Spectroscopy)

During my PhD studies and my research stay both in Bergen and at CERN, I had the privilege to work with many inspiring people who were strongly supporting my work and whom I would like to thank. I would like to begin by acknowledging my CERN supervisor, Michael Doser, for sharing his wisdom and knowledge with me, not only through the years of my thesis work, but also in the time prior to that. Thank you goes to him also for the constant help and advices concerning both theoretical and experimental physics, as well as administrative matters. Finally, if it weren’t for Michael I wouldn’t have met my PhD supervisor from the University of Bergen, Heidi Sandaker, and this thesis would have never happened. I thank him for all that. My second but not less important thank you is for my main PhD supervisor, Heidi, for all the help, support and encouragement from the very first to the very last day of my PhD studies. I thank her for all the patience and unquestioned belief in me, and especially for the guidance through my scientific work. Also thanks for the useful and motivational conversations every time I thought there is no way out and for the understanding you had for all the difficulties I went through, not only professional, bu