1,275 research outputs found
at four loops in QED
We review the four-loop QED corrections to the anomalous magnetic moment of
the muon. The fermionic contributions with closed electron and tau
contributions are discussed. Furthermore, we report on a new independent
calculation of the universal four-loop contribution and compare with existing
results.Comment: 6 pages, Contribution to the proceedings of the International
workshop on e+e- collisions from Phi to Psi 2017, v2: references adde
-on-shell quark mass relation up to four loops in QCD and a general SU gauge group
In this paper we compute the relation between heavy quark masses defined in
the modified minimal subtraction and on-shell scheme. Detailed results are
presented for all coefficients of the SU colour factors. The reduction
of the four-loop on-shell integrals is performed for a general QCD gauge
parameter. Some of the about 380 master integrals are computed analytically,
others with high numerical precision based on Mellin-Barnes representations,
and the rest numerically with the help of {\tt FIESTA}. We discuss in detail
the precise numerical evaluation of the four-loop master integrals. Updated
relations between various short-distance masses and the
quark mass to next-to-next-to-next-to-leading order accuracy are provided for
the charm, bottom and top quark. We discuss the dependence on the
renormalization and factorization scale.Comment: 53 pages, 11 figures, v2: minor changes, references added,
corresponds to published versio
Preserving Value in the Post-BAPCPA Era — An Empirical Study
Through the use of a multivariate regression model, this article studies the effect on debtor reorganization values of the shortened reorganization timeframe imposed by the Bankruptcy Abuse Prevention and Consumer Protection Act (“BAPCPA”). The study shows that BAPCPA is positively correlated at a statistically significant level with higher reorganization recoveries. This result is attributed to the increased proportion of prepackaged and prenegotiated bankruptcies observed in the post-2005 era, as these “fast-track” bankruptcy cases entail lower costs and better preserve the firm’s value
Eiszeitliche Ablagerungen in Hochlagen des Süntels (Süd-Hannover) und seinen Karstschlotten
Aus dem Karstgebiet des Riesenberges im Süntel werden hochgelegene kies- und steinführende Ablagerungen verschiedenen Alters beschrieben. Außer kiesführenden Höhlensedimenten präglazialen Alters treten kiesführende Ablagerungen auf, die eiszeitlich entstanden sind. Während die Kies- und Steinanteile der präglazialen Ablagerungen aus lokalen (Kalkstein des Malm) und z. T. ortsfremden Komponenten (Sandstein des Wealden) bestehen, enthalten die jüngeren Ablagerungen zusätzlich Kiesanteile aus nordisch-skandinavischen Gesteinen sowie resedimentierten Weserkies. Die eiszeitlichen Ablagerungen wurden im Kammbereich sowie in Karsthöhlen abgelagert.Gravel deposits positioned in high altitude areas of Süntel Mountains are described from the carst area of Riesenberg. Not only cave gravel of pre-glacial age, but also those of glacial age occur. While the pre-glacial deposits comprise local, but xenotopic components, the younger ones display also material of northern derivation as well as reworked gravels from the Weser-River. The sediments were deposited both in caves and at summit region of the Süntel Mountains. Conditions of deposition and age relation to the glaciations are discussed
Advanced parametrical modelling of 24 GHz radar sensor IC packaging components
This paper deals with the development of an advanced
parametrical modelling concept for packaging components of a 24 GHz radar
sensor IC used in automotive driver assistance systems. For fast and
efficient design of packages for system-in-package modules (SiP), a
simplified model for the description of parasitic electromagnetic effects
within the package is desirable, as 3-D field computation becomes inefficient
due to the high density of conductive elements of the various signal paths
in the package. By using lumped element models for the characterization of
the conductive components, a fast indication of the design's signal-quality
can be gained, but so far does not offer enough flexibility to cover the
whole range of geometric arrangements of signal paths in a contemporary
package. This work pursues to meet the challenge of developing a flexible
and fast package modelling concept by defining <i>parametric</i> lumped-element models for
all basic signal path components, e.g. bond wires, vias, strip lines, bumps
and balls
Constraining stochastic 3-D structural geological models with topology information using Approximate Bayesian Computation in GemPy 2.1
Acknowledgements. We would like to thank Total E&P UK in Aberdeen for funding this research. We also thank Fabian Stamm for providing the wonderful synthetic geomodel used in this paper. We are grateful for the constructive reviews from Ashton Krajnovich and an anonymous reviewer for helping us improve this manuscript.Peer reviewedPublisher PD
Phase II trial of the antiangiogenic agent IM862 in metastatic renal cell carcinoma
IM862 is a naturally occurring dipeptide (L-glu-L-trp) with immunomodulatory and antiangiogenic properties. A significant anticancer activity has been reported recently in AIDS-related Kaposi's sarcoma, a tumour of endothelial cell origin. The high vascularity and responsiveness to immunotherapy of renal cell carcinoma (RCC) makes such a tumour a potential target for IM862. In all, 25 patients were accrued in a prospective phase II trial using a standard two-step design. The main inclusion criteria were WHO performance status 3 months, normal marrow, kidney and liver functions. IM862 was given intranasally at a dose of 20 mg three times daily. Each cycle consisted of 8 consecutive weeks of treatment. All 25 patients were fully evaluable for response and 24 for toxicities. Median age was 62 years (range 42-76), median WHO PS was 1 (0-2). No grade 2 or 3 toxicities related to the study drug have been recorded. Eight patients had stable disease (SD) and 17 progressed while on treatment. Median survival was 7.9 months (range 2.7-20). Median time to progression was 1.9 months (range 1.2-12.6). Median duration of SD was 6 months (range 5.2-12.6+). Analysis of blood angiogenic markers showed a significant decrease of plasma vascular endothelial growth factor (VEGF) levels after 4 and 8 weeks of therapy. Treatment with IM862 has no toxicity, but does not lead to any significant objective responses in metastatic RCC. IM862 should not be further evaluated as a single agent at these doses and schedule for this population of patients. The decrease in VEGF levels warrants further investigation of IM862 as an antiangiogenic therapy
- …