Flavour always matters in scalar triplet leptogenesis

We present a flavour-covariant formalism for scalar triplet leptogenesis, which takes into account the effects of the different lepton flavours in a consistent way. Our main finding is that flavour effects can never be neglected in scalar triplet leptogenesis, even in the temperature regime where all charged lepton Yukawa interactions are out of equilibrium. This is at variance with the standard leptogenesis scenario with heavy Majorana neutrinos. In particular, the so-called single flavour approximation leads to predictions for the baryon asymmetry of the universe that can differ by a large amount from the flavour-covariant computation in all temperature regimes. We investigate numerically the impact of flavour effects and spectator processes on the generated baryon asymmetry, and find that the region of triplet parameter space allowed by successsful leptogenesis is significantly enlarged.Comment: 43 pages, 15 figures; comments and references added, cosmetic changes in Figs. 6 to 8, results unaffected. Version to appear in JHE

On Both Sides of the Wall

Since the emphasis of this paper is to be on the Cold War and its aftermath, I will only mention that the first ten years of my life I lived in Silesia, Germany, on the outskirts of Breslau/Wroclaw during the Nazi period of World War II. I will begin with the end of WWII, 1945, my experience for two years in the mountains of Silesia under Polish administration, and from 1947 to 1950 in the Soviet zone of occupation in Germany in Görlitz, and beginning in 1950 in Ost-Berlin, the capital of the German Democratic Republic

Homosexual orientation of girls and boys. A challenge to education

Die Autorin geht der Frage nach, wie pädagogische und therapeutische Fachkräfte Heranwachsende, die sich homosexuell entwickeln, unterstützen können. Dabei nähert sie sich dem Thema gleichgeschlechtlicher Orientierungen in der Kindheit von drei Seiten: zunächst auf theoretischem Wege, dann durch einen Bericht über Gespräche mit psychosozialen Fachkräften und schließlich durch eine Hinwendung zu pädagogischer Praxis. Die Ausführungen im ersten Teil dienen dazu, den praxisbezogenen Anregungen einen theoretischen Rahmen zu geben. Durch die Erkundungen im zweiten Teil wird verdeutlicht, in welcher Weise die fachliche Haltung zur Homosexualität die Art der Wahrnehmung und des Handelns prägt. (DIPF/Orig.)The author explores how girls and boys who are in the process of homosexual development can be supported by qualified practitioners in the field of education, pedagogics and childen\u27s psychotherapy. The issue of homosexual orientation during childhood is approached at three levels: first by discussing theoretical concepts, then by reporting interviews conducted with professionals from the fields of child psychotherapy, pediatric psychiatry and day-care, finally by dealing with problems in pedagogical structures. The theoretical discussion is based on results of new psychoanalytic and sexual scientific research and serves as a framework for practical problems and suggestions. The interviews show how professional attitudes towards homosexuality do influence the way of perception and pedagogical acting. (DIPF/Orig.

Characterization of Deficiencies in the Frequency Domain Forced Response Analysis Technique for Supersonic Turbine Bladed Disks

Turbine blades in rocket and jet engine turbomachinery experience enormous harmonic loading conditions. These loads result from the integer number of upstream and downstream stator vanes as well as the other turbine stages. Assessing the blade structural integrity is a complex task requiring an initial characterization of whether resonance is possible and then performing a forced response analysis if that condition is met. The standard technique for forced response analysis in rocket engines is to decompose a CFD-generated flow field into its harmonic components, and to then perform a frequency response analysis at the problematic natural frequencies. Recent CFD analysis and water-flow testing at NASA/MSFC, though, indicates that this technique may miss substantial harmonic and non-harmonic excitation sources that become present in complex flows. A substantial effort has been made to account for this denser spatial Fourier content in frequency response analysis (described in another paper by the author), but the question still remains whether the frequency response analysis itself is capable of capturing the excitation content sufficiently. Two studies comparing frequency response analysis with transient response analysis, therefore, of bladed-disks undergoing this complex flow environment have been performed. The first is of a bladed disk with each blade modeled by simple beam elements. Six loading cases were generated by varying a baseline harmonic excitation in different ways based upon cold-flow testing from Heritage Fuel Air Turbine Test. It was hypothesized that the randomness and other variation from the standard harmonic excitation would reduce the blade structural response, but the results showed little reduction. The second study was of a realistic model of a bladed-disk excited by the same CFD used in the J2X engine program. It was hypothesized that enforcing periodicity in the CFD (inherent in the frequency response technique) would overestimate the response. The results instead showed that the transient analysis results were up to 10% higher for "clean" nodal diameter excitations and six times larger for "messy" excitations, where substantial Fourier content around the main harmonic exists. Because the bulk of resonance problems are due to the "clean" excitations, a 10% underprediction is not necessarily a problem, especially since the average response in the transient is similar to the frequency response result, and so in a realistic finite life calculation, the life would be same. However, in the rare cases when the "messy" excitations harmonics are identified as the source of potential resonance concerns, this research does indicate that frequency response analysis is inadequate for accurate characterization of blade structural capability

Application of a Numerical Method for the Analysis of Metglas 2826 MB Crystallization Kinetics

Crystallization kinetics of y-FeNiMo solid solution in Metglas 2826 MB was studied by isothermal differential scanning calorimetry (DSC). The Johnson-Mehl-Avrami (JMA) equation was used to describe the crystallization process. In order to calculate the kinetic parameters, a new model of the numerical analysis of isothermally obtained DSC data was successfully applied. For the purposes of method evaluation, the classical analytical method of data analysis was also performed. The apparent activation energies obtained were (280 ± 22) kJ mol-1 and (296 ± 23) kJ mol-1 for the analytical and numerical methods, respectively. The Avrami exponents obtained by both methods lie between 1.75 and 1.95

Nouvelle physique dans le secteur des leptons

This thesis addresses some scenarios of new physics as well as their consequences on the lepton sector. The fact that neutrinos are massive is one of the problems left unsolved by the Standard Model. One of the possible solutions is the seesaw mechanism, that involves new heavy states whose decay violates lepton number. Because of this, these states can participate in leptogenesis, one of the scenarios that could explain the origin of the asymmetry between matter and antimatter in our universe. Here, we study leptogenesis with a scalar triplet and consider especially the impact of flavour effects. After that, we turn to supersymmetric models. We consider a model in which the fermionic partner of a pseudo-Goldstone boson, associated to a symmetry broken at high energy, plays the role of a sterile neutrino, that could explain some experimental anomalies. Finally, to be viable, supersymmetry should be broken in a hidden sector, and this breaking should be transmitted to the fields of the low energy theory. One of the most elegant scenarios for this is gauge mediation. Unfortunately, it cannot easily reproduce the mass of the Higgs boson measured at LHC. We study here extensions that could rehabilitate this scenario and relate it to the seesaw mechanism.Cette thèse aborde quelques scénarios de nouvelle physique, ainsi que leurs manifestations dans le secteur des leptons.Le fait que les neutrinos soient massifs est un des problèmes non élucidés par le Modèle Standard. Une des solutions possibles est le mécanisme de seesaw, qui fait intervenir de nouveaux états lourds dont la désintégration viole le nombre leptonique. À cause de ce dernier point, ces états peuvent jouer un rôle clé dans la leptogenèse, un des scénarios susceptibles d'expliquer l'origine de l'asymétrie observée entre matière et antimatière dans l'univers. Nous étudions ici la leptogenèse avec un triplet scalaire et nous intéressons tout particulièrement l'impact des effets de saveur.Dans un second temps, nous considérons des théories supersymétriques. Nous étudions un modèle où le partenaire fermionique d'un pseudo-boson de Goldstone joue le rôle d'un neutrino stérile, qui pourrait expliquer certaines anomalies expérimentales. Enfin, pour être viable, la supersymétrie doit être brisée dans un secteur caché, et cette brisure doit ensuite être transmise aux champs de la théorie à basse énergie. Un des scénarios les plus élégants pour cela est la médiation de jauge. Malheureusement, celle-ci peine à reproduire la masse du boson de Higgs mesurée au LHC. Nous nous intéressons ici à des extensions susceptibles de réhabiliter ce scénario tout en le reliant mécanisme de seesaw

Welchen Einfluss spielt das Geburtsgewicht bei Frühgeborenen auf die körperliche Entwicklung sowie das Verhalten im Schulkindalter?

Die vorliegende Studie untersucht die körperliche Entwicklung sowie das Verhalten von Frühgeborenen im Schulkindalter, die bei Geburt weniger als 1500g wogen. Dabei wurden die Geburtsgewichtsgruppen ELBW und VLBW hinsichtlich des Wachstum, des Gesundheitszustandes und der Prävalenz von Verhaltensauffälligkeiten im Alter von 5 bis 11 Jahren verglichen

Turbine Design and Analysis for the J-2X Engine Turbopumps

Pratt and Whitney Rocketdyne and NASA Marshall Space Flight Center are developing the advanced upper stage J-2X engine based on the legacy design of the J-2/J-2S family of engines which powered the Apollo missions. The cryogenic propellant turbopumps have been denoted as Mark72-F and Mark72-0 for the fuel and oxidizer side, respectively. Special attention is focused on preserving the essential flight-proven design features while adapting the design to the new turbopump configuration. Advanced 3-D CFD analysis has been employed to verify turbine aero performance at current flow regime boundary conditions and to mitigate risks associated with stresses. A limited amount of redesign and overall configuration modifications allow for a robust design with performance level matching or exceeding requirement

Microstructure and Flux Pinning of Reacted-and-Pressed, Polycrystalline Ba0.6K0.4Fe2As2 Powders

The flux pinning properties of reacted-and-pressed Ba0.6K0.4Fe2As2 powder were measured using magnetic hysteresis loops in the temperature range 20 K ≤ T ≤ 35 K. The scaling analysis of the flux pinning forces (Fp = jc × B, with jc denoting the critical current density) following the Dew-Hughes model reveals a dominant flux pinning provided by normal-conducting point defects (δl-pinning) with only small irreversibility fields, Hirr, ranging between 0.5 T (35 K) and 16 T (20 K). Kramer plots demonstrate a linear behavior above an applied field of 0.6 T. The samples were further characterized by electron backscatter diffraction (EBSD) analysis to elucidate the origin of the flux pinning. We compare our data with results of Weiss et al. (bulks) and Yao et al. (tapes), revealing that the dominant flux pinning in the samples for applications is provided mainly by grain boundary pinning, created by the densification procedures and the mechanical deformation applied