Mixed QCD-electroweak O(\alpha_s\alpha) corrections to Drell-Yan processes in the resonance region: pole approximation and non-factorizable corrections

Drell-Yan-like W-boson and Z-boson production in the resonance region allows for high-precision measurements that are crucial to carry experimental tests of the Standard Model to the extremes, such as the determination of the W-boson mass and the effective weak mixing angle. In this article, we establish a framework for the calculation of the mixed QCD-electroweak O(\alpha_s\alpha) corrections to Drell-Yan processes in the resonance region, which are one of the main remaining theoretical uncertainties. We describe how the Standard Model prediction can be successfully performed in terms of a consistent expansion about the resonance poles, which classifies the corrections in terms of factorizable and non-factorizable contributions. The former can be attributed to the W/Z production and decay subprocesses individually, while the latter link production and decay by soft-photon exchange. At next-to-leading order we compare the full electroweak corrections with the pole-expanded approximations, confirming the validity of the approximation. At O(\alpha_s\alpha), we describe the concept of the expansion and explicitly give results on the non-factorizable contributions, which turn out to be phenomenologically negligible. Our results, thus, demonstrate that for phenomenological purposes the O(\alpha_s\alpha) corrections can be factorized into terms associated with initial-state and/or final-state corrections. Moreover, we argue that the factorization properties of the non-factorizable corrections at O(\alpha_s\alpha) from lower-order O(\alpha_s) graphs generalize to any order in O(\alpha_s^n\alpha).Comment: 56 pages, 22 figure

Using Reference Models for Data Warehouse Metadata Management

Based on experience from applying the Common Warehouse Metamodel to metadata management at a large Swiss bank, the applicability of metadata reference models in complex application domains is analyzed. In order to explain the context of the case, the state-of-the-art of the Common Warehouse Metamodel and its application for data warehouse management are summarized. Based on the project experience documented in this paper, benefits of the reference model approach are described and recommendations for future developments of the Common Warehouse Metamodel are proposed

Threshold expansion of the gg(qq) -> QQ+X cross section at O(alpha_s^4)

We derive the complete set of velocity-enhanced terms in the expansion of the total cross section for heavy-quark pair production in hadronic collisions at next-to-next-to-leading order. Our expression takes into account the effects of soft-gluon emission as well as that of potential-gluon exchanges. We prove that there are no enhancements due to subleading soft-gluon couplings multiplying the leading Coulomb singularity.Comment: 11 pages, 2 figures, published erratum included at the end of the paper, updated attached Mathematica fil

α1D-Adrenoceptors are responsible for the high sensitivity and the slow time-course of noradrenaline-mediated contraction in conductance arteries

The objective of this study was to determine whether the different time-course characteristics of α1-adrenoceptor-mediated contraction in arteries can be related to the subtypes involved. Contractile responses to noradrenaline (NA) were compared with inositol phosphate accumulation and extracellular signal-regulated kinase (ERK)1/2 phosphorylation after α1-agonist stimuli in the same vessels in the presence or absence of α1-antagonists in rat or in α1-subtype knockout (KO) mice. Aorta, where α1D-AR is the main functional subtype, had higher sensitivity to NA (in respect of inositol phosphate [IP], pERK1/2, and contractile response) than tail artery, where the α1A-adrenoceptor subtype is predominant. Furthermore, the contraction in aorta exhibited a slower decay after agonist removal and this was consistent in all strains harboring α1D-adrenoceptors (from rat, α1B-KO, and wild-type [WT] mice) but was not observed in the absence of the α1D-adrenoceptor signal (α1D-adrenoceptor blocked rat aorta or aorta from α1D-KO). IP formation paralleled α1-adrenoceptor-mediated contraction (agonist present or postagonist) in aorta and tail artery. High sensitivity to agonist and persistence of response after agonist removal is a property of α1D-adrenoceptors. Therefore, the preponderance of this subtype in noninnervated conductance arteries such as aorta allows responsiveness to circulating catecholamines and prevents abrupt changes in vessel caliber when the stimulus fluctuates. Conversely, in innervated distributing arteries, high local concentrations of NA are required to activate α1A-adrenoceptors for a response that is rapid but short lived allowing fine adjustment of the contractile tone by perivascular sympathetic nerves