653 research outputs found

    Renormalization of four-fermion operators for higher twist calculations

    Get PDF
    The evaluation of the higher twist contributions to Deep Inelastic Scattering amplitudes involves a non trivial choice of operator bases for the higher orders of the OPE expansion of the two hadronic currents. In this talk we discuss the perturbative renormalization of the four-fermion operators that appear in the above bases.Comment: LATTICE98(matrixelement), 3 page

    Higher-twist contributions to the Structure Functions coming from 4-fermion operators

    Full text link
    We evaluate the contribution of a class of higher-twist operators to the lowest moment of the Structure Functions, by computing appropriate matrix elements of six four-fermion operators in the quenched approximation. Their perturbative renormalization constants and mixing coefficients are calculated in the 't Hooft-Veltman scheme of dimensional regularization, using codes written in the algebraic manipulation computer language FORM.Comment: Talk presented at LATTICE99(matrix elements), Pisa (Italy), June 29 - July 3; 3 pages; to be published in Nucl. Phys. B (Proc. Suppl.

    Self-cleaning and colour-preserving efficiency of photocatalytic concrete: case study of the Jubilee Church in Rome

    Get PDF
    The Jubilee Church in the south-eastern outskirts of Rome is one of the first buildings constructed with super white reinforced concrete with self-cleaning photocatalytic cement. However, 16 years after the opening of the building, the self-cleaning and colour-preserving properties arising from the titania particles (TiO2) within the concrete mix are not meeting the design requirements and the concrete is showing premature evidence of decay. While the form of the decay is affecting the appearance of the building and not its structural soundness, the ageing pattern of the building's components is resulting in a high maintenance cost, one not easily affordable within the ordinary budget supported by a small parish. This study comprises the first comprehensive step in understanding the causes of the accelerated ageing pattern of the concrete, highlighting methods to improve the long-term durability of the concrete and therefore reduce the cost of its maintenance. Moreover, this research offered the opportunity to test the durability and the effectiveness of the TiO2 in the real conditions on an actual building featuring non-standard geometries. The findings highlight how the ageing pattern directly connects with the geometry of the building and inadequate consideration of the local weathering at the design stage

    ‘It’s the best thing I’ve done in a long while’: teenage mothers’ experiences of educational alternatives

    Get PDF
    Pregnant and mothering schoolgirls have been identified as an educationally vulnerable group. Many are not welcomed in their mainstream schools and as a consequence, access a range of educational alternatives. This article presents the views and experiences of 14 young women in the English Midlands, who became pregnant while still of statutory school age, 12 of whom spent time in alternative educational settings. It is based on data gathered from repeat interviews over an 18-month period and shows that all who attended the educational alternatives rated them highly and benefitted from what they had to offer. Using the concept of ‘difference’ as a central analytic theme, the article examines how and why this was the case. The analysis shows that it was through recognising some differences but not others that the educational alternatives were successful in supporting young women’s learning and well-being. Importantly, those that were recognised were done so in non-stigmatising ways. The research also highlights some limitations of the alternatives, alongside the ways in which gender and class continue to impact the educational outcomes and career trajectories of this particular group of students

    Role of the nonperturbative input in QCD resummed Drell-Yan QTQ_T-distributions

    Get PDF
    We analyze the role of the nonperturbative input in the Collins, Soper, and Sterman (CSS)'s bb-space QCD resummation formalism for Drell-Yan transverse momentum (QTQ_T) distributions, and investigate the predictive power of the CSS formalism. We find that the predictive power of the CSS formalism has a strong dependence on the collision energy S\sqrt{S} in addition to its well-known Q2Q^2 dependence, and the S\sqrt{S} dependence improves the predictive power at collider energies. We show that a reliable extrapolation from perturbatively resummed bb-space distributions to the nonperturbative large bb region is necessary to ensure the correct QTQ_T distributions. By adding power corrections to the renormalization group equations in the CSS formalism, we derive a new extrapolation formalism. We demonstrate that at collider energies, the CSS resummation formalism plus our extrapolation has an excellent predictive power for WW and ZZ production at all transverse momenta QT≀QQ_T\le Q. We also show that the bb-space resummed QTQ_T distributions provide a good description of Drell-Yan data at fixed target energies.Comment: Latex, 43 pages including 15 figures; typos were correcte

    Differences in the signaling pathways of α1A- and α1B-adrenoceptors are related to different endosomal targeting

    Get PDF
    Aims: To compare the constitutive and agonist-dependent endosomal trafficking of α1A- and α1B-adrenoceptors (ARs) and to establish if the internalization pattern determines the signaling pathways of each subtype. Methods: Using CypHer5 technology and VSV-G epitope tagged α1A- and α1B-ARs stably and transiently expressed in HEK 293 cells, we analyzed by confocal microscopy the constitutive and agonist-induced internalization of each subtype, and the temporal relationship between agonist induced internalization and the increase in intracellular calcium (determined by FLUO-3 flouorescence), or the phosphorylation of ERK1/2 and p38 MAP kinases (determined by Western blot). Results and Conclusions: Constitutive as well as agonist-induced trafficking of α1A and α1B ARs maintain two different endosomal pools of receptors: one located close to the plasma membrane and the other deeper into the cytosol. Each subtype exhibited specific characteristics of internalization and distribution between these pools that determines their signaling pathways: α1A-ARs, when located in the plasma membrane, signal through calcium and ERK1/2 pathways but, when translocated to deeper endosomes, through a mechanism sensitive to ÎČ-arrestin and concanavalin A, continue signaling through ERK1/2 and also activate the p38 pathway. α1B-ARs signal through calcium and ERK1/2 only when located in the membrane and the signals disappear after endocytosis and by disruption of the membrane lipid rafts by methyl-ÎČ-cyclodextrin

    The processes of financialisation and economic performance

    Get PDF
    The paper considers the relationships between financialisation and economic performance. Financialisation is a persistent feature of industrialised capitalism, the nature of which differs over time and space. The present era of financialisation (since circa 1980) has been a world-wide phenomenon proceeding from different starting points and developing at different speeds, and can be viewed through the lens of variegated financialisation. The major features of the present era of financialisation are outlined. The increased scale of the financial sector leads to the issue of the relationship between financialisation and economic performance, and whether the additional resources used in the financial sector have been socially beneficial. The paper is completed by some brief remarks on the possibilities of de-financialisation
    • 

    corecore