ATLAS - AG Lohse
ATLAS is a multipurpose detector for elementary particles at the Large Hadron Collider (LHC) at CERN. Using highest-energy proton beams searches for New Physics beyond the standard model of elementary particle physics are performed. The ATLAS-collaboration consists of more than 2000 physicists from more than 35 different countries all over the world. The ATLAS-group located at Humboldt-University is especially involved in the following selection of topics: Search for heavy charged particles, search for a potentially existing fourth generation of quarks, measurements in the field of top-quark physics and implementing of the higher trigger level of the ATLAS detector.
The top quark is the heaviest known quark of the Standard Model. It is interesting in many aspects: Due to its huge mass it displays the strongest coupling to the Higgs boson, so a precise measurement of its properties and production cross-sections are crucial to interpret results from searches for the Higgs boson. Our analyses focus on a channel called "single top"-production that has to be precisely measured at the LHC. Furthermore, unlike all other quarks the top quark decays before it can hadronize, passing on spin information to its decay products. This spin information in combination with cross-section measurements of "single top"-production can be used to constrain SUSY models and other approaches beyond the standard model that predict anomalous couplings of the top quark to the W-boson.
Level 1 Calorimeter Trigger
The important task of the trigger system is the reduction of the enormous output rate of proton collision event records down by several orders of magnitude. The higher level part of the trigger comprises a few hundreds of computers working on the problem in parallel. A close monitoring of the trigger operation is essential.
The ALFA detector will be used for a calibration of the luminosity measurements within the ATLAS experiment at CERN. ALFA consists mainly of scintillating fibres for the detection of elastically scattered protons with very small scattering angles. Its components are currently being manufactured at the participating Institutes and shipped to CERN for assembly.
Postdoctoral research fellows