Precision spectroscopy of the 2S-4P transition in atomic hydrogen

Axel Beyer1, Ksenia Khabarova2, Randolf Pohl1, Thomas Udem1, Theodor W. Hansch1, 3, and Nikolai Kolachevsky1, 4 1Max Planck Institute of Quantum Optics, Hans-Kopfermann-Str. 1, D-85748 Garching, Germany 2National Research Institute of Physical, Technical and Radiotechnical Measurements, 141570 Mendeleevo, Russia 3Ludwig Maximilian University, 80799 Munich 4P.N. Lebedev Physical Institute, 119991 Moscow, Russia