High energy photon interactions at the LHC

Experimental prospects for studying high-energy photon-photon and photon-proton interactions at the CERN Large Hadron Collider (LHC) are discussed. Cross sections are calculated for many electroweak and beyond the Standard Model processes. Selection strategies based on photon interaction tagging techniques are studied. Assuming a typical LHC multipurpose detector, various signals and their irreducible backgrounds are presented after applying acceptance cuts. Prospects are discussed for the Higgs boson search, detection of supersymmetric particles and of anomalous quartic gauge couplings, as well as for the top quark physics.Comment: 17 pages, 16 tables and 14 figure

Hector, a fast simulator for the transport of particles in beamlines

Computing the trajectories of particles in generic beamlines is an important ingredient of experimental particle physics, in particular regarding near-beam detectors. A new tool, Hector, has been built for such calculations, using the transfer matrix approach and energy corrections. The limiting aperture effects are also taken into account. As an illustration, the tool was used to simulate the LHC beamlines, in particular around the high luminosity interaction points (IPs), and validated with results of the Mad-X simulator. The LHC beam profiles, trajectories and beta functions are presented. Assuming certain forward proton detector scenarios around the IP5, acceptance plots, irradiation doses and chromaticity grids are produced. Furthermore, the reconstruction of proton kinematic variables at the IP (energy and angle) is studied as well as the impact of the misalignment of beamline elements.Comment: 40 pages, 20 figures; added references, corrected typos ; submitted to JINS

Higgs and Beyond the Standard Model physics with the FP420 detector at the LHC

The physics case of the FP420 R&D project aiming at the installation of proton detectors in the LHC tunnel at 420 m from the ATLAS and CMS interaction points, is presented. The motivations of the measurements accessible with FP420 -- exclusive Higgs production (pp --> p H p) and photon-induced processes (pp --> p gamma p --> p X p, pp --> p gamma gamma p --> p X p, where X is sensitive to new physics) -- are outlined.Comment: Proceedings Moriond-QCD 2009. 5 pages, 3 fig

Are conventions solutions ? Contrasting visions of the relationship between convention and uncertainty

This paper maps out different conceptions and dynamic accounts of convention developed within game theory, Post Keynesian economics and the économie des conventions. These accounts are distinguished in terms of the way in which they conceive of uncertainty (as probabilistic or radical).

Ex Post and Ex Ante Coordination: Principles of Coherence in Organizations and Markets

In the traditional trade-off between internalization and externalization, economists tend to undervalue the role of intentionality (Williamson 1991) and to accord a dominant place to market coordinating devices (ex post coordination) compared to hierarchical coordinating devices (ex ante coordination). The aim of this paper is to show how the introduction of the concept of coherence, which is frequently invoked by economists in order to apprehend the firm specificities (Holmstrom 1999), may help to revaluate the trade-off between markets and firms in the advantage of the later. In particular, it will be shown that the attributes of coherence in ex post coordinating devices are fundamentally different from the ones that can be found in ex ante coordination systems.coherence; ex post coordination; ex ante coordination; order; rules; abstract rules; concrete rules; Hayek; Bateson

Sodium hydroxide pretreatment as an effective approach to reduce the dye/holes recombination reaction in P-Type DSCs

We report the synthesis of a novel squaraine dye (VG21-C12) and investigate its behavior as p-type sensitizer for p-type Dye-Sensitized Solar Cells. The results are compared with O4-C12, a well-known sensitizer for p-DSC, and sodium hydroxide pretreatment is described as an effective approach to reduce the dye/holes recombination. Various variable investigation such as dipping time, dye loading, photocurrent, and resulting cell efficiency are also reported. Electrochemical impedance spectroscopy (EIS) was utilized for investigating charge transport properties of the different photoelectrodes and the recombination phenomena that occur at the (un)modified electrode/electrolyte interface