QCD Mini-jet contribution to the total cross section

We present the predictions of a model for proton-proton total cross-section at LHC. It takes into account both hard partonic processes and soft gluon emission effects to describe the proper high energy behavior and to respect the Froissart bound.Comment: 7 pages, 3 figures, presented at MPI08, Perugia, October 27-31, 200

Zero momentum gluons and the total pp and pbarp cross-sections

We describe a QCD motivated model for total cross-sections which uses the eikonal representation and incorporates QCD mini-jets to drive the rise with energy of the cross-section, while the impact parameter distribution is obtained through the Fourier transform of the transverse momentum distribution of soft gluons emitted in the parton-parton interactions giving rise to mini-jets in the final state. A singular but integral expression for the running coupling constant in the infrared region is part of this model.Comment: 4 pages, 1 figure, uses slac_one.rtx, 34th ICHEP Conference, Philadelphia 200

Tailoring the magnetic ordering of the Cr4O5/Fe(001) surface via a controlled adsorption of C60 organic molecules

We analyse the spinterface formed by a C60 molecular layer on a Fe(001) surface covered by a two-dimensional Cr4O5 layer. We consider different geometries, by combining the high symmetry adsorption sites of the surface with three possible orientations of the molecules in a fully relaxed Density Functional Theory calculation.We show that the local hybridization between the electronic states of the Cr4O5 layer and those of the organic molecules is able to modify the magnetic coupling of the Cr atoms. Both the intra-layer and the inter-layer magnetic interaction is indeed driven by O atoms of the two-dimensional oxide. We demonstrate that the C60 adsorption on the energetically most stable site turns the ferromagnetic intra-layer coupling into an antiferromagnetic one, and that antiferromagnetic to ferromagnetic switching and spin patterning of the substrate are made possible by adsorption on other sites

Doprinosi QCD-a Froissartovoj granici ukupnog udarnog presjeka

We discuss the effect of infrared soft gluons on the asymptotic behaviour of the total cross-section. We use a singular but integrable expression for the strong coupling constant in the infrared limit and relate its behaviour to the satisfying of the condition of the Froissart bound, giving a specific phenomenological example.Raspravljamo učinak infracrvenih mekih gluona na asimptotsko ponašanje ukupnog udarnog presjeka. Primjenjujemo singularan ali integrabilan izraz za konstantu jakog vezanja u infracrvenoj granici i usklađujemo njeno ponašanje s Froissartovom granicom, dajući poseban fenomenološki primjer

Exploring the craft of visual accounts through arts: Fear, voids and illusion in corporate reporting practices

This paper explores the craft of visual accounts in corporate reporting practices through an arts-inspired perspective. We research the subtle mechanisms underpinning the craft of visual accounts since their preparation phase, as these accounts engage with the emotional sphere of their preparers, including the fear and the power struggles surrounding the preparers’ role within the organization. We rely upon an artistic line of inquiry based on baroque art to unpack the voids and absences underpinning accounting visualizations. By drawing on this lens, we examine the case of a large European bank where we investigate the craft of visual accounts in corporate reports from the perspective of the preparers of these accounts. We extend prior studies on the visual and emotional dimensions of accounting by showing that the craft of visual accounts evolves as the preparers of these accounts experience voids in the meanings that they attempt to represent and the fear of being excluded from their role. We also demonstrate that the mixed emotions of fear and self-celebration, illusion and disillusion experienced by the preparers of accounting visualizations may follow intra-organizational power struggles in between the different organizational roles involved in corporate reporting. In so doing, we reveal how the philosophical underpinnings of artistic movements, such as baroque art, can be drawn upon to critically delve into the power of voids and absences in accounting visualizations

Electronic structure and lifetime broadening of a quantum-well state on p(2x2) K/Cu(111)

We studied a quantum-well state (QWS) generated by the adsorption of one monolayer of K on Cu(111) surface by means of a first principles approach. We calculated the electronic properties of the system within the Inglesfield's embedding method, which enables us to investigate the elastic linewidth of surface states. Our findings are in good agreement with recent experimental results obtained from photoemission spectroscopy measurements for binding energy and k(vertical bar vertical bar) dispersion. We also studied the contributions to the QWS linewidth due to electron-electron many-body effects and electron-phonon scattering in Hedin's GW approach and within the Debye model, respectively. The main contribution to the linewidth is due to intraband transitions within the QWS itself, accounting for similar to 16 meV to the total width. The elastic, electron-phonon, and interband transition contributions are smaller than 3 meV each

Contact mechanics analysis of a soft robotic fingerpad

The precision grasping capabilities of robotic hands is a key feature which is more and more required in the manipulation of objects in several unstructured fields, as for instance industrial, medical, agriculture and food industry. For this purpose, the realization of soft robotic fingers is crucial to reproduce the human finger skills. From this point of view the fingerpad is the part which is mostly involved in the contact. Particular attention must be paid to the knowledge of the mechanical contact behavior of soft artificial fingerpads. In this paper, artificial silicone fingerpads are applied to the last phalanx of robotic fingers actuated by tendons. The mechanical interaction between the fingerpad and a flat surface is analyzed in terms of deformations, contact areas and indentations. A reliable model of fingertip deformation properties provides important information for understanding robotic hand performance, that can be useful both in the design phase and for defining control strategies. The approach is based on theoretical, experimental, and numerical methods. The results will be exploited for the design of more effective robotic fingers for precision grasping of soft or fragile objects avoiding damages

Relevance of ultra-soft gluons and k<SUB>t</SUB> resummation for total cross-sections

Inclusion of down to zero-momentum gluons and their kt resummation is shown to quench the too fast rise of the mini jet cross section and thereby obtain realistic total cross-sections

Photoproduction total cross-sections at very high energies and the Froissart bound

A previously successful model for purely hadronic total cross-sections, based on QCD minijets and soft-gluon resummation, is here applied to the total photoproduction cross section. We find that our model in the gamma p case predicts a rise with energy stronger than in the pp -pbarp case.Comment: 5 pages, 3 figures, presented at ISMD08, 15-20 September 2008, DES