September 1993 arXiv papers — page 6

Véronique Bernard, Norbert Kaiser, Armin Schmidt, Ulf-G. Meißner

We calculate the nucleons' electromagnetic polarizabilities in heavy baryon chiral perturbation theory including all terms to order ${\cal O} (q^4)$. The chiral prediction of the electric polarizabilities for the neutron and the proton are in good agreement with the data. In the case of the magnetic polarizabilities the big positive contribution from the

J. C. Montero, V. Pleitez

We consider effective interactions among excited spin-1/2 and spin-3/2 leptons with the usual ones. Assuming that these new leptons are lighter than the Z0 we will study the constraints on their masses and compositeness scale coming from the leptonic Z0 partial width.

Leszek Roszkowski

Several independent constraints on the minimal supersymmetric model with constraints from grand unifications and cosmology select the region of low-energy supersymmetry below ${\cal O}$(1~TeV). The resulting mass of the lightest Higgs boson can probably be covered at LEP II only if its beam energy exceeds 200~GeV, and is within the detectability range of the

Leszek Roszkowski

I discuss several promising $R$-parity violating processes at $e^+e^-$ colliders.

J. L. Hewett, T. G. Rizzo

We explore the possibility that $Z'$ couplings can be probed using decay modes which involve neutrinos once Standard Model backgrounds are directly determined by the data itself. For some models, sufficient statistics are available at either the SSC or LHC to render these modes useful for coupling determinations, provided the mass of the $Z'$ is not

Minos Axenides, A. Johansen, H. B. Nielsen

We discuss a novel manifestation of the $SU(2)$ global anomaly in an $SU(2)$ gauge theory with an odd number of chiral quark doublets and arbitrary Yukawa couplings. We argue that the massive 4-dim.($D=4$) Euclidean Dirac operator is nonhermitean with its spectrum of eigenvalues $(λ,-λ)$ lying in pairs in the complex plane. Consequently the existence of an o

A. D. Martin, W. J. Stirling, R. G. Roberts

We investigate the proposal of the CDF collaboration that same-side two-jet production in $p\bar{p}$ collisions may be used to determine the gluon distribution at small $x$.

Andrzej J. Buras, Markus E. Lautenbacher

Using the idea of the penguin box expansion we find an analytic expression for epsilon'/epsilon in the Standard Model as a function of m_t, m_s(m_c) and two non-perturbative parameters B_6 and B_8. This formula includes next-to-leading QCD/QED short distance effects calculated recently by means of the operator product expansion and renormalization group

G. Cvetic

We investigate CP-violation effects in the bosonic sector of the Standard Model (SM) with two Higgs doublets. First we calculate the mass eigenstates of the physical neutral Higgses for small but nonzero CP-violation parameter $ξ_{\ast}$, and then a ``forward-backward'' asymmetry ${\cal A}_{fb}$ for the decay $H \to W^+W^-Z$ that would be a signal of

Jose W. F. Valle

Invited lecture at Int. School on Particles and Cosmology, Baksan Valley, 1993

Jose W. F. Valle

Invited talk at Second Workshop on JINR CTau Factory, Dubna, April 1993, updated version of earlier review given at Second Workshop on Tau Lepton Physics, Ohio, september 1992

Kajia Yuan

The possible solution of dark matter problem with neutralinos of supersymmetric models within the supergravity framework is reviewed. A novel correlation between the neutralino relic abundance $Ω_χ$ and the soft supersymmetry breaking patterns is demonstrated. It is explained that, this generic result together with the proton-decay constraint could significa

I. P. Gent, T. Walsh

We describe an extensive study of search in GSAT, an approximation procedure for propositional satisfiability. GSAT performs greedy hill-climbing on the number of satisfied clauses in a truth assignment. Our experiments provide a more complete picture of GSAT's search than previous accounts. We describe in detail the two phases of search: rapid hill-clim

V. I. Belinicher, A. L. Chernyshev

A full three-band model for the CuO$_{2}$ plane with inclusion of all essential interactions - Cu-O and O-O hopping, repulsion at the copper and oxygen and between them - is considered. A general procedure of the low-energy reduction of the primary Hamiltonian to the Hamiltonian of the generalized $t$-$t'$-$J$ model is developed. An important role of the

J. W. Dufty, M. H. Ernst

Intrinsic fluctuations around the solution of the lattice Boltzmann equation are described or modeled by addition of a white Gaussian noise source. For stationary states a fluctuation-dissipation theorem relates the variance of the fluctuations to the linearized Boltzmann collision operator and the pair correlation function.

Mark Srednicki, Martin White, Douglas Scott, Emory T. Bunn

We analyze the Gamma Ursae Minoris (GUM) and Mu Pegasii (MuP) scans of the Millimeter-wave Anisotropy eXperiment in the context of cold dark matter (CDM) models of structure formation, paying particular attention to the two-dimensional nature of the GUM scan. If all of the structure in the (foreground subtracted) data is attributed to cosmic microwave backgr

G. A. Drukier, G. G. Fahlman, H. B. Richer, L. Searle

I-band CCD images of a large area of the nearby globular cluster NGC~6397 have been used to construct a surface density profile and two luminosity and mass functions. The surface density profile extends out to 14\arcm from the cluster center and shows no sign of a tidal cutoff. The inner profile is a power-law with slope -0.8 steepening to -1.7 outside of 1\

Matthias Steinmetz, Ewald Mueller

The formation of galaxies in a CDM cosmogony is investigated by following the evolution of dark and baryonic matter and of the frequency- dependent spatially averaged radiation field. The gas is allowed to form stars which are independently treated as a fourth collisionless component. By supernovae, energy and metal enriched gas is returned to the interstell

Uros Seljak, Edmund Bertschinger

We have used maximum-likelihood estimation to determine the quadrupole amplitude $Q_{\rm rms-PS}$ and the spectral index $n$ of the density fluctuation power spectrum at recombination from the \cobe\ DMR data. We find a strong correlation between the two parameters of the form $Q_{\rm rms-PS}=(15.7\pm 2.6)\exp[0.46(1-n)]\mk$ for fixed $n$. Our result is slig

Peter Tamblyn, Fulvio Melia

It is well known that Gamma-ray Burst spectra often display a break at energies $\simless 400$ keV, with some exceptions extending to several MeV.\ \ Modeling of a cosmological source population is thus non-trivial when comparing the catalogs from instruments with different energy windows since this spectral structure is redshifted across the trigger channel