Leptogenesis from supersymmetry breaking

We show that soft supersymmetry breaking terms involving the heavy sneutrinos can lead to sneutrino-antisneutrino mixing and to new sources of CP violation, which are present even if a single generation is considered. These terms are naturally present in supersymmetric versions of leptogenesis scenarios, and they induce indirect CP violation in the decays of the heavy sneutrinos, eventually generating a baryon asymmetry. This new contribution can be comparable to or even dominate over the asymmetry produced in traditional leptogenesis scenarios.     

A new approach to the solution of the Navier-Stokes equations

In the present paper a numerical algorithm is given for solving a standard problem in fluid dynamics, that of inviscid, irrotational, incompressible flow over an arbitrary symmetric profile. The purpose of the paper is to propose an alternative approach to solve certain fluid dynamic flows. This paper may be thought of as the first of a possible series of papers solving new and fundamental problems. In a sense, this new approach asks the question: what is the simplest and most efficient method of solving the problem considered by finite difference methods. It is believed that the following algorithm answers this question. Standard second-order finite difference techniques, such as SLOR and ADI, are used to solve numerically a mixed boundary value problem comprised of a pair of elliptic partial differential equations with constant coefficients.     

Leading particles and charged particle multiplicity in annihilation and non-annihilation interactions

Using data from our K^?p experiment at 8.25 GeV/c we have investigated the charged particle multiplicity, and the variation of charged pion multiplicity as a function of the effective mass squared of all pions, for various samples of data, and compared our results with $\text{p}$p annihilation data and pp data. Evidence is presented which suggests that the difference in behaviour between the annihilation and non-annihilation data is not due to some specific mechanism such as baryon exchange, but is related to the absence of leading particles in the former case.     

The relativistic Kronig-Penney Hamiltonian

Measurements of the microwave impedence of superconducting point contacts as a function of the phase difference ø yields a conductance of the form G(ø) = G₀(1 + α cos ø) which can be interpreted in terms of a relaxation time of the order parameter.     

U. Grigull zum 60. Geburtstag

Ohne Zusammenfassung     

The conductivity of a medium interrupted by voids

Résumé On calcule la conductivité d'un milieu en forme de parallelépipède (ou rectangle) percé par une répartition de trous et cadré par des surfaces de conductivité infini ou nul. On emploie un modèle stochastique où on associe une variable aléatoire au processus physique. Les résultats obtenus sont comparés avec les théories de Maxwell, Rayleigh, Wiener et Hashin-Shtrikman.     

Author index to volume 44B

Evidence is presented to show that the gross features of the pion distributions in $\text{p}$p and $\text{e}$e annihilation are essentially the same.     

Optimization problems in magnetohydrodynamic flows

Résumé On traite le problème des conditions de maximum de conversion d'énergie dans les générateurs magnétohydrodynamique pour les écoulements incompressibles et compressibles, et pour les cas ou les électrodes sont répartis soit en sections finies soit en sections continues. Les conditions d'optimalité sont trouvées pour les cas finis par le principe de Bellman, et pour le cas de repartition infinie des électrodes par l'équation fondamentale de la programmation dynamique.