Atom-molecule coexistence and collective dynamics near a Feshbach resonance of cold fermions

Degenerate Fermi gas interacting with molecules near Feshbach resonance is unstable with respect to formation of a mixed state in which atoms and molecules coexist as a coherent superposition. Theory of this state is developed using a mapping to the Dicke model, treating molecular field in the single mode approximation. The results are accurate in the strong coupling regime relevant for current experimental efforts. The exact solution of the Dicke model is exploited to study stability, phase diagram, and nonadiabatic dynamics of molecular field in the mixed state.Comment: 5 pages, 2 figure

Geometric phases and quantum phase transitions

Quantum phase transition is one of the main interests in the field of condensed matter physics, while geometric phase is a fundamental concept and has attracted considerable interest in the field of quantum mechanics. However, no relevant relation was recognized before recent work. In this paper, we present a review of the connection recently established between these two interesting fields: investigations in the geometric phase of the many-body systems have revealed so-called "criticality of geometric phase", in which geometric phase associated with the many-body ground state exhibits universality, or scaling behavior in the vicinity of the critical point. In addition, we address the recent advances on the connection of some other geometric quantities and quantum phase transitions. The closed relation recently recognized between quantum phase transitions and some of geometric quantities may open attractive avenues and fruitful dialog between different scientific communities.Comment: Invited review article for IJMPB; material covered till June 2007; 10 page

Non Local Theories: New Rules for Old Diagrams

We show that a general variant of the Wick theorems can be used to reduce the time ordered products in the Gell-Mann & Low formula for a certain class on non local quantum field theories, including the case where the interaction Lagrangian is defined in terms of twisted products. The only necessary modification is the replacement of the Stueckelberg-Feynman propagator by the general propagator (the ``contractor'' of Denk and Schweda) D(y-y';tau-tau')= - i (Delta_+(y-y')theta(tau-tau')+Delta_+(y'-y)theta(tau'-tau)), where the violations of locality and causality are represented by the dependence of tau,tau' on other points, besides those involved in the contraction. This leads naturally to a diagrammatic expansion of the Gell-Mann & Low formula, in terms of the same diagrams as in the local case, the only necessary modification concerning the Feynman rules. The ordinary local theory is easily recovered as a special case, and there is a one-to-one correspondence between the local and non local contributions corresponding to the same diagrams, which is preserved while performing the large scale limit of the theory.Comment: LaTeX, 14 pages, 1 figure. Uses hyperref. Symmetry factors added; minor changes in the expositio

Anthrazykline und Herceptin® als neue Therapieoption beim metastasierten Mammakarzinom

Single-agent treatment with the humanized monoclonal antibody trastuzumab (herceptin) has shown remarkable activity in patients with metastatic breast cancer overexpressing the HER-2/neu proto-oncogen. Further significant advances could be achieved with the combined use of herceptin and paclitaxel or doxorubicin/cyclophosphamide. However, cardiotoxicity remains a significant and thus far unresolved problem of the herceptin-doxo-rubicin combination. Thus, several studies have recently been initiated to identify equally effective but less toxic first-line regimens. Epirubicin, the taxanes paclitaxel and docetaxel, Navelbine(R), cisplatin, and Caelyx(R), a liposomal encapsulated formulation of doxorubicin, were selected for combination with herceptin in these studies because the appeared the most promising agents

Learning from each other: A handbook for language teacher associations

The publication is aimed at those involved in the running of language teacher associations at international, national, regional and local levels. This may include paid employees or, more frequently, volunteers. It provides guidance on the effective running and networking of associations. It encourages language teacher associations to collaborate in order to support teachers more effectively, and to contribute to improvements in the quality of language teaching. It enables language teachers across the world to share their own ideas, to be involved in research, and to learn about the cutting-edge work of the ECML and its European project

The role of infrared divergence for decoherence

Continuous and discrete superselection rules induced by the interaction with the environment are investigated for a class of exactly soluble Hamiltonian models. The environment is given by a Boson field. Stable superselection sectors emerge if and only if the low frequences dominate and the ground state of the Boson field disappears due to infrared divergence. The models allow uniform estimates of all transition matrix elements between different superselection sectors.Comment: 11 pages, extended and simplified proo

Subtraction at NNLO

We propose a framework for the implementation of a subtraction formalism at NNLO in QCD, based on an observable- and process-independent cancellation of infrared singularities. As a first simple application, we present the calculation of the contribution to the e+e- dijet cross section proportional to C_F T_RComment: 42 pages Latex; 7 figures included. Modifications to the text, and references added; the results are unchange

Retrospektive Analyse zur Dosisintensität von Epirubicin beim Mammakarzinom

Objective: In breast cancer the efficacy of epirubicin-based chemotherapy is possibly related to the actual dose intensity applied. We retrospectively determined the administered dose intensity and the relative toxicity and efficacy of an epirubicin-containing regimen in patients with primary or metastatic breast cancer. Patients and Methods: Fluorouracil, epirubicin, and cyclophosphamide (FEC) were either given at a standard dose of 500/50/500 mg/m(2) (FE50C) or at an intensified dose of 500/75/500 mg/m(2) (FE75C) every 3 weeks. Of the 66 patients treated, 63 were evaluable; 43 had metastatic breast cancer, and 20 patients with an increased risk of relapse received FEC as an adjuvant treatment. Results: Dose intensity and absolute dose of adjuvant treatment were 81 and 70% for FE50C and 96 and 88% for FE75C In metastatic breast cancer, the dose intensity for FE50C was 94% and for FE75C 92%. In a retrospective comparison, the 4-year overall survival following adjuvant FE50C and FE75C was 40 and 48%, respectively (p = 0.47). The dose intensification led to a higher response rate of 34 vs. 44%. There were no significant differences in response duration and survival time. The toxicity profiles were comparable between FE50C and FE75C Conclusions: In genera I, the doses applied were lower than initially planned. Higher doses of epirubicin did not result in a significant increase of toxicity. Despite the limitations of a retrospective analysis, our observations support the importance of adherence to the planned dose intensity as a prerequisite for optimal treatment of patients suffering from breast cancer. As our results could be related to selection bias, dose-intensified anthracycline-containing regimens should be further evaluated in prospective trials. Copyright (C) 2001 S. Karger AG, Basel

Voneinander Lernen: Ein Handbuch für Sprachlehrerverbände

The publication is aimed at those involved in the running of language teacher associations at international, national, regional and local levels. This may include paid employees or, more frequently, volunteers. It provides guidance on the effective running and networking of associations. It encourages language teacher associations to collaborate in order to support teachers more effectively, and to contribute to improvements in the quality of language teaching. It enables language teachers across the world to share their own ideas, to be involved in research, and to learn about the cutting-edge work of the ECML and its European projects

Loschmidt Echo and Berry phase of the quantum system coupled to the XY spin chain: Proximity to quantum phase transition

We study the Loschmidt echo (LE) of a coupled system consisting of a central spin and its surrounding environment described by a general XY spin-chain model. The quantum dynamics of the LE is shown to be remarkably influenced by the quantum criticality of the spin chain. In particular, the decaying behavior of the LE is found to be controlled by the anisotropy parameter of the spin chain. Furthermore, we show that due to the coupling to the spin chain, the ground-state Berry phase for the central spin becomes nonanalytical and its derivative with respect to the magnetic parameter $\lambda$ in spin chain diverges along the critical line $\lambda=1$, which suggests an alternative measurement of the quantum criticality of the spin chain.Comment: 15 pages, 5 figure