My stay at Jefferson Lab was a very interesting and profitable experience, and I would like first to thank Chaden Djalali who has made it possible, with the cooperation of the Department of Physics and Astronomy of the University of South Carolina.
I also express my gratitude to Arne Freyberger and Mark Ito with whom I enjoyed working, 1 and with Jefferson Lab's staff in general, especially the people from the hockey team, with whom I had great fun, every noon I was able to unstick myself from the computer screen.
I had a great time with all the frenchies and frenchies friends. I would like to thank Sebastien and Eric, for having hosted me for one month, and for the countless activities they were always ready to lead us, also to my climbing-partners at the Rock Gym, and Paul Gueye, for his everyday smile and the so hard Viet Voo Dao training he gave us.
This list wouldn't be complete without mentioning all the many people from IRC Undernet[3] that prevented me from working too much at night and offered some company in front of the screen. There are too many, and I'll forget a lot of them : Aline, bd, Clode, deborahf, DeeBaser, domi, Garance, harmonie, impulsive, jimmic, laodice, layla, leila-, Licorne, marykaa, Marylou, _Misha_, Myriaam, Myskha, neige, owen, rayon, roro, S_K_, Terrie... A big thanks to those who kicked me from channels and encouraged me to write this [Expletive deleted] thesis !