Acknowledgments

I am very thankful to my supervisor Prof. Günter Zech for the opportunity to work with the Inner Tracker group at HERA-B and for the productive discussions, his advice and for all the help he gave me during my stay in the University of Siegen. I would like to thank Prof. Peter Buchholz for his willingness to take the duties of the second referee.

I am also thankful to Dr. Torsten Zeuner for his enormous help during my stay in Hamburg and Siegen.

I wish to thank Dr. Dmitriy Emelianov for his support and readiness to help and Dr. Ivan Kisel who was always very cooperative.

Special thanks to all present and former colleagues from the Inner Tracker group which worked with me during this time. Special thanks to Ulrich Husemann for his help with Monte Carlo production and Dr. Mikhail Zavertiaev for the fruitful discussions.

Many thanks to all who helped me to go through with this manuscript: Torsten, Carsten and Hartmut, especially to find all missing articles.

I would like to thank my parents and relatives, they always give me the needed support.

I am gratefull to all my colleges from HERA-B experiment for their help in various aspects of work and life at Hamburg.

Hiermit erkläre ich, daß ich diese Arbeit selbständig verfaßt und alle Daten und Ergebnisse anderer Autoren als solche kenntlich gemacht habe.

Siegen, den 26.10.2003 (Iouri Gorbounov)