Latest documents http://publikationen.stub.uni-frankfurt.de/index/index/ Wed, 16 Nov 2005 09:44:27 +0100 Wed, 16 Nov 2005 09:44:27 +0100 http://publikationen.stub.uni-frankfurt.de/frontdoor/index/index/docId/3297 Abstract Geant4 is a toolkit for simulating the passage of particles through matter. It includes a complete range of functionality including tracking, geometry, physics models and hits. The physics processes offered cover a comprehensive range, including electromagnetic, hadronic and optical processes, a large set of long-lived particles, materials and elements, over a wide energy range starting, in some cases, from 250 eV and extending in others to the TeV energy range. It has been designed and constructed to expose the physics models utilised, to handle complex geometries, and to enable its easy adaptation for optimal use in different sets of applications. The toolkit is the result of a worldwide collaboration of physicists and software engineers. It has been created exploiting software engineering and object-oriented technology and implemented in the C++ programming language. It has been used in applications in particle physics, nuclear physics, accelerator design, space engineering and medical physics. PACS: 07.05.Tp; 13; 23 S. Agostinelli; Dennis Dean Dietrich; Walter Greiner; Kerstin Anja Paech; Stefan Scherer; Horst Stöcker; Henning Weber; Detlef Zschiesche; et al.; Geant4 Collaboration article http://publikationen.stub.uni-frankfurt.de/frontdoor/index/index/docId/3297 Wed, 16 Nov 2005 09:44:27 +0100 http://publikationen.stub.uni-frankfurt.de/frontdoor/index/index/docId/3415 String theory suggests the existence of a minimum length scale. An exciting quantum mechanical implication of this feature is a modification of the uncertainty principle. In contrast to the conventional approach, this generalised uncertainty principle does not allow to resolve space time distances below the Planck length. In models with extra dimensions, which are also motivated by string theory, the Planck scale can be lowered to values accessible by ultra high energetic cosmic rays (UHECRs) and by future colliders, i.e. M f approximately equal to 1 TeV. It is demonstrated that in this novel scenario, short distance physics below 1/M f is completely cloaked by the uncertainty principle. Therefore, Planckian effects could be the final physics discovery at future colliders and in UHECRs. As an application, we predict the modifications to the e+ e- to f+ f- cross-sections. Sabine Hossenfelder; Marcus Bleicher; Stefan Hofmann; Jörg Ruppert; Stefan Scherer; Horst Stöcker preprint http://publikationen.stub.uni-frankfurt.de/frontdoor/index/index/docId/3415 Thu, 27 Oct 2005 16:18:06 +0200