Study on the electronic calibration of the liquid-argon calorimeteand teh detection of invisbly decaying Higgs bosons in the ATLAS experiment

At the LHC in Geneva the ATLAS experiment will start at 2007. The present work studies methods of the calibration of the liquid argon calorimeters and show the potential for the invisible decaying higgs-boson searches at the ATLAS experiment. Two calibration methods were studied and tested. Both fullfill the requirements for noise dependency and uniformity. In addition a test beam analysis were performed. The analysis of the invisible decaying higgs-boson were performed in the ttH and gluon-fusion channels. The gluon fusion channel is hopeless, but the ttH can contribute to the discovery potential. The results were combined with the VBF analysis and interpreted in the Phion-model and SUSY. (orig.)