May 1993 arXiv papers — page 3

Boguslaw Broda

An explicit derivation of the elements of the representation ring of SU(2) needed to implement the four-dimensional Kirby calculus is sketched.

Omar Foda, Michio Jimbo, Tetsuji Miwa, Kei Miki

We formulate the basic properties of q-vertex operators in the context of the Andrews-Baxter-Forrester (ABF) series, as an example of face-interaction models, derive the q-difference equations satisfied by their correlation functions, and establish their connection with representation theory. We also discuss the q-difference equations of the Kashiwara-Miwa (

C. M. Hull

The quantization of a free boson whose momentum satisfies a cubic constraint leads to a $c=\ha$ conformal field theory with a BRST symmetry. The theory also has a $W_\infty $ symmetry in which all the generators except the stress-tensor are BRST-exact and so topological. The BRST cohomology includes states of conformal dimensions $0,\si,\ha$, together with \

Alexander A. Belov, Karen D. Chaltikian

In development of the started activity on lattice analogues of $W$-algebras, we define the notion of lattice $W_{\infty}$-algebra, accociated with lattice integrable system with infinite set of fields. Various kinds of reduction to lattice $W_N$-algebras, related to discrete $N$-KdV hierarchies are described. We also discuss the connection of our results wit

Natalia A. Boikova, Valeri V. Dvoeglazov, Yuri N. Tyukhtyaev, Rudolf N. Faustov

The quasipotential in the fourth order of perturbation theory is calculated in the Coulomb gauge for the unequal mass particles. It could be used for the future calculations of energy spectra in two-body systems.

Wai-Keung Tang

We studied the high energy quark anti-quark elastic scattering with an exchange of a mesonic state in the $t$ channel with $-t/Λ_{QCD}^{2} \gg 1$. Two methods are proposed to eliminate the strong background from bare pomeron, reggized gluon and odderon exchange. The feasibility of measuring mesonic reggeon exchange is discussed.

Aneesh V. Manohar

The basic ideas and power counting rules of chiral perturbation theory are discussed. The formalism of velocity dependent fields for baryons, and for hadrons containing a heavy quark, is explained. (Invited Talk, 1993 QCD Rencontres de Moriond)

Hung Jung Lu, Stanley J. Brodsky, Valery A. Khoze

We study rapidity-gap events in $e^+e^-$ annihilation at the Z boson peak initiated by the emission of a virtual photon. This mechanism is suppressed by the QED coupling constant, but it is enhanced due to a large propagator term from the virtual photon. For typical kinematics, we find a smaller event rate than analogous QCD type gap events. In the small jet

Xiao-Gang He

We construct a Left-Right symmetric model in which the number of generation is related to Grassmann variables. We introduce two sets of complex Grassmann variables ($θ^1_q$,$θ^2_q$), ($θ^1_l$, $θ^2_l$) and associate each variable with left- and right-handed quark and lepton fields, respectively. Expanding quark and lepton fields in powers of the Grassmann va

Howard D. Trottier, R. M. Woloshyn

The role of monopoles in the confining behavior of compact lattice $QED_3$ is studied using an adiabatic cooling method. Monopole-antimonopole pairs with large separation suvive cooling and the presence or absence of such plasma monopoles provides a useful classification of the lattice gauge field configurations at large $β$. By calculating observables in su

M. Chaichian, R. Gonzalez Felipe, P. Presnajder

Assuming that there exist operators which form an irreducible representation of the q-superoscillator algebra, it is proved that any two such representations are equivalent, related by a uniquely determined superunitary transformation. This provides with a q-supersymmetric generalization of the well-known uniqueness theorem of von Neumann for any finite numb

David R. Nelson

Concepts from elementary quantum mechanics can be used to understand vortex line fluctuations in high-temperature superconductors. Flux lines are essentially classical objects, described by a string tension, their mutual repulsion, and interactions with pinning centers. The classical partition function, however, is isomorphic to the imaginary time path integ

G. Troll

We treat here the interrelation between formal languages and those dynamical systems that can be described by cellular automata (CA). There is a well-known injective map which identifies any CA-invariant subshift with a central formal language. However, in the special case of a symbolic dynamics, i.e. where the CA is just the shift map, one gets a stronger r

Ari Laor, John N. Bahcall, Buell T. Jannuzi, Donald P. Schneider

We analyze the ultraviolet (UV) emission line and continuum properties of five low-redshift active galactic nuclei (four luminous quasars: PKS~0405$-$123, H1821+643, PG~0953+414, and 3C273, and one bright Seyfert 1 galaxy: Mrk~205). The HST spectra have higher signal-to-noise ratios (typically $\sim 60$ per resolution element) and spectral resolution ($R = 1

Jae-Suk Park

We propose $N=2$ holomorphic Yang-Mills theory on compact Kähler manifolds and show that there exists a simple mapping from the $N=2$ topological Yang-Mills theory. It follows that intersection parings on the moduli space of Einstein-Hermitian connections can be determined by examining the small coupling behavior of the $N=2$ holomorphic Yang-Mills theory. T

Keith R. Dienes

Two of the important unresolved issues concerning fractional superstrings have been the appearance of new massive sectors whose spacetime statistics properties are unclear, and the appearance of new types of ``internal projections'' which alter or deform the worldsheet conformal field theory in a highly non-trivial manner. In this paper we provide a

Philip C. Argyres, Keith R. Dienes

Fractional superstrings in the tensor-product formulation experience ``internal projections'' which reduce their effective central charges. Simple expressions for the characters of the resulting effective worldsheet theory are found. All states in the effective theory can be consistently assigned definite spacetime statistics. The projection to the e

B. K. Agrawal, A. Ansari

Employing a cranking Hamiltonian, in the static path approximation to the partition function, we have studied the behaviour of the moment of inertia of $^{64}Zn$ at a few values of temperatures as a function of the rotation frequency. At a low temperature T = 0.5 MeV and J=16 rotational alignment of $0g_{9/2}$ orbitals takes place. But at a high temperature

M. T. Peña, P. U. Sauer, A. Stadler, G. Kortemeyer

The description of the three-nucleon system in terms of nucleon and $Δ$ degrees of freedom is extended to allow for explicit pion production (absorption) from single dynamic $Δ$ de-excitation (excitation) processes. This mechanism yields an energy dependent effective three-body hamiltonean. The Faddeev equations for the trinucleon bound state are solved with

Nikolaos Kalogeropoulos

We discuss the existence of Gribov ambiguities in $SU(m)\times U(1)$ gauge theories over the $n-$spheres. We achieve our goal by showing that there is exactly one conjugacy class of groups of gauge transformations for the theories given above. This implies that these transformation groups are conjugate to the ones of the trivial $SU(m)\times U(1)$ fiber bund

Peter G. O. Freund, Anton V. Zabrodin

We analyse the spectral problem for the q-Knizhnik-Zamolodchikov equations for $U_q(\widehat{sl_2}) (0 < q \leq 1)$ at level zero. The case of 2-point functions in the fundamental representation is studied in detail. The scattering states are found explicitly in terms of continuous q-Jacobi polynomials. The corresponding S-matrix is shown to coincide, up to

Felix Schlumpf

The magnetic moments of the baryon decuplet are calculated in a relativistic constituent quark model using the light-front formalism. Of particular interest are the magnetic moments of the $Ω^-$ and $Δ^{++}$ for which new recent experimental measurements are available. Our calculation for the magnetic moment ratio $μ(Δ^{++})/μ(p)$ is in excellent agreement w

Jose Wudka

I review the use of effective lagrangians in describing the physics beyond the standard model, several theoretical and practical aspects are discussed. It is argued that the only situations where new physics can be observed corresponds to cases where the standard model cntributions are extremely suppressed and where high quality data is avaliable.

Ian I. Kogan

We consider the effective $1+1$-dimensional chiral theory describing fluctuations of the order parameter of the Disoriented Chiral Condensate (DCC) which can be formed in the central rapidity region in a relativistic nucleus-nucleus or nucleon-nucleon collisions at high energy. Using $1+1$-dimensional reduction of QCD at high energies and assuming spin polar

V. Azcoiti, X. Q. Luo, C. E. Piedrafita, G. DiCarlo

We study the phase diagram of non compact $QED_3$ using the microcanonical fermionic average method described elsewhere. We present evidence for a continuous phase transition line in the $β, N$ plane, extending down to arbitrarily small flavour number $N$.

W. Janke, T. Sauer

To further improve the performance of Monte Carlo simulations of first-order phase transitions we propose to combine the multicanonical approach with multigrid techniques. We report tests of this proposition for the $d$-dimensional $Φ^4$ field theory in two different situations. First, we study quantum tunneling for $d = 1$ in the continuum limit, and second

José A. Cuesta, Froilán C. Martínez, Juan M. Molera, Angel Sánchez Escuela

We introduce two simple two-dimensional lattice models to study traffic flow in cities. We have found that a few basic elements give rise to the characteristic phase diagram of a first-order phase transition from a freely moving phase to a jammed state, with a critical point. The jammed phase presents new transitions corresponding to structural transformatio

Bertrand I. Halperin

Recent experiments have shown that a quantized Hall plateau can occur in double layer systems at total filling factor v=1/2, though there is no plateau at v=1/2 in a normal single layer system. For the single layer system, considerable insight has been provided by a theory based on the fermion Chern-Simons picture, where the electrons are transformed into fe

Rita Pardini, Francesca Tovena

We study the behaviour of the topological fundamental group under totally ramified abelian covers (a special case of abelian Galois covers) of complex projective varieties of dimension at least 2.

David Eisenbud, Bernd Sturmfels

For several computational procedures such as finding radicals and Noether normalizations, it is important to choose as sparse as possible a system of parameters in a polynomial ideal or modulo a polynomial ideal. We describe new strategies for these tasks, thus providing solutions to problems (1) and (2) posed in [Eisenbud-Huneke-Vasconcelos 1992].

Vahid Karimipour

{Although q-oscillators have been used extensively for realization of quantum universal enveloping algebras,such realization do not exist for quantum matrix algebras ( deformation of the algebra of functions on the group ). In this paper we first construct an infinite dimensional representation of the quantum matrix algebra $ M_q ( 3 ) $(the coordinate ring

Vahid Karimipour

It is shown that the finite dimensional ireducible representations of the quantum matrix algebra $ M_q(3) $ ( the coordinate ring of $ GL_q(3) $ ) exist only when q is a root of unity ( $ q^p = 1 $ ). The dimensions of these representations can only be one of the following values: $ p^3 , { p^3 \over 2 } , { p^3 \over 4 } $ or $ { p^3 \over 8 } $ . The topol

Vahid Karimipour

It is shown that the finite dimensional irreducible representaions of the quantum matrix algebra $ M_{ q,p}(2) $ ( the coordinate ring of $ GL_{q,p}(2) $) exist only when both q and p are roots of unity. In this case th e space of states has either the topology of a torus or a cylinder which may be thought of as generalizations of cyclic representations.

J. M. Richard, J. Fröhlich, G. M. Graf, M. Seifert

We sketch two rigorous proofs of the stability of the hydrogen molecule in quantum mechanics. The first one is based on an extrapolation of variational estimates of the groundstate energy of a positronium molecule to arbitrary mass ratios. The second one is an extension of Heitler-London theory to nuclei of finite mass.

Jeremy Schiff

For $N\ge 3$ there are $S_N$ and $D_N$ actions on the space of solutions of the first nontrivial equation in the $SL(N) MKdV hierarchy, generalizing the two $Z_2$ actions on the space of solutions of the standard MKdV equation. These actions survive scaling reduction, and give rise to transformation groups for certain (systems of) ODEs, including the second,

José A. Cuesta, Froilán C. Martínez, Juan M. Molera, Angel Sánchez

We introduce two simple two-dimensional lattice models to study traffic flow in cities. We have found that a few basic elements give rise to the characteristic phase diagram of a first-order phase transition from a freely moving phase to a jammed state, with a critical point. The jammed phase presents new transitions corresponding to structural transformatio

Aric Hagberg, Ehud Meron

Patterns in reaction-diffusion systems often contain two spatial scales; a long scale determined by a typical wavelength or domain size, and a short scale pertaining to front structures separating different domains. Such patterns naturally develop in bistable and excitable systems, but may also appear far beyond Hopf and Turing bifurcations. The global behav

R. S. Bhalerao, M. Barma

(The systematics of photon absorption cross sections in nuclei and small metal particles are examined as a function of the number of constituent fermions $A$. It is pointed out that the shell-structure-linked oscillations in the full width at half maximum (FWHM) of the photoneutron cross section in nuclei, earlier recognized for $A > 63$, in fact persist dow

A. Gerasimov

Gauged Wess-Zumino-Witten theory for compact groups is considered. It is shown that this theory has fermionic BRST-like symmetry and may be exactly solved using localization approach. As an example we calculate functional integral for the case of SU(2) group on the arbitrary Riemann surface. The answer is the particular case of Verlinde formula for the numbe

Ramzi R. Khuri

We discuss some recent work in the field of classical solitonic solutions in string theory. In particular, we construct instanton and monopole solutions and discuss the dynamics of string-like solitons. Some of the motivation behind this work is that instantons may provide a nonperturbative understanding of the vacuum structure of string theory, while monopo

N. P. Landsman

A new approach to the quantization of constrained or otherwise reduced classical mechanical systems is proposed. On the classical side, the generalized symplectic reduction procedure of Mikami and Weinstein, as further extended by Xu in connection with symplectic equivalence bimodules and Morita equivalence of Poisson manifolds, is rewritten so as to avoid t

S. Aoyama, S. Vandoren

We show that the Kaehler structure can be naturally incorporated in the Batalin-Vilkovisky formalism. The phase space of the BV formalism becomes a fermionic Kaehler manifold. By introducing an isometry we explicitly construct the fermionic irreducible hermitian symmetric space. We then give some solutions of the master equation in the BV formalism.

S. B. Giddings, J. Polchinski, A. Strominger

Exact solutions of heterotic string theory corresponding to four-dimensional charge Q magnetic black holes are constructed as tensor products of an SU(2)/Z(2Q+2) WZW orbifold with a (0,1) supersymmetric SU(1,1)/U(1) WZW coset model. The spectrum is analyzed in some detail. ``Bad&#39;&#39; marginal operators are found which are argued to deform these theories

Stephen-wei Chung, Masafumi Fukuma, Alfred Shapere

We construct and classify topological lattice field theories in three dimensions. After defining a general class of local lattice field theories, we impose invariance under arbitrary topology-preserving deformations of the underlying lattice, which are generated by two new local lattice moves. Invariant solutions are in one--to--one correspondence with Hopf

Andy Acker, Hisashi Kikuchi, Ernest Ma, Utpal Sarkar

Recently a model of chaotic inflation was proposed, where the right handed sneutrinos drive the baryogenesis. We study some of the details of the model, particularly the aspect of CP violation, and determine the number of right handed sneutrinos required for the viability of such models.

Lisa Randall, Raman Sundrum

The rates of the rare flavor-changing processes, $b \rightarrow s γ$ and $B_s \rightarrow μ^+ μ^-$ are estimated in extended technicolor models with and without a GIM mechanism. We find the $b \rightarrow s γ$ rate in ETC models with a GIM mechanism to be at most slightly larger than the standard model rate, whereas there is no significant extra model-indepe

V. Barger, M. S. Berger, P. Ohmann, R. J. N. Phillips

In minimal SUSY-GUT models with $M_{SUSY}\alt 1$ TeV, the renormalization group equations have a solution dominated by the infrared fixed point of the top Yukawa coupling. This fixed point predicts $m_t\simeq (200\; {\rm GeV})\sin β$; combined with the LEP results it excludes $m_t\alt 130$ GeV. For $m_t$ in the range 130--160 GeV, it predicts that the lighte

Frank Cuypers, Geert Jan van Oldenborgh, Reinhold Rückl

We consider the production and decay of selectrons and charginos in $e^-e^-$ collisions. The advantage over usual $e^+e^-$ collisions is the very low level of standard model backgrounds which should make the discovery of selectrons or charginos relatively straightforward. The use of polarized beams provides an additional powerful tool to determine the supers

Boris Kopeliovich

Color transparency (CT) is an effect of suppression of nuclear shadowing of hard reactions, closely related to the color screening. A brief review of theoretical development and experimental search for CT, failed and successful, are presented. A special emphasis is made on a quantum-mechanical nature of CT, as opposed to a wide spread erroneousclassical trea

O. Narayan, A. Alan Middleton

The critical behavior of charge-density waves (CDWs) in the pinned phase is studied for applied fields increasing toward the threshold field, using recently developed renormalization group techniques and simulations of automaton models. Despite the existence of many metastable states in the pinned state of the CDW, the renormalization group treatment can be

K. Schönhammer, V. Meden

In connection with recent publications we discuss spectral sum rules for the Tomonaga-Luttinger model without using the explicit result for the one-electron Green&#39;s function. They are usefull in the interpretation of recent high resolution photoemission spectra of quasi-one-dimensional conductors. It is shown that the limit of infinite frequency and band

V. L. Pokrovsky, L. P. Pryadko

We study the resonant tunneling of quasiparticles through an impurity between the edges of a Fractional Quantum Hall sample. We show that the one-particle momentum distribution of fractionally charged edge quasiparticles has a quasi-Fermi character. The density of states near the quasi-Fermi energy at zero temperature is singular due to the statistical inter

D. Tytler, X. -M Fan, V. T. Junkkarinen, R. D. Cohen

We present Lick Observatory slit spectra of 38 objects which were claimed to have pronounced ultraviolet excess and emission lines by Zhan \& Chen. Most of our spectra have FWHM spectral resolutions of about 4~Å, and relatively high S/N of about 10 -- 50, although some have FWHM $\simeq 15$~Å~or lower S/N. We find eleven QSOs, four galaxies at $z \simeq 0.1$

V. F. Polcaro, R. Viotti

We have found previously unreported observations of the galactic Luminous Blue Variable $η~Car$ covering the period 1860-1865. Contrary to the current belief, these data suggest that the star reached the first magnitude in 1860-1862, with possible large luminosity fluctuations, followed by a steep fading in 1865. A revised historical light curve of this most

R. Viotti, V. F. Polcaro, C. Rossi

Long slit spectra of the region around the Luminous Blue Variable AG Car obtained in June 1990, just before the onset of its new brightening phase, indicate that AG Car was in the hottest phase so far recorded. The spectrum shows strong broad emissions of He II 468.6 nm, and [Fe III] 465.8-470.1 nm, and He I, N II, Si III, Al III and Fe III with a P Cygni pr

Janusz Gwoździewicz, Arkadiusz Płoski

We give a simplified approach to the Abhyankar--Moh theory of approximate roots. Our considerations are based on properties of the intersection multiplicity of local curves.

Janusz Gwoździewicz

Let $k$ be an algebraically closed field of characteristic zero. Let $H:k^2\to k^2$ be a polynomial mapping such that the Jacobian $\text{Jac}\,H$ is a non-zero constant. In this note we prove, that if there is a line $l \subset k^2$ such that $H|_l:l\to k^2$ is an injection, then $H$ is a polynomial automorphism.

Arkadiusz Płoski

We give an estimate of the growth of a polynonial mapping of $C^n$.

Arkadiusz Płoski

For any polynomial mapping $F=(F_1,\dots ,F_n)$ of $\Cal C^n$ with a finite number of zeros we define the Noether exponent $ν(F)$. We prove the Jacobi formula for all polynomials of degree strictly less than $\sum_{i=1}^n (°F_i-1)-ν(F)$.

E. S. Cheng, D. A. Cottingham, D. J. Fixsen, C. A. Inman

Observations from the first flight of the Medium Scale Anisotropy Measurement (MSAM) are analyzed to place limits on Gaussian fluctuations in the Cosmic Microwave Background Radiation (CMBR). This instrument chops a 30\arcmin\ beam in a 3 position pattern with a throw of $\pm40\arcmin$; the resulting data is analyzed in statistically independent single and d

S. Bellucci, E. Ivanov, S. Krivonos, A. Pichugin

We study the integrability properties of the one-parameter family of $N=2$ super Boussinesq equations obtained earlier by two of us (E.I. \& S.K., Phys. Lett. B 291 (1992) 63) as a hamiltonian flow on the $N=2$ super-$W_3$ algebra. We show that it admits nontrivial higher order conserved quantities and hence gives rise to integrable hierarchies only for thre

Stephen W. Morris, Eberhard Bodenschatz, David S. Cannell, Guenter Ahlers

We report experiments on convection patterns in a cylindrical cell with a large aspect ratio. The fluid had a Prandtl number of approximately 1. We observed a chaotic pattern consisting of many rotating spirals and other defects in the parameter range where theory predicts that steady straight rolls should be stable. The correlation length of the pattern dec

Daniel L. Cox, Andrei E. Ruckenstein

We consider a $SU(N)\times SU(M)$ generalization of the multichannel single-impurity Kondo model which we solve analytically in the limit $N\rightarrow \infty$, $M\rightarrow\infty$, with $γ=M/N$ fixed. Non-Fermi liquid behavior of the single electron Green function and of the local spin and flavor susceptibilities occurs in both regimes, $N\le M$ and $N > M

Fred Cooper, Harvey Shepard, Pasquale Sodano

We study the class of generalized Korteweg-DeVries equations derivable from the Lagrangian: $ L(l,p) = \int \left( \frac{1}{2} \vp_{x} \vp_{t} - { {(\vp_{x})^{l}} \over {l(l-1)}} + α(\vp_{x})^{p} (\vp_{xx})^{2} \right) dx, $ where the usual fields $u(x,t)$ of the generalized KdV equation are defined by $u(x,t) = \vp_{x}(x,t)$. This class contains compactons,

Wayne N. Polyzou

I give a sufficient condition for a relativistic front-form quantum mechanical model to be scattering equivalent (unitarily equivalent with the same S-matrix elements) to a relativistic front-form quantum model with an interaction-independent front-form spin.

H. Hersbach

In this paper a relativistic quantum theory introduced by de Groot and \mbox{Ruijgrok} in 1975, is used as a quark model in momentum space. The complete spectrum, with the exception of the selfconjugate light unflavoured mesons, is calculated. The potential used consists of an one-gluon-exchange (OGE) part and a confining part. For the confining part a relat

Alan Dow, Klaas Pieter Hart

We show that many spaces that look like the half~line~$\halfline=[0,\infty)$ have, under~$\CH$, a Čech-Stone-remainder that is homeomorphic to~$\Hstar$. We also show that $\CH$ is equivalent to the statement that all standard subcontinua of~$\Hstar$ are homeomorphic. The proofs use Model-theoretic tools like reduced products and elementary equivalence; rathe

Asim Gangopadhyaya, Prasanta K. Panigrahi, Uday P. Sukhatme

We analyze transition potentials $(V(r) \stackrel{r\sim 0}{\rightarrow} {αr^{-2}})$ in non-relativistic quantum mechanics using the techniques of supersymmetry. For the range $-1/4 < α< 3/4$, the eigenvalue problem becomes ill-defined (since it is not possible to choose a unique eigenfunction based on square integrability and boundary conditions). It is show

Joaquim Fort, Tanmay Vachaspati

Hawking has shown that the emission of gravitational radiation cannot prevent circular loops of gauged cosmic strings from collapsing into black holes. Here we consider the corresponding question for global strings: can Goldstone boson emission prevent circular loops of global cosmic strings from forming black holes? Our results show that for every value of

A. Losev, I. Polyubin

We study flows on the space of topological Landau-Ginzburg theories coupled to topological gravity. We argue that flows corresponding to gravitational descendants change the target space from a complex plane to a punctured complex plane and lead to the motion of punctures.It is shown that the evolution of the topological theory due to these flows is given by

A. J. Niemi, K. Palo

Certain phase space path integrals can be evaluated exactly using equivariant cohomology and localization in the canonical loop space. Here we extend this to a general class of models. We consider hamiltonians which are {\it a priori} arbitrary functions of the Cartan subalgebra generators of a Lie group which is defined on the phase space. We evaluate the c

HoSeong La

In the standard model with two Higgs doublets it is shown that the existence of the electroweak Z-string in general requires the same characteristic length for the two Higgs fields as well as a specific ratio of the two Higgs vacuum expectation values, i.e. $\tanβ$. This ratio can be determined in terms of the couplings in the Higgs potential. Some remarks o

Duane A. Dicus, Wayne W. Repko

The cross section for photon neutrino scattering is calculated in the standard model assuming that the neutrino is massless and that the center of mass energy is small compared to any charged lepton mass. Although the scattered photons can acquire a (parity violating) circular polarization of order unity, the cross section in this limit is highly suppressed.

Bo-Qiang Ma

The spin structure of the pion is discussed by transforming the wave function for the pion in the naive quark model into a light-cone representation. It is shown that there are higher helicity ($λ_{1}+λ_{2}=\pm1$) states in the full light-cone wave function for the pion besides the ordinary helicity ($λ_{1}+λ_{2}=0$) component wave functions as a consequence

T. Elliott, S. F. King, P. L. White

Within the context of an effective potential formalism we calculate the contribution to Higgs boson masses in the next--to--minimal supersymmetric standard model from squark loops. We then supplement a previously performed renormalisation group analysis of the Higgs sector of this model with these results in order to determine the shift in the bound on the l

M. PraszaŁOWICZ, A. Blotz, K. Goeke

The paper describes the quantization of the SU(3) smibosonized Nambu-Jona-Lasinio model and results for mass splittings, including isospin splittings, and axial couplings. The agreement with the data is surprisingly good.

Andreas Ringwald

There exists the possibility that the cross-section for the nonperturbative production of many, ${\cal O}(α_W^{-1} \simeq 30 )$, weak gauge bosons may be as large as ${\cal O}(100\ {\rm pb}\ -\ 10\ μ$b$)$ above a parton-parton center-of-mass threshold in the range $2.4\ -\ 30$ TeV. We review the theoretical considerations which lead to this suggestion and ou

Alan Daughton, Jorma Louko, Rafael D. Sorkin

We consider quantization of the positive curvature Friedmann cosmology in the unimodular modification of Einstein&#39;s theory, in which the spacetime four-volume appears as an explicit time variable. The Hamiltonian admits self-adjoint extensions that give unitary evolution in the Hilbert space associated with the Schrödinger equation. The semiclassical est

Donald Marolf

A nonperturbative approach to quantum gravity that has generated much discussion is the attempt to construct a ``loop representation.&#34; Despite it&#39;s success in linear quantum theories and a part of 2+1 quantum gravity, it has recently been noticed that difficulties arise with loop representations in a different ``sector&#34; of 2+1 gravity. The proble

Hisa-aki SHINKAI, Kei-ichi MAEDA

To investigate the cosmic no hair conjecture, we analyze numerically 1-dimensional plane symmetrical inhomogeneities due to gravitational waves in vacuum spacetimes with a positive cosmological constant. Assuming periodic gravitational pulse waves initially, we study the time evolution of those waves and the nature of their collisions. As measures of inhomog

A. P. Gottlob, M. Hasenbusch

We present the results of a study of the three-dimensional $XY$-model on a simple cubic lattice using the single cluster updating algorithm combined with improved estimators. We have measured the susceptibility and the correlation length for various couplings in the high temperature phase on lattices of size up to $L=112$. At the transition temperature we st

Mark Abney

The hydrodynamic stability of deflagration and detonation bubbles for a first order electroweak and QCD phase transition has been discussed recently with the suggestion that detonations are stable. We examine here the case of a detonation more carefully. We find that in front of the bubble wall perturbations do not grow with time, but behind the wall modes e

Russel P. Kauffman, Wendy Schaffer

Models of electroweak symmetry breaking with more than a single doublet of Higgs scalars contain a neutral pseudoscalar boson. The production of such a pseudoscalar in hadron collisions proceeds primarily via gluon fusion through a top-quark loop (except for those models in which the pseudoscalar coupling to bottom quarks is strongly enhanced). We compute th

Marc Kamionkowski, John N. Bahcall

We re-evaluate the matrix element for the proton-proton reaction which is important for stellar-evolution calculations and for the solar-neutrino problem. We self-consistently determine the effect of vacuum polarization on the matrix element by first correcting the low-energy scattering data to account for vacuum polarization. We then calculate the proton-pr

Konstadinos Sfetsos

Following recent work on the effective quantum action of gauged WZW models, we suggest such an action for {\it chiral} gauged WZW models which in many respects differ from the usual gauged WZW models. Using the effective action we compute the conformally exact expressions for the metric, the antisymmetric tensor, and the dilaton fields in the $\s$-model aris

W. Siegel

We extend spacetime duality to superspace, including fermions in the low-energy limits of superstrings. The tangent space is a curved, extended superspace. The geometry is based on an enlarged coordinate space where the vanishing of the d&#39;Alembertian is as fundamental as the vanishing of the curl of a gradient.

Glennys R. Farrar, M. E. Shaposhnikov

We study the interactions of quarks and antiquarks with the changing Higgs field during the electroweak phase transition, including quantum mechanical and some thermal effects, with the only source of CP violation being the known CKM phase. The magnitude and sign of the predicted BAU agrees with the observed value, with moderately optimistic assumptions abou

M. B. Halpern, N. A. Obers

The affine-Virasoro Ward identities are a system of non-linear differential equations which describe the correlators of all affine-Virasoro constructions, including rational and irrational conformal field theory. We study the Ward identities in some detail, with several central results. First, we solve for the correlators of the affine-Sugawara nests, which

David Seibert

Regression with $χ^2$ constructed from the covariance matrix should not be used for some combinations of covariance matrices and fitting functions. Using the technique for unsuitable combinations can amplify systematic errors. This amplification is uncontrolled, and can produce arbitrarily inaccurate results that might not be ruled out by a $χ^2$ test. In ad

Ovid C. Jacob

Parity violation is a long standing problem in light-cone quantization. \REF\CPT{D. Soper, SLAC-REP-137, 1970, Chap. I . } \refend We propose a new quantization on the light-cone which treats both the $x^{+}$ and the $x^{-}$ coordinates as light-cone &#39;times.&#39;This quantization respects both parity and time-reversal. We find that now both $P^{-}$ and $

Y. Aharonov, S. Popescu, D. Rohrlich, L. Vaidman

An analysis of errors in measurement yields new insight into the penetration of quantum particles into classically forbidden regions. In addition to ``physical&#34; values, realistic measurements yield ``unphysical&#34; values which, we show, can form a consistent pattern. An experiment to isolate a particle in a classically forbidden region obtains negative

Gia Dvali, Goran Senjanović

We show that for a large range of parameters in a $SU(2)_L\times U(1)$ electroweak theory with two Higgs doublets there may exist classically stable flux tubes of Z boson magnetic field. In a limit of an extra global $\tilde U(1)$ symmetry, these flux-tubes become topologically stable. These results are automatically valid even if $\tilde U(1)$ is gauged.

V. Barger, Kingman Cheung, T. Han, D. Zeppenfeld

We reanalyze the extraction of the heavy Higgs boson signal $H\rightarrow W^+W^-\rightarrow \bar\ellν,\ell\barν$ $(\ell=e\hbox{ or }μ)$ from the Standard Model background at hadron supercolliders, taking into account revised estimates of the top quark background. With new acceptance criteria the detection of the signal remains viable. Requiring a forward jet

C. Giunti, C. W. Kim, J. A. Lee

We discuss neutrino oscillations in the framework of the quantum field theory without introducing the concept of neutrino weak eigenstates. The external particles are described by wave packets and the different mass eigenstate neutrinos propagate between the production and detection interactions, which are macroscopically localized in space-time. The time-av

Glennys R. Farrar, M. E. Shaposhnikov

We calculate the baryon asymmetry of the Universe which would arise during a first order electroweak phase transition due to minimal standard model processes. It agrees in sign and magnitude with the observed baryonic excess, for resonable KM parameters and m$_t$ in the expected range, and plausible values of bubble velocity and other high temperature effect

A. Denner, W. Hollik, B. Lampe

The leading heavy-top two-loop corrections to the \Zbb~vertex are determined from a direct evaluation of the corresponding Feynman diagrams in the large \Mt~limit. %The calculation is done in the naive %dimensional regularization scheme with anticommuting $\ga_5$. The leading one-loop top-mass effect is enhanced by $[1+\GF\Mt^2(9-π^2/3)/(8π^2\sqrt{2})]$. Our

H. G. Evertz, M. Marcu

Within a general cluster framework, we discuss the loop-algorithm, a new type of cluster algorithm that reduces critical slowing down in vertex models and in quantum spin systems. We cover the example of the 6-vertex model in detail. For the F-model, we present numerical results that demonstrate the effectiveness of the loop algorithm. We discuss how to modi

P. Coleman, E. Miranda, A. Tsvelik

We discuss the possibility that heavy fermion superconductors involve odd-frequency pairing of the kind first considered by Berezinskii. Using a toy model for odd frequency triplet pairing in the Kondo lattice we are able to examine key properties of this new type of paired state. To make progress treating the strong $n_f=1$ constraint in the Kondo lattice m

Christian Muenkel, Dieter W. Heermann

We present structural properties of two-dimensional polymers as far as they can be described by percolation theory. The percolation threshold, critical exponents and fractal dimensions of clusters are determined by computer simulation and compared to the results of percolation theory. We also describe the dependence of the typical cluster structures on the r

T. H. Hansson, Anders Karlhede, Erik Westerberg

We reconsider the problem of anyons on higher genus surfaces by embedding them in three dimensional space. From a concrete realization based on three dimensional flux tubes bound to charges moving on the surface, we explicitly derive all the representations of the spinning braid group. The component structure of the wave functions arises from winding the flu