Two-photon mediated resonance production in e+e- collisions: cross sections and density matrices

Earlier described model amplitudes are used in this paper to evaluate both cross sections and density matrices for two-photon mediated resonance production in e^+e^- collisions. All 25 q\bar{q} low-lying ^1S_0, ^3P_J and ^1D_2 resonances can thus be treated. Two independent methods are described to obtain the resonance production density matrices and cross sections. These density matrices combined with a resonance decay density matrix give the detailed angular distributions of the resonance decay products. For two particular decays, \chi_{c2},\chi_{c1}\to\gamma J/\psi the details are given. Several numerical results are presented as well.Comment: 27 pages, 4 figure

Eine DSL für Harel-Statecharts mit PetitParser

Eine AuDSL genannte domänenspezifische Sprache zur Beschreibung von Harel-Statechart-Automaten wird benutzt, um exemplarisch die Eignung von PetitParser, einem zum Helvetia-Framework gehörenden Parser-Combinator, als Baustein einer Language-Workbench zu erproben. Verwendet wird die Pharo1-Implementierung von Petit-Parser. Neben der Implementierung der AuDSL als PetitParser-Skript wird auch die Laufzeitumgebung vorgestellt, die die Ausführung der Automaten ermöglicht. Die Einbettung von AuDSL-Texten in die Wirtssprache Smalltalk wird gezeigt. Die gemachten Erfahrungen zeigen grundsätzlich die Einfachheit des Baus von DSLs mit PetitParser. Die Integration einer DSL in die Werkzeuge der Entwicklungsumgebung bleibt ohne die Nutzung des Helvetia-Frameworks aber unvollständig. Die Übertragbarkeit der Vorgehensweise auf andere Programmiersprachen (z. B. Scala) wird angedeutet. --

Intra- and interspecies interactions between prion proteins and effects of mutations and polymorphisms

Recently, crystallization of the prion protein in a dimeric form was reported. Here we show that native soluble homogenous FLAG-tagged prion proteins from hamster, man and cattle expressed in the baculovirus system are predominantly dimeric. The PrP/PrP interaction was confirmed in Semliki Forest virus-RNA transfected BHK cells co-expressing FLAG- and oligohistidine-tagged human PrP. The yeast two-hybrid system identified the octarepeat region and the C-terminal structured domain (aa90-aa230) of PrP as PrP/PrP interaction domains. Additional octarepeats identified in patients suffering from fCJD reduced (wtPrP versus PrP+90R) and completely abolished (PrP+90R versus PrP+90R) the PrP/PrP interaction in the yeast two-hybrid system. In contrast, the Met/Val polymorphism (aa129), the GSS mutation Pro102Leu and the FFI mutation Asp178Asn did not affect PrP/PrP interactions. Proof of interactions between human or sheep and bovine PrP, and sheep and human PrP, as well as lack of interactions between human or bovine PrP and hamster PrP suggest that interspecies PrP interaction studies in the yeast two-hybrid system may serve as a rapid pre-assay to investigate species barriers in prion diseases

Radiative Decay of Vector Quarkonium: Constraints on Glueballs and Light Gluinos

Given a resonance of known mass, width, and J^{PC}, we can determine its gluonic branching fraction, b(R->gg), from data on its production in radiative vector quarkonium decay, V -> gamma+R. For most resonances b(R->gg) is found to be O(10%), consistent with being q-qbar states, but we find that both pseudoscalars observed in the 1440 MeV region have b(R->gg) ~ 1/2 - 1, and b(f_0^{++}->gg) ~ 1/2. As data improves, b(R->gg) should be a useful discriminator between q-qbar and gluonic states and may permit quantitative determination of the extent to which a particular resonance is a mixture of glueball and q-qbar. We also examine the regime of validity of pQCD for predicting the rate of V -> gamma+eta_gluino, the ``extra'' pseudoscalar bound state which would exist if there were light gluinos. From the CUSB limit on peaks in Upsilon -> gamma X, the mass range 3 GeV < m(eta_gluino) < 7 GeV can be excluded. An experiment must be significantly more sensitive to exclude an eta_gluino lighter than this.Comment: 36pp (inc figs),RU-94-04. (Replaces original which didn't latex correctly and didn't have figures.

Meson Decay Constants from Isospin Mass Splittings in the Quark Model

Decay constants of $D$ and $B$ mesons are estimated within the framework of a heavy-quark approach using measured isospin mass splittings in the $D$, $D^*$, and $B$ states to isolate the electromagnetic hyperfine interaction between quarks. The values $f_D = (262 \pm 29)$ MeV and $f_B = (160 \pm 17)$ MeV are obtained. Only experimental errors are given; possible theoretical ambiguities, and suggestions for reducing them, are noted.Comment: 7 pages, LaTeX, EFI-92-3

Updating the Unitarity Triangle: Top Quark Mass Versus Nonperturbative Uncertainties

We summarize the present knowledge on the non-perturbative hadronic inputs needed in the analysis of $B^0$-$\bar B^0$ mixing and the CP-violating parameter $\varepsilon$ of the $K^0$-$\bar K^0$ system. Using this information, together with the recently determined value of the top-quark mass, we update the phenomenological constraints on the unitarity triangle.Comment: 21 pages, Plain LateX, 7 figures included, preprint FTUV/94-37, IFIC/94-32, NBI-94-3

Anti-PrP antibodies block PrPSc replication in prion-infected cell cultures by accelerating PrPC degradation.

manuscript received October 15, 2003; revised manuscript received December 15, 2003; accepted December 16, 2003. We thanks P. Rondard, O Bischof, J.-L. Laplanche and J.-P. Pin for their fruitful discussions. we are grateful to S. barrère for her assistance in the statistical analysis of the data and H. McMahon for her assistance in reading the manuscript