The measurement challenge of the LHC project

The Large Hadron Collider (LHC) is CERN's next accelerator project, to be commissioned in 2005. The project presents unprecedented challenges in the accurate control of high currents up to 13 kA. Arou nd 1700 superconducting magnet circuits are deployed in the underground, 27 km circumference, tunnel. A new concept with quasi-on-line calibration is proposed

Emittance measurements in the CERN PS complex

The LHC project, with its demand for small emittance beams and their monitoring, constitutes a challenge for the instruments of the CERN PS complex used hitherto to measure emittances of generally larger beams with less precision. Among these instruments, one (Beamscope) measures the betatron amplitude distribution, while the other two (SEM-grids, fast wire scanner) are recording the projected beam density. Emittances are quoted as derived from one standard width of the projected beam density, and the goal is to provide figures which refer to this definition regardless of the measurement instrument and method. The paper recalls the principles of these measurement systems and describes the mathematical methods applied to eliminate noise and measurement errors, to transform between the phase plane and its projection and the formalism used to determine the matching between machines

Physics opportunities with future proton accelerators at CERN

We analyze the physics opportunities that would be made possible by upgrades of CERN's proton accelerator complex. These include the new physics possible with luminosity or energy upgrades of the LHC, options for a possible future neutrino complex at CERN, and opportunities in other physics including rare kaon decays, other fixed-target experiments, nuclear physics and antiproton physics, among other possibilities. We stress the importance of inputs from initial LHC running and planned neutrino experiments, and summarize the principal detector R&D issues.Comment: 39 page, word document, full resolution version available from http://cern.ch/pofpa/POFPA-arXive.pd

The Large Hadron Electron Collider

An overview is given on key physics, detector and accelerator aspects of the LHeC, including its further development, with emphasis to its role as the cleanest microscope of parton dynamics and a precision Higgs facility.Comment: 13 pages, 4 figure

New LHC bound on low-mass diphoton resonances

We derive a new bound on diphoton resonances using inclusive diphoton cross section measurements at the LHC, in the so-far poorly constrained mass range between the Upsilon and the SM Higgs. This bound sets the current best limit on axion-like particles that couple to gluons and photons, for masses between 10 and 65 GeV. We also estimate indicative sensitivities of a dedicated diphoton LHC search in the same mass region, at 7, 8 and 14 TeV. As a byproduct of our analysis, we comment on the axion-like particle interpretation of the CMS excesses in low-mass dijet and diphoton searches.Comment: 7 pages + appendices, 5 figures, 2 tables. v2: discussion improved, new bound derived also from Tevatron, conclusions unchanged. v3: matches PLB versio

The International Linear Collider

In this article, we describe the key features of the recently completed technical design for the International Linear Collider (ILC), a 200-500 GeV linear electron-positron collider (expandable to 1 TeV) that is based on 1.3 GHz superconducting radio-frequency (SCRF) technology. The machine parameters and detector characteristics have been chosen to complement the Large Hadron Collider physics, including the discovery of the Higgs boson, and to further exploit this new particle physics energy frontier with a precision instrument. The linear collider design is the result of nearly twenty years of R&D, resulting in a mature conceptual design for the ILC project that reflects an international consensus. We summarize the physics goals and capability of the ILC, the enabling R&D and resulting accelerator design, as well as the concepts for two complementary detectors. The ILC is technically ready to be proposed and built as a next generation lepton collider, perhaps to be built in stages beginning as a Higgs factory.Comment: 41 page