We use this result to construct some cycles on the moduli space of algebraic curves. The paper also contains a review of some well known notions and results