October 1993 arXiv papers — page 7

S. Yu. Khlebnikov

We present arguments in favor of the idea that supersymmetric sigma models with compact symmetric Kähler spaces as target manifolds have a second-order phase transition in four dimensions. When applied to electroweak symmetry breaking, these models then do not require a light Higgs boson or techni-resonances but predict fermionic superpartners of longitudina

Frank Cuypers

We consider the effect of a massless gluino on the evolution of a parton shower. The hadron multiplicity distribution is predicted to evolve as a function of the collider energy in the same way as in the absence of gluinos, except for a slower running of $α_s$. A comparison of the predicted average hadron multiplicity with experimental data is presented as a

S. Kelley

I define the Standard Supersymmetric Model (SSM) as the minimal supersymmetric extension ofthe Standard Model with gauge coupling unification and universal soft supersymmetry breaking at the unification scale. This well-defined model has a five-dimensional space of unknown parameters ($m_t, \tanβ, m_{1/2}, m_0, A$). I outline the top-down and bottom-up metho

R. Rosenfeld

We investigate the feasibility of distinguishing among different models of electroweak symmetry breaking by studying the process $γγ\rightarrow Z_L Z_L$ at photon colliders. For models with a low mass Higgs-like scalar resonance, the $s$-channel contribution provides a distinct resonance structure and large cross sections. However, the absence of a resonance

B. Holdom, M. Sutherland, J. Mureika

We extend our relativistic quark model to the study of the decay Lambda_b -> Lambda_c ell nu and verify that the model satisfies the heavy-quark symmetry constraints at order 1/mQ^2. We isolate a strong dependence on a parameter which measures the relative distortion in the light-quark wave functions of the Lambda_b and Lambda_c. This parameter and the 1/mQ^

M. Bastero-Gil, J. Perez-Mercader

In this paper we study and compare susy unification using two different approaches in order to take into account the effect of light particle thresholds on the evolution of gauge couplings: the step--function approximation, on the one hand, and a mass dependent procedure, which gives a more accurate description of the dependence of the results on the masses,

Paul Hoyer

I discuss some questions related to hard scattering processes in nuclei and corrections to the leading twist approximation. The QCD factorization theorem requires that high energy partons do not lose energy while traversing the nucleus. I explain the physical reason for this. The theorem also states that spectator partons, not involved in the hard collision,

Probir Roy

Review of the electroweak sector of the minimal standard model, Basic LEP processes at the tree level, 1-loop radiative corrections in the on-shell renormalization scheme, Star scheme and oblique corrections, Introduction to oblique parameters.

F. M. Borzumati

We present a re-analysis of the decay $\bsgamma$ in the Minimal Supersymmetric Standard Model with radiatively induced breaking of $SU(2) \times U(1)$. We extend this analysis to regions of the supersymmetric parameter space wider than those previously studied. Results are explicitly presented for $m_t=150\GeV$. We emphasize the consequences for future searc

Jonathan Feng, Donald Finnell

Current mass limits allow the possibility that squarks may be produced in large numbers at the next generation of linear $e^+e^-$ colliders. In this paper we investigate the prospects for precision studies of squark masses at such colliders. We assume that squarks are lighter than gluinos, and discuss both direct and cascade decay scenarios. By exploiting th

C. F. Baillie, D. A. Johnston

It has been suggested that the peak in the specific heat observed numerically for random surface actions with extrinsic curvature on dynamical lattices might be the result of a low mass bound state in an asymptotically free theory, rather than the signal for a real phase transition. The $O(3)$ model on a fixed lattice displays just such behaviour, but in gen

J. Fernando Barbero

We show in this paper that it is possible to formulate General Relativity in a phase space coordinatized by two $SO(3)$ connections. We analyze first the Husain-Kuchař model and find a two connection description for it. Introducing a suitable scalar constraint in this phase space we get a Hamiltonian formulation of gravity that is close to the Ashtekar one,

H. H. Soleng

The gravitational effect of vacuum polarization in space exterior to a particle in (2+1)-dimensional Einstein theory is investigated. In the weak field limit this gravitational field corresponds to an inverse square law of gravitational attraction, even though the gravitational mass of the quantum vacuum is negative. The paradox is resolved by considering a

C. R. Stephens, G. 't Hooft, B. F. Whiting

An approach to black hole quantization is proposed wherein it is assumed that quantum coherence is preserved. A consequence of this is that the Penrose diagram describing gravitational collapse will show the same topological structure as flat Minkowski space. After giving our motivations for such a quantization procedure we formulate the background field app

Albert Stebbins

Methods for inferring the velocity field from the peculiar velocity data are described and applied to old and newer data. Inhomogeneous Malmquist bias and ways to avoid it are discussed and utilized. We infer that these biases are probably important in interpreting the data.

Andrew Newsam, John F. L. Simmons, Martin Hendry

We investigate the effect of using different distance estimators on the recovery of the peculiar velocity field of galaxies using Potent. An inappropriate choice of distance estimator will give rise to spurious flows. We discuss methods of minimising these biases and the levels of accuracy required of distance estimators to retrieve velocity fields to a give

John F. L. Simmons, Andrew Newsam, Martin Hendry

Although Potent purports to use only radial velocities in retrieving the potential velocity field of galaxies, the derivation of transverse components is implicit in the smoothing procedures. Thus the possibility of using nonradial line integrals to derive the velocity field arises. In the case of inhomogeneous distributions of galaxies, the optimal path for

Marek Biesiada

In this letter we propose a physical explanation for recently reported correlations between pairs of close and antipodal gamma-ray bursts from publicly available BATSE catalogue. Our model is based on the cosmological scenario in which bursters are located at cosmological distances of order of 0.5--2~Gpc. Observed distribution of gamma-ray bursts strongly su

S. Aoyama

We introduce the Virasoro symmetry in the BV formalism and give an explicit construction of the anti-bracket, which is Virasoro invariant. It is shown that the master equation with this anti-bracket has an infinite number of solutions. The base space of the BV formalism is a fermionic version of the Virasoro manifold $Diff(S^1)/S^1$. We discuss also the Ricc

V. Khatsymovsky

As basic variables in general relativity (GR) are chosen antisymmetric connection and bivectors - bilinear in tetrad area tensors subject to appropriate (bilinear) constraints. In canonical formalism we get theory with polinomial constraints some of which are II class. On partial resolving the latter we get another polinomial formulation. Separating self- an

V. Khatsymovsky

(3+1) (continuous time) Regge calculus is reduced to Hamiltonian form. The constraints are classified, classical and quantum consequences are discussed. As basic variables connection matrices and antisymmetric area tensors are used supplemented with appropriate bilinear constraints. In these variables the action can be made quasipolinomial with $\arcsin$ as

Viqar Husain

Starting from the Ashtekar Hamiltonian variables for general relativity, the self-dual Einstein equations (SDE) may be rewritten as evolution equations for three divergence free vector fields given on a three dimensional surface with a fixed volume element. From this general form of the SDE, it is shown how they may be interpreted as the field equations for

V. Kurasov

The kinetics of the multicomponent condensation after the instantaneous creation of the metastable state is described analytically. Manydimensional problem is reduced to the one-dimensional case. All the main characteristics of the process are obtained analytically with the help of iteration procedure. As the result the analytical theory for the decay of the

Sanjay K. Ghosh, S. C. Phatak, Pradip K. Sahu

The neutrino emissivity from two and three flavour quark matter is numerically calculated and compared with Iwamoto's formula. We find that the calculated emissivity is smaller than Iwamoto's result by orders of magnitude when $p_{f}(u)+p_{f}(e)-p_{f}(d(s))$ is comparable with the temperature. We attribute it to the severe restriction imposed by mome

Robert H. Brandenberger, David M. Kaplan, Stephen A, Ramsey

Good statistics for measuring large-scale structure in the Universe must be able to distinguish between different models of structure formation. In this paper, two and three dimensional ``counts in cell" statistics and a new ``discrete genus statistic" are applied to toy versions of several popular theories of structure formation: random phase cold d

Nemanja Kaloper

The effective action of string theory in three dimensions is investigated, incorporating the Lorentz and gauge Chern-Simons terms in the definition of the Kalb-Ramond axion field strength. Since in three dimensions any three-form is trivial, the action can be reformulated by properly integrating the axion out. The circumstances under which it can be recast i

T. E. Clarke, O. Blaes, adn S. Tremaine

We examine the possibility that gamma-ray bursts arise from sources in the Oort comet cloud, basing most of our arguments on accepted models for the formation and spatial distribution of the cloud. We identify three severe problems with such models: (1) There is no known mechanism for producing bursts that can explain the observed burst rate and energetics w

Lev Borisov

We propose a combinatorical duality for lattice polyhedra which conjecturally gives rise to the pairs of mirror symmetric families of Calabi-Yau complete intersections in toric Fano varieties with Gorenstein singularities. Our construction is a generalization of the polar duality proposed by Batyrev for the case of hypersurfaces.

David A. Lowe

Withdrawn due to error. See D. Lowe, L. Susskind and J. Uglum, hep-th/9402136, for correct treatment. Apologies to all recipients.

R. Brooks

Observables in the quantum field theories of $(D-1)$-form fields, $\ca$, on $D$-dimensional, compact and orientable manifolds, $M$, are computed. Computations of the vacuum value of $T_{ab}$ find it to be the metric times a function of the volume of spacetime, $Ω(M)$. Part of this function of $Ω$ is a finite zero-mode contribution. The correlation functions

Chung Kao

A two Higgs doublet model is employed to study the production of a CP-odd Higgs boson ($A$) associated with a large transverse momentum jet ($j$) at hadron supercolliders. The cross section of $pp \to jA+X$ is evaluated with four subprocesses: $gg \to gA$, $gq \to qA$, $g\bar{q} \to \bar{q}A$ and $q\bar{q} \to gA$. We find that $pp \to jA+X$ is a significant

A. K. Rebhan

It is shown that by defining the Debye mass through the relevant pole of the static gluon propagator rather than the zero-momentum limit of the time-time component of the gluon self-energy, a gauge-independent result for the next-to-leading order correction can be derived upon resummation of hard-thermal-loop contributions. The result turns out to be logarit

A. L. Chernyshev, A. V. Dotsenko, O. P. Sushkov

Using an analytical variational approach we calculate the hole-hole contact interaction on the Néel background. Solution of the Bethe-Salpeter equation with this interaction gives bound states in $d$- and p-waves with binding energies close to those obtained by numerical methods. At $t/J \ge 2-3$ the bound state disappears. In conclusion we discuss the relat

F. Krmpotić

Simple formulae for the $0^+\to 0^+$ double beta decay matrix elements, as a function of the particle-particle strength $g^{pp}$, have been designed within the quasiparticle random phase approximation. The $2ν$ amplitude is a bilinear function of $g^{pp}$, and all $0ν$ moments behave as ratios of a linear function and the square root of another linear functi

C. Gong, S. G. Matinyan, B. Mueller, A. Trayanov

We show that a high frequency standing wave in SU(2) gauge theory is unstable against decay into long wavelength modes. This provides a non-perturbative mechanism for energy transfer from initial high momentum modes to final states with low momentum excitations. The abelian case does not manifest such instability. Our analysis is supported by lattice simulat

Svante Janson, Donald E. Knuth, Tomasz Łuczak, Boris Pittel

Limiting distributions are derived for the sparse connected components that are present when a random graph on $n$ vertices has approximately $\half n$ edges. In particular, we show that such a graph consists entirely of trees, unicyclic components, and bicyclic components with probability approaching $\sqrt{2\over 3} \cosh\sqrt{5\over 18}\approx0.9325$ as $

Charles Radin

We discuss two new results on tilings of the plane. In the first, we give sufficient conditions for the tilings associated with an inflation rule to be uniquely ergodic under translations, the conditions holding for the pinwheel inflation rule. In the second result we prove there are matching rules for the pinwheel inflation rule, making the system the first

Palle E. T. Jorgensen, Steen Pedersen

We describe a class of measurable subsets $Ω$ in $\br^d$ such that $L^2(Ω)$ has an orthogonal basis of frequencies $e_λ(x)=e^{i2πλ\cdot x}(x\inΩ)$ indexed by $λ\inΛ\subset\br^d$. We show that such spectral pairs $(Ω,Λ)$ have a self-similarity which may be used to generate associated fractal measures $μ$ with Cantor set support. The Hilbert space $L^2(μ)$ doe

Jeannette C. M. Janssen

The Dinitz conjecture states that, for each $n$ and for every collection of $n$-element sets $S_{ij}$, an $n\times n$ partial latin square can be found with the $(i,j)$\<th entry taken from $S_{ij}$. The analogous statement for $(n-1)\times n$ rectangles is proven here. The proof uses a recent result by Alon and Tarsi and is given in terms of even and odd or

Jenny Harrison

Much of the vast literature on the integral during the last two centuries concerns extending the class of integrable functions. In contrast, our viewpoint is akin to that taken by Hassler Whitney [{\it Geometric integration theory}, Princeton Univ. Press, Princeton, NJ, 1957] and by geometric measure theorists because we extend the class of integrable {\it d

John Hannah, K. C. O&#39;Meara

A new dimension function on countable-dimensional algebras (over a field) is described. Its dimension values for finitely generated algebras exactly fill the unit interval $[0,1]$. Since the free algebra on two generators turns out to have dimension 0 (although conceivably some Noetherian algebras might have positive dimension!), this dimension function prom

Fritz Gesztesy, Helge Holden, Barry Simon, Zhong Xin Zhao

We extend the well-known trace formula for Hill&#39;s equation to general one-dimensional Schrödinger operators. The new function $ξ$, which we introduce, is used to study absolutely continuous spectrum and inverse problems.

Graciela Chichilnisky

Two classical problems in economics, the existence of a market equilibrium and the existence of social choice functions, are formalized here by the properties of a family of cones associated with the economy. It was recently established that a necessary and sufficient condition for solving the former is the nonempty intersection of the family of cones, and o

A. R. Calderbank, A. Roger Hammons, P. Vijay Kumar, N. J. A. Sloane

The Nordstrom-Robinson, Kerdock, and (slightly modified) Pre\- parata codes are shown to be linear over $\ZZ_4$, the integers $\bmod~4$. The Kerdock and Preparata codes are duals over $\ZZ_4$, and the Nordstrom-Robinson code is self-dual. All these codes are just extended cyclic codes over $\ZZ_4$. This provides a simple definition for these codes and explai

Walter Bergweiler

This paper attempts to describe some of the results obtained in the iteration theory of transcendental meromorphic functions, not excluding the case of entire functions. The reader is not expected to be familiar with the iteration theory of rational functions. On the other hand, some aspects where the transcendental case is analogous to the rational case are

Martin T. Barlow, Richard F. Bass

Uniform Harnack inequalities for harmonic functions on the pre- and graphical Sierpinski carpets are proved using a probabilistic coupling argument. Various results follow from this, including the construction of Brownian motion on Sierpinski carpets embedded in $\R^d$, $d\geq 3$, estimates on the fundamental solution of the heat equation, and Sobolev and Po

Victor M. Villalba

In the present article we have found the complete energy spectrum and the corresponding eigenfunctions of the Dirac oscillator in two spatial dimensions. We show that the energy spectrum depends on the spin of the Dirac particle.

D. Bailin, A. Love, W. A. Sabra, S. Thomas

The moduli dependence of string loop threshold corrections to gauge coupling constants is investigated for those ${\bf Z}_N$ Coxeter orbifolds with the property that some twisted sectors have fixed planes for which the six-torus ${\bf T}_6$ can not be decomposed into a direct sum ${\bf T}_4 \bigoplus{\bf T}_2$ with the fixed plane lying in ${\bf T}_2.$

D. B. Fairlie

Necessary conditions for a field theoretic equation of motion to be the consequence of variation of an infinite number of inequivalent Lagrangians are examined.

D. B. Fairlie, J. A. Mulvey

The Born-Infeld equation in two dimensions is generalised to higher dimensions whilst retaining Lorentz Invariance and complete integrability. This generalisation retains homogeneity in second derivatives of the field.

Boris Feigin, Feodor Malikov

We define and calculate the fusion algebra of WZW model at a rational level by cohomological methods. As a byproduct we obtain a cohomological characterization of admissible representations of $\widehat{\gtsl}_{2}$.

Andrew Toon

General covariance in quantum gravity is seen once one integrates over all possible metrics. In recent years topological field theories have given us a different route to general covariance without integrating over all possible metrics. Here we argue that Einstein quantum gravity may be viewed as a topological field theory provided a certain constrant from t

G. Ferretti

It is shown that the bosonic angular degrees of freedom in the one dimensional Marinari-Parisi superstring can be integrated out exactly in the Hamiltonian formulation without having to perform the Dabholkar truncation. The resulting Hamiltonian is that of a supersymmetric Calogero system plus a four fermions interaction. This extra interaction vanishes for

M. Chaichian, A. P. Demichev

Using differential and integral calculi on the quantum plane which are invariant with respect to quantum inhomogeneous Euclidean group E(2)q , we construct path integral representation for the quantum mechanical evolution operator kernel of q-oscillator.

Ursula Carow-Watamura, Satoshi Watamura

We consider the $q$-deformed Schrödinger equation of the harmonic oscillator on the $N$-dimensional quantum Euclidian space. The creation and annihilation operator are found, which systematically produce all energy levels and eigenfunctions of the Schrödinger equation. In order to get the $q$-series representation of the eigenfunction, we also give an altern

Joannis Papavassiliou, Kostas Philippides

We use the S-matrix pinch technique to derive to one loop-order gauge independent $γW^{+} W^{-} $ and Z $W^{+} W^{-}$ vertices in the context of the Standard Model,with all three incoming momenta off-shell. We show that the $γW^{+} W^{-}$ vertex so constructed is related to the gauge-independent W self-energy,derived by Degrassi and Sirlin,by a very simple Q

M. Drees, M. M. Nojiri

We study the production and decay of a scalar \stst\ bound state \sigst\ at hadron supercolliders, where \st\ is the lighter stop eigenstate. If \st\ has no tree--level 2--body decays, the dominant decay modes of \sigst\ are $gg$ or, if $m_h < \mst \ll \mstt$, a pair of light scalar Higgs bosons $h$. Nevertheless the branching ratio into two photons is often

P. Labelle, G. P. Lepage, U. Magnea

We discuss how contributions to the order ${\cal O} (m α^8)$ orthopositronium decay rate can be separated into two categories, one due to relativistic momenta and calculable in terms of QED scattering amplitudes, the other due to low momenta and calculable in the simpler framework of a low-energy effective theory (NRQED). We report new results for all low-mo

Andy Acker, Sandip Pakvasa

We re-examine the neutrino decay solution to the solar neutrino problem in light of the new data from Gallex II and Kamiokande III. We compare the experimental data with the solar models of Bahcall and Pinsonneault and Turck-Chieze and find that neutrino decay is ruled out as a solution to the solar neutrino problem at better than the 98\% c.l. even when sol

Loyal Durand, Bernd Kniehl, Kurt Riesselmann

We present the dominant two-loop ${\rm O}\left(G_F^2M_H^4\right)$ electroweak corrections to the fermi\-onic decay widths of a high-mass Higgs boson in the Standard Model. The corrections are negative and quite significant, and are larger in magnitude than the one-loop electroweak corrections for $M_H\gsim 400\ {\rm GeV}$. This indicates the onset of a break

E. Leader, Sridhar K

We present the results of a detailed study of the large transverse momentum Drell-Yan process, pp --> (Gamma^*, Z^*)X --> l^+l^- X at collider energies, with either one or both protons polarised, allowing the study of single- and double-spin asymmetries respectively. We show how these asymmetries obtained from angular distributions of the leptons in the Gamm

D. T. Barclay, C. J. Maxwell, M. T. Reader

We show that standard next-to-leading order (NLO) perturbative QCD analyses used to extract $α_{s}$ from LEP data do not serve to disentangle the completely unknown renormalization scheme (RS) invariant next-NLO (NNLO) and higher-order uncalculated corrections from those dependent on the renormalization scale in a predictable manner. The resulting quoted val

Jonathan A. Bagger

Invited talk presented at the Workshop on Physics at Current Accelerators and the Supercollider, Argonne, Illinois, and at the 17th Johns Hopkins Workshop on Current Problems in Particle Theory, Budapest, Hungary.

Jeroen C. Vink

It is described how to obtain an almost gauge invariant lattice action $S$ for chiral gauge theories, or other models in which a straightforward discretization leads to a lattice action $S^\pr$ in which gauge invariance is broken. The lattice action is `almost&#39; gauge invariant, because a local gauge transformation leaves the action the same, up to a glob

Sourendu Gupta

We study the dynamics of the first order phase transition in the two dimensional 15-state Potts model, both at and off equilibrium. We find that phase changes take place through nucleation in both cases, and finite volume effects are described well through an instanton computation. Thus a dynamical measurement of the surface tension is possible. We find that

G. W. Gibbons, C. G. Wells

Recently Penrose, Sorkin and Woolgar have developed a new technique for proving the positive mass theorem in general relativity. We extend their result to produce a new inequality relating the mass, electric and scalar charges in theories coupling to a dilaton in the usual way. Using a five dimensional formalism, our result provides new information not avail

Marco Cavaglia&#39;, Vittorio de Alfaro

We investigate the properties of a quantum Robertson - Walker universe described by the Wheeler -- DeWitt equation. The universe is filled with a quantum Yang -- Mills uniform field. This is then a quantum mini copy of the standard model of our universe. We discuss the interpretation of the Wheeler -- DeWitt wave function using the correspondence principle t

S. C. Phatak, S. Suresh Rao

The logistic map is one of the simple systems exhibiting order to chaos transition. In this work we have investigated the possibility of using the logistic map in the chaotic regime ({\sc logmap}) for a pseudo random number generator. To this end we have performed certain statistical tests on the series of numbers obtained from the {\sc logmap}. We find that

Leon Balents

The equilibrium behavior of a system of elastic layers under tension in the presence of correlated disorder is studied using functional renormalization group techniques. The model exhibits many of the features of the Bose glass phase of type II superconductors induced by columnar defects, but may be more directly applicable to charge density waves, incommens

T. Tokuyasu, M. Kamal, G. Murthy

A numerical renormalization group technique based on Wilson&#39;s momentum shell method is presented for interacting, finite fermi systems. Results for small fullerene analogs show that the method is quite accurate to moderate values of $U$, and qualitatively better than other approximation methods. The method has potential applicability far beyond the fulle

August Evrard, Joseph Mohr, Daniel Fabricant, Margaret Geller

We employ N--body/$3D$ gas dynamic simulations of the formation of galaxy clusters to determine whether cluster X--ray morphologies can be used as cosmological constraints. Confirming the analytic expectations of Richstone, Loeb, \& Turner, we demonstrate that cluster evolution is sensitive to the cosmological model in which the clusters form. We further sho

R. Moessner, L. Perivolaropoulos, R. Brandenberger

Using an analytical model for the string network we show that the kurtosis of cosmic microwave background (CMB) temperature gradient maps is a good statistic to distinguish between the cosmic string model and inflationary models of structure formation. The difference between the stringy and inflationary value for the kurtosis is inversely proportional to the