3,752 research outputs found
Electron-Positron colliders
An electron-positron linear collider in the energy range between 500 and 1000
GeV is of crucial importance to precisely test the Standard Model and to
explore the physics beyond it. The physics program is complementary to that of
the Large Hadron Collider. Some of the main physics goals and the expected
accuracies of the anticipated measurements at such a linear collider are
discussed. A short review of the different collider designs presently under
study is given including possible upgrade paths to the multi-TeV region.
Finally a framework is presented within which the realisation of such a project
could be achieved as a global international project.Comment: 14 pages, 16 figures, Proceedings of the XX International Symposium
on Lepton and Photon Interactions at High Energies, Rome, Italy, 23-28 July,
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Deep-Elastic pp Scattering at LHC from Low-x Gluons
Deep-elastic pp scattering at c.m. energy 14 TeV at LHC in the momentum
transfer range 4 GeV*2 < |t| < 10 GeV*2 is planned to be measured by the TOTEM
group. We study this process in a model where the deep-elastic scattering is
due to a single hard collision of a valence quark from one proton with a
valence quark from the other proton. The hard collision originates from the
low-x gluon cloud around one valence quark interacting with that of the other.
The low-x gluon cloud can be identified as color glass condensate and has size
~0.3 F. Our prediction is that pp differential cross section in the large |t|
region decreases smoothly as momentum transfer increases. This is in contrast
to the prediction of pp differential cross section with visible oscillations
and smaller cross sections by a large number of other models.Comment: 10 pages, including 4 figure
CERN and the future of particle physics
This paper presents CERN and its current scientific programme and outlines options for high-energy colliders at the energy frontier for the years to come. The immediate plans include the exploitation of the LHC at its design
luminosity and energy as well as upgrades to the LHC and its injectors. This may be followed by a linear electron-positron collider, based on the technology being developed by the Compact Linear Collider and by the International Linear Collider, or by a high-energy electron-proton machine, the LHeC. This contribution describes the past, present and future directions, all of which have a unique value to add to experimental particle physics, and concludes by outlining key messages for the way forward
Cosmos and Republic: Arendtian Explorations of the Loss and Recovery of Politics
In 20 essays inspired by Hannah Arendt's analysis of crisis-ridden modernity, Wolfgang R. Heuer addresses aspects of depoliticization and the loss of politics, and thus of freedom. The wide-ranging essays are grouped in five sections: When Politics Vanishes, The Call of Responsibility, Images and Emotions, Federations, and From Plurality to Cosmos. They lead to the insight that the crises of our time require a common change of perspective towards ecological and political sustainability, the unity of "Cosmos and Republic"
Failure of a Large Circular Excavation
A circular excavation, 117 feet (36 m) in diameter by 90 feet (27 m) deep, was designed by an experienced engineering firm and construction was performed by an experienced contractor. Nevertheless, the excavation support system suffered a complete collapse long before the maximum depth was reached. The failure is described and its causes are discussed
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