Zugl.: Wuppertal, Universiẗat, Diss., 2001.

Heidelberg, University, Diss., 2003.

No description available.

No description available.

A measurement of the top quark mass from dilepton decay channels is presented, using approximately 360 pb-1 of data colleced by the D0 experiment at Fermilab. The mass is measured from a total of 21 candidate dilepton events, using the neutrino weighting scheme. The measured mass is found to be 175.6+/-10.7(stat.)+/-6.0(syst.) GeV. This result is in good agreement with the current world average of the top quark mass.

We compute, to next-to-leading order in perturbation theory, the rate of energy loss suffered by a heavy quark moving nonrelativistically in the quark-gluon plasma. This quantity is essentially a measure of the scattering rates of this quark against plasma constituents, and of their efficiency in slowing it down. The next-to-leading order correction is sensitive to the physics of overlapping scatterings, as well as to the self-interactions of gauge fields with small momenta (of order the electric screening scale). We find the next-to-leading order correction to be remarkably large, suggesting that the perturbative series is unreliable unless the coupling constant of the theory assumes unrealistically small values.

Frankfurt (Main), University, Diss., 2007.

Zugl.: Tübingen, Univ., Diss., 2007

Regensburg, Univ., Diss., 2008.

Wuppertal, Univ., Diss., 2001. / Computerdatei im Fernzugriff.