Discriminating New Physics Scenarios at NLC: The Role of Polarization

We explore the potential of the Next Linear Collider (NLC), operating in the $e\gamma$ mode, to disentangle new physics scenarios on single $W$ production. We study the effects related with the exchange of composite fermion in the reaction $e\gamma \to W \nu_e$, and compare with those arising from trilinear gauge boson anomalous couplings. We stress the role played by the initial state polarization to increase the reach of this machine and to discriminate the possible origin of the new phenomena.Comment: 26 pages, LaTeX file using ReVTeX. 10 Figure

Excited Leptonic States in Polarized e^-\gamma and e^+ e^- Collisions

We analyze the capability of the next generation of linear electron--positron colliders to unravel the spin and couplings of excited leptons predicted by composite models. Assuming that these machines will be able to operate both in the $e^+e^-$ and $e^-\gamma$ modes, we study the effects of the excited electrons of spin $\frac{1}{2}$ and $\frac{3}{2}$ in the reactions $e^-\gamma \rightarrow e^-\gamma$ and $e^+e^- \rightarrow \gamma\gamma$. We show how the use of polarized beams is able not only to increase the reach of these machines, but also to determine the spin and couplings of the excited states.Comment: 22 pages, RevTeX, 8 figure

The Marsupial Mitochondrial Genome and the Evolution of Placental Mammals

The entire nucleotide sequence of the mitochondrial genome of the American opossum, Didelphis virginiana, was determined. Two major features distinguish this genome from those of other mammals. First, five tRNA genes around the origin of light strand replication are rearranged. Second, the anticodon of tRNA(Asp) is posttranscriptionally changed by an RNA editing process such that its coding capacity is altered. When the complete protein-coding region of the mitochondrial genome is used as an outgroup for placental mammals it can be shown that rodents represent an earlier branch among placental mammals than primates and artiodactyls and that artiodactyls share a common ancestor with carnivores. The overall rates of evolution of most of the mitochondrial genome of placentals are clocklike. Furthermore, the data indicate that the lineages leading to the mouse and rat may have diverged from each other as much as 35 million years ago

Complete DNA sequence of the mitochondrial genome of the ascidian Halocynthia roretzi (Chordata, Urochordata).

The complete nucleotide sequence of the 14,771-bp-long mitochondrial (mt) DNA of a urochordate (Chordata)-the ascidian Halocynthia roretzi-was determined. All the Halocynthia mt-genes were found to be located on a single strand, which is rich in T and G rather than in A and C. Like nematode and Mytilus edulis mtDNAs, that of Halocynthia encodes no ATP synthetase subunit 8 gene. However, it does encode an additional tRNA gene for glycine (anticodon TCT) that enables Halocynthia mitochondria to use AGA and AGG codons for glycine. The mtDNA carries an unusual tRNA(Met) gene with a TAT anticodon instead of the usual tRNA(Met)(CAT) gene. As in other metazoan mtDNAs, there is not any long noncoding region. The gene order of Halocynthia mtDNA is completely different from that of vertebrate mtDNAs except for tRNA(His)-tRNA(Ser)(GCU), suggesting that evolutionary change in the mt-gene structure is much accelerated in the urochordate line compared with that in vertebrates. The amino acid sequences of Halocynthia mt-proteins deduced from their gene sequences are quite different from those in other metazoans, indicating that the substitution rate in Halocynthia mt-protein genes is also accelerated

Elektrochemische und radiochemische Korrosionsuntersuchungen an UO_2 in endlagerrelevanten Elektrolytsystemen Abschlussbericht

By means of electrochemical methods it was shown that there is a correlation between the corrosion potentials and the corrosive surface removal rates of UO_2. Hence this opens up the possibility to derive surface removal rates of UO_2 for a variety of electrolyte systems exclusively by means of potentials measurement and based on a calibration curve. Other than with the conventional analytical methods, there is no need any more to produce measurable amounts of wastage by appropriately long leaching times, in order to determine the corrosion rates. The two electrolyte solutions, saturated NaCl and bentonite pore water, are characterized by the same correlation at equal temperatures, as none of the two systems contains complexing agents leading to measurable complexing reactions with the electrode surface. Thus there are the same kinetic conditions in both solutions governing the charge transfer from electrode to solution, and this correlation can be applied to any solution free of complexing agents in order to determine the potential-dependent corrosive removal rates. If, however, the kinetic conditions are altered by a complexing agent, eg. carbonate, another correlation has to be established reflecting the specific kinetic conditions in each case. (orig./CB)Es wurde elektrochemisch gezeigt, dass eine Korrelation zwischen den Korrosionspotentialen und den Abtragsraten von UO_2 besteht. Somit wird die Moeglichkeit eroeffnet, Abtragsraten von UO_2 in verschiedensten Elektrolytsystem beim Vorliegen einer Kalibrierungskurve ausschliesslich durch Potentialmessung zu bestimmen. Im Gegensatz zu den konventionellen analytischen Verfahren ist man damit nicht mehr darauf angewiesen, analytisch erfassbare Abtragsmengen von UO_2 durch eine mehr oder weniger lange Einwirkzeit des Laugensystems zu erzeugen, um die Korrosionsraten bestimmen zu koennen. Fuer die Elektrolytloesungen gesaettigte NaCl-Loesung und Bentonit-Porenwasser gilt bei gleicher Temperatur dieselbe Korrelation, da in keinem der beiden Systeme Komplexbildner vorliegen, die messbare Komplexbildungsreaktionen mit der Elektrodenoberflaeche liefern. Auf diese Weise herrschen in beiden Loesungen die gleichen kinetischen Bedingungen fuer den Ladungsuebergang Elektrode/Loesung. Somit kann diese Korrelation fuer saemtliche komplexbildnerfreien Loesungen zur potentialabhaengigen Abtragsratenbestimmung herangezogen werden. Werden jedoch die kinetischen Bedingungen durch einen Komplexbildner, wie z.B. Carbonat, veraendert, muss jeweils eine andere Korrelation in Betracht gezogen werden, welche die jeweilige kinetische Bedingung beruecksichtigt. (orig.)Available from TIB Hannover: F98B1223 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEBundesministerium fuer Bildung, Wissenschaft, Forschung und Technologie, Bonn (Germany)DEGerman